Stereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Evidence synthesis and guideline recommendations regarding use of SRS/SBRT for symptomatic bone metastases (spine and non-spine) and management of brain metastases, intended to inform radiation oncology coverage decisions and clinical use.
Policy Summary
PayerUnitedHealthcare
PolicyStereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Policy CodePolicy N/A
Change TypeCoverage criteria revised and new indications added (material changes)
Effective Date02/01/2026
Next Review DateN/A
Key ActionDocument prior authorization with guideline-concordant indication, performance status, lesion count/size, prior treatments, and planned dose/fractionation.
Policy applies to individuals 19 years of age and older; SRS and SBRT are covered without further review for individuals younger than 19 years of age.
Added proven and medically necessary indications including bone metastasis (non-spine) when symptomatic and treated in up to five fractions; neurologic conditions refractory to medical treatment; spinal lesions with specified criteria.
Revised coverage criteria for newly diagnosed brain metastasis to require absence of diffuse brain metastases and changed leptomeningeal metastases criterion to 'absence of diffuse leptomeningeal metastases'; removed small cell carcinoma from excluded diagnoses (now only lymphoma or germ cell tumor).
Revised criteria for repeat stereotactic radiation for brain metastasis to replace leptomeningeal language with 'absence of diffuse leptomeningeal metastases' and to allow extra-cranial disease that is well-controlled or has accessible effective systemic options.
Added intrahepatic bile duct cancer (cholangiocarcinoma) for unresectable tumors and small cell lung cancer Stage I/IIA as definitive treatment indications with specified criteria.
Extracranial oligometastatic disease criteria changed: performance status wording standardized and total metastatic lesions allowed increased from up to three to up to five.
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02/01/2026policy revision date
2022ASTRO guideline year
up to 5max lesions allowed (extracranial oligometastatic)
up to 5non-spine bone fractions allowed
97%SBRT HCC 2-yr local control
Coverage Criteria for SRS and SBRT
Coverage-relevant clinical criteria
Coverage considerations based on guideline recommendations and trial evidence:
SBRT for symptomatic nonspine bone metastases: SBRT is recommended for symptomatic nonspine bone metastases with typical single-fraction prescriptions of 1,200–1,600 cGy, with patient selection informed by prognosis, prior RT, normal tissue risk, quality of life, and patient goals.dose: 1200-1600 cGy x1
ASTRO: strong; quality: moderate
SBRT for symptomatic spinal metastases: SBRT is recommended for symptomatic spinal metastases with commonly cited regimens including 2,400 cGy in two fractions; evaluation of spine stability and surgical indications is required before RT.dose: 2400 cGy in 2 fractions
ASTRO: strong; quality: moderate
Conditional preference for SBRT vs conventional palliative RT: For patients with symptomatic bone metastases who have ECOG performance status 0–2, no planned surgical intervention, and absent neurologic symptoms, SBRT may be conditionally preferred over conventional palliative RT; consider life expectancy and tumor radiosensitivity.ECOG 0-2
ASTRO: conditional; quality: moderate
Reirradiation to symptomatic nonspine bone sites: For symptomatic nonspine bone metastases requiring reirradiation to the same site, acceptable options include single-fraction 800 cGy or multifraction conventional palliative regimens (2,000 cGy in 5 fractions or 2,400 cGy in 6 fractions).800 cGy x1 or 2000 cGy/5fx or 2400 cGy/6fx
ASTRO: strong; quality: moderate
SRS vs WBRT for limited brain metastases: Randomized data support SRS alone for 1–3 brain metastases to reduce short-term cognitive decline compared with SRS+WBRT, with WBRT reducing intracranial relapse but not improving overall survival or duration of functional independence.1-3 BMs for SRS alone evidence
Brown et al.; EORTC Kocher trial
SRS for multiple brain metastases in selected patients: Prospective observational series support SRS alone in selected patients with up to 10 brain metastases with acceptable outcomes in well-selected cohorts.up to 10 BMs
Yamamoto et al. JLGK0901
Covered with criteria (procedure- and disease-specific)
Covered when ALL of the following are met (per guideline or trial evidence in this segment):
Brain metastases — SRS candidacy: Patient has ECOG/WHO performance status 0–2 AND a limited number of intact brain metastases (up to 4 favored; 5–10 conditional) AND lesion size and location appropriate for the planned SRS fractionation.ECOG 0–2; <=4 lesions preferred
ASTRO strong rec; single-fraction 20–24 Gy for <2 cm; multifraction options 27 Gy/3 fx or 30 Gy/5 fx
Postoperative management for resected brain metastasis: Post-resection management chosen from observation, postoperative SRS to the resection cavity, or WBRT based on goals; SRS is preferred over WBRT to preserve neurocognitive function when limited additional metastases are present.
Per ASTRO, NCCN, and EORTC randomized trial findings
Repeat SRS for recurrent brain metastasis: Selected patients with recurrent or progressive brain metastases may undergo repeat SRS after careful assessment of control probability versus increased radionecrosis and neurologic risk.
Coverage for SBRT in primary liver cancers
Covered when ALL of the following context- and evidence-based conditions are met:
Liver-confined HCC or unresectable intrahepatic cholangiocarcinoma: Patient has liver-confined HCC or unresectable intrahepatic cholangiocarcinoma without regional or distant metastasis AND is not a candidate for curative surgery or catheter-based therapies or has failed those therapies.
ASTRO strong rec; ISRS systematic reviews support SBRT in selected patients
Technical capability and image guidance: SBRT delivered at experienced centers with appropriate image-guidance and ability to meet organ-at-risk dose constraints; fractionation chosen based on tumor location and liver function (commonly 3–5 fractions for intrahepatic tumors).
Consideration of baseline liver function: Baseline liver function (e.g., Child-Pugh class) must be considered because worse baseline class is associated with higher rates of grade ≥3 hepatic complications after SBRT.
Meta-analysis: Child-Pugh correlated with hepatic complications
Coverage for SBRT in early-stage NSCLC
Covered when ALL of the following are met:
Early-stage NSCLC — staging and operability: Patient has stage I (T1–T2, N0, M0) NSCLC and is medically inoperable or has declined surgery after appropriate thoracic surgical evaluation; SBRT may be considered in operable high-risk patients after multidisciplinary discussion but is not recommended as an alternative to surgery for standard-operative-risk patients outside clinical trials.
ASTRO 2018; NCCN 2025
Dose/BED considerations: SBRT prescription should aim for a biologically effective dose (BED10) ≥100 Gy when safe, because BED ≥100 Gy is associated with lower local recurrence and improved long-term outcomes in multiple series.BED >= 100 Gy
HypoFXSRT series median BED 111 Gy; Onishi et al. data
Tumor location and fractionation adaptation: Risk-adapted fractionation (e.g., 3–8 fractions) should be used based on tumor size and proximity to central structures; central tumors may require more fractions or adjusted dosing to limit toxicity.
