ModifiedUnitedHealthcarePolicy CS105NM.D

Proton Beam Radiation Therapy (for New Mexico Only)

Policy governing coverage and medical necessity criteria for proton beam radiation therapy (PBT) for members in New Mexico aged 19 and older; PBT for individuals under 19 is covered without further review.

Policy Summary

PayerUnitedHealthcare

PolicyProton Beam Radiation Therapy (for New Mexico Only)

Policy CodePolicy CS105NM.D

Change TypeMultiple additions & revisions (proven indications expandedcodes removed)

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionSubmit prior authorization with documentation comparing PBT and photon-based treatment plans when photon techniques cannot meet organ-at-risk constraints.

SourceLink

POLICY UPDATE CHANGES

Primary Head and Neck Cancers were added as a proven and medically necessary indication for definitive PBT when tumors are near critical anatomical structures and photon techniques cannot spare surrounding normal tissue.

Primary Central Nervous System Tumors (e.g., brain or spinal cord) were added as a proven and medically necessary indication when tumors are near critical structures and photon techniques cannot spare surrounding normal tissue.

Primary mediastinal tumors (e.g., thymomas, mediastinal lymphomas, thoracic sarcomas) were added to the list of proven indications.

Reirradiation was added as a covered indication when prior radiation was to the same anatomic site and photon techniques cannot achieve adequate tissue sparing.

The policy broadened the liver indication language from specifically hepatocellular carcinoma to 'primary liver malignancies, such as hepatocellular carcinoma and intrahepatic cancer' with the same documentation requirement about photon techniques and other therapies.

Exception request evaluation requirement changed: plan comparison now requires PBT versus photon-based radiation therapy (such as IMRT or SBRT) rather than specifically listing IMRT and SBRT separately.

Definitions were added for Base of Skull Tumors, Central Nervous System Tumors, and Head and Neck Cancer; the definition of 'Definitive Therapy' was updated.

CPT/HCPCS codes 77385, 77386, G6015, G6016, and G6017 were removed from the Applicable Codes section.

Added language that benefit coverage is determined by federal, state, or contractual requirements and that medical records may be required to assess criteria but do not guarantee coverage.

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NMApplies only to

19+Adults covered under criteria

5+New proven indications

5CPT/HCPCS codes removed

105.6 GyBED threshold (NSCLC)

Coverage and Medical Necessity Criteria

inv-01: Proven/Covered Indications

Covered when ALL of the following are met for adults (19+):

Definitive skull base tumors: PBT is proven and medically necessary for definitive therapy of base of skull tumors (e.g., chordomas, chondrosarcomas, paranasal sinus or nasopharyngeal tumors)

Primary head and neck cancers: PBT for primary head and neck cancers (not base of skull) is covered when tumors are near critical anatomical structures (e.g., orbit, skull base, cavernous sinus) or have intracranial extension or perineural invasion AND documentation shows sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

Primary CNS tumors: PBT for primary central nervous system tumors (e.g., brain or spinal cord) is covered when tumors are near critical anatomical structures (e.g., optic nerve, brainstem, spinal cord) AND documentation shows sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

Intracranial AVMs: PBT (including proton stereotactic radiosurgery approaches) is covered for intracranial arteriovenous malformations

Ocular tumors: PBT is covered for ocular tumors including intraocular/uveal melanoma (iris, ciliary body, choroid)

Primary liver malignancies: PBT is covered for localized, unresectable primary liver malignancies (e.g., hepatocellular carcinoma, intrahepatic cancer) in the curative setting when documentation shows sparing cannot be achieved with standard radiation techniques (including IMRT, SBRT, selective internal radiation spheres) and transarterial therapy is contraindicated or not technically feasible

Primary mediastinal tumors: PBT is covered for primary mediastinal tumors (e.g., thymomas, mediastinal lymphomas, thoracic sarcomas)

Reirradiation: PBT is covered for reirradiation when the individual previously received radiation to the same anatomical site AND documentation shows sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

inv-02: Prostate cancer stance

Prostate cancer: PBT and IMRT are considered clinically equivalent for prostate cancer; medical necessity is determined by the member-specific benefit plan

inv-03: Not proven / Exception pathway

Other indications (not listed): PBT is unproven and not medically necessary for indications not listed as proven; exceptions may be considered on a case-by-case basis when (1) documentation shows sparing of surrounding normal tissue cannot be achieved with standard radiation therapy techniques AND (2) evaluation includes a comparison of treatment plans for PBT and photon-based radiation therapy (such as IMRT or SBRT) for the specific individual

