Stereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Clinical coverage policy for SRS and SBRT for UnitedHealthcare Commercial and Individual Exchange plans addressing indications, definitions, and applicable billing codes for individuals aged 19 and older (with special note for those under 19).
Policy Summary
PayerUnitedHealthcare
PolicyStereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Policy CodePolicy 2026T0611K
Change TypeTemplate consolidationshared policy for Oxford
Effective DateJan 1, 2026
Next Review DateN/A
Key ActionObtain prior authorization per the member-specific benefit plan and document indication, lesion count, performance status, prior treatments, and planned dose/fractionation.
Created shared policy version to support application to Oxford plan membership and archived previous policy versions.
19+Policy applies to individuals ages
<=5 frSBRT defined as delivered in
up to 5Oligometastatic lesion limit
<15 ccBrain mets cumulative volume
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90.8%
10‑yr VS local control after SRS
15+Pages of references cited
Coverage Criteria for SRS and SBRT
Covered Indications (selected list)
Stereotactic radiation therapy (SRS and SBRT) is considered proven and medically necessary for the following indications when the specified criteria are met:
Covered diagnostic/clinical indications: Acoustic neuroma (vestibular schwannoma); Bone metastasis (non-spine) when symptomatic and delivered in up to five fractions; Brain metastasis (newly diagnosed or retreatment) under specified criteria; Skull-base chordoma and chondrosarcoma; Craniopharyngioma (residual or recurrent); Definitive treatment for select primary cancers (hepatocellular carcinoma without regional/distant metastasis, unresectable intrahepatic cholangiocarcinoma, stage I–IIA node‑negative NSCLC when inoperable or after informed decision, pancreatic adenocarcinoma in selected neoadjuvant/definitive contexts, localized prostate cancer, renal stage I when nonoperative, early-stage node‑negative SCLC when combined with systemic therapy); Extracranial oligometastatic disease meeting lesion- and disease‑control limits; Glomus jugulare tumors; Cavernous sinus and intraorbital hemangiomas; Intracranial arteriovenous malformations (AVMs), including repeat or staged SRS strategies; Meningioma (sporadic and NF2-associated) as appropriate; Recurrent gliomas; Pituitary and pineal region tumors; Trigeminal neuralgia refractory to medical therapy; Spinal lesions meeting listed palliative or other indications; Uveal melanoma.
Indication-specific criteria and limits are defined in the following criteria groups.
Brain metastasis — Newly diagnosed
Covered when ALL of the following are met:
Performance and disease extent: Individual has good performance status (KPS ≥ 70 or ECOG 0–2) AND absence of diffuse brain metastases AND absence of diffuse leptomeningeal metastases.KPS ≥70 or ECOG 0-2
ASTRO recommendations and policy selection criteria apply.
Histology and systemic disease: Individual does not have lymphoma or germ cell tumor AND extracranial disease is well‑controlled or effective systemic therapy options are available AND life expectancy > 6 months for selected oligometastatic management.life expectancy > 6 months when listed
Certain histologies (lymphoma, germ cell) are excluded from brain‑metastasis SRS/SBRT indication.
Lesion count and volume: Number of intracranial lesions and cumulative intracranial tumor volume are within policy limits (commonly up to 4 intact BMs per strong ASTRO recommendation; conditional consideration for 5–10 BMs in selected patients) AND cumulative tumor volume generally < 15 cc when specified in selection.up to 4 BMs (strong); 5–10 BMs (conditional); cumulative volume <15 cc
Extracranial Oligometastatic Disease
Covered when ALL of the following are met:
Primary tumor types: Primary tumor is one of: colorectal cancer, melanoma, non‑small cell lung cancer, prostate cancer, renal cancer, or sarcoma.
Policy limits primary tumor types to those listed in trial/guideline evidence.
Control of primary and timing: Primary tumor is controlled (≥ 3 months since definitive treatment) with no progression at the primary site and patient has life expectancy ≥ 6 months.≥3 months since definitive treatment; life expectancy ≥6 months
Consistent with trial eligibility for oligometastatic MDT.
Performance status: KPS ≥ 70 or ECOG 0–2.KPS ≥70 or ECOG 0-2
Selection aligns with trial inclusion criteria and guideline recommendations.
Spinal lesions — Palliative and other indications
Covered when one of the following is met:
Palliative painful spinal metastasis: Palliative treatment of symptomatic spinal bone metastasis using stereotactic techniques delivered in five fractions or less when the individual has no spinal cord or cauda equina compression and spinal stability has been assessed and addressed as needed.≤5 fractions
ASTRO recommendations and randomized trials (Guckenberger, Sahgal) support SBRT for select painful vertebral metastases with specific eligibility/exclusion criteria.
Primary spinal lesions: Primary spinal tumors that cannot be treated with surgical resection or conventional 3D conformal techniques and are amenable to stereotactic treatment.
Consider multidisciplinary evaluation and prior authorization documentation for technical feasibility.
Previously irradiated spine field: SRS/SBRT to treat disease within a previously irradiated spinal field when prior RT dose, interval since prior RT, cumulative spinal cord dose constraints, and expected benefit justify reirradiation and documentation provided.
Evidence-summarized coverage considerations
Contextual coverage-relevant findings and guideline-backed recommendations extracted from evidence and guideline sources:
Vestibular schwannoma evidence: Single‑fraction SRS achieves high local control (three-, five-, 10‑year KM local control ~96.6%, 92.3%, 90.8%) with low rates of severe toxicity; typical prescription doses in series centered around 11.5–15 Gy single fraction. SRS may be used as primary therapy for small-to-medium tumors or as adjuvant treatment after subtotal resection with early post‑op imaging to define residual disease.median Rx dose ~13 Gy in cited series
Single‑center series and guideline statements support SRS in selected VS patients.
Non‑spine bone metastases: High‑dose single‑fraction SBRT produced higher early pain response rates versus multifraction RT (e.g., 1200–1600 cGy single‑fraction nonspine recommended by ASTRO), with noninferiority on longer endpoints and similar toxicity in trials. Patient selection should consider prognosis, prior RT, and normal tissue constraints.1200–1600 cGy single fraction (nonspine)
Phase II RCT and ASTRO guideline references.
SRS for intact brain metastases (ASTRO recommendations)
Covered when ALL of the following are met
Performance status and candidacy: Patient has ECOG 0–2 (or equivalent KPS) AND clinical and imaging assessment supports focal SRS (lesions amenable to stereotactic targeting) AND consideration of patient goals regarding cognitive preservation.ECOG 0-2
ASTRO strongly recommends SRS for up to four intact BMs and conditionally for 5–10 BMs.
Lesion size and fractionation: Intact brain metastases <2 cm in diameter are appropriate for single‑fraction SRS (recommended dose 20–24 Gy); larger lesions or resection cavities may be treated with multifraction SRS (e.g., 27 Gy in 3 fractions or 30 Gy in 5 fractions) to meet normal tissue constraints.<2 cm for single-fraction SRS; multifraction options noted
ASTRO dose‑fractionation recommendations apply.