Covered indications and supporting thresholds
SBRT/ultrahypofractionated radiotherapy is supported in specific circumstances per evidence and guideline recommendations:
Stage I NSCLC — medically inoperable: SBRT/HypoFXSRT is appropriate for medically inoperable stage I NSCLC; higher BED (>=100 Gy) is associated with improved local control and survival.BED >= 100 Gy
HypoFXSRT multicenter data; improved local recurrence with BED>=100 Gy
Stage I NSCLC — operable patients: For patients at standard operative risk, SBRT is not recommended as an alternative to lobectomy outside clinical trials; for high operative risk patients, SBRT may be reasonable after multidisciplinary evaluation and informed consent regarding long-term uncertainty.operative mortality <1.5% defines standard operative risk
Covered when ALL of the following are met (scenario-based summaries from guidelines and trials):
Prostate cancer — definitive SBRT: SBRT/SABR may be used as definitive radiotherapy for primary prostate cancer across risk groups when delivered in practices with appropriate technology, physics, and clinical expertise and when image-guidance and dose/fractionation are guideline-concordant.guideline-concordant technology and expertise
NCCN 2025 endorsement
Renal cell carcinoma — definitive SBRT for non-surgical candidates: SBRT may be considered definitive therapy for primary RCC in medically inoperable or high surgical risk patients with tumor size and location consistent with published regimens (e.g., <=4–5 cm: 26 Gy ×1; larger tumors: 42–48 Gy in 3 fractions or 40 Gy in 5 fractions if OAR constraints prevent 3-fraction regimens).tumor <=4-5 cm single-fraction 26 Gy; >4-5 cm: 42-48 Gy/3fx or 40 Gy/5fx
ISRS and FASTRACK II guidance
Small cell lung cancer — stage I–IIA medically inoperable:
Consolidative local therapy (SBRT/SRS) for oligometastatic disease
Covered when ALL of the following are met
Patient selection for consolidative SBRT/SRS: Patient has oligometastatic disease defined as a limited number of extracranial metastases (commonly up to 3 per ARS after upfront systemic therapy or up to 5 per ASTRO/ESTRO), lesions are amenable to radiation, and there is no progression after 2–3 months or cycles of systemic therapy when guideline-specified.metastases_count<=5
ARS recommends ≤3 after upfront systemic therapy; ASTRO/ESTRO allow up to 5; multidisciplinary tumor board discussion recommended
Technique and intent: Treatment uses highly conformal stereotactic techniques (SBRT/SRS) with dose/fractionation intended for durable local control and respecting OAR constraints; BED and dose selection per guideline to achieve durable local control.BED10>75Gy preferred
ASTRO/ESTRO: durable local control targets and BED guidance
Special considerations for pulmonary metastases:
Intracranial benign and vascular lesion SRS coverage
Covered when ALL of the following are met
Glomus jugulare tumors: SRS is an appropriate primary or alternative treatment for glomus jugulare tumors given high pooled tumor control (~95%) and symptomatic improvement in series and meta-analyses; selection and multidisciplinary review recommended.
Systematic reviews/meta-analyses support high tumor control
Cavernous sinus and orbital hemangiomas: SRS may be offered for symptomatic cavernous sinus or orbital hemangiomas with reported tumor regression and symptomatic improvement; reported median margin doses approximately 12–15 Gy with optic nerve dose constraints observed.
Case series report long-term tumor regression and symptomatic benefit
Intracranial cavernous malformations (ICMs): SRS may be considered for surgically inaccessible or eloquently located ICMs after symptomatic hemorrhage to reduce rebleed risk, and for ICMs causing medically refractory epilepsy to improve seizure control; SRS is not typically recommended for asymptomatic ICMs.
Covered clinical scenarios with supportive evidence
Scenarios in which SRS / repeat or staged SRS is supported by cited evidence:
ICM with prior symptomatic hemorrhage: SRS is recommended for surgically inaccessible or eloquent intracranial cavernous malformations with prior symptomatic hemorrhage to reduce subsequent hemorrhage risk (ISRS: conditional, low-quality evidence).
Tos et al. 2024
ICM causing refractory epilepsy: SRS may be used for ICMs causing medication-refractory epilepsy to improve seizure control (ISRS conditional recommendation).
Tos et al. 2024
AVM — repeat SRS for incomplete obliteration: Repeat SRS is a reasonable option for residual/recurrent AVMs after initial SRS, with pooled obliteration ~60.8%; selection favors smaller residual volume and lower Spetzler-Martin grade to optimize outcomes and limit complications.
Maroufi et al. 2024 meta-analysis
Guideline-supported indications
Covered when supported by guideline-recommended indications and evidence for low-volume or specific histology/context
Meningioma — guideline-supported SRS: SRS is associated with excellent tumor control and may be considered especially for WHO grade 1 meningiomas and selected grade 2/recurrent disease per NCCN guidance.
NCCN 2025
Reirradiation for recurrent glioma — focused techniques: Recurrent glioma management with reirradiation should use highly focused techniques such as SRS for lower-volume disease per NCCN guidance.
NCCN 2025
Essential tremor — SRS candidacy: SRS is recommended for medically refractory essential tremor in patients who are not candidates for invasive surgery; Gamma Knife thalamotomy techniques and dose ranges described in ISRS guidance apply.
ISRS consensus; Martínez-Moreno et al. 2018
Evidence-informed coverage considerations
Consider SRS covered when patient and disease characteristics align with outcomes reported in systematic reviews/series
Pituitary adenoma — recurrent/residual NFPA: SRS or hypofractionated stereotactic RT is appropriate after prior surgical resection for recurrent or residual nonfunctioning pituitary adenomas, with expected tumor control around 92% and a measurable risk of hypopituitarism (approximately 14–21% depending on series).
Systematic reviews/meta-analyses report high control and hypopituitarism risk
Pineal region tumors — GKRS use: GKRS can be used for selected pineal region tumors with reported mean marginal doses around 14–15 Gy and local control approximately 80% at median ~36 months; reliable histologic diagnosis informs selection.
Gagliardi et al. 2023 systematic review
Recurrent malignant glioma — salvage SRS/CyberKnife: SRS/CyberKnife may be reasonable salvage therapy for selected recurrent WHO grade III/IV gliomas with expected median OS after treatment in the range of ~8–11 months; better outcomes associated with smaller target volume, higher prescription dose, younger age, and combined systemic therapy.
Coverage criteria for SBRT/SRS in spinal and nonspinal bone metastases
Covered when ALL of the following are met (per cited guideline recommendations and RCT evidence):
Spine SBRT — general appropriateness: Patient has symptomatic spinal metastasis or oligometastatic spinal disease where focal ablation or durable local control is intended.
ASTRO/NCCN/NICE support
Performance and prognosis: Patient has adequate performance status (ECOG 0–2 or KPS ≥60) and life expectancy generally >3 months appropriate for ablative intent.
Referenced in RCT inclusion criteria and guidance
Lesion volume/number constraints: Disease limited to low-volume lesions or oligometastatic burden (trial-defined limits such as up to 1–3 vertebral levels or other guideline constraints) without excessive contiguous vertebral involvement.
Covered when ALL of the following are met for focal recurrent glioma:
Focal, low-volume recurrence: Patient has a focal, low-volume recurrent glioma suitable for stereotactic radiosurgery (SRS) as salvage/local therapy.
Younger patients and smaller recurrences derive more benefit; higher prescription dose associated with improved survival
Prior treatment interval and selection: An interval since prior surgery or prior RT that permits focal reirradiation is present and selection favors patients with limited target volume and good performance status.
