ICD-10-PCS Section D
Radiation Oncology

Radiation oncology procedure codes have a first character value of “D”. The second character specifies the body system (e.g., central nervous, musculoskeletal) irradiated. The third character root type specifies the general modality used (e.g., beam radiation) and the fifth character further specifies the radiation modality used (e.g., photons, electrons). The fourth character specifies the body part that is the focus of the radiation therapy. The sixth character specifies the isotopes introduced into the body, if applicable, or whether the beam used is a gamma beam or other photon. The seventh character is not specified in the radiation oncology section, and always has the value None.