Adjuvant WBRT after resection or radiosurgery
Covered considerations
Effect of adjuvant WBRT: Adjuvant whole‑brain radiotherapy after resection or radiosurgery reduces intracranial relapse and neurologic death (example: WBRT 30 Gy in 10 fractions) but has not been shown to improve duration of functional independence or overall survival; tradeoffs between intracranial control and cognitive preservation should guide decisions.WBRT 30 Gy in 10 fractions referenced
Use when intracranial control is prioritized over neurocognitive outcomes; salvage therapy should be available.
SRS alone versus SRS + WBRT (cognitive outcomes)
Key comparative evidence
Cognitive outcome trade-off and intracranial control: For patients with 1–3 brain metastases (<3.0 cm), SRS alone produced less cognitive deterioration at three months compared with SRS plus WBRT with no difference in overall survival, but had shorter time to distant intracranial failure; clinical selection should weigh cognitive preservation versus intracranial control needs.1–3 BMs, lesions <3.0 cm
Brown et al. randomized trial: significantly less cognitive decline with SRS alone.
SRS for skull-base chordoma and chondrosarcoma
When SRS is appropriate
Chordoma/chondrosarcoma treatment context: SRS (commonly Gamma Knife) may be used for skull‑base chordoma or chondrosarcoma for small to medium residual or recurrent disease, frequently following maximal safe resection; better local control is reported with smaller residual volumes (often <20 mL) and margin doses commonly ≥15 Gy.residual volume <20 mL; margin dose ≥15 Gy often used
Meta-analyses and multicenter series report meaningful control and modest adverse event rates.
SRS/FSRT for craniopharyngioma
Indications for radiosurgery/fractionated stereotactic RT
Craniopharyngioma residual/recurrent disease: SRS or fractionated stereotactic RT is reasonable for residual or recurrent craniopharyngioma to achieve tumor control and visual function improvement when tumor size and proximity to optic structures permit, with common margin prescription doses around 12–13 Gy for single‑fraction GKRS or FSRT regimens in multiple fractions as appropriate.median volumes often 1.0–5.5 mL; common margin dose ~12–13 Gy
Systematic review and pooled series report high PFS and acceptable hypopituitarism rates.
SBRT for small recurrent hepatocellular carcinoma (HCC)
Comparative coverage stance
Small recurrent HCC: For small, solitary recurrent HCC without extrahepatic metastasis or vascular invasion, SBRT demonstrated superior local progression‑free survival versus radiofrequency ablation (RFA) (e.g., two‑year LPFS 92.7% SBRT vs 75.8% RFA in randomized trial), with similar OS and safety in selected patients.≤5 cm inclusion in trial; strongest benefit ≤2 cm
Xi et al. randomized trial supports SBRT as a coverage‑supported option in these circumstances.
SBRT for liver-confined primary hepatic tumors (HCC and IHC)
Covered when ALL of the following are met:
Disease extent and liver function: Tumor is liver‑confined HCC or unresectable intrahepatic cholangiocarcinoma without regional or distant metastasis AND underlying liver function (e.g., Child‑Pugh class) supports safe SBRT delivery.
ASTRO and ISRS guidance recommend SBRT for liver‑confined disease when surgery/ablation not feasible.
Prior therapies and indication: Patient is not a candidate for curative surgery or catheter‑based therapies OR has incomplete response to ablation/embolization OR is a salvage candidate after local therapy failure.
NCCN and ASTRO recommendations support EBRT/SBRT in these settings.
Tumor burden and technical feasibility: Typically limited tumor number (commonly 1–3 tumors), individual tumor sizes and locations permit safe dose delivery with established organ‑at‑risk constraints, and the treating center can deliver image‑guided, dose‑escalated hypofractionated RT.
Meta‑analyses report high one‑ to three‑year local control (85–97%) with acceptable grade ≥3 toxicity when selected appropriately.
SBRT for early-stage inoperable or high-risk NSCLC
Covered when ALL of the following are met:
Disease stage and operability: Patient has stage I (T1–T2, N0, M0) NSCLC AND is medically inoperable or declines surgery after thoracic surgical evaluation, or is a high‑operative‑risk patient where SBRT is an appropriate alternative after shared decision‑making.tumor generally ≤5 cm per trial criteria
ASTRO and NCCN recommend surgical evaluation and caution against routine replacement of lobectomy in standard‑risk operable patients.
Tumor location and size are appropriate for SBRT (peripheral tumors commonly studied; proximity to central structures should guide fractionation and constraints).tumor diameter < =5 cm typical in trials
RTOG 0236 and other trials provide trial‑based regimens and outcomes.
Prescription regimens and BED: Planned SBRT regimen uses established fractionation (commonly 3–5 fractions with BED ≥100 Gy associated with optimal local control) and is deliverable within organ‑at‑risk constraints.
Definitive SBRT for early-stage NSCLC
Covered when ALL of the following are met (per evidence and guidelines cited):
Definitive SBRT candidate: Patient has stage I (T1–T2), N0, M0 NSCLC with tumor size within trial limits (commonly ≤5 cm) AND is medically inoperable or at high operative risk after thoracic surgical assessment.tumor size ≤5 cm in key trials
ASTRO recommends surgical evaluation for operability prior to SBRT consideration.
Technology and planning: Treatment is planned and delivered with appropriate SBRT technique, image guidance, and adherence to dose constraints consistent with trial regimens (e.g., 54 Gy in 3 fractions used in RTOG 0236) and institutional capabilities.
Use of risk‑adapted fractionation for central tumors is expected.
SBRT for pancreatic adenocarcinoma (neoadjuvant or definitive)
Covered when ANY of the following condition-specific criteria are met:
Neoadjuvant SBRT for borderline resectable pancreatic cancer: SBRT is used after induction systemic chemotherapy to facilitate resection (neoadjuvant intent) in borderline resectable pancreatic adenocarcinoma, with multifraction regimens (commonly 30–33 Gy in 5 fractions or dose‑painted approaches) and documentation of prior chemotherapy and restaging demonstrating resectability potential.typical regimens 30–33 Gy in 5 fractions; chemo prior to SBRT
ASTRO conditionally recommends chemo followed by multifraction SBRT for BRPC/LAPC.
Definitive SBRT for unresectable locally advanced pancreatic cancer: SBRT may be used as definitive local therapy in select unresectable locally advanced patients when systemic therapy has been considered, and planned dose/fractionation and OAR constraints are feasible and documented.regimens include 30–33 Gy in 5 fractions or dose‑painted schemes
Meta‑analyses and phase II studies report modest OS benefit and reduced acute toxicity compared with CFRT in selected series.