Longer interval associated with improved post-SRS survival in cohorts; NCCN supports focused reirradiation
Coverage criteria for SRS in tumor-related trigeminal neuralgia
Covered when ALL of the following are met for trigeminal neuralgia secondary to tumor:
Refractory pain attributable to tumor: Trigeminal neuralgia attributable to tumor (e.g., meningioma, vestibular schwannoma, trigeminal schwannoma) that is refractory to appropriate medical therapy.
Systematic reviews/meta-analyses report pooled complete pain-free and adequate relief rates
Specialized center and multidisciplinary care: Procedure planned and performed by a specialized center with multidisciplinary expertise in trigeminal neuralgia management.
NICE recommends multidisciplinary selection and specialized centers
Appropriate governance and consent: Appropriate clinical governance, informed consent, and audit arrangements are in place prior to SRS.
NICE guidance requirement
Coverage criteria for stereotactic radiotherapy in uveal melanoma
Covered when ALL of the following are met for uveal melanoma treated with stereotactic approaches:
Appropriate tumor stage/size and indication: Patient has uveal melanoma for which stereotactic radiotherapy (CyberKnife, Gamma Knife, or FSRT) is an appropriate eye-preserving or primary therapy option based on tumor size, location, and multidisciplinary evaluation.
Systematic reviews report high local control and eye preservation rates
Center expertise and ophthalmologic follow-up: Treatment performed at centers experienced in ocular stereotactic radiotherapy with planned ophthalmologic follow-up to monitor visual outcomes and radiation-related complications.
Authors recommend specialized reporting and follow-up
Evidence summaries — uveal melanoma
Clinical evidence summaries and practice guidance for SRS/FSRT/CyberKnife/Gamma Knife in uveal melanoma
CyberKnife evidence summary: Systematic review/meta-analysis of CyberKnife studies reported pooled three-year local control ~0.89 and three-year eye preservation ~0.84 with notable rates of radiation retinopathy (~20%), glaucoma (~19%), and retinal detachment (~22%); evidence largely retrospective and single-arm.
Du & Luo 2025
Gamma Knife evidence summary: Systematic review/meta-analysis of GKRS studies reported pooled local control ~0.96 and tumor regression in ~0.81 of cases, supporting GKRS as an effective primary method for uveal melanoma with similar efficacy to plaque brachytherapy in available series.
Parker et al. 2020
Yazici multicenter series findings: Multi-center CyberKnife SRS/FSRT series showed higher control and enucleation-free survival correlated with doses ≥45 Gy in three fractions for larger tumors; limiting maximum eye and lens doses was recommended to improve eye retention.dose >=45 Gy associated with better control
Revised/Added Coverage Criteria
Revised and added covered indications and criteria include the following grouped areas:
Age applicability: Policy applies to individuals 19 years of age and older; SRS and SBRT are covered without further review for individuals younger than 19 years of age.age >= 19
Policy revision 02/01/2026
Nonspine bone metastasis: Nonspinal bone metastasis is covered when symptomatic and treated in up to five fractions.fractions <= 5
Added as proven and medically necessary in policy revision
Neurologic functional disorders (epilepsy, Parkinson disease, essential tremor) refractory to medical therapy and/or invasive surgical interventions are covered indications for stereotactic procedures when selection criteria and specialty guidance are met.refractory to medical and/or invasive surgical treatment
No single, explicit list of absolute coverage exclusions is provided in the cited guideline excerpts. Rather, guidance emphasizes individualized assessment of prognosis, prior radiation exposure, anatomic constraints, neurologic status, and patient goals when selecting SRS/SBRT regimens; these clinical factors can effectively preclude certain stereotactic approaches in specific patients. The ASTRO palliative bone metastasis guidance explicitly notes that an assessment of prior RT doses, normal tissue risks, quality of life, and patient values and goals is required before choosing a regimen, and dose/fractionation choices should be adapted accordingly.
Randomized trials and guideline reviews inform decision-making about whole-brain radiotherapy (WBRT) versus focal stereotactic approaches. SRS alone for limited brain metastases produces less early cognitive deterioration than SRS plus WBRT, while WBRT reduces intracranial relapse after surgery or radiosurgery but does not improve overall survival or duration of functional independence. ASTRO guidance therefore frames WBRT use around expected tradeoffs in intracranial control versus cognition and functional outcomes rather than as a blanket superior option.
In the systematic review of SBRT for intrahepatic cholangiocarcinoma by Bisello et al., studies of adjuvant SBRT after radical surgical resection were explicitly excluded from the review. This indicates that the published evidence base summarized there does not support routine adjuvant SBRT following radical resection and that such adjuvant contexts were not evaluated in that synthesis.
ASTRO guidance for early-stage non–small cell lung cancer (NSCLC) recommends surgical evaluation by a thoracic surgeon and states that for patients at <1.5% anticipated operative mortality (standard operative risk), SBRT is not recommended as an alternative to surgery outside of clinical trials. Thus SBRT should not be substituted for surgery in standard-risk operable stage I NSCLC except within research or agreed institutional protocols.
ASTRO's pancreatic cancer guideline specifies that adjuvant SBRT after surgical resection is recommended only in the context of a clinical trial or multi‑institutional registry. For borderline resectable or select locally advanced cases, multifraction SBRT after systemic chemotherapy may be used for downstaging, but adjuvant use following complete resection is not supported outside studies.
Clinical trial and guideline exclusion criteria illustrate practical examples where SBRT/SABR was not studied or is not feasible: tumors abutting the bowel, tumors larger than trial-specified size limits (e.g., >10 cm in FASTRACK II), prior overlapping high‑dose radiation to the same anatomic area, and severely impaired renal function (eGFR <30 mL/min/1.73 m2) were grounds for exclusion in renal SABR studies. These anatomic and physiologic constraints should be documented when considering SBRT and may preclude safe delivery.
The ARS Appropriate Use Criteria recommend consolidative radiotherapy for patients with limited metastatic burden but do not recommend consolidative RT for patients with six or more metastatic sites outside a clinical trial. This ARS position is a practical selection boundary for consolidative metastasis-directed RT.
ISRS guidance for intracranial cavernous malformations indicates that SRS may reduce hemorrhage risk or improve seizure control in selected symptomatic, surgically inaccessible lesions, but it is not typically recommended for asymptomatic cavernous malformations. The recommendation is conditional and based on low‑quality evidence.
The ISRS systematic review and guideline for intracranial cavernous malformations characterizes the evidence as low quality for many recommendations and issues conditional statements—for example, endorsing SRS for previously hemorrhaged, surgically inaccessible lesions or for seizure control, while advising against routine treatment of asymptomatic lesions.
Evidence for SRS in epilepsy and other neurologic functional indications is limited by sparse Level‑1 data. Systematic reviews note a lack of randomized trials for many epilepsy indications; one RCT comparing SRS to anterior temporal lobectomy (ATL) found lower seizure remission with SRS, supporting SRS mainly for patients who are not candidates for or who decline open surgery.
Trials and guidelines consistently exclude patients with spinal instability or neurologic deficits requiring immediate surgical decompression from SBRT/SRS trials of spinal metastases. ASTRO guidance and randomized trial protocols require evaluation of spine stability and surgical management where indicated before radiotherapy, so urgent surgical indications preclude primary radiotherapeutic management until addressed.
