ModifiedUnitedHealthcarePolicy CS064NM.B

Intensity‑Modulated Radiation Therapy (for New Mexico Only)

Policy governing coverage and medical necessity criteria for IMRT for members in New Mexico; applies to individuals aged 19 and older (IMRT covered without further review for those under 19).

Policy Summary

PayerUnitedHealthcare

PolicyIntensity‑Modulated Radiation Therapy (for New Mexico Only)

Policy CodePolicy CS064NM.B

Change TypeRevised coverage list and definition updates

Effective DateJun 1, 2025

Next Review Date

Key ActionWhen requesting IMRT for indications not listed as proven, provide comparative treatment plans (IMRT vs non‑IMRT) demonstrating that non‑IMRT would increase clinically meaningful normal tissue toxicity or document prior irradiation requiring sculpted dosing.

SourceLink

POLICY UPDATE CHANGES

Revised list of conditions for which IMRT for Definitive Therapy for the primary site is proven and medically necessary, adding vulvar cancer and replacing 'anal cancer' with 'anus/anal canal cancer'.

Updated definition of 'Definitive Therapy'.

Updated Description of Services, Clinical Evidence, and References sections to reflect the most current information.

Archived previous policy version CS064NM.A.

New MexicoApplies only to

≥19Age rule

20+Proven indications

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518HA‑WBRT trial N

Coverage and Medical Necessity Criteria

inv-01: Proven and Medically Necessary Indications

IMRT is considered proven and medically necessary for definitive therapy of the primary site for the following conditions:

Listed Indications: Any one of the following primary-site conditions: anus/anal canal cancer; breast cancer when left-sided internal mammary nodes are being treated; accelerated partial breast irradiation (APBI) up to 5 fractions; central nervous system (CNS) tumors (primary or benign) including brain, brainstem, and spinal cord; cervical cancer; endometrial cancer; esophageal cancer; head and neck cancers (including lymphoma and solitary plasmacytomas) when treatment includes pharynx (nasopharynx, oropharynx, hypopharynx), larynx (stage III or IV glottic cancer), salivary glands, oral cavity (including tongue), nasal cavity, or paranasal sinuses; mediastinal tumors (e.g., lymphomas, thymomas) including tracheal cancer; non-small cell lung cancer, stage III, undergoing chemoradiation therapy; pancreatic cancer; prostate cancer; vulvar cancer; compensator-based beam modulation when combined with an above-listed IMRT indication; hippocampal-avoidance whole brain radiation therapy (HA-WBRT) of up to 10 fractions for brain metastasis.

inv-02: Exceptions / Case-by-Case Coverage (Selected Conditions)

IMRT may be covered for conditions not listed above when AT LEAST one of the following is present:

Exception Criteria: At least one of the following: (1) A clinically appropriate radiation dose delivered by a non-IMRT technique would increase the probability of clinically meaningful normal tissue toxicity, demonstrated by a comparison of treatment plans (IMRT vs non-IMRT, e.g., 3D-CRT) referencing RTOG/QUANTEC constraints; OR (2) the same or an immediately adjacent area has been previously irradiated and the dose distribution must be sculpted to avoid exceeding the cumulative tolerance dose of nearby normal tissues.

inv-03: Site‑specific coverage rationale

Evidence and guideline‑based coverage rationale for IMRT by indication — summarized as Covered with clinical rationale where guidelines or trials report maintained efficacy with reduced toxicity.

Anal cancer — DP‑IMRT: Dose-painted IMRT (DP‑IMRT) with concurrent 5‑FU/MMC demonstrated comparable long‑term efficacy to conventional RT while reducing several acute and late toxicities; supported by RTOG 0529 and guideline preference for IMRT. Clinical delivery should follow trial dosing and QA procedures.

Breast cancer — APBI‑IMRT and cardiac sparing: APBI delivered with IMRT in selected early‑stage patients showed low 10‑year ipsilateral recurrence and reduced acute/late toxicity and improved cosmesis; IMRT with DIBH reduces cardiac dose for left‑sided cases when internal mammary nodes are treated, per randomized trials and guideline statements.

