Thoracic Radiation Normal Tissue Injury

Abstract

Thoracic malignancies are often a difficult group of tumors to treat definitively as the radiation doses needed to achieve a high probability for tumor control are often associated with high rates of radiation-induced toxicities. The lungs are particularly radiosensitive and are susceptible to radiation pneumonitis in the acute and subacute settings and pulmonary fibrosis in the late setting. Acute esophagitis is common and affects patient quality of life. Beyond acute pericarditis, late cardiac toxicities are increasingly being recognized as clinically relevant when delivering thoracic radiotherapy and can affect overall survival. This review details the common and dose-limiting acute and late toxicities associated with thoracic radiation therapy. As radiation-induced toxicities are often amplified with concurrent chemotherapy, this article focuses on the toxicities associated with irradiation for lung cancer, the most common thoracic malignancy, which is often treated with multimodality therapy. The management of radiation-induced toxicities and the changing patterns of toxicities with advanced radiation delivery modalities are also described.