Within the document excerpts there are no single-sentence absolute exclusions listed for all stereotactic indications; instead, selection relies on individualized assessment of performance status, prior treatments, anatomic constraints, and treatment goals. The ASTRO statements emphasize tailoring regimen selection to these clinical factors rather than enumerating universal exclusions.
The policy revisions explicitly exclude individuals with diffuse brain metastases or diffuse leptomeningeal metastases from the newly diagnosed and repeat brain metastasis coverage criteria, and they also note age applicability: the policy applies to individuals 19 years and older, with SRS/SBRT covered without further review for those younger than 19.
Whole-brain radiotherapy may reduce intracranial relapse rates after surgery or radiosurgery, but randomized evidence has not demonstrated improvement in overall survival or duration of functional independence; these outcome considerations should guide selection of WBRT versus focal stereotactic approaches based on patient goals and expected tradeoffs.
Multiple randomized trials indicate that adding WBRT to focal therapy does not improve overall survival or functional independence and is associated with greater cognitive decline; therefore, WBRT is not routinely supported solely to improve survival or duration of functional independence when focal options (SRS) are appropriate and consistent with patient goals.
Randomized and comparative data in primary liver tumors indicate SBRT is not categorically superior to other local modalities for the smallest HCC lesions (≤2 cm) where RFA performs well; however, SBRT demonstrated superior local control for lesions >2 cm and is an important option when ablation or surgery are not appropriate or have failed.
For operable stage I NSCLC patients at standard operative risk, ASTRO guidance does not recommend SBRT as a substitute for lobectomy outside clinical trials. SBRT remains a reasonable option for medically inoperable or high‑operative‑risk patients after multidisciplinary evaluation.
Guidelines and phase II data for primary renal cell carcinoma indicate surgery remains standard for operable patients. SBRT/SABR is an alternative for medically inoperable patients or those who decline surgery, with specific tumor size and dose regimens guiding candidacy.
Randomized trials of intensified surveillance after colorectal resection have not demonstrated an overall survival benefit; therefore, more intensive follow-up solely to detect asymptomatic metastases earlier has not reliably improved survival and should not be assumed to change outcomes without other therapeutic implications.
ISRS guidance and systematic review results indicate that asymptomatic intracranial cavernous malformations are generally not treated with SRS; treatment is reserved for symptomatic, surgically inaccessible lesions or for medically refractory epilepsy.
A randomized trial comparing SRS with anterior temporal lobectomy for mesial temporal lobe epilepsy showed lower seizure remission with SRS versus ATL, indicating surgical resection achieves higher remission rates when feasible. This randomized evidence frames SRS as an alternative when open surgery is contraindicated or declined.
Phase III randomized trials of SBRT/SRS versus conventional external beam RT for vertebral metastases produced mixed results for superiority in pain outcomes; one trial found SBRT superior at six months for pain reduction, while another favored conventional RT at three months for the primary endpoint. These outcomes indicate that SBRT is not universally superior for pain relief and that selection should consider trial inclusion criteria, timing, and patient priorities.
NCCN guidance for uveal melanoma notes that stereotactic radiosurgery is the least often used form of definitive radiotherapy for intraocular tumors; the guideline describes planning and localization approaches consistent with particle therapy but does not categorically exclude stereotactic approaches when appropriate expertise and technology are available.
Prior policy language that had specified palliative spine SBRT as proven and medically necessary when delivered in ≤2 fractions was removed in the revision. Current spinal palliative criteria provide alternative fractionation limits and base decisions on updated guideline and trial context rather than that specific two‑fraction assertion.
Prior Authorization and Documentation Requirements
Prior Authorization
Provide guideline-based clinical context for PA
ASTRO and NCCN guidance and trial contexts that justify SRS/SBRT use (including recommended dose/fractionation and performance status) should be included in the prior-authorization submission to demonstrate clinical context and medical necessity.
Prior Authorization
Document SRS indication and dose/fractionation
Specify the SRS indication, planned dose and fractionation, and patient performance status (ECOG 0–2 favored for SRS) in the authorization request; single-fraction 20–24 Gy or multifraction options (27 Gy/3 fx, 30 Gy/5 fx) should be documented when applicable.
Prior Authorization
Show unresectable liver tumor candidacy and technical capability
For liver-confined HCC or unresectable intrahepatic cholangiocarcinoma, document that the patient is not a candidate for curative surgery/ablation or catheter-based therapies and that planned SBRT dose constraints and institutional image-guidance capability are available.
Key Dosage, Fractionation, and Coding Parameters
inv-42: ECOG performance status (selection parameter)
ECOG performance status0–2 (used in conditional recommendation favoring SBRT over conventional palliative RT)
Context for useECOG 0–2 required along with no surgical intervention and absent neurologic symptoms for conditional SBRT preference
Documentation implicationPerformance status should be recorded in prior authorization and treatment planning notes
inv-43: Biologically effective dose (BED) — association with outcomes
BED definition contextBED calculated with α/β = 10 (BED10) used to compare regimens
Association with outcomes (NSCLC)BED ≥100 Gy associated with lower local recurrence and improved 5‑year overall survival in stage I NSCLC series
Definitions and Terms
inv-98: Brain Metastasis Velocity (BMV)
BMV definitionBrain Metastasis Velocity (BMV) = cumulative number of new brain metastases after the first SRS divided by years since initial SRS
BMV categoriesClassified as ≤3, 4–13, and ≥14 based on BMV score
Prognostic useHigher BMV classes are associated with shorter median survival after repeat SRS
SRS definitionHighly focused radiation to intracranial targets delivered as single‑fraction or multifraction stereotactic radiosurgery (single‑fraction 20–24 Gy; multifraction examples 27 Gy/3 fx or 30 Gy/5 fx)
PurposeUsed for intact brain metastases, postoperative cavities, and select functional/benign targets
Clinical Background and Evidence Context
Bone and brain metastases are common indications for palliative and local‑control radiotherapy. Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT) provide highly conformal, high‑dose treatments that can improve local control and, for bone metastases, yield higher rates of pain response compared with some conventional regimens. Selection between focal stereotactic approaches and whole‑brain or conventional RT depends on prognosis, prior radiation, neurologic symptoms, metastatic burden, and patient goals; guideline-recommended dose/fractionation examples include 1,200–1,600 cGy ×1 (non‑spine) and 2,400 cGy ×2 (spine) for symptomatic bone metastases and performance status‑based consideration for SBRT over conventional RT when ECOG 0–2.
Policy Revision History
02/01/2026policy_revisionLatest
Applied an age threshold: policy applies to individuals 19 years and older; SRS and SBRT are covered without further review for individuals younger than 19 years.
02/01/2026policy_revision
Revised and expanded proven and medically necessary indications: added non-spine bone metastasis when symptomatic (allowed up to five fractions); added neurologic conditions (epilepsy, Parkinson’s disease, essential tremor) refractory to medical or surgical therapy; clarified spinal lesion criteria including palliative treatment using five fractions or less and primary spinal lesions not amenable to surgery or 3D conformal techniques.
02/01/2026
Policy Summary
PayerUnitedHealthcare
PolicyStereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Policy CodePolicy N/A
Change TypeCoverage criteria revised and new indications added (material changes)
Effective Date02/01/2026
Next Review DateN/A
Key ActionDocument prior authorization with guideline-concordant indication, performance status, lesion count/size, prior treatments, and planned dose/fractionation.