CNS tumors — conformal IMRT: IMRT/VMAT is recommended for tumors near critical OARs (e.g., IDH‑mutant diffuse gliomas, complex skull base lesions) to reduce acute and late toxicity while maintaining local control; supported by ASTRO and NCCN guidance and prospective institutional series.

inv-04: Guideline-supported coverage rationale

Guideline-based coverage considerations (summarized findings relevant to coverage decisions):

Cervical cancer postoperative: ASTRO recommends IMRT for postoperative RT with or without chemotherapy to decrease acute and chronic toxicity (strong); for definitive RT IMRT is conditionally recommended to decrease toxicity.

Endometrial cancer adjuvant RT: ASTRO strongly recommends IMRT to reduce acute and late toxicity for adjuvant pelvic external beam RT, with daily IGRT and appropriate vaginal ITV definition advised.

Esophageal cancer: NCCN states IMRT (or proton therapy) may be used where dose reduction to organs at risk (heart, lungs) is required and is standardly used in preoperative, definitive, and postoperative settings.

inv-05: Evidence summaries

Selected evidence summaries relevant to clinical benefit:

Reduced acute/late toxicity (gynecologic): Randomized trials and meta-analyses show IMRT reduces acute GI and GU toxicities and late GI events compared with 3D‑CRT/2D‑RT in cervical and endometrial cancer, with similar survival outcomes.

Dysphagia-optimized IMRT benefits: A phase 3 RCT of dysphagia-optimized IMRT (DO‑IMRT) demonstrated improved patient‑reported swallowing function at 12 and 24 months compared with standard IMRT.

Parotid-sparing outcomes: Parotid‑sparing IMRT reduces grade ≥2 xerostomia at 12 and 24 months and improves saliva recovery and related QOL without compromising locoregional control.

inv-06: Covered indications and supportive evidence

Covered when supported by clinical indications and guideline recommendations:

IMRT preferred for OAR sparing in selected sites: IMRT is preferred when reduction of dose to critical organs (e.g., salivary glands, temporal lobes, cochlea, optic structures, larynx, pharyngeal constrictors, brachial plexus, esophagus, heart, lungs) is necessary to reduce long-term toxicity or improve quality of life.

HA-WBRT plus memantine: HA‑WBRT combined with memantine preserves cognitive function versus WBRT plus memantine in patients without hippocampal lesions and is supported by a phase III RCT (NRG CC001); use is appropriate when guideline criteria are met.

DO-IMRT for dysphagia reduction: DO‑IMRT is supported to reduce dose to dysphagia-related structures and improve swallowing‑related patient‑reported outcomes in oropharyngeal/hypopharyngeal SCC.

inv-07: HA-WBRT with memantine

HA-WBRT with memantine — supported when ALL of the following are met

HA-WBRT coverage criteria: Patient is receiving whole‑brain radiotherapy for brain metastases; no metastases in the hippocampal‑avoidance region (e.g., no metastases within 5 mm of the hippocampus); expected survival ≥ 4 months; good performance status (e.g., ECOG ≤ 2 or KPS ≥ 70); memantine is planned or administered during WBRT.

inv-08: IMRT for stage III NSCLC

IMRT for definitive chemoradiation in locally advanced (stage III) NSCLC — considered reasonable when ALL of the following apply

IMRT in stage III NSCLC: Patient has unresectable or locally advanced stage III NSCLC planned for definitive concurrent chemoradiation; IMRT planning demonstrates reduced heart dose or improved OAR metrics compared with 3D‑CRT and intent is to reduce high‑grade radiation pneumonitis and spare cardiac dose; clinical team documents dosimetric advantage per plan review.

inv-09: IMRT for mediastinal and pancreatic indications

IMRT may be appropriate when ALL of the following are met

IMRT for mediastinal lymphoma and thymic tumors: Advanced RT techniques (including IMRT) are appropriate when they reduce dose to critical OARs (heart, esophagus, breasts) without compromising target coverage, particularly in patients with long expected survivorship; dosimetric benefit should be demonstrated.