Requests for exceptions evaluated case-by-case

inv-04: Guideline- and evidence-supported indications

Covered when supported by guidelines or evidence showing clinical benefit or when photon therapy cannot meet normal tissue constraints:

Base of skull tumors: PBT is considered beneficial for skull-base chordomas and chondrosarcomas with improved long-term outcomes and acceptable complications per systematic reviews and guideline statements

Head and neck cancers (select): PBT may be considered for select head and neck tumors (e.g., oropharynx, nasopharynx, paranasal sinus, salivary glands, mucosal melanoma) when normal tissue constraints cannot be met with photon-based therapy; evidence shows favorable toxicity and oncologic outcomes in pooled OPC series

Central nervous system tumors: PBT may be appropriate for primary CNS tumors (e.g., spinal ependymoma, medulloblastoma, meningioma, select diffuse gliomas) particularly when sparing uninvolved brain and critical OARs is important; systematic reviews show comparable survival and potential neurocognitive benefit in select settings

Intracranial AVMs:

inv-05: Covered with criteria (disease-site and technical justification)

PBT is considered appropriate when ALL of the following guideline-driven conditions are met for the relevant disease site

Guideline-based appropriateness: The treatment site or clinical scenario is one for which PBT is supported by evidence or guideline recommendation (examples include ocular tumors, select HCC/ICC cases, and mediastinal lymphomas where dosimetric benefit to OARs is clinically important)

Multidisciplinary care and technical capability: Treatment is planned and delivered at a center with requisite multidisciplinary expertise and technical capability, and planning demonstrates a dosimetric advantage or expected clinical benefit over photon techniques

Disease-site specific evidence considerations: Disease-site evidence supports PBT where local control or toxicity reduction is shown (for example ocular melanoma, selected unresectable liver tumors with dose-escalation benefit, and mediastinal lymphoma where cardiac/breast dose reduction is meaningful)

inv-06: Situations where PBT may be reasonable

Covered when clinical circumstances indicate clear dosimetric or clinical advantage over advanced photon techniques

Mediastinal lymphoma indications: PBT is appropriate for mediastinal lymphoma when disease extends near the heart (including below the left main stem coronary artery) where proton therapy can significantly reduce cardiac and breast dose, or in heavily pretreated individuals at high risk of marrow, cardiac, or pulmonary toxicity

Reirradiation: PBT may be appropriate for reirradiation when individualized assessment (prior dose, extent of overlap, interval since prior RT, tumor location) shows PBT enables safer delivery compared with photon options

Prostate cancer: PBT is an acceptable treatment option for localized prostate cancer but has not been shown superior to other radiation modalities; selection should follow member benefit terms and local practice

inv-07: Unproven indications

Not routinely covered or considered unproven

Ophthalmologic indications (AMD): PBT (and other radiation) for neovascular age-related macular degeneration is unproven; systematic reviews and RCTs do not demonstrate clear benefit and show risk of vision loss and radiation complications

inv-08: Coverage considerations by indication

Coverage considerations by indication based on available evidence and guideline statements in chunks 72–91:

Age-related macular degeneration (neovascular AMD): Evidence is uncertain for RT/PBT in neovascular AMD; older studies predate anti-VEGF therapy and modern RT techniques, and RCTs did not show benefit

Bladder cancer (muscle-invasive): PBT has been used as part of multimodality bladder-preserving therapy with limited data; guidelines advise against RT alone as curative therapy and long-term data are needed

Breast cancer (early): Systematic reviews suggest PBT may reduce heart/lung dose and some adverse events, but evidence quality is low and randomized trials with long follow-up are needed

Choroidal hemangioma: Comparative retrospective data suggest PBT and PDT yield similar functional outcomes for tumors ≤3 mm; PBT may be preferable for tumors >3 mm due to single-session treatment and better anatomical outcomes

inv-09: Coverage considerations and evidence summary

Coverage considerations when contemplating PBT based on the presented evidence and guideline positions

Dose-sparing justification: PBT is appropriate when dose reduction to organs at risk is necessary and cannot be achieved with 3D-CRT or IMRT

