Cardiac Events After Treatment With High-Dose Radiation Therapy +/– Chemotherapy for Non-Small Cell Lung Cancer

Abstract

radiosurgery or Linac-based coplanar IMRT or VMAT treatment plans. Median follow-up imaging was 14 months. The presence or absence of fracture was identified from the most recent CT scan then compared to pretreatment and follow-up scans. Results: Of 236 patients reviewed 27 had thoracic vertebral compression fractures. Ten of the 27 patients developed fractures after radiation therapy and 7 were at the same vertebral level as the treated lesion. Treatment doses for these patients ranged from 20/1, 25/1, 30/1, 50/4, and 54 Gy/3 fractions. Fractures occurred between 7 and 28 months after SABR in the 7 patients. Two of the 7 patients had pre-existing thoracic fractures and 2 of the patients developed at least one fracture during the follow-up period at a vertebral level that did not receive radiation dose. Two of the 7 patients had rib fractures attributed to radiation dose. There were a total of 8 fractures as one patient had 3 lesions treated and 2 different vertebral levels affected. Six of the 7 patients were women and ages ranged from 64-89. CT scans revealed diffuse osteopenia in each of the patients. Four of the PTVs were 6-10 cm from the affected vertebral body and the other 3 PTVs abutted the affected vertebral body. Conclusions: Vertebral fractures after SABR to cancers in the lung are infrequent but may be associated with radiation dose. Patients at greatest risk appear to be postmenopausal women with diffuse osteopenia. With increased numbers and dosimetric evaluation we may soon be able to better define discrete risks. Understanding these risks and limiting vertebral body dose in high-risk patients could help avoid potentially severe fractures. Author Disclosure: T.A. Aguilera: None. N. Trakul: None. D. Shultz: None. P.G. Maxim: E. Research Grant; Varian, RaySearch. F. Honoraria; Varian. M. Diehn: E. Research Grant; Varian. B.W. Loo: E. Research Grant; Varian, RaySearch. F. Honoraria; Varian.