IMRT for pancreatic cancer: IMRT is appropriate when it improves PTV coverage and reduces dose to stomach and duodenum versus 3D‑CRT, producing reduced acute and late GI toxicity while maintaining comparable OS/PFS; use supported by retrospective series, systematic reviews, and guidelines (ASTRO, NCCN).

inv-10: IMRT for prostate cancer — QOL

IMRT for prostate cancer — expected outcomes

Prostate IMRT QOL considerations: Conventional or moderately hypofractionated IMRT is associated with transient worsening of quality of life at treatment end that largely recovers by six months; acute GI/GU toxicity is most impactful on short‑term functioning while long‑term toxicity rates remain low with modern IMRT and daily IGRT and dose‑escalated moderately hypofractionated regimens show acceptable long‑term control.

inv-11: Supported clinical indications and technique considerations

Guideline and evidence-supported uses and outcomes for IMRT by site

Pancreatic adenocarcinoma: NCCN states 3D‑CRT, IMRT, and SBRT can improve PTV coverage and reduce OAR dose; IMRT is increasingly applied for locally advanced and adjuvant settings to increase tumor dose while minimizing toxicity.

Prostate cancer: Multiple guidelines (AUA/ASTRO, NCCN, ACR) support IMRT as a standard EBRT technique for prostate cancer with recommended technical parameters (e.g., photon energy ≥6 MV; pelvic node doses 45–52 Gy when indicated) and evidence of reduced acute and late GU/GI toxicity versus 3D‑CRT.

Vulvar cancer: Guidelines (ESGO, NCCN) recommend IMRT with daily set‑up verification and image guidance for vulvar cancer, particularly when simultaneous integrated boost (SIB) is used, to account for edema and regression and optimize OAR sparing.

Technique concordance: Guidelines recommend documenting adherence to technical parameters (e.g., photon energy, IGRT use) and demonstrating dosimetric advantage for requests when IMRT is selected over alternative techniques.

inv-12: Definitive Therapy — updated covered conditions

Policy revision summary for definitive IMRT coverage

Definitive IMRT primary-site conditions: The list of primary-site conditions for which IMRT for Definitive Therapy is proven and medically necessary was revised to add 'vulvar cancer' and to replace the term 'anal cancer' with 'anus/anal canal cancer'.

IMRT delivered in conjunction with proton beam radiation therapy is considered unproven and not medically necessary because the available clinical literature does not provide sufficient evidence of efficacy for a combined IMRT-plus-proton single treatment approach.

The available studies have limitations that affect generalizability of results, including small sample sizes and single‑center designs; therefore, absence of explicit exclusions in the cited excerpts should not be interpreted as broad endorsement for all off‑label uses without case-specific justification.

Per NCCN guidance, IMRT should not be used as a routine alternative to brachytherapy for treatment of central cervix disease in individuals with an intact cervix; brachytherapy remains the standard for central disease control and IMRT is only appropriate when brachytherapy is not feasible and clinical justification is documented.

Hippocampal‑avoidance whole‑brain radiotherapy (HA‑WBRT) is intended for patients who have no metastases in the hippocampal‑avoidance region and who are appropriate candidates for WBRT. Trials and guideline groups support combining HA‑WBRT with memantine to reduce cognitive decline; therefore HA‑WBRT should be administered with planned concurrent or sequential memantine per the evidence and guideline recommendations.

Guidelines specify that patients with hippocampal lesions or with an expected survival less than 4 months are not candidates for HA‑WBRT; HA‑WBRT is recommended only for individuals who meet the hippocampal‑region‑free and prognosis thresholds described in the guideline statements.

No clinical evidence was identified to support planning or delivering a single combined treatment plan that integrates IMRT and proton beam therapy; therefore combined IMRT+proton single‑plan approaches are unsupported in the literature and should be considered not medically necessary / unproven.

This policy is informational and must be reconciled with applicable federal, state, or contractual benefit plan terms; where those governing terms differ from this policy, the federal, state, or contractual requirements control coverage decisions.

Requests proposing combined IMRT and proton beam therapy in a single plan are reiterated as not medically necessary / unproven given the absence of supporting clinical evidence.

A Cochrane review comparing immediate versus delayed radiotherapy for low‑grade gliomas found no difference in overall survival between early and delayed RT (median OS approximately 7.4 vs 7.2 years), indicating timing of RT did not alter long‑term survival in the identified trial.

A randomized trial comparing radiation dose escalation for esophageal cancer (50.4 Gy versus 61.6 Gy) found no significant improvement in local control or survival with dose escalation to 61.6 Gy, supporting that routine escalation above standard 50.4 Gy is not beneficial based on this RCT.