Reflects NCCN statement for esophageal/esophagogastric junction cancers

Evidence supportive contexts: Supportive evidence or rationale exists for: (a) locoregionally advanced esophageal cancer with reports of high response and reduced intrathoracic OAR dose; (b) node-positive uterine or cervical cancer where PBT reduced dose to bowel, bone marrow, and kidneys in small studies; (c) select early-stage NSCLC using hypofractionated high BED where PBT showed favorable LC and OS in meta-analyses

Contexts with insufficient evidence: For nonmetastatic rectal cancer and many GI malignancies, evidence is insufficient to establish superiority of PBT over conventional RT despite dosimetric advantages; some NCCN guidelines do not address PBT for gastric, ovarian, uterine, or vulvar cancers

inv-10: Lung cancer (NSCLC) — evidence summary

Evidence and guideline context for PBT in non-small cell lung cancer:

NSCLC evidence considerations: Systematic reviews identified mainly small, nonrandomized studies (mostly stage I) with 2- to 5-year local control rates of 57%–87% and radiation pneumonitis observed in ~10%; no phase 3 trials have established superiority, and charged particle therapy for lung cancer is considered experimental by some reviewers pending higher-quality evidence

inv-11: Pancreatic cancer — evidence summary

Evidence considerations for PBT in pancreatic adenocarcinoma:

Pancreatic cancer evidence: Robust clinical evidence evaluating PBT for pancreatic cancer is lacking; larger prospective studies are warranted and NCCN does not address PBT for pancreatic adenocarcinoma

inv-12: Vestibular schwannoma (VS) — evidence summary

Evidence and guideline context for PBRT in vestibular schwannomas:

VS tumor control vs functional outcomes: Meta-analysis reported high overall tumor control (~95.4%) with PBRT but low hearing preservation (~40.6%); authors concluded PBRT did not demonstrate advantage in hearing preservation and may have lower facial nerve preservation compared with many SRS series

Guideline uncertainty: Systematic reviews and guideline statements found no comparative trials among Gamma Knife, LINAC-based radiosurgery, and proton beam therapy and made no outcome recommendation comparing modalities

inv-13: Definitive Therapy - Primary Head and Neck Cancers

Covered when ALL of the following are met for newly added or revised indications

Head and Neck Cancers (new): Primary head and neck tumors located near critical anatomical structures (e.g., orbit, skull base, cavernous sinus) or with intracranial extension or perineural invasion AND documentation that sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

Requires documentation comparing PBT and photon-based treatment planning when requested for exception.

inv-14: Definitive Therapy - Primary Central Nervous System Tumors

Covered when ALL of the following are met for CNS tumors

Primary CNS Tumors (new): Primary CNS tumors near critical anatomical structures (e.g., optic nerve, brainstem, spinal cord) AND documentation that sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

inv-15: Reirradiation

Covered when ALL of the following are met for reirradiation

Reirradiation (new): Individual previously received radiation to the same anatomical site AND requires additional radiation to that same site AND documentation that sparing of surrounding normal tissue cannot be achieved with standard photon radiation therapy techniques

inv-16: Primary Liver Malignancies

Covered when ALL of the following are met for primary liver malignancies

Primary liver malignancies (revised): Primary liver malignancies (e.g., hepatocellular carcinoma, intrahepatic cancer) that are localized and unresectable AND documentation that sparing of surrounding normal tissue cannot be achieved with standard radiation therapy techniques (including IMRT, SBRT, selective internal radiation spheres) AND transarterial therapy is contraindicated or not technically feasible

Proton beam therapy (PBT) is considered unproven and not medically necessary for indications not listed as proven in this policy. Exceptions may be granted on a case-by-case basis only when both of the following are provided: documentation that surrounding normal tissue sparing cannot be achieved with standard photon radiation therapy techniques, and an evaluation that includes a comparison of treatment plans for PBT and photon-based radiation therapy (such as IMRT or SBRT) for the individual under review. Requests lacking these elements are not consistent with the policy’s exception pathway.

For adults with unruptured intracranial arteriovenous malformations (AVMs), randomized trial evidence (ARUBA) showed that interventional management — which can include endovascular therapy, surgery, or radiation therapy — increased the risk of death or dependency at one year compared with conservative management. Conservative management was superior to intervention for functional outcome in the trial population; consequently, interventional radiation approaches for similar adult patients should be carefully justified and may be judged not medically necessary in the absence of strong individualized rationale and supporting documentation.

