Proton and Neutron Beam Therapies

This policy covers proton beam therapy (and very selective use of neutron beam therapy) for tumors requiring highly conformal dose delivery — examples include inoperable tumors, intraocular melanomas, primary and metastatic CNS and spine tumors, skull‑base tumors (e.g., chordoma/chondrosarcoma), hepatobiliary cancers, pediatric solid/hematologic tumors (≤21 years), re‑irradiation cases, and other sites where photon dose constraints cannot be met. Major limitations include exclusion of IDH wild‑type glioblastoma, very limited availability/use of neutron therapy, routine coverage restricted to the policy’s listed indications (and ASTRO 2023 guidance), and requirement for enrollment in qualifying IRB‑approved trials or CED‑compliant registries for certain indications (eg, prostate) due to limited comparative evidence versus photon/IMRT.

"Proton beam therapy (PBT) for tumors that are inoperable or when precise dose delivery is needed to minimize radiation to surrounding healthy tissue or critical structures."