Across head and neck cancer studies and guideline syntheses, evidence is insufficient to conclude that IMRT improves overall survival or locoregional control compared with 3D‑CRT or 2D‑RT; the primary demonstrated benefits of IMRT are reduced toxicity and improved organ‑at‑risk sparing, and selection should be based on those considerations.

Randomized evidence in stage III NSCLC indicates that high‑dose radiotherapy (e.g., 74 Gy) with concurrent chemotherapy was not superior to standard‑dose (60 Gy) and may be harmful; caution is warranted for dose escalation in this setting.

The provided document excerpts do not present an explicit, exhaustive list of items labeled as 'not medically necessary' within these chunks; interpretive determinations should rely on the full policy language for definitive NMN statements.

Procedure, Device, and Billing Codes

Applicable CPT CodesCPT

77301	Intensity modulated radiotherapy plan, including dose-volume histograms for target and critical structure partial tolerance specifications.
77338	Multi-leaf collimator (MLC) device(s) for intensity modulated radiation therapy (IMRT), design and construction per IMRT plan.
77385	Intensity modulated radiation treatment delivery (IMRT), includes guidance and tracking, when performed; simple.
77386	Intensity modulated radiation treatment delivery (IMRT), includes guidance and tracking, when performed; complex.
77387	Guidance for localization of target volume for delivery of radiation treatment, includes intrafraction tracking, when performed.
77520	Proton treatment delivery; simple, without compensation.
77522	Proton treatment delivery; simple, with compensation.
77523	Proton treatment delivery; intermediate.
77525	Proton treatment delivery; complex.

Applicable HCPCS G-codesHCPCS

G6015	Intensity modulated treatment delivery, single or multiple fields/arcs, via narrow spatially and temporally modulated beams, binary, dynamic MLC, per treatment session.
G6016	Compensator-based beam modulation treatment delivery of inverse planned treatment using three or more high resolution (milled or cast) compensator, convergent beam modulated fields, per treatment session.
G6017	Intra-fraction localization and tracking of target or patient motion during delivery of radiation therapy (e.g., 3D positional tracking, gating, 3D surface tracking), each fraction of treatment.

Relevant guideline-referred techniquesmixed

No codes listed

Procedure and treatment modalities discussedmixed

No codes listed

Procedure codes referencedmixed

none listed

No specific CPT/HCPCS/ICD-10 codes provided in this document section.

FDA Device Product Codesmixed

MUJ	FDA product code referenced for IMRT devices
IYE	FDA product code referenced for IMRT devices

Radiation dose comparison — esophageal primary (RCT)

Esophageal dose comparison (RCT)Randomized trial (Hulshof et al., 2021) compared standard-dose 50.4 Gy to dose-escalation 61.6 Gy to the primary tumor and found no significant improvement in local control or survival with 61.6 Gy; higher-grade toxicities were not meaningfully reduced.

Trial population260 participants with medically inoperable and/or irresectable esophageal carcinoma randomized; median follow-up 50 months.

Primary endpoint resultThree-year local progression-free survival: 70% (50.4 Gy) vs 73% (61.6 Gy) — not significant.

Clinical conclusionDose escalation to 61.6 Gy did not provide a survival or local control benefit over 50.4 Gy and therefore routine escalation beyond 50.4 Gy is not supported by this RCT.

Prior Authorization, Documentation, and Operational Guidance

Note

Clinical rationale for IMRT

IMRT clinical rationale: IMRT (including VMAT/helical-IMRT) should be considered when advanced conformal techniques are required to spare nearby organs-at-risk (OARs) and reduce clinically meaningful acute or late normal-tissue toxicity while maintaining target coverage. Reference guideline-concordant indications (e.g., NCCN, ASTRO, ACR, ESGO) when sparing salivary glands, temporal lobes, hippocampus, bowel, heart, lungs, brachial plexus, optic structures, and other critical OARs. Document how IMRT achieves meaningful dosimetric OAR reductions compared with non-IMRT techniques (for example, dose-volume histogram comparisons).

Use IMRT when dose-sparing of OARs cannot be achieved with 3D techniques.
Provide comparative planning (IMRT vs non-IMRT) demonstrating reduced OAR dose when requesting exceptions.