The evidence base for many adult indications is limited, heterogeneous, and often retrospective. The policy notes a lack of randomized controlled trials (RCTs) or high-quality comparative data for numerous disease sites, and several systematic reviews cited in the policy state that further well-designed RCTs and prospective studies are needed. Because of these limitations, routine coverage is constrained to indications with supportive guideline or evidence-based justification and individualized technical demonstration of OAR sparing when appropriate.

Radiation therapy, including proton beam therapy, for neovascular age-related macular degeneration (AMD) and many ophthalmologic indications is not supported by high-quality, contemporary evidence. Systematic reviews and randomized trials summarized in the policy conclude that RT/PBT for neovascular AMD is of uncertain benefit, with older studies predating anti-VEGF therapy and modern techniques and with some trials showing substantial vision loss and radiation-related complications; routine use is therefore considered unproven.

Multidisciplinary guideline panels strongly advise against using radiation therapy alone as a curative approach for nonmetastatic muscle‑invasive bladder cancer. When bladder preservation is pursued, guidelines recommend a multimodality approach (maximal transurethral resection plus chemotherapy and EBRT); RT alone as definitive curative therapy is strongly discouraged, and PBT is not described as a standalone recommended curative option.

Some reviewers and systematic assessments conclude that charged particle therapy (including PBT) for lung cancer — particularly non‑small cell lung cancer — lacks robust phase 3 comparative evidence. The policy highlights that available studies are small, mainly stage I series, and that charged particle therapy should be considered experimental for lung cancer until higher‑quality randomized data are available to establish clinical effectiveness versus standard photon-based approaches.

The policy notes that no clinical evidence was identified supporting the combined use of PBT and IMRT delivered within a single treatment plan. Requests proposing a combined PBT+IMRT plan lack supportive literature and therefore are not supported by the evidence base summarized in this policy.

Coverage determinations are governed by applicable federal, state, and contractual benefit requirements and applicable laws. The policy emphasizes that even when medical necessity criteria are met, benefit coverage may be limited or mandated by the member’s specific contract, state or federal law, and medical-record documentation may be required to assess whether an individual meets the policy criteria.

Outside of the indications enumerated as proven and medically necessary in this policy, PBT is considered unproven and not medically necessary for all other indications due to insufficient evidence of efficacy. Such requests may be considered only through the documented exception pathway that demonstrates photon techniques cannot meet normal tissue constraints and includes comparative treatment planning.

Based on RCT evidence (ARUBA), interventional treatments — which can include radiation therapy — for adults with unruptured brain AVMs were associated with increased death or dependency at one year compared with conservative management. For adults who match the ARUBA trial population, interventional treatment (including RT) may be judged not medically necessary relative to conservative management unless a clear, individualized clinical justification and supporting evidence are provided.

This segment of the policy does not introduce new explicit 'not medically necessary' statements beyond the general rule that indications not listed as proven are unproven and not medically necessary. Instead, the policy provides evidence summaries and guideline-based considerations and relies on the exception pathway and documentation requirements to evaluate non‑listed indications on a case‑by‑case basis.

Multiple systematic reviews and an RCT evaluating radiation approaches for age‑related macular degeneration report limited or unfavorable outcomes and notable radiation‑related complications. The policy therefore concludes that PBT for age‑related macular degeneration is not supported by high‑quality evidence and is considered unproven; routine coverage is not recommended.

For neovascular age‑related macular degeneration, the policy summarizes that randomized trials and systematic reviews do not demonstrate clear clinical benefit of RT or PBT relative to current anti‑VEGF standards and contemporary practice. Consequently, RT/PBT for neovascular AMD is considered of uncertain benefit and not a proven therapeutic option based on the available evidence.

Systematic reviews comparing PBT with conventional photon radiotherapy for nonmetastatic rectal cancer show dosimetric advantages (reduced dose to bowel, bladder, and pelvic bone marrow) but insufficient clinical outcome data. The policy states that routine superiority of PBT for nonmetastatic rectal cancer cannot be established, and current evidence is inadequate to support routine coverage without additional high‑quality trials or individualized justification.