SBRT for localized prostate cancer
Covered when ALL of the following are met:
Disease and risk group: Patient has localized prostate adenocarcinoma consistent with trial inclusion (commonly low‑ or intermediate‑risk, T1–T2, life expectancy ≥5 years) and is appropriate for definitive radiotherapy.T1–T2; life expectancy ≥5 years per PACE‑B criteria
PACE‑B and pooled evidence support five‑fraction SBRT as non‑inferior to CRT for select patients.
Treatment delivery and technique: SBRT is delivered with appropriate technology, image guidance, and advanced treatment planning consistent with AUA/ASTRO expectations for dose escalation and OAR sparing.five‑fraction SBRT regimens typical
Document counseling regarding toxicity tradeoffs and appropriate follow‑up.
Evidence supports SBRT/ultrahypofractionation as an effective option for localized prostate cancer under these conditions:
Candidate and technology: Patient has localized prostate cancer suitable for radiotherapy and treatment will be delivered with appropriate technology, image guidance, and physics support (adequate motion management and target localization).
NCCN accepts SBRT across risk groups when appropriate expertise and resources are available.
Trial‑consistent exclusions: Exclude patients with prior pelvic radiotherapy, prior definitive prostate treatment, or other trial‑defined exclusions unless individualized justification and documentation provided.as per trial inclusion/exclusion
PACE‑B trial criteria inform typical exclusions.
Renal: Definitive SABR
SABR may be considered as definitive therapy for localized renal cell carcinoma in patients who are not surgical candidates or decline surgery when criteria are met:
Candidate selection: Biopsy‑confirmed primary renal cell carcinoma (single lesion) AND patient is medically inoperable or declines surgery AND ECOG 0–2 AND tumor size and location amenable to SBRT (not abutting bowel) AND multidisciplinary decision supports nonoperative SABR.tumor ≤7 cm typically considered; avoid tumors abutting bowel
FASTRACK II and ISRS guidance support SABR in non‑surgical candidates.
Dose regimens: Use established dose regimens by tumor size/feasibility: 26 Gy x1 for tumors ≤4–5 cm; 42–48 Gy in 3 fractions for tumors >4–5 cm; consider 40 Gy in 5 fractions if OAR constraints preclude 3‑fraction schedules.size‑based fractionation per ISRS
Document planning and OAR constraints; surgical management remains standard for operable patients.
SCLC: Definitive SBRT (node-negative early-stage)
SBRT/SABR is an option for early‑stage, node‑negative SCLC in combination with systemic therapy when appropriate:
Candidate criteria: Patient has T1–T2, N0, M0 (stage I–IIA) SCLC AND is medically inoperable or declines surgery AND planned management includes systemic chemotherapy per guideline recommendations.stage I–IIA (T1‑2 N0 M0)
ASTRO and NCCN provide conditional recommendations supporting SBRT plus systemic therapy for inoperable early‑stage SCLC.
SBRT/SABR as metastasis‑directed therapy (MDT) may be considered for selected patients with limited extracranial disease when the following considerations are met:
Evidence summary: Phase II RCTs and systematic reviews show improvements in progression‑free survival and in some trials overall survival with SBRT to all metastases in selected patients (e.g., SABR‑COMET), but evidence quality and histology heterogeneity vary and increased toxicity may occur; typical trial lesion counts were 1–5 metastases.1–5 lesions commonly studied
Persson et al., SABR‑COMET and meta‑analyses inform efficacy and risk tradeoffs.
Candidate selection and staging: Multidisciplinary selection with appropriate staging imaging confirming limited metastatic burden (commonly 1–5 extracranial lesions), controlled or controllable primary tumor, and expected survival sufficient to benefit from local ablative therapy.1–5 lesions; appropriate imaging staging
ARS and ESTRO‑ASTRO consensus statements define acceptable lesion counts and post‑systemic therapy consolidative contexts.
Indications for consolidative local therapy (SBRT/SABR) in oligometastatic NSCLC and other malignancies
Covered when ALL of the following are met
Primary conditions for consolidative local therapy: Patient has oligometastatic disease (commonly 1–5 extracranial metastases) AND all metastatic sites are safely treatable with SBRT/SABR or other definitive local therapy AND appropriate staging imaging and multidisciplinary discussion documented.1–5 lesions
Most trial patients had 1–2 lesions; consider this when applying results.
Systemic therapy context: For NSCLC and some other histologies, consolidative local therapy is appropriate when no progression is documented after initial systemic therapy (e.g., after 2–3 months or cycles), with documentation of non‑progression before SBRT/SABR.post‑induction nonprogression
ARS and ASTRO/ESTRO guidance recommend consolidative RT after upfront systemic therapy in selected patients.
Tumor‑type evidence and trial support:
Glomus Jugulare Tumors — SRS
Evidence supports SRS as an effective primary or salvage treatment for glomus jugulare tumors.
Glomus jugulare SRS criteria: SRS may be considered for glomus jugulare tumors based on series and meta‑analyses reporting high tumor control (overall tumor control ~93% at last follow‑up; pooled ~97%) and clinical control; selection should consider prior surgery or EBRT and cranial nerve status.
Document tumor characteristics and prior interventions when requesting authorization.
Cavernous Sinus / Orbital Hemangiomas — SRS
SRS is effective for cavernous sinus and intraorbital hemangiomas with high rates of tumor regression and symptomatic improvement.
Hemangioma SRS criteria: SRS (commonly Gamma Knife) may be used for cavernous sinus or intraorbital hemangiomas to achieve tumor regression and symptom relief when optic apparatus dose constraints can be met; typical margin doses reported ~12.6–14.5 Gy and optic nerve dose frequently kept <9 Gy.optic nerve dose <9 Gy in cited series
Document symptomatic status and imaging demonstrating lesion amenability to SRS.
Intracranial Cavernous Malformations (ICMs) — SRS
ISRS recommends conditional use of SRS for selected symptomatic ICMs.
ICM SRS indications: SRS may be considered for surgically inaccessible or eloquently located intracranial cavernous malformations with prior symptomatic hemorrhage to reduce subsequent hemorrhage risk, or for medically refractory epilepsy attributable to an ICM; SRS is not typically recommended for asymptomatic ICMs.
Recommendations are conditional and supported by low‑quality evidence per ISRS.
Arteriovenous Malformations (AVMs) — SRS and Repeat/Staged SRS
SRS is an effective option for AVMs with outcomes dependent on nidus volume, Spetzler‑Martin grade, margin dose, and prior hemorrhage; repeat and staged strategies are used for incompletely obliterated or large lesions.
Initial SRS candidacy for AVM: SRS is appropriate for small‑volume, low Spetzler‑Martin grade AVMs or lesions in deep/eloquent locations where surgery is high risk; anticipated obliteration rates for grade I–II AVMs are ~80% in selected series.
ISRS and multicenter data support front‑line SRS for many grade I–II AVMs.
