Radiation Fibrosis Syndrome

Abstract

Approximately 50% of all cancer patients receive radiation therapy (RT) during their disease course. Radiation can be used as monotherapy (i.e., cervical cancers), as neoadjuvant or adjuvant therapy (i.e., breast cancer), or in combination with chemotherapy (i.e., head and neck cancer.) Despite advances in technique, normal tissue is often still involved in the radiation field and subject to damage. The side effects of radiation occur early (within days) or late (within years), and can affect any organ system. Skin and mucosa are predominantly affected in the acute phase. In the late phase, vascular damage and fibrosis are the primary reactions. Radiation fibrosis (RF) is typically a delayed complication of radiation therapy and refers to the pathologic formation of fibrotic tissue over time. Risk factors include a patient’s age, comorbidities, and concurrent oncologic treatment in addition to specific radiation factors such as size of radiation field, total dose, dose per fraction, type of tissue radiated and the time from initial radiation treatment.