A systematic review of charged particle therapy for lung cancer found mainly small, nonrandomized studies with heterogeneous outcomes and no phase 3 trials; reviewers concluded that particle therapy should be considered experimental for lung cancer until more definitive data exist. The policy therefore treats charged particle therapy for lung cancer as experimental given the lack of substantial clinical‑effectiveness data.

Applicable Procedure and Diagnosis Codes

Applicable CPT/Procedure 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.
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 Diagnosis Codes (selected examples from list)ICD-10

C11.0	Malignant neoplasm of superior wall of nasopharynx.
C22.0	Liver cell carcinoma.
C31.0	Malignant neoplasm of nasal cavity.
C41.0	Malignant neoplasm of bones of skull and face.
C61	Malignant neoplasm of prostate.
C69.0	Malignant neoplasm of conjunctiva.
C69.3	Malignant neoplasm of unspecified choroid (and related C69.x series).
D09.20	Carcinoma in situ of unspecified eye.
D14.0	Benign neoplasm of middle ear, nasal cavity and accessory sinuses.
Q28.2	Arteriovenous malformation of cerebral vessels.

No explicit codes in this segmentmixed

No codes listed

Removed/Updated CPT/HCPCS CodesCPT | HCPCS

77385	Removed from Applicable Codes
77386	Removed from Applicable Codes
G6015	Removed from Applicable Codes
G6016	Removed from Applicable Codes
G6017	Removed from Applicable Codes

Biologically effective dose (BED) — key threshold

BED thresholdBiologically effective dose (BED) threshold: 105.6 Gy (RBE)

ContextMedian BED reported in hypofractionated NSCLC series; higher BED (≥105.6 Gy RBE) associated with improved OS, DFS, and local control.

Toxicity trade-offHigher BED (≥105.6 Gy RBE) linked to increased late grade ≥2 toxicities (e.g., rib fractures) despite similar acute grade ≥2 toxicity rates.

Fractionation definitionHypofractionated PBT in studies defined as ≥3 Gy (RBE) per fraction; BED metric used to compare schedules.

Prior Authorization, Documentation, and Provider Requirements

Prior Authorization

Prior Authorization Required for Adults; Pediatric Coverage Without Review

Prior authorization is required for individuals 19 years of age and older. Proton beam therapy (PBT/PBRT) is covered without further prior authorization review for individuals younger than 19 years of age. For adult requests, submit complete clinical documentation to support medical necessity.

Applicable to members age ≥ 19 years
Pediatric patients (<19 years): covered without prior authorization review

Prior Authorization

Authorization When Photon Constraints Unmet

Prior authorization requests must document when PBT is being considered specifically because photon techniques (e.g., IMRT, VMAT, 3D‑CRT, SBRT) cannot meet normal tissue or organ-at-risk (OAR) dose constraints. If photon-based approaches can meet constraints, photon-first approaches are expected.

Provide explicit statement that photon constraints cannot be met
List photon techniques considered and reasons they are inadequate (dosimetric or clinical)

Background and Evidence Summary

Proton beam therapy uses charged particles to deliver dose more confined to tumor tissue with minimal exit dose beyond the target. This physical property underlies the clinical rationale for PBT: to reduce dose to surrounding normal tissues and organs‑at‑risk, which may translate into clinical benefit in selected disease sites or reirradiation scenarios when photon techniques cannot adequately spare critical structures.

Key Definitions

Base of Skull Tumors

DefinitionBase of Skull Tumors: A diverse group of lesions arising in the anatomically complex region at the base of the skull, including chordomas and chondrosarcomas.

Anatomic structuresRegion includes anterior cranial fossa, clivus, petrous bone, middle cranial fossa, cavernous sinus, and infratemporal fossa.

Clinical implicationTumors in this area involve critical endocrine, neurologic, and vascular components, influencing treatment planning and OAR considerations.

Central Nervous System Tumors

DefinitionCentral Nervous System Tumors: Tumors originating in the CNS, examples include brainstem glioma, craniopharyngioma, medulloblastoma, and meningioma.

ScopeIncludes tumors of the brain and spinal cord referenced by NCI definitions in the policy.

Policy Updates and Revision History

2026-05-01Effective date & major revisionLatest

Policy updated effective 05/01/2026 to revise the list of proven and medically necessary indications for PBT, adding primary head and neck cancers, primary central nervous system tumors, primary mediastinal tumors, and reirradiation; broadened liver indication language to 'primary liver malignancies'; and added definitions for key terms.