Prior Authorization

Prior authorization guidance (clinical basis)

Prior authorization (PA) guidance — clinical basis: Prior authorization should reflect guideline-based, evidence-supported indications for IMRT. PA reviews will evaluate performance status, prognosis, disease site/stage, prior radiation, and dosimetric justification. For HA-WBRT and other hippocampal-sparing requests, PA should confirm absence of metastases within the hippocampal-avoidance region and expected survival consistent with guideline recommendations. InterQual or similar clinical tools may be used to assist benefit administration.

Key Terms and Definitions

Definitive Therapy — definition

DefinitionRadiation treatments for cancer with curative intent.

Scope note'Definitive Therapy' label was updated in the policy revision to operationalize which primary-site conditions are proven and medically necessary for definitive IMRT (policy change 06/01/2025).

Use contextApplies when intent of radiotherapy is curative rather than palliative or neoadjuvant/adjuvant in select settings.

IMRT — intensity-modulated radiation therapy

DefinitionIntensity-modulated radiation therapy (IMRT) is an advanced, high-precision RT technique that uses computer-controlled linear accelerators to deliver precisely modulated radiation doses, conforming dose to the 3D tumor shape while minimizing dose to surrounding normal tissues.

Clinical advantage

Background and Evidence Overview

Intensity‑modulated radiation therapy (IMRT) is an advanced, high‑precision external beam technique that modulates beam intensity to conform dose to three‑dimensional tumor shapes and spare nearby critical structures; it is commonly delivered with image guidance to maximize accuracy and organ‑at‑risk protection.

inv-03 (supporting placement): Site‑specific evidence highlights and trial references that underpin background rationale

Site‑specific evidence highlights and trial references that underpin background rationale

RTOG 0529 (Anal cancer): Prospective multi‑institutional phase II trial showed DP‑IMRT reduced several acute toxicities and had comparable long‑term efficacy to conventional CRT; long‑term follow‑up reported maintained local control and reduced late high‑grade toxicities (median follow‑up 7.9 years).

APBI‑IMRT (Breast): Phase III randomized APBI‑IMRT trial (Florence) with median follow‑up >10 years demonstrated low ipsilateral recurrence and reduced acute/late toxicity with IMRT‑delivered APBI (30 Gy in 5 fractions).

DO‑IMRT (Head & Neck):

Policy Updates and Revision History

2025-06-01policy_revisionLatest

Revised Definitive Therapy coverage: added 'vulvar cancer' to the list of primary-site conditions and replaced 'anal cancer' with 'anus/anal canal cancer'; updated definition of 'Definitive Therapy' and refreshed supporting sections; prior version CS064NM.A archived.

This policy revision operationalizes the list of primary‑site conditions considered proven and medically necessary for definitive IMRT, noting a material update that added vulvar cancer and relabeled 'anal cancer' as anus/anal canal cancer. The Description of Services, Clinical Evidence, and References sections were refreshed and the prior policy version was archived. When applying this guidance, check applicable federal, state, or contractual plan terms as they may govern coverage.

When coverage determinations conflict with federal, state, or contractual benefit plan terms, those governing terms take precedence and will control the decision; providers should verify plan‑specific requirements before requesting authorization.

References and supporting literature were updated in the policy revision; the references section includes recent randomized trials, guidelines, and systematic reviews that inform the coverage rationale and technical recommendations.

Policy Summary

PayerUnitedHealthcare

PolicyIntensity‑Modulated Radiation Therapy (for New Mexico Only)

Policy CodePolicy CS064NM.B

Change TypeRevised coverage list and definition updates

Effective DateJun 1, 2025

Next Review Date

SourceLink

On This Page

Cervical cancer — pelvic IMRT: Randomized and cohort studies indicate IMRT reduces bowel dose and lowers acute and late GI/GU toxicities compared with 3D‑CRT; IMRT is recommended in postoperative and selected definitive settings to reduce toxicity.

Hippocampal proximity threshold for HA-WBRT eligibility

Hippocampal proximity requirementHA-WBRT eligibility requires absence of metastases within 5 mm of the hippocampus (no metastases within 5 mm of hippocampus).

Associated guidelineNCCN 2024: HA-WBRT plus memantine preferred for individuals with better prognosis and no metastases within 5 mm of the hippocampus.

Trial supportNRG CC001 (Brown et al., 2020) phase III trial used hippocampal-avoidance technique and memantine and required hippocampal region to be free of metastases; showed preserved cognition versus WBRT + memantine.

