ModifiedUnitedHealthcarePolicy CS105KY.11

Proton Beam Radiation Therapy (for Kentucky Only)

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

Policy Summary

PayerUnitedHealthcare

PolicyProton Beam Radiation Therapy (for Kentucky Only)

Policy CodePolicy CS105KY.11

Change TypeRevised coverage criteria; removed codes; documentation clarifications

Effective DateMay 1, 2026

Next Review DateN/A

Key ActionWhen requesting PBT exceptions for non-proven indications, submit a comparison of PBT and photon-based treatment plans demonstrating that photon techniques cannot meet necessary normal tissue sparing.

SourceLink

POLICY UPDATE CHANGES

Revised coverage criteria for evaluation of exception requests for a covered diagnosis of proton beam radiation therapy (PBT) that is not listed as proven; replaced requirement to compare PBT, IMRT, and SBRT plans with requirement to compare PBT and photon-based radiation therapy (such as IMRT or SBRT) plans for the specific individual.

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

Medical records documentation language was added clarifying that benefit coverage is determined by federal/state/contractual requirements and that medical records may be required to assess clinical criteria but do not guarantee coverage.

Removed reference link to the Medical Policy titled Intensity-Modulated Radiation Therapy (for Kentucky Only) Coverage Rationale.

Updated Clinical Evidence and References sections to reflect the most current information.

May 1, 2026effective date

CS105KY.11

Medical Necessity and Clinical Coverage Criteria

Medical Necessity and Coverage Criteria

Covered when ALL of the following are met

Age rule: Individual is younger than 19 years OR (if 19 years or older) medical necessity is established per InterQual® CP: Procedures, Proton Beam Radiotherapy (PBRT).age < 19

Individuals under 19 are covered without further review; those 19+ require InterQual PBRT criteria.

Proven indication — Prostate cancer: Proton beam radiation therapy (PBT) may be covered for localized prostate cancer when medical necessity is met and InterQual PBRT criteria apply.N/A

If InterQual cannot determine necessity, principles of medical necessity apply; PBT and IMRT are considered clinically equivalent for prostate cancer.

Exceptions for other diagnoses: For diagnoses other than specified proven indications, PBT may be covered only when BOTH of the following are met: (1) documentation shows surrounding normal tissue sparing cannot be achieved with standard radiation therapy techniques; AND (2) evaluation includes a comparison of treatment plans for PBT versus photon-based radiation therapy (such as IMRT or stereotactic body radiation therapy) for the specific individual.N/A

Requests for exceptions evaluated case-by-case.

Prostate Cancer — evidence overview

Evidence and guideline summaries for prostate cancer:

Prostate cancer evidence summary: Comparative studies and guideline reviews show IMRT and PBT yield comparable cancer control and quality-of-life outcomes; population-based analyses reported greater GI toxicity with PBT in some cohorts. AUA/ASTRO (2022) conditionally recommends proton therapy as an option but states it has not demonstrated superiority to other radiation modalities; NCCN notes photon RT and PBRT are appropriate and yield comparable outcomes.

References include Sheets et al. (2012), Kim et al. (2011), AUA/ASTRO guideline (2022), NCCN (2026).

Ocular indications — AMD

Ocular indications — evidence characterized as limited or unproven:

Age-related macular degeneration (AMD): Systematic reviews and randomized trials provide uncertain evidence regarding RT/PBT for neovascular AMD; trials and reviews noted no clear benefit and potential for adverse outcomes, and the American Academy of Ophthalmology does not consider RT a proven beneficial therapy for AMD pending further research.

Evans et al. (2020), Bekkering et al. (2009), Zambarakji et al. (2006), AAO Preferred Practice Pattern (2024).

Bladder Cancer — evidence overview

Bladder cancer — evidence limited and inconclusive regarding role of PBT:

Muscle-invasive bladder cancer: Small registry and retrospective series report similar short-term OS, PFS, and local control with PBT as part of multimodality bladder-preserving therapy compared with photon-based approaches; guidelines advise against RT alone for curative intent and do not specifically address PBT. Larger, longer-term studies are needed to establish PBT's role.

Araya et al. (2023), Takaoka et al. (2017), Miyanaga et al. (2000), Holzbeierlein et al. guideline (2024), NCCN (2025).