Case series report: local control & radionecrosis trade-offs (Minniti et al.)
Skull-base chordoma/chondrosarcoma: SRS may be used as primary, adjuvant, or salvage therapy for small residual skull-base chordomas or chondrosarcomas, particularly for small volumes (e.g., <20 ml) with appropriate margin dosing to optimize long-term control.tumor volume <20 ml; margin dose >=15 Gy
Systematic reviews and series report favorable control
Craniopharyngioma—residual or recurrent disease: SRS/FSRT may be considered for residual or recurrent craniopharyngioma with reported high tumor control and acceptable endocrine risk when complete radiosurgical coverage is achievable.
Meta-analyses/series show high PFS with FSRT/SRS
Definitive SBRT for small recurrent HCC: Patient has a solitary recurrent HCC ≤5 cm without extrahepatic disease or vascular invasion and is a candidate for SBRT; SBRT demonstrated superior local progression-free survival versus RFA in randomized data.<=5 cm solitary nodule
Xi et al. randomized trial: 2-year LPFS 92.7% vs 75.8%
SBRT for unresectable intrahepatic cholangiocarcinoma: SBRT may be considered for unresectable, non-metastatic intrahepatic cholangiocarcinoma when dose constraints can be met and institutional expertise exists, typically with median regimens around 45 Gy in 3–5 fractions.
ASTRO/NCCN/series support; median dose ~45 Gy
Trials and series report higher toxicity for central tumors; adapt fractionation accordingly
SBRT may be used after induction chemotherapy for selected borderline resectable or locally advanced pancreatic cancer to facilitate resection or as definitive therapy when appropriate; multifraction regimens are favored for neoadjuvant/downstaging use.
commonly 30 Gy in 5 fractions or 33 Gy in 5 fractions in studies
ASTRO 2019 conditional recommendations; meta-analyses and phase II trials
Prostate cancer — definitive ultrahypofractionation: Five-fraction SBRT is an acceptable definitive option for low- and intermediate-risk prostate cancer with non-inferior biochemical/clinical failure outcomes compared with conventional/moderate hypofractionation in RCTs (e.g., PACE-B); seven-fraction regimens (e.g., 42.7 Gy/7) are alternative examples.example regimens: 5 fractions (PACE-B), 42.7 Gy in 7 fx
ECRI review; PACE-B trial
For medically inoperable stage I–IIA node-negative SCLC, SBRT is an acceptable definitive thoracic RT option typically delivered with chemotherapy as per guideline recommendations.
medically inoperable or non-optimal surgical candidate
ASTRO/NCCN support
Oligometastatic disease — metastasis-directed SBRT/SABR: SBRT/SABR to all metastatic sites may be used as metastasis-directed therapy in patients with limited (commonly 1–5) metastases when trial evidence shows PFS benefit and some trials show OS benefit; selection requires multidisciplinary review, appropriate technology, and patient-specific considerations.1-5 metastases; controlled primary or after systemic therapy
RCTs and phase II trials (SABR-COMET, Gomez, Palma) show PFS benefit; patient selection critical
For pulmonary oligometastases, choice between SBRT and metastasectomy should be multidisciplinary and consider patient preference; ultracentral lesions carry increased toxicity and require careful assessment.
ISRS recommendations; simultaneous SBRT for 2–5 peripheral lesions if OAR constraints met
Repeat SRS for AVMs: Repeat single-session SRS is a viable option for residual or recurrent AVMs after initial SRS, achieving pooled obliteration rates around 60.8% with selection based on nidus volume and SM grade.
Meta-analysis supports repeat SRS in selected subgroups
Predictors of optimal AVM outcome: Optimal outcomes after SRS for SM Grade III AVMs are more likely with unruptured AVMs, no prior embolization, smaller nidus volume, absence of associated aneurysms, and higher margin dose.
Ding et al. 2017
Staged volumetric SRS for large AVMs: Volume-staged SRS is an option for large AVMs unsuitable for single-session SRS or surgery; a suggested minimum margin dose of ~17 Gy per stage is associated with a reasonable chance of benefit and multiple procedures are often required.margin dose >= 17 Gy
Kano and cohort analyses; Marchetti ISRS guidance
Meningioma — single-fraction SRS: Single-fraction SRS (typical prescription 12–16 Gy) provides high local control for benign intracranial meningiomas particularly in skull-base or small-volume lesions; lower margin dose (<13 Gy) and prior surgery/radiation are associated with higher progression risk.margin dose typically 12-16 Gy; avoid <13 Gy
ISRS reviews and Pollock/Santacroce studies
Systematic reviews (De Maria et al., cohort analyses)
Neurologic and surgical evaluation: No neurologic compromise requiring immediate surgical decompression; spine stability should be evaluated and surgical options considered prior to RT.
ASTRO guidance and trial exclusions require surgical evaluation before RT for cord compression
Dose-fractionation consistency: Planned SBRT dose/fractionation aligns with guideline-supported regimens (examples include 2,400 cGy in 2 fractions for spine or 1,200–1,600 cGy x1 for nonspine symptomatic lesions) or other regimens with equivalent BED as clinically indicated.
ASTRO recommended regimens
Yazici et al. 2017
Guideline context: NCCN notes SRS is the least often used definitive radiotherapy for intraocular tumors and emphasizes planning and localization consistent with particle therapy approaches.
NCCN 2025
Added indication in policy revision
Spinal lesions — palliative or primary: Covered for palliative treatment of symptomatic spinal bone metastasis when using five fractions or less with no spinal cord or cauda equina compression, or for primary spinal lesions not amenable to surgical resection or 3D conformal techniques.fractions <= 5; no cord/cauda equina compression
Spinal criteria revised/added
Newly diagnosed brain metastasis revisions: Coverage for newly diagnosed brain metastasis requires absence of diffuse brain metastases and absence of diffuse leptomeningeal metastases; exclusions include diagnosis of lymphoma or germ cell tumor.no diffuse brain or diffuse leptomeningeal metastases
Revised criteria in policy update
Repeat stereotactic radiation for brain metastasis revisions: Repeat stereotactic radiation for brain metastasis is covered when there is absence of diffuse leptomeningeal metastases and extracranial disease is well-controlled or there are accessible and effective systemic treatment options available.extra-cranial disease controlled or treatable
Definitive treatment additions: Definitive indications expanded to include unresectable intrahepatic bile duct cancer (cholangiocarcinoma) and small cell lung cancer stage I or node-negative IIA when medically inoperable or non-optimal surgical candidates.stage I or node-negative IIA for small cell; unresectable cholangiocarcinoma
Added in policy revision
Extracranial oligometastatic disease update: Extracranial oligometastatic disease covered when performance status is KPS ≥70% or ECOG 0–2 and the individual has up to five metastatic lesions (treated lesions count toward total).KPS >=70% or ECOG 0-2; lesions <=5
Lesion count increased from up to 3 to up to 5 in policy revision
Prior Authorization
Authorize by guideline-consistent indication and regimen
Ensure prior authorization materials demonstrate the indication aligns with guideline-recommended uses (e.g., medically inoperable stage I–II NSCLC, neoadjuvant/downstaging pancreatic protocols) and specify the intended SBRT regimen.
Prior Authorization
Confirm technology, expertise, and eligibility criteria
Confirm and document that the treating facility has appropriate technology, physics support, and expertise, and that tumor size/location meets guideline constraints (e.g., RCC size thresholds) before authorization.