Verify ECOG ≤ 2 or KPS ≥ 70 and expected survival ≥ 4 months when applicable (e.g., HA-WBRT).
Confirm absence of leptomeningeal disease for HA-WBRT.
PA reviewers will expect comparison plans and guideline citations supporting the IMRT approach.

Prior Authorization

Prior authorization expectation for HA‑WBRT and IMRT in stage III NSCLC

Prior authorization expectations for HA‑WBRT and IMRT in stage III NSCLC: For HA‑WBRT, PA should document no metastases within 5 mm of the hippocampus, no leptomeningeal disease, expected survival ≥ 4 months, and use of memantine per guidelines when applicable. For stage III NSCLC receiving definitive chemoradiation, document stage III disease, intent of therapy (definitive), and rationale that IMRT is preferred to reduce high‑grade radiation pneumonitis as supported by RTOG 0617/NCCN.

HA‑WBRT: imaging confirming hippocampal region clear (no lesions ≤ 5 mm) and memantine plan if indicated.
Stage III NSCLC: documentation of stage, concurrent systemic therapy plan, and dosimetric rationale for IMRT.

Documentation Required

Prior authorization and benefit verification

Prior authorization and benefit verification: Before submitting PA, verify the member’s specific federal/state/contractual benefit terms as these control over the standard policy when conflicts exist. Use UnitedHealthcare prior‑authorization tools and third‑party criteria (e.g., InterQual) where applicable. Requests lacking required documentation may be delayed or denied.

Check plan benefit language and any state/federal mandates prior to PA submission.
Use UnitedHealthcare PA portals and include all required clinical documentation elements listed below.

Denial Risk

IMRT with Proton Therapy / Combined IMRT+Proton not supported

IMRT with proton therapy and combined IMRT+proton: IMRT used concurrently in a single treatment plan with proton beam therapy is considered unsupported by current evidence and is unproven. Requests proposing combined single‑plan IMRT + proton delivery should include strong justification; absent high‑quality evidence such requests may be denied.

Combined IMRT + proton in a single plan: no clinical evidence identified — denial risk.
If submitting for sequential or combined-modality treatments, clearly distinguish phases and provide evidence supporting clinical benefit.

Documentation Required

Radiation quality assurance and IGRT expectations

Radiation quality assurance (QA) and IGRT expectations: Real‑time QA and appropriate radiation QA processes are expected for IMRT delivery (RTOG trial experience emphasizes this). Routine image‑guided radiation therapy (IGRT) — orthogonal imaging and/or volumetric imaging (e.g., cone‑beam CT) — is required to ensure target coverage and OAR sparing for pelvic, parenchymal, and head & neck IMRT treatments. Failure to use recommended IGRT or QA may not meet guideline‑based practice and can impact coverage determinations.

Document QA processes used (peer review, chart rounds, machine QA, plan QA) for IMRT treatments.
Document IGRT approach (orthogonal imaging and/or CBCT) used for daily setup verification when delivering IMRT to pelvic or parenchymal targets.

Documentation Required

Required clinical documentation elements

Required clinical documentation elements: PA submissions should include key clinical data to support medical necessity — diagnosis and stage, ECOG/KPS, prognosis, intent of therapy (definitive/adjuvant/palliative), prior radiation history, prescription dose/fractionation, target volumes and OAR constraints, comparative dose‑volume histograms (IMRT vs non‑IMRT) when claiming superiority, device/technology used, and expected benefits (toxicity reduction). Reference applicable guidelines (NCCN, ASTRO, ACR, ASCO/SNO/ASTRO, ESGO) when relevant.

Stage and disease site, prior RT to same/adjacent area (include prior dose).
Planned dose and fractionation, photon energy (e.g., ≥6 MV for prostate), number of fields or technique (VMAT/IMRT), and image guidance method.
Comparative plans (DVH) showing OAR sparing or risk of exceeding cumulative tolerance dose.
Performance status (ECOG/KPS), prognosis, and whether memantine will be used for HA‑WBRT.

Documentation Required

Image guidance and imaging/planning documentation

Image guidance and imaging/planning documentation: For pelvic, head & neck, prostate, and other IMRT treatments, document use of orthogonal or volumetric imaging for daily setup and any motion management (DIBH, respiratory gating) when used. For HA‑WBRT, include imaging confirming no metastases within the hippocampal‑avoidance distance (e.g., no lesions within 5 mm), and provide contouring and planning information supporting hippocampal avoidance.