Breast Cancer — evidence overview

Breast cancer — early evidence suggests dosimetric and some toxicity advantages but high-quality comparative data lacking:

Breast cancer evidence summary: Systematic reviews and case series indicate PBT can spare heart and lung dose and may reduce some adverse events compared with photon RT, but evidence quality is low, no randomized trials directly compare PBT with photon RT, and ongoing trials are expected to clarify benefits especially for regional nodal irradiation and cardiac sparing.

Holt et al. (2023), Hayes assessment (2022/2024), Cuaron et al. (2015), Jimenez et al. (2025), NCCN (2025).

Choroidal Hemangiomas — evidence overview

Choroidal hemangiomas — mixed retrospective evidence:

Choroidal hemangioma outcomes: Retrospective multicenter and single-center studies report generally high treatment success; PBT and photodynamic therapy (PDT) produced similar functional outcomes for tumors ≤ 3 mm, while PBT may provide superior single-session treatment and better anatomical outcomes for tumors > 3 mm. Evidence is limited by retrospective designs and small sizes.

Mathis et al. (2021); Hocht et al. (2006).

Esophageal Cancer — evidence overview

Esophageal cancer — pooled analyses suggest dosimetric and toxicity advantages and potential survival benefits:

Esophageal cancer meta-analysis: Meta-analysis and retrospective series show PBT is associated with reduced dose to organs at risk, lower rates of some radiation-related toxicities (e.g., pneumonitis, pericardial effusion, lymphocytopenia), and in some analyses improved overall survival compared with photon therapy; evidence is heterogeneous and limited by lack of randomized data, so clinical trial enrollment is recommended when using PBT.

Zhou et al. (2023); Wang et al. (2013); Mizumoto et al. (2010, 2011); NCCN (2025); STS/ASTRO guidance (Worrell et al., 2024).

Guideline-based considerations

Contextual guidance from professional guidelines:

NCCN guidance for esophageal cancers: PBT is appropriate when dose reduction to organs at risk is necessary and cannot be achieved by 3D-CRT; because data are early and evolving, NCCN recommends that individuals receive PBT in a clinical trial.

NCCN (2025).

STS/ASTRO guidance: Guidelines note IMRT is preferred over 3D-CRT for esophageal cancer and recommend IMRT when 3D-CRT cannot meet dose constraints; these guidelines do not specifically mandate PBT but emphasize using techniques that meet OAR constraints.

Worrell et al. (2024).

Evidence summaries by tumor site

Evidence summaries that inform coverage rationale:

Choroidal hemangiomas: Retrospective series report high overall treatment success (~91% collectively) with RT; comparative advantage of proton versus photon therapy has not been definitively demonstrated.

Hocht et al. (2006); Mathis et al. (2021).

Esophageal cancer: Meta-analyses and HTAs report that PBT reduces OAR doses and some toxicities and may improve overall survival in some analyses, but evidence quality is low and heterogeneous; RCTs are needed.

Zhou et al. (2023); related retrospective series.

Gastrointestinal (rectal) cancer: Dosimetric analyses show PBT reduces dose to bowel, bladder, and pelvic bone marrow versus photon RT, but clinical outcome data are insufficient to establish superiority.

Dosimetric studies summarized in policy.

Coverage considerations

Coverage considerations based on available evidence and guideline positions:

General evidence summary: Small prospective and retrospective studies indicate PBT can enable higher tumor doses with potentially lower rates of certain toxicities, but prospective randomized evidence is limited; systematic reviews consider charged-particle therapy experimental for lung cancer until phase 3 data are available.

Sejpal et al.; Harada et al.; Pijls-Johannesma et al.; related systematic reviews and HTAs.

Guideline alignment: When PBT is requested for non-proven indications, documentation should demonstrate that advanced technologies are needed to deliver curative RT safely or to limit normal tissue toxicity and that photon techniques cannot meet OAR constraints.

Consistent with NCCN and ACR statements; prior authorization should request treatment-plan comparisons.

Tumor-specific evidence notes: Tumor-specific summaries (e.g., high tumor control but limited hearing preservation for vestibular schwannoma; insufficient evidence for pancreatic cancer; mixed lung cancer results) should be used to justify or deny requests based on strength of evidence.