Prior Authorization
Document oligometastatic status and systemic therapy sequencing
For consolidative RT in oligometastatic disease, prior authorization should confirm the number of metastases (≤3 per ARS or up to 5 per ASTRO/ESTRO), prior systemic therapy interval/response when required, and that all sites are amenable to radiation.
Prior Authorization
Include prior treatments, target volume, and margin dose for repeat/staged SRS
When requesting repeat or staged SRS (e.g., for AVM), provide prior-treatment details (embolization, prior SRS), nidus/target volume, proposed margin dose (minimum suggested ~17 Gy for staged volumetric SRS), and prior hemorrhage history to inform authorization.
Prior Authorization
Capture prior surgery and planned dose/fractionation for pituitary SRS
For pituitary adenoma SRS/HSRT, document prior surgical resection for recurrent/residual disease, intended fractionation (single-fraction SRS vs HSRT), target volume, and planned marginal dose to support expected control and toxicity profiles.
Prior Authorization
Document indication and dose for bone metastasis SBRT/SRS
For spinal or nonspinal bone metastases, include clinical indication per guideline (e.g., symptomatic lesion, life expectancy ≥3 months, radioresistant histology or focal low-volume recurrence) and planned dose-fractionation consistent with ASTRO/NCCN recommendations.
Note
No additional explicit PA triggers stated — supply guideline-based documentation
The document does not specify additional explicit prior-authorization triggers; use guideline-aligned documentation (indication, dose, staging, multidisciplinary input) to support requests where required by plan processes.
Prior Authorization
Age-based coverage note — under 19 covered without further review
Policy notes that SRS and SBRT are covered without further review for individuals under 19; for patients ≥19, the policy criteria and usual prior-authorization process apply and should be followed.
Documentation Required
Document clinical selection criteria prior to SBRT
Before selecting SBRT, document clinical factors supporting SBRT over conventional RT: ECOG performance status (0–2), life expectancy, absence of neurologic symptoms or surgical indication, and expected benefit for durable control.
Prior Authorization
Document tumor size and prior therapies when preferring SBRT over RFA
When considering SBRT instead of RFA for recurrent small HCC, document tumor size (≤5 cm solitary nodule), prior local therapy history, and reference randomized trial outcomes if applicable to justify modality selection.
Documentation Required
State sequencing vs other local therapies and rationale
Document sequencing relative to other local therapies: note whether EBRT/SBRT is first-line because surgery/ablation/catheter therapies are not options or whether SBRT is being used as consolidation or salvage after incomplete response.
Prior Authorization
Document prior chemotherapy before pancreatic SBRT
For pancreatic cancer SBRT requests, include documentation of prior systemic chemotherapy (neoadjuvant induction) and the intent (downstaging vs definitive) per ASTRO recommendations.
Prior Authorization
Demonstrate inoperability or refusal before renal SBRT
For renal tumors, document operative candidacy; surgery is the standard for operable patients, so prior authorization for definitive SBRT should show the patient is medically inoperable, declined surgery, or is high surgical risk.
Step Therapy
Provide evidence of prior systemic therapy trial when guideline-recommended
When guidelines recommend a trial of systemic therapy before consolidative RT, provide documentation of prior systemic therapy (duration such as 2–3 months or cycles) and imaging showing no progression, if required for authorization.
Prior Authorization
Specify sequencing and rationale for repeat or staged SRS
For repeat or staged SRS, document planned sequencing (intervals between stages or repeat treatments), rationale (incompletely obliterated nidus or large AVM unsuitable for surgery), and expected number of stages based on evidence.
Step Therapy
Require prior medical therapy failure for essential tremor SRS
For essential tremor, document failure of medical therapy and that the patient is not a candidate for invasive surgery (or declined surgery) before considering SRS thalamotomy.
Step Therapy
Document consideration of conventional RT/surgery prior to SBRT
Guidelines recommend assessing conventional palliative RT and surgical options before SBRT for some palliative indications; document prior consideration of conventional RT when applicable.
Note
Provider action — see related PA and documentation requirements
No additional provider-action summary specified for this placeholder; follow the policy's stated documentation and authorization requirements above.
Step Therapy
No explicit step therapy protocols specified
The policy does not define explicit step therapy protocols for SBRT/SRS; note that no mandated stepwise medication or procedural sequence is specified in this section.
Documentation Required
Pre-treatment evaluation and goals documented
Before treatment, document prognosis, prior RT doses to the target and overlapping regions, normal tissue risks, goals of care, and quality-of-life expectations to support choice of SBRT/SRS regimen.
Documentation Required
Document lesion count, size, prior RT, and performance status
Include lesion-specific details in authorization and chart documentation: number of lesions, lesion sizes, prior radiation treatments, and performance status (ECOG or KPS) to justify treatment selection and fractionation.
Documentation Required
Document use of image-guided RT for intrahepatic SBRT
When treating intrahepatic tumors with SBRT, document that image-guided radiotherapy will be used to improve targeting accuracy and reduce toxicity.
Documentation Required
Provide operability assessment and multidisciplinary review
For stage I NSCLC considered for SBRT, include documentation that a thoracic surgeon evaluated operability within a multidisciplinary team and record the patient’s operative risk status.
Documentation Required
Document post-SBRT imaging schedule for primary RCC
For primary RCC treated with SBRT, include follow-up imaging plans consistent with ISRS recommendations (cross-axial abdominal imaging of kidneys/adrenals every six months and at least chest surveillance).
Documentation Required
Include staging and multidisciplinary discussion documentation
Prior-authorization dossiers for oligometastatic or complex cases should include staging imaging and documentation of multidisciplinary tumor board discussion to confirm number of metastases and site amenability to SBRT.
Documentation Required
Document imaging modality and follow-up plan for AVM obliteration
For AVM obliteration or repeat SRS, provide imaging baseline and planned follow-up imaging modality (angiography or MRI) and intervals to document obliteration outcomes as described in the literature.
Documentation Required
Require histology, volume, dose, and follow-up documentation for pineal lesions
For pineal region lesions, provide reliable histologic diagnosis or strong diagnostic evidence, lesion volume, prescribed margin dose, and planned follow-up imaging because outcomes vary markedly by histology.
Documentation Required
Provide spine stability, prior RT, and neurologic status documentation
For spine RT requests, document spine stability evaluation, prior RT doses to the site, performance status (ECOG/KPS), neurologic symptoms, number/location of involved vertebrae, and life expectancy to support appropriateness of SBRT.
Note
Device approvals informational — FDA product codes MUJ and IYE
FDA device approvals for SBRT/SRS systems (product codes MUJ and IYE) are informational; providers may reference FDA device listings but device approval alone is not a basis for coverage.
Documentation Required
Reference plan terms and decision context in submissions
When submitting documentation, include the clinical decision context (applicable federal/state/contractual plan terms) because benefit plan terms govern coverage determinations in the event of conflict with this policy.
Note
Lack of explicit administrative PA/billing triggers — provide complete clinical info
The policy does not list explicit administrative prior-authorization or billing denial triggers; however, failure to provide the guideline-aligned clinical information (indication, dose, staging, technology) may impede authorization decisions.