2026-05-01Exception request evaluation change

Revised exception request evaluation to require comparison of treatment plans for PBT versus photon-based radiation therapy (such as IMRT or SBRT) rather than specifically listing IMRT and SBRT separately.

Policy Summary

PayerUnitedHealthcare

PolicyProton Beam Radiation Therapy (for New Mexico Only)

Policy CodePolicy CS105NM.D

Change TypeMultiple additions & revisions (proven indications expandedcodes removed)

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionSubmit prior authorization with documentation comparing PBT and photon-based treatment plans when photon techniques cannot meet organ-at-risk constraints.

SourceLink

On This Page

PBT/PSRS may be considered for intracranial arteriovenous malformations with reported high obliteration rates in modern series, but randomized trial data support conservative management for many unruptured AVMs — careful patient selection required

Ocular tumors (uveal/choroidal melanoma): PBT demonstrates high local control and favorable overall survival in case-series and meta-analyses and is an accepted definitive option for uveal melanoma in guideline statements

Esophageal cancer: Meta-analyses show PBT reduces OAR doses and some toxicities versus photons and may improve prognosis in some analyses, but data are heterogeneous and RCTs are needed; NCCN recommends PBT when OAR dose reduction is necessary

Dose and toxicity trade-offs: Higher biologically effective doses (e.g., >= 105.6 Gy [RBE] in hypofractionated NSCLC) are associated with improved tumor control but increased late toxicities and require careful selection and counselingBED >= 105.6 Gy (RBE)

From Volpe et al. meta-analysis

Prior Authorization

Guideline-Based Indication and Planning Required

Prior authorization must include guideline-based justification when PBT is requested for ocular tumors, unresectable intrahepatic tumors (HCC/ICC), mediastinal lymphomas and thymic tumors, and other indications noted by specialty guidelines. Cite applicable guideline recommendations (NCCN, ASTRO, STS/ASTRO, etc.) and explain how PBT aligns with these recommendations for the individual.

Cite guideline name and year (e.g., NCCN 2025, ASTRO 2022)
Explain how the individual meets guideline-based indication

Prior Authorization

PBT Prior Authorization: OAR Sparing Justification

Authorization must justify PBT based on dose-sparing to critical organs-at-risk (OARs). Documentation should show that PBT is needed to reduce dose to OARs or to meet constraints that cannot be achieved with advanced photon techniques.

Describe critical OARs at risk and target‑to‑OAR proximity
Provide dose constraints and expected OAR doses with PBT vs photon plans

Prior Authorization

Plan Comparison Required for Exceptions

When an indication is not listed as proven in this policy, prior authorization requests must include a comparative treatment‑planning analysis. A comparison of PBT and photon-based treatment plans (such as IMRT, SBRT, or VMAT) for the specific individual is required to evaluate whether PBT provides meaningful dosimetric advantage.

Include comparative dose-volume histograms and plan summaries
Highlight differences in OAR dose metrics and target coverage

Denial Risk

Documentation May Support Denial Risk

Incomplete or missing medical-record documentation that does not fully support medical necessity may result in denial. Ensure records are legible and include relevant history, physical exam, diagnostic test results, prior treatment details, and the clinical rationale for PBT.

Failure to provide complete documentation may trigger denial
Medical records must be available upon request

Documentation Required

AVM Intervention vs Conservative Management Risk

For intracranial arteriovenous malformations (AVMs), providers should be aware that randomized trial evidence in adults (ARUBA) showed increased death or dependency with interventional treatment versus conservative management for unruptured AVMs. Prior authorization should reflect this evidence when intervention is proposed.

Discuss ARUBA trial findings when requesting PBT for unruptured AVMs
Document rationale for intervention despite trial results

Note

None Specified Regarding Step Therapy in This Segment

No additional step-therapy sequencing requirements are specified in this document segment beyond the photon‑first expectation for indications where photon techniques can meet constraints.

No separate step‑therapy protocol specified in this section

Prior Authorization

Selection and Availability Constraint

Selection of PBT should be reserved for cases with clear benefit over advanced photon techniques. Limited availability and resource considerations mean PBT is not appropriate for marginal indications; document why PBT is the preferred modality for the individual.

