This policy applies billing/coding guidelines for radiation therapy services under LCD L39553 (it does not itself change coverage determinations) and does not exclude non‑cancer indications but requires especially specific documentation when treating non‑malignant conditions (e.g., epilepsy, trigeminal/facial nerve, movement disorders). Key requirements: maintain complete, legible medical records with patient identifiers, dates, clinician signatures/credentials, ICD‑10 and CPT/HCPCS codes at the highest specificity, and detailed clinical documentation including primary diagnosis, history, comorbidities, performance status (as required), relevant imaging, proposed treatment plan, tumor number/location/size/stage and anatomic site of radiation.