Denial Risk
Be aware of WBRT tradeoffs — relapse reduction without OS benefit
Adjuvant WBRT after surgery or radiosurgery reduces intracranial relapses but does not improve overall survival or duration of functional independence; omission of indicated salvage therapies or inappropriate substitution may increase intracranial progression risk.
Denial Risk
Dose-constraint capability required for intrahepatic cholangiocarcinoma SBRT
For intrahepatic cholangiocarcinoma, SBRT is preferred only when dose constraints can be met; failure to demonstrate ability to meet organ-at-risk constraints or image-guidance capability may risk denial.
Denial Risk
Document operability/trial enrollment for NSCLC SBRT to avoid denial
Using SBRT instead of surgery for standard-operative-risk stage I NSCLC is not recommended outside a clinical trial; lack of documentation of high operative risk or clinical trial enrollment may put authorization at risk.
Denial Risk
Be aware of trial-based exclusions that may limit coverage (FASTRACK II)
FASTRACK II exclusions (e.g., tumors >10 cm, tumors abutting bowel, prior overlapping high-dose RT, prior systemic RCC therapy, eGFR <30 mL/min/1.73 m²) identify scenarios where supporting evidence is limited and could affect coverage if present.
Denial Risk
Consolidative RT not recommended for ≥6 metastatic sites outside trials
ARS does not recommend consolidative RT for patients with six or more metastatic sites outside a clinical trial; proposing consolidative RT for ≥6 sites without trial context may not be supported.
Denial Risk
Avoid sub-threshold margin doses for staged SRS — document margin dose ≥17 Gy when applicable
Planned margin doses below recommended thresholds (e.g., <17 Gy for staged volumetric SRS) may lower probability of benefit; authorization should show proposed margin dose meets evidence-based guidance when indicated.
Denial Risk
Reirradiation should use highly focused techniques for low-volume glioma
NCCN recommends reirradiation for recurrent glioma with highly focused techniques such as SRS for lower-volume disease; failure to use or document a highly focused approach for low-volume recurrence may not align with guidance.
Denial Risk
Observe trial selection/exclusion criteria for spinal SBRT; document surgical evaluation
Randomized trial exclusions for spinal metastasis treatments included prior RT to the site, spinal instability, extensive contiguous vertebral involvement, and neurologic symptoms requiring immediate surgery; treating patients with these exclusion features without surgical evaluation or justification may risk denial.
Denial Risk
Ocular SRS less commonly used — document center expertise for intraocular cases
NCCN notes SRS is less often used for intraocular tumors; absence of strong justification or specialized center experience for ocular SRS may affect acceptability.
Documentation Required
Cite applicable benefit plan terms — plan terms govern coverage
Coverage determinations must follow federal, state, or contractual benefit plan terms; when plan terms conflict with this policy, plan terms govern and should be cited in authorization decisions.
Reported median exampleMedian BED reported 111 Gy in HypoFXSRT series for stage I NSCLC
inv-44: BED threshold for improved local control (NSCLC)
BED threshold (NSCLC)>= 100 Gy (BED10) — associated with improved local control and survival
Clinical implicationWhen safe, prescribe SBRT regimens achieving BED ≥100 Gy for early-stage NSCLC to optimize local control
Evidence sourceHypoFXSRT multi-center series demonstrating lower local recurrence with BED ≥100 Gy
inv-45: Prostate SBRT fractionation examples
Common prostate SBRT regimensFive-fraction regimens (e.g., PACE-B) — commonly used and non-inferior in trials
Alternative fractionation example42.7 Gy in 7 fractions (ultrahypofractionation per Widmark et al.)
Patient selection noteUsed across risk groups when delivered with appropriate technology and expertise
inv-46: Tumor size thresholds for RCC SBRT dosing
Tumor size ≤4–5 cm26 Gy in 1 fraction (recommended when tumor ≤4–5 cm)
Tumor size >4–5 cm42–48 Gy in 3 fractions (preferred for larger tumors)
OAR-constrained alternative40 Gy in 5 fractions if organ-at-risk constraints prevent a 3‑fraction regimen
inv-47: Tumor size limit for definitive SBRT in non-surgical kidney candidates (NCCN)
NCCN tumor size limit for definitive SBRT (non-surgical candidates)Consider definitive SBRT for T1 tumors <7 cm in non-surgical candidates
Anatomic exclusionTumors abutting bowel should be considered not amenable to SBRT per NCCN
Clinical preferenceSurgery remains standard for operable patients; SBRT for those medically inoperable or declining surgery
inv-48: Common SABR dose examples for early-stage SCLC
Typical SABR dose range (early-stage SCLC)Approximately 50 Gy delivered in 3–5 fractions (median 50 Gy in 4 fractions reported)
Indication contextUsed for medically inoperable T1-2N0M0 SCLC in combination with chemotherapy as appropriate
inv-49: Suggested minimum margin dose for staged volumetric SRS
Suggested minimum margin dose (staged volumetric SRS)>= 17 Gy (minimum margin dose suggested to have reasonable chance of benefit)
Staging implicationVolume-staged approaches often require multiple procedures; margin dose depends on AVM location and anatomy
Adjunct strategiesStaged SRS may be combined with embolization to improve obliteration and reduce hemorrhage risk
inv-50: Typical margin dose reported for AVM SRS cohorts
Typical margin dose reported (AVM SRS cohorts)Around 18–20 Gy margin dose commonly reported in AVM SRS series
Outcome relationHigher margin doses (≥17–20 Gy) associated with higher obliteration rates in AVMs
Dose-risk tradeoffHigher margin dose increases obliteration probability but also risk of radiation-induced changes and hemorrhage
inv-51: SRS/FSRT dose associated with better control (>=45 Gy in 3 fx)
Dose associated with better control (uveal melanoma series)>= 45 Gy in 3 fractions associated with better control and enucleation‑free survival
Clinical recommendation (author)Authors recommended increasing radiation dose when feasible and respecting eye/lens constraints to improve retention
Organ constraints exampleLimit maximum eye dose to 50 Gy and lens dose to 15 Gy (author recommendation)
inv-52: Maximum recommended organ doses (author recommendation)
Maximum recommended eye dose (author recommendation)Limit maximum eye dose to 50 Gy
Maximum recommended lens dose (author recommendation)Limit maximum lens dose to 15 Gy
RationaleDose limits recommended to increase eye preservation and reduce radiation-related ocular toxicity
Guideline contextASTRO and NCCN recommend SRS alone for limited brain metastases to preserve cognition vs WBRT
inv-100: Stereotactic body radiotherapy (SBRT) definition
SBRT definitionAblative external‑beam radiotherapy delivered in a small number of high‑dose fractions (commonly 3–5 fractions; examples for HCC 45–60 Gy in 3 fractions)
ApplicationsUsed for primary liver tumors, lung tumors, prostate, kidney, spine and extracranial oligometastases
Technical requirementDelivered with image guidance and organ‑at‑risk constraints to limit toxicity
inv-101: SBRT fractionation (1–9 fractions)
SBRT fractionation rangeSBRT may be delivered in one to nine fractions depending on tumor site and constraints
Liver guideline noteISRS recommends 1–9 fractions for liver‑confined HCC with no single optimal schedule
Clinical implicationFractionation choice should be individualized based on location, size, and organ function
inv-102: BED threshold (definition context)
BED threshold definition contextBED here referenced using α/β =10 (BED10) to compare ablative regimens; used to link dose-fractionation to outcomes