Repeat SRS for residual AVM: Repeat SRS may be considered for incompletely obliterated AVMs after initial SRS when residual nidus volume is suitable, acknowledging progressive obliteration over years (meta‑analysis ~60.8% obliteration) and measurable rates of hemorrhage and radiation‑related effects.
Document prior SRS details, residual volume, and interval since prior treatment.
Volume‑staged SRS for large AVMs: Planned volume‑staged SRS may be used for large AVMs unsuitable for single‑session SRS, often employing minimum margin doses around 17 Gy or greater across stages, with understanding of latency‑period hemorrhage risk and need for multidisciplinary planning (embolization adjuncts when indicated).
Meningioma — SRS (including NF2-associated)
SRS (particularly Gamma Knife) yields high tumor control and favorable survival in sporadic and NF2‑associated meningiomas, with risk factors for progression and complications identified.
Meningioma SRS criteria: Single‑fraction SRS provides high local control for benign intracranial meningiomas (five‑ and 10‑year control reported in series ~96% and 89% in select cohorts); factors increasing progression or complications include tumor margin dose <13 Gy, prior surgeries, larger tumor volume, and certain convexity/parasagittal locations.margin dose <13 Gy associated with increased progression in cited series
Consider NF2 status, prior RT, and tumor volume when evaluating appropriateness and expected risks.
Indication-level evidence summaries
Evidence‑supported indications and key outcomes summarized by condition
Meningioma evidence summary: SRS/GKRS yields high local control for benign meningiomas with durable PFS in many series; tumor location, prior surgery, and lower margin dose are associated with worse outcomes; toxicity rates are generally low but increase with larger volumes and certain locations.
Multiple multicenter series and meta‑analyses summarized.
Functional neurologic conditions: SRS may be an option for medically refractory epilepsy or essential tremor in patients who are not candidates for invasive surgery or decline it, though evidence is variable and often retrospective; expect delayed clinical response and variable complication rates.
Randomized data for MTLE show higher seizure remission with ATL versus SRS but SRS remains an option for select patients.
Pituitary adenoma summary: SRS for recurrent/residual nonfunctioning pituitary adenomas achieves high tumor control (~92% pooled) with hypopituitarism as the most common toxicity (rates variable across series); dose selection and prior surgery history influence outcomes.
Evidence-supported Indications and Contexts
Coverage supported when clinical and imaging features align with evidence and guideline‑recommended contexts (examples below):
Pituitary adenoma context: SRS as primary or salvage therapy may be considered based on symptoms, tumor location, morphometry, prior surgery, and endocrine status; outcomes and hypopituitarism risk vary by adenoma subtype and dose delivered.follow‑up evidence mean ~67 months in some series
Histology and prior therapy should be documented.
Recurrent high‑grade glioma context: Stereotactic reirradiation may be reasonable salvage for selected recurrent WHO grade III–IV gliomas in patients with favorable performance status and limited target volumes; expected benefit is modest and combined modality approaches may improve outcomes in select patients.median OS from SRS series ~8–11 months
Document prior treatments and rationale for reirradiation.
Spine metastases evidence context:
Evidence summaries for covered indications
Evidence and guideline statements summarized for selected indications:
Trigeminal neuralgia (drug‑resistant): Radiosurgery (Gamma Knife, LINAC, or CyberKnife) is supported for classical trigeminal neuralgia refractory to medical therapy, with variable rates of initial pain freedom (GKS mean ~53%) and expected complications (hypesthesia/paresthesia) depending on target location; multidisciplinary selection and specialized center capability are recommended.N/A
ISRS systematic review provides pooled outcome ranges and cautions on heterogeneity.
Uveal melanoma: SRS/FSRT (CyberKnife, GKRS) demonstrates high local control and eye preservation rates in systematic reviews and series (e.g., CyberKnife 3‑year local control ~89% and 3‑year eye preservation ~84% pooled), with common radiation‑related ocular toxicities; dose selection (e.g., ≥45 Gy in 3 fractions for larger tumors) and OAR constraints influence enucleation risk.dose examples: ≥45 Gy in 3 fractions for better control of large tumors; eye/lens dose limits referenced
Evidence largely retrospective; specialized center experience recommended.
Individuals with a diagnosis of lymphoma or germ cell tumor are excluded from the brain metastasis SRS/SBRT indication because the policy’s brain metastasis criteria explicitly require the member to not have these histologies when considering stereotactic cranial treatment.
The source document does not list additional explicit procedural exclusions, but guideline and trial context inform procedural selection: WBRT is not favored for many limited brain metastasis indications because randomized data show no survival benefit and worse cognitive outcomes compared with observation or focal therapy, which has driven a move away from routine WBRT in these settings. Prior RT doses, prognosis, normal tissue risks, and patient goals should be assessed before choosing stereotactic approaches or WBRT.
If intracranial recurrence is too diffuse or widespread to be effectively addressed with focal therapies such as SRS, the policy notes that WBRT may be reconsidered as a broader treatment strategy; focal SRS/SBRT is intended for limited, discrete lesions rather than diffuse intracranial disease.
The randomized trial of SBRT versus RFA for small recurrent HCC excluded patients with extrahepatic metastasis or vascular invasion at recurrence; therefore the trial evidence supporting SBRT in that context does not apply to patients with disseminated extrahepatic disease or tumor vascular invasion.
ASTRO guidance does not recommend using SBRT as a routine alternative to lobectomy for stage I NSCLC patients who are at standard operative risk (anticipated operative mortality < 1.5%). Use of SBRT instead of surgery in standard-risk operable patients should be limited to clinical trials or require specific justification.
NCCN guidance identifies tumors abutting the bowel as anatomically unsuitable for SBRT; such proximity to bowel structures is an exclusion that should preclude SBRT candidacy unless alternative safe planning and dose constraints can be documented.
Applicable Codes and Coding-related Criteria
Applicable CPT Codes (part 1)CPT
32701
Thoracic target(s) delineation for stereotactic body radiation therapy (SRS/SBRT), (photon or particle beam), entire course of treatment.
61796
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); 1 simple cranial lesion.
61797
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); each additional cranial lesion, simple (List separately in addition to code for primary procedure).
61798
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); 1 complex cranial lesion.
61799
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); each additional cranial lesion, complex (List separately in addition to code for primary procedure).
61800
Application of stereotactic headframe for stereotactic radiosurgery (List separately in addition to code for primary procedure).
63620
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); 1 spinal lesion.
63621
Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator); each additional spinal lesion (List separately in addition to code for primary procedure).
77301
Intensity modulated radiotherapy plan, including dose-volume histograms for target and critical structure partial tolerance specifications.
77371
Radiation treatment delivery, stereotactic radiosurgery (SRS), complete course of treatment of cranial lesion(s) consisting of 1 session; multi-source Cobalt 60 based.
1–10 of 12
1/2
Applicable CPT/HCPCS Codes (part 2)mixed
77432
Stereotactic radiation treatment management of cranial lesion(s) (complete course of treatment consisting of 1 session).