PBT is classified as unproven and not medically necessary for indications other than those specifically identified as covered (for example, certain pediatric uses and proven adult indications). Requests for exceptions may be considered on a case-by-case basis only when both of the following are documented: (1) evidence that sparing of surrounding normal tissue cannot be achieved with standard photon radiation techniques; and (2) an evaluation that includes a comparison of treatment plans for PBT and photon-based radiation therapy (such as IMRT or stereotactic body radiation therapy) for the specific individual.

Evidence for treating neovascular age-related macular degeneration (AMD) with radiation, including proton therapy, is limited and inconclusive. Systematic reviews and guideline assessments have found insufficient high-quality data to demonstrate benefit, and the American Academy of Ophthalmology states that radiation is not considered a proven beneficial therapy for neovascular AMD and that further research is needed to evaluate long-term safety and effectiveness of stereotactic approaches.

Current NCCN guidance does not address the use of proton beam therapy for several gynecologic and gastric sites. Specifically, NCCN guidelines do not provide recommendations for PBT in the management of gastric cancer or for ovarian, uterine, or vulvar neoplasms, indicating that PBT is not a guideline-supported standard option for these disease sites at this time.

Systematic review authors conclude that charged particle therapy for lung cancer remains experimental until higher-quality comparative evidence (including phase 3 trials) is available. The existing literature for NSCLC is limited to nonrandomized and early-phase studies, and no substantial phase 3 data were identified to support routine adoption of PBT for lung cancer.

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Unless an indication is explicitly listed as covered, PBT is considered unproven and not medically necessary because current evidence is insufficient to establish clear superiority or consistent clinical benefit over standard photon-based radiation therapy for most adult solid tumor indications.

Treating neovascular AMD with radiation therapy, including proton beam therapy, is considered unproven. Given the AAO conclusion that RT is not a proven beneficial therapy for AMD and the limited quality of randomized data, requests for PBT for neovascular AMD should be supported by compelling new evidence or offered only in the context of a clinical trial.

For vestibular schwannoma, meta-analysis and critical reviews report high overall tumor control rates with proton therapy (approximately 95%) but show no clear advantage for hearing preservation compared with stereotactic radiosurgery techniques; facial nerve preservation rates may also be lower in some series. These findings indicate that PBT does not demonstrate superiority to stereotactic modalities for cranial nerve preservation despite achieving good tumor control.

Within the chunks cited here there are no additional explicit statements labeled as 'not medically necessary' beyond the general unproven stance for nonlisted indications and guidance on exception evaluation.

Applicable Codes and Coding Notes

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 ICD-10 Codes (selected examples from list)ICD-10

C11.0	Malignant neoplasm of superior wall of nasopharynx.
C61	Malignant neoplasm of prostate.
C22.0	Liver cell carcinoma.
C69.0	Malignant neoplasm of conjunctiva.
D09.20	Carcinoma in situ of unspecified eye.
D31.30	Benign neoplasm of unspecified choroid.
Q28.2	Arteriovenous malformation of cerebral vessels.

Removed Applicable CPT/HCPCS Codesmixed

77385	CPT/HCPCS code removed from Applicable Codes
77386	CPT/HCPCS code removed from Applicable Codes
G6015	CPT/HCPCS code removed from Applicable Codes
G6016	CPT/HCPCS code removed from Applicable Codes
G6017	CPT/HCPCS code removed from Applicable Codes

Biologically effective dose threshold — early-stage NSCLC

Biologically effective dose thresholdBiologically effective dose >= 105.6 Gy (RBE) associated with improved outcomes (OS, CSS, DFS, LC) in hypofractionated PBT for early-stage NSCLC; 4-year OS 78% at >=105.6 Gy RBE vs 56% below.

Median BED in studiesMedian biologically effective dose delivered across included studies was 105.6 Gy (RBE).

Associated toxicity signalLate grade ≥2 toxicities were nearly three times more frequent in the higher-dose group, with rib fractures notably more common.

Prior Authorization, Documentation, and Exception Requests

Prior Authorization

Prior Authorization Required and Medical Necessity Determination

Prior authorization and medical necessity for proton beam radiation therapy (PBRT/PBT) for individuals 19 years and older must be determined using InterQual® PBRT criteria. Requests must include documentation sufficient to demonstrate the clinical indication meets medical necessity per InterQual; absence of supporting documentation may result in denial. Note that PBT is covered without further review for individuals younger than 19.