Use in decision-makingBED calculations inform selection of dose/fractionation to achieve desired tumor control while respecting OAR constraints
ExampleBED ≥100 Gy (BED10) associated with superior control in early-stage NSCLC series
inv-103: BED (median BED example)
Median BED exampleMedian calculated BED reported as 111 Gy (BED10) in the multi‑institution HypoFXSRT stage I NSCLC series
Range reportedBED range reported from 57 to 180 Gy in that series
Clinical relevanceHigher median BED in series associated with better local control and survival metrics
inv-104: Ultrahypofractionation / SBRT (prostate)
Ultrahypofractionation (prostate)Five‑fraction SBRT regimens (e.g., PACE‑B) or seven‑fraction regimens (42.7 Gy in 7 fx) are validated options for localized prostate cancer
Trial evidencePACE‑B and Widmark trials support non‑inferiority of ultrahypofractionation versus conventional regimens
Practice noteRequires appropriate technology, image guidance, and patient selection (WHO/ECOG 0–2 in trials)
inv-105: SBRT / SABR term
SBRT / SABR termSBRT (stereotactic body radiotherapy) / SABR (stereotactic ablative radiotherapy) — high‑precision, high‑dose RT delivered in few fractions for ablative intent
Acceptable usesUsed for primary tumors and metastasis‑directed therapy in settings with appropriate technology and expertise
NCCN noteRecommended for metastasis‑directed therapy in limited metastatic disease and symptomatic lesions
inv-106: Oligometastatic disease (definition)
Oligometastatic disease definitionLimited number of metastatic lesions (commonly 1–5) where metastasis‑directed therapy may improve progression‑free survival and sometimes overall survival
Controlled primary optionalPrimary tumor control optional; all metastatic sites must be safely treatable
Guideline consensusASTRO/ESTRO and other groups commonly define OMD as up to five lesions for decision‑making
inv-107: One to five metastatic lesions (OMD detail)
Common numeric detail — OMDOne to five metastatic lesions (controlled primary optional); all metastatic sites must be safely treatable
Clinical implicationGuidelines recommend MDT for up to 5 lesions with multidisciplinary evaluation
Trial enrollment noteMost trials enrolled patients with 1–2 lesions despite allowance up to 5; factor into decision‑making
inv-108: ARS oligometastatic categorization (3 sites or less; 4–5 case-by-case; ≥6 not recommended)
ARS oligometastatic categorizationRecommend consolidative RT for patients with ≤3 sites after upfront systemic therapy; 4–5 sites considered case‑by‑case; ≥6 not recommended outside trials
Implementation remarkARS suggests waiting 2–3 months or cycles of therapy to confirm no progression before consolidative RT
Comparison to ASTRO/ESTROASTRO/ESTRO generally allow up to 5 sites; ARS is more restrictive
inv-109: Margin dose definition and implication
Margin dose definitionMargin dose = prescribed radiation dose delivered to the lesion margin; higher margin doses (e.g., ≥17–20 Gy) linked to higher obliteration/control rates
Implication for outcomesHigher margin doses associated with improved obliteration in AVMs and better local control in meningiomas and other benign lesions
Dose selection cautionHigher margin dose increases risk of radiation‑induced changes; select based on volume, location, and prior treatments
inv-110: Obliteration definition (AVM)
Obliteration definition (AVM)Obliteration = radiographic disappearance of AVM nidus documented by MR imaging or angiography after SRS
Timeframe and ratesRepeat SRS series report mean time to obliteration ~33–39 months with actuarial obliteration rates increasing over years
DeterminantsSmaller nidus volume, lower SM grade, absence of prior embolization, and higher margin dose predict higher obliteration rates
inv-111: SRS definition (alternate phrasing)
Alternative SRS definition phrasingHighly focused, image‑guided radiation delivered in one or a few fractions (includes Gamma Knife, LINAC, CyberKnife, hypofractionated SRS)
Functional applicationsUsed for functional targets (e.g., thalamotomy for tremor) and intracranial tumors
Device examplesGamma Knife, LINAC‑based systems, CyberKnife referenced as common platforms
inv-112: GKRS definition
Gamma Knife radiosurgery (GKRS)Single‑fraction stereotactic radiosurgery technique commonly used for functional targets and small intracranial lesions
Use casesEmployed for essential tremor, AVMs, small brain metastases, meningiomas, and pituitary lesions
Dose examples (functional)GKRS thalamotomy performed with single 4‑mm collimator and single‑fraction max dose 130–150 Gy in some series
inv-113: SBRT/SRS recommended spine doses (ASTRO)
Recommended spine SBRT exampleASTRO recommends 2,400 cGy in two fractions for spine SBRT; other regimens with similar BED in 3–5 fractions may be reasonable
Conventional palliative comparatorsConventional RT options include 800 cGy x1, 1,600 cGy x2, 2,000 cGy x5, or 3,000 cGy x10
Pre-treatment requirementEvaluate spine stability and consider surgical decompression before RT when indicated
inv-114: Local control (LRFS) definition
Local control (LRFS) definitionLocal control defined as lack of tumor progression (increase in tumor volume)
Response definitionsComplete response = disappearance of tumor; Partial response = >50% decrease in tumor volume
ApplicationUsed as primary efficacy endpoints in SRS/FSRT uveal melanoma and other focal therapy series
inv-115: Response definitions (complete/partial)
Response definitions (tumor)Complete response: disappearance of the tumor; Partial response: >50% decrease in tumor volume
Use in reportingThese definitions applied in SRS/FSRT series to report LRFS and response rates
Clinical relevanceResponse categories help determine need for further local therapy or surveillance
Oligometastatic Disease (OMD) updated definitionPolicy records an updated definition for OMD in the revisions (refer to Definitions section for exact wording)
ApplicationUsed to set lesion-number thresholds and patient selection in consolidative SBRT/SRS coverage criteria
NoteGuideline consensus generally uses up to five metastatic lesions; policy aligns coverage to that range for many indications
policy_revision
Revised brain metastasis criteria: required absence of diffuse brain metastases and replaced prior leptomeningeal language with 'absence of diffuse leptomeningeal metastases'; removed small cell carcinoma from the excluded diagnoses (now only lymphoma or germ cell tumor).
02/01/2026policy_revision
Updated repeat stereotactic radiation for brain metastasis criteria: replaced prior 'absence of leptomeningeal metastases' wording with 'absence of diffuse leptomeningeal metastases' and allowed repeat treatment when extracranial disease is well-controlled or accessible/effective systemic options exist; removed prior limit on total brain metastases treated in past 12 months.
02/01/2026policy_revision
Added definitive treatment indications: included unresectable intrahepatic bile duct cancer (cholangiocarcinoma) and stage I/IIA small cell lung cancer as definitive treatment indications with specified criteria.
02/01/2026policy_revision
Extracranial oligometastatic disease criteria revised: standardized performance status wording and increased allowed total metastatic lesions from up to three to up to five.
This policy is informational and must be applied in the context of applicable federal, state, and contractual benefit terms. The policy history notes a revision (02/01/2026) and archives a prior version (CS180.I); UnitedHealthcare may modify policies and use third‑party tools to assist benefit administration, and plan terms govern in case of conflict.