77435
Stereotactic body radiation therapy, treatment management, per treatment course, to 1 or more lesions, including image guidance, entire course not to exceed 5 fractions
G0339
Image guided robotic linear accelerator-based stereotactic radiosurgery, complete course of therapy in one session or first session of fractionated treatment.
G0340
Image guided robotic linear accelerator-based stereotactic radiosurgery, delivery including collimator changes and custom plugging, fractionated treatment, all lesions, per session, second through fifth sessions, maximum five sessions per course of treatment.
G0563
Stereotactic body radiation therapy, treatment delivery, per fraction to 1 or more lesions, including image guidance and real-time positron emissions-based delivery adjustments to 1 or more lesions, entire course not to exceed 5 fractions
FDA product codes referencedmixed
MUJ
FDA product code for certain stereotactic radiosurgery devices (informational)
IYE
FDA product code for certain stereotactic radiosurgery devices (informational)
Cumulative brain metastasis tumor volume — threshold value
Application contextApplies to newly diagnosed brain metastases as part of SRS/SBRT eligibility (all lesions treated in single SRS or 2–5 fraction SBRT).
Related lesion-count allowanceUsed alongside lesion-count criteria (up to 10 lesions in some brain metastasis criteria).
Maximum number of lesions for Oligometastatic Disease / brain mets
Oligometastatic disease lesion limitUp to 5 metastatic lesions (OMD definition used in coverage criteria and ESTRO‑ASTRO consensus).
Provider Actions, Prior Authorization, and Documentation Requirements
Prior Authorization
Prior Authorization for Listed Procedure Codes
Prior Authorization Required: Prior authorization is required for the listed SRS/SBRT procedure codes. Inclusion of a code in this policy does not guarantee coverage — obtain prior authorization per the member's plan and verify member-specific benefits and state/federal mandates before scheduling or rendering services.
Obtain prior authorization for all SRS/SBRT procedure codes referenced in this policy.
Listing of a code does not imply coverage or reimbursement; refer to the member specific benefit plan.
Documentation Required
SRS/SBRT Indication and Dosing Guidance
Indication and dosing should align with guideline-based recommendations (e.g., ASTRO, NCCN). Expected dose/fractionation examples: single-fraction nonspine SBRT SRS 1200–1600 cGy for palliative bone metastases (ASTRO); single-fraction SRS 2000–2400 cGy for intact brain metastases <2 cm, or multifraction options such as 2700 cGy in 3 fx or 3000 cGy in 5 fx where indicated. Dose-escalation, image guidance, advanced planning, and normal tissue sparing techniques are expected when EBRT or SBRT is used as definitive therapy.
Background and Evidence Context
Stereotactic body radiation therapy (SBRT or SABR) delivers high per‑fraction doses to well‑defined extracranial targets with extreme geometric precision, typically completed in five fractions or less. SRS (stereotactic radiosurgery) refers to very high‑dose, highly conformal treatment most often delivered in a single fraction for intracranial targets; fractionated stereotactic approaches (FSRT/HSRT) of 2–5 fractions are used when tumor size or proximity to critical structures makes single‑fraction treatment unsafe.
Definitions and Terminology
Definitive Treatment — definition
Definition (Definitive Treatment)Radiation treatments for cancer with curative intent.
ContextUsed to distinguish curative‑intent SBRT/SRS (definitive) from palliative or symptom‑directed therapy.
Reference sourcesDefinition derived from NCCN and NCI concepts cited in policy definitions.
Oligometastatic Disease (OMD) — definition
Definition (Oligometastatic Disease)A state of limited metastatic disease where eradication of all metastatic sites could result in long‑term survival or cure; commonly defined as 1–5 metastatic lesions with controlled primary tumor optional.
Policy lesion-count limitPolicy criteria and ESTRO‑ASTRO consensus reference 1–5 lesions as typical OMD definition for treatment candidacy.
Policy Revision History
2026-01-01template_update_and_consolidationLatest
Created a shared policy version to support application to Oxford plan membership and archived previous policy versions (2025T0611J and RADIOLOGY 042.7).
Policy Summary
PayerUnitedHealthcare
PolicyStereotactic Body Radiation Therapy and Stereotactic Radiosurgery
Policy CodePolicy 2026T0611K
Change TypeTemplate consolidationshared policy for Oxford
Effective DateJan 1, 2026
Next Review DateN/A
Key ActionObtain prior authorization per the member-specific benefit plan and document indication, lesion count, performance status, prior treatments, and planned dose/fractionation.
Yamamoto et al. and ASTRO guidance inform lesion-count thresholds and selection.
Treatment delivery feasibility: All lesions are amenable to definitive focal stereotactic treatment (SRS delivered as a single session or FSRT in 2–5 fractions for larger lesions or cavities) and planned dose/fractionation is consistent with guideline dose ranges (single‑fraction SRS 20–24 Gy for small intact BMs or multifraction options for larger lesions).SRS single fraction or FSRT 2–5 fractions
ASTRO dose recommendations for intact BMs apply.
Retreatment allowance: Retreatment with SRS/SBRT is permitted when prior treatment history, cumulative dose to critical structures, interval since prior RT, and expected benefit/risk justify repeat stereotactic therapy and documentation supports selection (see prior‑authorization documentation requirements).
Policy allows repeat stereotactic therapy when criteria for retreatment are met and documented.
Metastatic burden: Total number of metastatic lesions is up to five AND each lesion is ≤ 5 cm AND no malignant pleural effusion, leptomeningeal or peritoneal carcinomatosis is present.≤5 lesions; each lesion ≤5 cm
All metastatic lesions must be safely treatable with SBRT and be treated concurrently in a single episode of care.
Treatment episode and fractionation: All metastatic lesions are to be treated concurrently in a single episode of care AND SBRT for the entire course must be completed in ≤ 5 fractions (policy-defined SBRT course).SBRT completed in ≤5 fractions
ASTRO/ESTRO/ARS and consensus statements inform fractionation and lesion limits.
Trials excluded spinal instability, neurologic compression, and prior RT at the site in many cases; careful selection is required.
Brain metastases — cognitive tradeoff: Randomized trials demonstrate that SRS alone yields less early cognitive deterioration than SRS plus WBRT for limited brain metastases (1–3 lesions <3 cm) with no OS advantage to adding WBRT, though intracranial distant failure is more frequent after SRS alone; ASTRO endorses SRS for up to four intact BMs and conditionally for 5–10 in selected patients.1–3 BMs for cognitive trial evidence; ASTRO: up to 4 (strong), 5–10 (conditional)
Brown et al., Yamamoto, and ASTRO guideline findings summarized.
BED ≥100 Gy associated with superior LC
Trials (RTOG 0236, pooled analyses) support high local control with these regimens.