Demonstrate clear dosimetric or clinical advantage over IMRT/VMAT
Consider center experience and access when justifying PBT

Documentation Required

Bladder Cancer — RT‑Alone Discouraged

For muscle-invasive bladder cancer, radiation therapy alone as a curative approach is strongly discouraged by multidisciplinary guidelines. When PBT is requested as part of bladder‑preserving therapy, documentation should describe the multimodality approach and rationale for including PBT.

RT-alone discouraged as curative intent
For trimodality bladder-preserving therapy, document TURBT, chemotherapy, and role of PBT

Prior Authorization

Combined PBT + IMRT Requests — No Supporting Evidence Identified

Requests proposing combined PBT and IMRT within a single treatment plan should include strong supporting rationale because no evidence was identified supporting combined use. Prior authorization reviewers will expect justification and may request alternatives.

State why combination is necessary and provide evidence if available
Be prepared to provide alternative single-modality plans

Documentation Required

Medical Record and Reirradiation Documentation Needs

Medical record requirements for prior authorization reviews include tumor site and stage, intent of therapy, prior and concurrent therapies, prior radiation dose and overlap (for reirradiation), time since previous treatment, planned dose/fractionation, and contact information for multidisciplinary team members.

Tumor type/stage, intent of therapy, planned dose and fractionation
Prior radiation details (dose, overlap, time since prior RT) for reirradiation requests
Multidisciplinary team members and their roles

Documentation Required

Clinical Rationale, OAR Documentation, and Multidisciplinary Team Requirements

Provider submissions should include the clinical rationale that ties the indication to the expected benefit from PBT, with documentation of tumor location, proximity to OARs, and dosimetric comparisons where available. Multidisciplinary team documentation (e.g., ophthalmic oncology for eye tumors, radiation physics) is expected for site‑specific indications.

State therapeutic intent and expected clinical benefit from PBT
Include multidisciplinary tumor board or specialist consultation notes when applicable

Prior Authorization

Exception / Step Evaluation for Non‑Listed Indications

For diagnoses not listed as proven, exception requests will be evaluated on a case-by-case basis. Evaluation requires demonstration that normal tissue sparing cannot be achieved with standard photon therapy and includes comparative planning for PBT versus photon-based therapy.

Show that photon techniques cannot meet dose constraints
Provide comparative treatment plans per individual

Note

Benefit Governance

Benefit coverage is governed by federal, state, and contract-specific requirements. Prior authorization and medical necessity determinations do not supersede contractual or regulatory coverage mandates.

Coverage subject to member's benefit plan and applicable laws
Prior authorization does not guarantee payment

Treatment relevanceProximity to critical structures (optic apparatus, brainstem, spinal cord) affects appropriateness of PBT for tissue-sparing reasons.

Definitive Therapy

DefinitionDefinitive Therapy: Radiation treatments given with curative intent (aimed at disease eradication and maintaining quality of life).

Source guidanceDefinition references NCI and NCCN usage as provided in the policy definitions and updated policy history.

Clinical useApplied to primary disease settings where PBT is intended as curative rather than palliative or adjuvant alone.

Head and Neck Cancer

DefinitionHead and Neck Cancer: Cancers arising in tissues of the head and neck region (nasal cavity, sinuses, mouth, salivary glands, pharynx, larynx), typically of squamous cell origin.

Risk factorsKey risk factors include tobacco, alcohol, and high-risk HPV infection.

Treatment relevanceTumor proximity to critical structures influences selection of PBT to spare OARs when photon techniques cannot meet constraints.

OAR — Organ-at-risk

DefinitionOAR — Organ-at-risk: normal tissues adjacent to the treatment target for which dose sparing is clinically important.

ExamplesIncludes structures such as brainstem, eyes, pituitary gland, hippocampus, cochleae, thyroid, heart, lungs, kidneys, and spinal cord referenced in practice parameters.

RelevanceIdentifying OARs is essential for justifying PBT when photon-based techniques cannot adequately spare these organs.

When PBT is reasonable (ASTRO)

ASTRO positionASTRO: PBT is reasonable when sparing surrounding tissue cannot be adequately achieved with photon-based RT and the added clinical benefit is expected.

Clinical implicationUse of PBT should be considered when photon techniques (e.g., IMRT/VMAT) cannot meet normal tissue dose constraints.