Include imaging reports and treatment planning contours that demonstrate hippocampal‑avoidance eligibility.
Document motion management, breath‑hold, and other techniques used to meet OAR constraints.

Note

Clinical justification references and device listing

Clinical justification references and device listing reference: Cite applicable guideline recommendations (NCCN, ASTRO, ACR, ASCO/SNO/ASTRO, ESGO) relevant to the disease site and rationale for IMRT. For informational device reference, FDA product codes MUJ and IYE may be used to identify IMRT‑related devices; FDA approvals alone do not determine coverage.

Reference NCCN/ASTRO/ACR/ESGO/ASCO guidelines supporting the selected technique and OAR constraints.
Optional: FDA device info (product codes MUJ, IYE) for vendor/device identification; FDA approval is informational only.

Note

Operational guidance, step therapy, and exceptions

Operational notes: No explicit step‑therapy sequences or mandated prior use of older modalities (e.g., 3D‑CRT) are required before IMRT. Exceptions to standard indications may be authorized when non‑IMRT techniques would increase clinically meaningful normal tissue toxicity or when prior radiation requires sculpted dose distributions to avoid exceeding cumulative tolerances; such exception requests must include comparative treatment plans and clear dosimetric justification.

No step therapy is mandated; comparative outcomes support IMRT in many scenarios but prior use of 3D‑CRT is not required.
Exception authorization: provide comparative DVH/plans showing increased toxicity risk with non‑IMRT and rationale for sculpting after prior RT.

IMRT allows higher tumor doses with reduced exposure to organs at risk (OARs) compared with conventional techniques, improving PTV coverage and reducing OAR dose.

Common delivery modesIncludes static-field IMRT and rotational techniques such as VMAT; often delivered with image guidance (IGRT) for accuracy.

IGRT — image-guided radiation therapy

DefinitionImage-guided radiation therapy (IGRT) employs imaging during planning and delivery to maximize accuracy and precision in target delineation and treatment delivery, often used with IMRT to account for anatomical and positional changes.

PurposeUsed to verify setup, track target motion, and adapt therapy to anatomic changes over time to ensure intended dose to the target while sparing OARs.

DocumentationPolicy recommends documentation of IGRT use (orthogonal or volumetric imaging) when delivering pelvic or para‑aortic IMRT to demonstrate target coverage and OAR sparing.

IMRT/VMAT recommendation context

Guideline contextProfessional guidelines (ESMO, NCCN, ASTRO) recommend IMRT or VMAT to spare organs at risk and reduce acute and late toxicity, particularly for tumors near critical structures.

Preference over 3D‑CRTGuidelines often prefer IMRT/VMAT over 3D‑CRT when dosimetric advantages reduce normal tissue toxicity while maintaining tumor control.

Typical clinical scenariosCommonly applied for head & neck, anal, select breast, CNS tumors near critical OARs, pelvic and mediastinal indications where OAR sparing is clinically important.

IG-IMRT — image-guided IMRT

TermIG-IMRT: Image-guided intensity-modulated radiation therapy — IMRT delivered with image guidance to ensure accurate targeting.

RationaleIG-IMRT is indicated when imaging during treatment is necessary to account for target motion or anatomical changes (e.g., edema, tumor regression) to maintain target coverage and OAR sparing.

Documentation implicationPolicy expects documentation of IGRT when used with IMRT for pelvic or para‑aortic treatments to show target coverage and OAR sparing per NCCN guidance.

DO-IMRT — dysphagia-optimized IMRT

TermDO-IMRT: Dysphagia-optimized IMRT — an IMRT planning approach that reduces dose to swallowing-related structures to improve swallowing outcomes.

EvidencePhase 3 RCT (Nutting et al., 2023) demonstrated improved MDADI scores at 12 and 24 months with DO-IMRT versus standard IMRT and fewer serious adverse reactions in the DO-IMRT arm.

Clinical useApplied in oropharyngeal/hypopharyngeal squamous cell carcinoma to reduce dysphagia and aspiration-related toxicity while maintaining tumor control.