Prior authorization required for all members ≥19 years unless InterQual criteria confirm coverage without further review.
Medical necessity determinations follow InterQual® CP: Procedures, Proton Beam Radiotherapy (PBRT).

Prior Authorization

Prior Authorization Recommended for Unproven Indications

For indications considered unproven or with limited evidence, prior authorization is recommended and may be denied without strong rationale or enrollment in a clinical trial. When requesting PBT for an unproven indication, include a statement of the medical rationale and, if applicable, documentation of clinical trial enrollment or justification for off-trial use.

Background and Rationale

Proton beam therapy uses positively charged protons to deliver radiation with a dose distribution characterized by the Bragg peak, concentrating energy within the target and reducing exit dose beyond the tumor. This physical property can potentially reduce radiation exposure to adjacent normal tissues compared with photon-based therapies, which is the principal rationale for considering PBT in scenarios where normal-tissue sparing is clinically important.

Key Definitions

Proton beam radiation therapy (PBT) — definition

DefinitionProton beam radiation therapy (PBT) uses positively charged protons to deliver radiation that deposits most energy in the tumor with minimal dose beyond tumor boundaries, providing a more confined dose distribution than photons.

Clinical intentIntended to deliver higher, more targeted radiation with less collateral healthy tissue damage compared with photon external beam RT for selected solid tumors.

Evidence contextUsed for several adult tumor types and pediatric cancers, though clear benefit over photon EBRT is lacking for most adult indications.

Clinically localized prostate cancer (AUA/ASTRO usage)

Definition (AUA/ASTRO usage)Clinically localized prostate cancer is defined as up to clinical stage T3 prostate cancer without nodal or distant metastasis (N0M0) on conventional imaging.

Policy Revisions and Version History

Policy Summary

PayerUnitedHealthcare

PolicyProton Beam Radiation Therapy (for Kentucky Only)

Policy CodePolicy CS105KY.11

Change TypeRevised coverage criteria; removed codes; documentation clarifications

Effective DateMay 1, 2026

Next Review DateN/A

SourceLink

On This Page

Prior Authorization

Demonstrate OAR Constraint Necessity with Plan Comparisons

When PBT is requested to spare organs at risk (OARs), prior authorization must include plan comparisons demonstrating that dose constraints to OARs cannot be achieved with appropriate photon techniques. Provide a comparison of PBT and photon-based plans that shows how PBT reduces dose to the relevant OARs and the magnitude of dose reduction.

Submit dose-volume histograms (DVHs) and quantitative OAR dose metrics for both PBT and the best-available photon plan (e.g., IMRT/VMAT, SBRT) for the individual.
If IMRT or other photon techniques can meet established OAR constraints, document why PBT is still preferred or why photon techniques are inadequate.

Documentation Required

Provide Guideline-Concordant Justification

When evidence is evolving, requests should cite guideline sources and provide a guideline-concordant justification. If national guidelines (e.g., NCCN, AUA/ASTRO) recommend PBT only in select circumstances or advise trial enrollment, include the guideline citation and explain how the requested treatment aligns with or differs from guideline recommendations.

Include specific guideline excerpts or references (e.g., NCCN, AUA/ASTRO, STS/ASTRO) supporting the requested use.
If deviating from guideline recommendations, provide clinical justification and supporting evidence.

Prior Authorization

Exception Request Evaluation — Treatment Plan Comparison Required

Exception requests for diagnoses not listed as proven require thorough evaluation. The request must include a direct comparison of the proposed PBT treatment plan with a photon-based plan (e.g., IMRT, SBRT) demonstrating clinically meaningful dose reductions to OARs and any other supporting documentation (imaging, pathology, prior treatments). Exception requests lacking plan comparison data or rationale may be denied.

Provide PBT and photon plan DVHs, target coverage metrics, and OAR dose metrics.
Include imaging, surgical/pathology reports, prior radiation details, and any other documentation that supports the inability to meet constraints with photon techniques.

Documentation Required

Documentation and Coverage Determination

Coverage determinations are governed by federal, state, and contractual rules; medical record documentation may be required to assess whether criteria are met but does not guarantee coverage. Lack of complete, legible documentation that supports medical necessity may lead to denial or noncoverage.