Evidence from randomized and controlled trials (e.g., SABR‑COMET, Gomez, Iyengar, others) supports improved PFS and in some studies OS in selected patients; applicability depends on primary tumor histology and trial eligibility.
evidence‑dependent
Discuss tumor‑specific guidelines (e.g., NCCN) and trial applicability.
minimum margin dose ~17 Gy suggested for staged approach
Staged approaches often require multiple procedures and careful risk discussion.
median SRS dose ~15 Gy in many series
Long‑term endocrine monitoring recommended.
Recurrent glioma context: Stereotactic reirradiation (CyberKnife or LINAC SRS/FSRT) for recurrent high‑grade gliomas yields modest median OS/PFS as salvage (median OS ~8–11 months) with low but nontrivial rates of radiation necrosis; combining reirradiation with chemotherapy may be associated with longer OS in selected series.median OS from reirradiation series ~8–11 months
Evidence largely single‑arm and retrospective; selection is critical.
SBRT/SRS is supported for painful vertebral metastases in selected patients and may provide superior complete pain response in some trials, though other RCTs showed no superiority for short‑term pain endpoints; selection should exclude spinal instability and neurologic compression unless managed surgically.
trial outcomes vary (Guckenberger, Ryu, Sahgal)
Assess spinal stability and prior RT before SBRT/SRS.
Astro brain metastasis lesion guidance
ASTRO recommends SRS for up to 4 intact brain metastases and conditionally for 5–10 intact lesions (ECOG 0–2).
Policy nuancePolicy allows brain metastasis criteria that in some contexts include up to 10 lesions when cumulative volume and performance status criteria are met.
Brain Metastasis Velocity (BMV) classes
BMV class — LowBMV ≤ 3 (low).
BMV class — IntermediateBMV 4–13 (intermediate).
BMV class — HighBMV ≥ 14 (high).
DefinitionBMV = cumulative number of new brain metastases after first SRS divided by years since initial SRS; used to stratify prognosis and survival after repeat SRS.
Lesion size/volume thresholds referenced
Single‑fraction size threshold (intact BMs)Single‑fraction SRS commonly recommended for intact brain metastases < 2 cm in diameter (ASTRO guidance).
Cumulative volume considerationCumulative intracranial tumor volume used in policy: < 15 cc supports SRS/SBRT candidacy when combined with lesion count and performance status.
Lesion size limit for OMD extracranial lesionsPolicy criteria for OMD list each lesion ≤ 5 cm in size for extracranial metastases.
BED threshold
BED threshold linked to superior outcomesBiologically effective dose (BED) ≥ 100 Gy is associated with superior local control and survival in stage I NSCLC.
Clinical implicationSelect regimens and fractionation should achieve BED ≥ 100 Gy when curative SBRT intent for stage I NSCLC is pursued, per cited studies.
Supporting trial contextOnishi et al. and related reports compared outcomes by BED and reported improved 5‑year OS/local control with BED ≥ 100 Gy.
Common SBRT pancreatic regimens
Common pancreatic SBRT regimens33 Gy in 5 fractions (e.g., GEM + 33 Gy/5f) and 30 Gy in 5 fractions reported in pancreas neoadjuvant/definitive series.
Dose‑painted approach exampleDose‑painted strategies reported (e.g., higher dose to vessel interface while sparing adjacent bowel) in selected series.
Higher‑dose regimens referencedSome studies reference 60–66 Gy in 3 fractions (from lung SBRT experience) as high‑BED examples used in investigational or selected settings.
Follow ASTRO/NCCN dose/fractionation guidance and tailor regimen to tumor size, location, and OAR constraints.
Document rationale when diverging from common regimens (e.g., multifraction SRS for larger cavities).
Prior Authorization
Prior Authorization: SRS for Brain Metastases — Required Documentation
For intracranial SRS for brain metastases, prior authorization must include documentation of the number of intact brain metastases, ECOG/Eastern Cooperative Oncology Group or Karnofsky performance status, maximum lesion diameters or cumulative intracranial tumor volume, and planned dose/fractionation. Indicate whether treatment is for intact lesions, postoperative cavity, or re-treatment and provide prior radiation history.
Number of intact BMs (count) and imaging confirming lesions.
Performance status (ECOG/KPS).
Maximum lesion diameter for each lesion and cumulative intracranial tumor volume when available.
Prior cranial radiation and systemic therapy status.
Planned SRS dose and fractionation per lesion.
Prior Authorization
Prior Authorization: Indication and Capability
Prior authorization for SBRT/SRS for extracranial indications (e.g., liver HCC/IHC, kidney, lung, pancreas) must document that SBRT was considered after assessment of other curative options or that other options are contraindicated/failed, and that the treating center has appropriate capability and experience (image guidance, physics support, multidisciplinary team). Demonstrate ability to meet dose constraints.
Statement that curative or catheter-based options were assessed and reasons SBRT is chosen.
Center capability: specialized experience, image-guidance, dedicated physics support, and multidisciplinary tumor board involvement.
Plan demonstrates how dose constraints for organs-at-risk will be met.
Documentation Required
Confirm Guideline-Based Indication
Confirm guideline-based indication: document that the patient meets guideline-concordant indications (e.g., medically inoperable or high surgical risk for early-stage NSCLC; oligometastatic disease per ASTRO/ESTRO/NCCN definitions). For prostate, liver, kidney, and other indications, show that institutional expertise and technology meet guideline expectations.
Evidence patient is medically inoperable or high operative risk when SBRT offered as alternative to surgery.
Number and staging of metastases consistent with oligometastatic recommendations (commonly ≤5 distant metastases).
Documentation of multidisciplinary evaluation when recommended.
Prior Authorization
Information Required for Authorization
Information required for authorization generally includes clinical history, prior treatments, tumor histology or presumptive diagnosis, imaging, tumor dimensions/volume, performance status, and proposed treatment plan with dose and fractionation. Absence of required documentation may lead to denial or inability to adjudicate the request.
Clinical indication and relevant history (including prior surgeries, ablation, embolization, or RT).
Histology or presumptive diagnosis and pathology reports if available.
Relevant imaging (MRI/CT/PET) with measurements and radiology report.
Performance status (ECOG/KPS) and comorbidities affecting eligibility.
Proposed treatment plan with dose, fractionation, device/technology, and how OAR constraints will be respected.
Prior Authorization
Confirm Prior Authorization per Member Plan
Verify prior authorization and member-specific benefit: Always confirm the member's benefit plan, prior authorization status, and any state or federal coverage mandates before proceeding. In the event of conflict, the member-specific benefit document governs.
Check member-specific benefit plan document and any applicable mandates.
Confirm that an approved prior authorization exists and that it matches the planned service date, procedure codes, laterality, and site.
Documentation Required
Documentation May Be Required
Documentation May Be Required: Medical records, including imaging and operative reports, may be requested to assess whether clinical criteria are met. Lack of documentation may result in denial or inability to adjudicate the request.