HA-WBRT — hippocampal-avoidance WBRT and memantine

DefinitionHA-WBRT: Hippocampal-avoidance whole-brain radiotherapy — a WBRT technique using IMRT planning to spare the hippocampal neurogenic niche to preserve cognitive function, typically combined with memantine.

Supporting evidencePhase III trial (Brown et al., 2020) showed HA-WBRT + memantine reduced cognitive failure versus WBRT + memantine without differences in OS or intracranial PFS.

Guideline recommendationNCCN and ASCO/SNO/ASTRO endorse HA-WBRT plus memantine for patients with good prognosis and no metastases within 5 mm of the hippocampus (preferred regimen: 30 Gy in 10 fractions with memantine).

HA-WBRT (expanded)

Expanded definitionHA-WBRT is a WBRT technique using IMRT to spare the hippocampal neurogenic niche to preserve cognitive function, typically combined with memantine; intended for patients receiving WBRT who have no hippocampal lesions and expected survival ≥4 months.

Intended benefitPreservation of cognitive function and reduction in patient-reported cognitive symptoms compared with standard WBRT, per phase III evidence.

Eligibility constraintsPatients must have no metastases within the hippocampal-avoidance region and sufficient prognosis/performance status (guideline cutoff commonly ≥4 months).

IMRT — conformal radiotherapy technique

Concise term definitionIMRT is a conformal radiotherapy technique that modulates beam intensities across multiple fields to improve PTV coverage and reduce dose to organs at risk compared with 3D-CRT.

MechanismModulation of beam intensity allows shaping of dose distributions to closely conform to tumor geometry while reducing OAR exposure.

Clinical implicationOften used when critical structures are adjacent to the target and OAR sparing is a priority per guideline recommendations.

IMRT (alternate phrasing)

Alternate phrasingIntensity-modulated radiation therapy — an advanced form of 3D-conformal radiotherapy producing improved PTV coverage and decreased dose to OARs.

Clinical applicationsUsed across multiple tumor sites (e.g., prostate, pancreas, head & neck, CNS, breast) to improve dose conformity and spare normal tissues.

Delivery considerationsMay be delivered with VMAT and is frequently combined with IGRT to manage motion and setup variability.

IGRT for motion/changes

Use for motion/changesIGRT is used with IMRT to account for target motion or anatomic changes during treatment delivery (example: vulvar edema) to maintain accurate dose delivery.

Clinical exampleESGO and other guidelines recommend daily set-up verification and image guidance for vulvar cancer IMRT, particularly with simultaneous integrated boost or when tissue edema/regression is expected.

ExpectationPolicy expects documentation of IGRT use and appropriate imaging for targets subject to motion or change to support IMRT requests.

Definitive Therapy (updated)

Updated definitionDefinitive Therapy: Radiation treatments for cancer with curative intent; definition text was updated in the 06/01/2025 policy revision to clarify application to listed primary-site conditions for definitive IMRT.

Policy change noteRevision operationalized which primary-site conditions are proven and medically necessary for definitive IMRT; vulvar cancer was added and 'anal cancer' replaced with 'anus/anal canal cancer'.

ApplicationUsed throughout the policy to distinguish curative-intent IMRT indications from palliative or other RT intents.

Phase 3 randomized trial of dysphagia‑optimized IMRT demonstrated sustained improvements in patient‑reported swallowing outcomes at 12 and 24 months versus standard IMRT.

NRG CC001 (HA‑WBRT): Phase III RCT (Brown et al.) showed HA‑WBRT plus memantine reduced cognitive failure versus WBRT plus memantine without compromising OS or intracranial PFS in patients without hippocampal metastases.

inv-05 (supporting placement): Selected evidence summaries relevant to clinical benefit used in background

Selected evidence summaries relevant to clinical benefit used in background

Gynecologic cancer trials and outcomes: Randomized and cohort studies plus meta‑analyses indicate IMRT reduces acute GI/GU toxicity and late bowel obstruction rates in cervical and endometrial cancer while maintaining similar survival endpoints.

Parotid‑sparing RCT: Randomized evidence demonstrates parotid‑sparing IMRT reduces grade ≥2 xerostomia at 12 and 24 months and improves salivary recovery and QOL measures versus conventional RT.

HA‑WBRT phase III evidence: NRG CC001 showed cognitive preservation with HA‑WBRT plus memantine compared with WBRT plus memantine in patients meeting hippocampal‑avoidance eligibility.