Medical records must include relevant history, physical exam, diagnostic test results, prior treatments, and clearly documented rationale for PBT.
Records must be legible and made available upon request to support the review.

Note

Clinical-Trial Recommendation May Affect Coverage

When evidence is evolving for a condition, national guideline panels may recommend enrollment in clinical trials. Document trial availability and enrollment status; absence of trial enrollment may influence coverage decisions for certain indications (for example, esophageal cancer and other indications with evolving evidence).

If applicable, provide clinical trial identifiers and enrollment documentation.
If trial enrollment is not feasible, explain why (e.g., eligibility limits, geographic access) and provide alternate supporting evidence.

Denial Risk

Combined PBT and IMRT — Not Supported Without Evidence

Requests combining PBT and IMRT in a single treatment plan have no supporting evidence and are generally not supported. Separate sequential treatments may be considered with justification, but combined-use plans should include strong rationale and supporting data; absence of evidence may result in denial.

Do not submit combined PBT+IMRT single-plan requests without explicit justification and supporting literature.
If proposing sequential or hybrid approaches, include rationale, expected benefit, and comparative planning data.

Documentation Required

Medical Record Requirements

Medical records must fully support the requested services: include relevant medical history, physical examination findings, diagnostic test results, prior surgical and radiation treatments, and any prior toxicity. Documentation must be legible, maintained in the medical record, and available upon request. Failure to provide complete records may delay review or lead to denial.

Include operative reports, pathology, imaging, prior RT summaries, chemotherapy records, and performance status.
Document prior RT fields, doses, and dates when applicable.

Documentation Required

Toxicity and Follow-Up Documentation

Document baseline and on-treatment toxicity assessments and follow-up outcomes using standardized grading (e.g., CTCAE). Include acute and late toxicity grades, management, and clinical outcomes to support continued medical necessity or to document benefit/risk.

Provide CTCAE-graded toxicity reports, dates of onset/resolution, interventions, and outcomes.
Include follow-up imaging, symptom scores, and quality-of-life data when available.

Denial Risk

Lung Cancer — Experimental Designation (Charge Particle Therapy)

For lung cancer, charged particle therapy (including PBT) is considered experimental until phase 3 evidence demonstrates definitive benefit. Prior authorization requests for lung cancer should reference current trial evidence and may be denied in the absence of phase 3 data or trial enrollment.

Include references to ongoing phase 3 trials (e.g., NCT01993810) and enrollment status when applicable.
Provide justification if requesting PBT outside of a trial, including comparative plan data and expected clinical benefit.

Hypofractionated PBT — definition

DefinitionHypofractionated PBT: proton beam therapy delivered with fraction sizes of at least 3 Gy (RBE) per fraction in curative-intent regimens for early-stage NSCLC.

Study eligibilityVolpe et al. included studies using hypofractionated schedules (≥3 Gy RBE per fraction) reporting OS, LC, and treatment-related toxicities.

Typical outcomes evaluatedOutcomes assessed include overall survival, local control, disease-free survival, and acute and late toxicities.

PSPT (Passive Scattering Proton Therapy) — definition

DefinitionPassive scattering proton therapy (PSPT): a proton delivery technique that uses scattering devices to broaden the proton beam and was compared with IMRT in randomized trials for NSCLC.

Trial contextIn the Liao et al. randomized trial, PSPT was compared with IMRT with both modalities planned to meet the same prespecified organ-at-risk dose–volume constraints.

Dosimetric notePSPT exposed less lung tissue to low doses (5–10 Gy RBE) but more lung tissue to ≥20 Gy RBE and exposed less heart tissue across dose levels compared with IMRT in that trial.

Dose-limiting toxicity (DLT) — definition

DefinitionDose-limiting toxicity (DLT): severe (grade 3) toxicities related to PBT occurring during days 1 to 90, as defined in Harada et al.'s dose-escalation trial.

Trial useIn the Harada phase 1 trial, each dose level was tested in cohorts of participants and escalated only if no DLTs occurred, with additional enrollment when one DLT was observed.

Examples reportedReported DLTs included grade 3 infection and, in one case at the higher dose level, a grade 3 esophageal fistula occurring at 9 months after initiation of PBT.