Provide imaging, operative reports, pathology, and prior therapy summaries when requested.
Ensure records support stated lesion counts, sizes, and prior therapy status.
Denial Risk
Dose Constraints and Selection
Dose Constraints and Selection: Authorization depends on the ability to meet established dose constraints for organs-at-risk. If the planned treatment cannot meet accepted OAR constraints or deliver an adequate therapeutic dose, coverage may be precluded.
Include OAR constraint assessment in the plan and demonstrate how constraints will be met.
If tumor abuts critical structures (e.g., bowel for abdominal tumors, spinal cord), document alternative strategies or reasons SBRT is appropriate.
Documentation Required
SBRT vs Surgery in Operable NSCLC
SBRT vs Surgery in Operable NSCLC: For standard-risk operable stage I NSCLC patients (anticipated operative mortality <1.5%), SBRT is not routinely recommended as an alternative to lobectomy outside of a clinical trial. Document thoracic surgery evaluation and multidisciplinary discussion when SBRT is proposed instead of surgery.
Documentation of thoracic surgery evaluation and rationale if SBRT is used in potentially operable patients.
If patient is high operative risk or refuses surgery after informed consent, include that documentation.
Prior Authorization
Lesion Count and Staging
Lesion Count and Staging: Document lesion count and staging with appropriate imaging. Definitive local therapy is generally recommended for patients with up to five distant metastases (most trials treated 1–2 lesions); consolidative SBRT is typically considered after systemic therapy with stable or responding disease.
Provide imaging confirming number of extracranial metastases and staging.
Document prior systemic therapy and response when consolidative SBRT is proposed (e.g., 2–3 cycles or months of chemotherapy/immunotherapy with no progression).
Denial Risk
Risk Factors for Complications
Risk Factors for Complications: Authorization and treatment planning should account for risk factors such as large tumor volume, prior surgery or radiation, tumor location near critical structures, and patient comorbidities. These factors increase the risk of permanent radiation-related complications and may influence fractionation or eligibility.
Document tumor volume and location relative to critical structures.
Note prior surgeries, prior RT, or embolization that may increase complication risk.
Documentation Required
Expected Post‑treatment Toxicity
Expected Post‑treatment Toxicity: Document anticipated toxicities and monitoring plans (for example, hypopituitarism risk after pituitary SRS, cranial nerve deficits for skull base lesions, or fracture risk after spinal SBRT). Ensure follow-up and endocrine/neurologic surveillance plans are described.
Include anticipated adverse events specific to site (e.g., hypopituitarism after pituitary SRS, radiation necrosis after brain SRS, vertebral compression fracture after spinal SBRT).
Provide plan for post-treatment monitoring and management.
Denial Risk
Exclusion‑related Denial Risk
Exclusion‑related Denial Risk: Trials and indications commonly exclude patients with spinal instability, symptomatic spinal cord compression, diffuse/widespread intracranial disease unsuitable for focal SRS, tumors abutting bowel limiting safe SBRT delivery, or prior RT to the same site — presence of these exclusion criteria may lead to denial.
Document absence of spinal instability or neurologic compression when requesting spinal SBRT/SRS.
For intracranial disease, document that disease is amenable to focal therapy (not diffuse).
If tumor abuts bowel or critical OARs making SBRT unsafe, document alternatives considered.
Documentation Required
Center and Team Requirements (NICE)
Center and Team Requirements: Some indications (e.g., trigeminal neuralgia, complex liver or spine SBRT) should be performed at specialized centers with a multidisciplinary team and appropriate device/technology. NICE and other guidance recommend established clinical governance, consent, and audit processes.
Document center experience, multidisciplinary team involvement, and availability of specialized technology and physics support.
Confirm clinical governance, consent, and audit processes are in place.
Prior Authorization
Member‑specific Benefit Verification; Medical Records and Site‑specific Documentation
Member‑specific Benefit Verification and Medical Records: Always verify member-specific benefits and supply complete medical records. Postoperative imaging (e.g., first post-op MRI within 3–6 months for residual vestibular schwannoma) and specific clinical documentation (histology, renal function for renal SBRT, prior systemic therapy for oligometastatic SBRT) are required when applicable.
Verify member-specific benefits and any mandates prior to authorization.
Provide post-op imaging when indicated (first MRI 3–6 months post microsurgery for vestibular schwannoma).
Include histology/pathology reports and renal function for renal SBRT; prior systemic therapy details for consolidative SBRT.
Prior Authorization
Required Clinical Documentation for Spinal and Intracranial SRS/SBRT Decisions
Required Clinical Documentation for Spinal and Intracranial SRS/SBRT Decisions: For spinal SRS/SBRT include spinal stability assessment (e.g., SINS), neurologic exam, prior RT details, and imaging with lesion measurements. For intracranial SRS include lesion count, size, cumulative intracranial volume, performance status, surgical cavity status, and prior cranial RT.
Spinal: SINS score or statement on spinal stability, neurologic status, prior surgery or RT to the site, imaging with measurements.
Intracranial: lesion count and sizes, KPS/ECOG, surgical cavity dimensions if postoperative SRS is planned, prior brain RT history.
Documentation Required
Recommended Clinical Documentation Elements and Required Plan/Regulatory Checks
Recommended Clinical Documentation Elements and Regulatory Checks: Include the treatment plan (dose, fractions, device), physics evaluation, OAR constraints, informed consent noting risks/alternatives, and confirmation of any required registry or trial enrollment if treatment is delivered in a research context.
Submit full treatment plan and physics checklist with authorization when available.
Provide informed consent documentation that demonstrates discussion of alternatives, risks, and rationale.
If treatment is delivered on trial or per registry, document trial-based selection criteria and regimen.
Note
Sequencing, Radiation Technique Expectations, and Evidence Context
Sequencing and Technique Expectations: Document sequencing where relevant (e.g., planned subtotal resection followed by SRS for vestibular schwannoma; systemic chemotherapy before consolidative SBRT for borderline resectable pancreatic cancer) and indicate use of advanced planning/delivery techniques (image-guidance, motion management) when EBRT/SBRT is primary treatment.
Document planned sequence of surgery, systemic therapy, and SRS/SBRT when applicable.
Describe radiation technique: image-guidance, motion management, advanced planning, and expected dose escalation as appropriate.
Prior Authorization
Confirm Medical Therapy Failure Before SRS
Confirm Medical Therapy Failure Before SRS for Certain Indications: For functional indications such as trigeminal neuralgia, document failure or intolerance of adequate medical therapy prior to SRS per guideline recommendations.
Document trials of and response to medical therapies and reasons for failure or intolerance.
Include multidisciplinary evaluation supporting SRS for refractory cases.
Clinical requirementsOMD coverage criteria require controlled primary tumor (≥3 months), KPS ≥70/ECOG 0–2, life expectancy ≥6 months, and lesions ≤5 cm.