Disease examplesASTRO frequently cites ocular tumors among disease sites supporting PBT use.

Surrounding normal tissues (OARs) important for dose sparing

DefinitionSurrounding normal tissues for which dose sparing is clinically important: organs at risk (OARs) such as heart, lungs, breast tissue, bone marrow, and other nearby critical structures.

Guideline notesILROG and NCCN note that reducing dose to these OARs can lower long-term toxicity and secondary cancer risk, particularly in younger patients or mediastinal disease.

Implication for PBTDocumented dosimetric advantage in sparing these tissues supports PBT prior authorization when photon plans cannot meet constraints.

Reirradiation

DefinitionReirradiation: administration of radiation therapy to a site that previously received radiation; requires assessment of prior dose, overlap, and interval since prior treatment.

Evidence summarySystematic reviews show charged particle reirradiation can be feasible with reported 2-year LC 50%–86% for protons and notable late grade 3 toxicity up to 37%; careful selection is required.

Documentation needsPrior radiation dose, extent of overlap, time since prior RT, tumor location, and individualized justification should be provided for PBT reirradiation requests.

CGE — Cobalt Gray Equivalent

DefinitionCGE — Cobalt Gray Equivalent: dose unit used in proton therapy dose reporting as cited in PBT trials (e.g., Zambarakji AMD trial).

UsageCGE used historically in ocular PBT trials to report proton dose levels (e.g., 16-CGE vs 24-CGE arms).

RelevanceUnderstanding CGE is important when interpreting older proton literature and dose comparisons.

Hypofractionated PBT

DefinitionHypofractionated PBT: proton therapy delivered with fractions of at least 3 Gy (RBE) per fraction, as defined in hypofractionated NSCLC studies.

Clinical contextUsed in early-stage NSCLC series evaluating higher BED regimens; median BED reported in meta-analysis was 105.6 Gy (RBE).

ImplicationHypofractionated schedules may achieve higher BED and improved local control but can increase late toxicity risk.

Biologically effective dose (BED) — definition and implications

DefinitionBiologically effective dose (BED): a dose metric used to compare different fractionation schedules; in hypofractionated NSCLC, a BED of 105.6 Gy (RBE) or higher was associated with better outcomes but increased late toxicity in some series.

Observed effectHigher BED (≥105.6 Gy RBE) correlated with improved OS and LC but higher late grade ≥2 toxicities (e.g., rib fractures) per Volpe et al. meta-analysis.

Documentation notePlanned dose/fractionation and BED should be documented in prior authorization requests where applicable.

PBRT / PBT — terminology

DefinitionPBRT / PBT: Proton beam radiation therapy (PBT) or proton beam radiotherapy (PBRT) — charged-particle external beam radiation modalities evaluated across multiple tumor types.

DistinctionsPolicy notes distinctions from heavier charged particles (e.g., carbon ions) in some studies and summarizes evidence by modality where relevant.

Clinical relevanceTerminology used interchangeably in literature and policy when discussing proton-specific outcomes and recommendations.

Base of Skull Tumors (duplicate)

Duplicate entryBase of Skull Tumors — see canonical definition: diverse lesions in complex skull base anatomy (chordomas, chondrosarcomas).

NoteIncluded in policy definitions and reiterated in revisions documenting added definitions.

Central Nervous System Tumors (duplicate)

Duplicate entryCentral Nervous System Tumors — see canonical definition: tumors originating in the CNS (examples provided).

NoteAdded to definitions in policy history for clarity.

Head and Neck Cancer (duplicate)

Duplicate entryHead and Neck Cancer — see canonical definition: cancers of head and neck region, typically squamous cell origin.

NoteDefinition added/clarified in policy revisions.

Definitive Therapy — updated definition

Definitional updateDefinitive Therapy — definition updated in the policy; refers to curative-intent radiation treatments per NCCN/NCI definitions.

Policy noteUpdate documented in Policy History/Revision Information.

ImplicationUsed to operationalize coverage criteria for newly added proven indications (e.g., primary HN and CNS tumors).

2026-05-01Documentation clarification

Added clarification that medical records documentation may be required to assess criteria and must fully support medical necessity, and that documentation does not guarantee coverage.

2026-05-01Coding update - removed codes

Removed CPT/HCPCS codes 77385, 77386, G6015, G6016, and G6017 from the Applicable Codes section.