Brain Metastasis Velocity (BMV) — definition and stratification
Definition (BMV)Brain Metastasis Velocity (BMV) = cumulative number of new brain metastases after first SRS divided by years since initial SRS; used to stratify risk and predict survival after repeat SRS.
Definition (SRS)Stereotactic radiosurgery (SRS): single‑ or few‑fraction, high‑dose, highly conformal radiation delivered precisely to intracranial targets (single‑fraction doses commonly referenced for BMs).
Typical dosing examplesSingle‑fraction SRS doses for intact brain metastases commonly 2000–2400 cGy for lesions <2 cm; multifraction options (e.g., 2700 cGy in 3 fractions) used for larger lesions.
Clinical useUsed for intact BMs, postoperative cavities, reirradiation, and select benign intracranial lesions per guideline recommendations.
SBRT — definition (extracranial stereotactic body radiotherapy)
Definition (SBRT)Stereotactic body radiotherapy (SBRT): high‑dose, hypofractionated, conformal external beam radiotherapy for extracranial tumors, typically delivered in a small number of fractions (commonly ≤5).
Fractionation contextPolicy and guidelines describe SBRT regimens commonly delivered in 1–5 fractions; selection depends on tumor site, size, and proximity to organs at risk.
SBRT — alternate definition and typical fractionation range
Alternate SBRT definitionDose‑escalated, hypofractionated external beam radiotherapy delivered in typically 1–9 fractions for focal tumors to achieve high local control while sparing normal tissue.
Typical fractionation rangeCommonly 1–5 fractions; other established regimens of 3–5 fractions used depending on site and BED goals.
EBRT — definition and relation to SBRT
Definition (EBRT)External beam radiotherapy (EBRT): conventional or advanced external radiation techniques, including hypofractionated and stereotactic approaches used for a range of primary and metastatic cancers.
Relation to SBRTEBRT includes SBRT as a high‑dose hypofractionated subset; ASTRO guidance references EBRT/SBRT choice based on tumor, liver function, and technology.
BED (biologically effective dose) — definition and relevance
Definition (BED)Biologically effective dose (BED): a dose metric used to compare hypofractionated regimens; cited studies report improved local control and survival with BED ≥ 100 Gy in stage I NSCLC.
RelevanceBED informs regimen selection to achieve curative‑intent outcomes when using SBRT for lung tumors.
Definition (CRT)Conventionally fractionated or moderately hypofractionated radiotherapy used as a comparator in prostate and other trials (e.g., PACE‑B).
UsageCRT denotes standard external beam schedules against which ultrahypofractionation/SBRT are compared in randomized trials.
Ultrahypofractionation / SBRT — definition and trial examples
Definition (Ultrahypofractionation / SBRT)High‑dose per fraction radiotherapy delivered in a small number of fractions (examples include 5 fractions for prostate SBRT, 7 fractions for ultrahypofractionation in trials, and single‑ or 3‑fraction regimens for renal SABR).
Trial examplesPACE‑B and other RCTs provide examples of ultrahypofractionation schedules used in definitive prostate treatment comparisons.
Oligometastatic disease — typical lesion counts used in consensus/practice (1–5)
Consensus lesion-count for OMDOligometastatic disease is typically defined as one to five metastatic lesions, with controlled primary tumor optional and all sites safely treatable.
Repeat SRS — definition for repeat radiosurgery sessions for AVMs
Definition (Repeat SRS for AVMs)An additional radiosurgery procedure performed for recurrent or residual AVM after incomplete obliteration from an initial SRS session; repeat SRS can achieve substantial additional obliteration over years.
Outcome contextMeta-analysis reports ~60.8% obliteration after repeat SRS with measurable risks (radiation‑induced changes, post‑radiosurgery hemorrhage).
Volume-staged SRS — definition and staging interval concept
Definition (Volume‑staged SRS)A planned approach delivering SRS in two or more stages to large‑volume AVMs unsuitable for single‑session SRS, often with intervals of months between stages to reduce toxicity and improve obliteration chance.
Dose considerationMinimum margin dose of ~17 Gy or greater suggested depending on location to improve chance of benefit.
SRS — definition for benign intracranial lesions and typical dose ranges
SRS for benign intracranial lesions — definitionSingle‑fraction, high‑dose stereotactic radiosurgery typically with prescription doses in the range of 12–15 Gy for benign intracranial meningiomas and median SRS doses ~15 Gy for pituitary adenomas.
Typical dose rangesMeningioma prescription doses typically 12–15 Gy single fraction; NFAs median SRS dose 15 Gy (range 5–35 Gy) in pooled series.
Definition (HSRT)Hypofractionated stereotactic radiotherapy (HSRT): stereotactic treatment delivered in multiple fractions (e.g., 3–5) often used for select pituitary adenomas or larger benign lesions.
Usage exampleHSRT total doses reported around 21 Gy in 3–5 fractions for select nonfunctioning pituitary adenomas.
SBRT/SRS dose-fractionation examples — typical regimens per ASTRO guidelines
Dose‑fractionation examples (ASTRO)Examples: 1200–1600 cGy x1 (nonspine bone metastases), 2400 cGy x2 (spine), other established SBRT regimens include 3–5 fractions with similar BEDs.
Pancreas exampleFractionated SBRT 33 Gy in 5 fractions (gemcitabine + SBRT) reported in pancreatic neoadjuvant/definitive studies.
cEBRT comparators — common conventional palliative regimens for spine
cEBRT palliative spine regimensCommon conventional palliative external beam radiotherapy regimens for spine include 800 cGy x1, 1600 cGy x2, 2000 cGy x5, or 3000 cGy x10.
Comparative contextThese regimens are used as comparators in trials (e.g., SBRT vs cEBRT) and inform patient‑selection decisions.
Anterior retrogasserian targeting — definition in trigeminal neuralgia radiosurgery
Anterior retrogasserian targeting — definitionA radiosurgical targeting approach aimed at the anterior portion of the trigeminal nerve used in trigeminal neuralgia radiosurgery; associated with hypesthesia and paresthesia risks.
Clinical implicationTarget choice affects rates of hypesthesia and other complications; documented in ISRS systematic review.
Local control (uveal melanoma) — definition as used in evidence summaries
Local control (uveal melanoma) — definitionAbsence of tumor progression or recurrence at the primary ocular site after radiosurgery, commonly reported at 3‑ and 5‑year intervals in meta‑analyses.
Outcome examplesCyberKnife 3‑year local control ~89% and 3‑year eye preservation ~84% reported in pooled analyses.
Radiation oncology definition (ESTRO‑ASTRO) of OMDOligometastatic disease: one to five metastatic lesions, controlled primary optional, all metastatic sites must be safely treatable; used to select patients for metastasis‑directed SBRT.
Policy alignmentPolicy applies this radiation oncology definition in coverage criteria for consolidative local therapy.