Impact of Overall Treatment Time on Local Control After Stereotactic Body Radiation Therapy for Lung Cancer

Purpose/Objective(s): To evaluate the clinical outcomes of stereotactic body radiation therapy for lung cancer in octogenarians. Materials/Methods: Thirty-one patients who were over 80 years old at the time of therapy and 33 lesions, treated between September 2006 and February 2011, were included in this study. Seventeen patients had Stage IA lung cancer, 7 had Stage I B, one patient had Stage IIIA (the metastasis of a different lobe of the ipsilateral side and no lymph node metastasis), one patient had Stage IV (contralateral lung metastasis and no lymph node metastasis) and the other 5 had recurrence within the first 5 years after surgery for lung cancer. Threedimensional treatment planning using 7-8 non-coplanar beams was performed to maintain the target dose homogeneity and to decrease the irradiated lung volume >20 grays (Gy). All but one patient received five single, high doses of radiation of 10 Gy at the isocenter for 5-8 days. The median follow-up period was 32 months (range, 1360 months). Results: Ten patients died during the follow-up period: Six of these died of lung cancer, and the remaining 4 died of other causes. No patients died of the radiation therapy itself. Ten patients had recurrence: 3 local recurrences, 3 regional lymph node metastases and 4 distal metastases. Overall survival rates, cause-specific survival rates and local control after 1 year/2 years were 93.5%/ 66.6%, 100%/79.6% and 93.8%/90.0%, respectively. One patient had radiation-induced pneumonitis of Grade 3 (G3). Three patients had rib fracture in line with the radiation field. Three patients had G1 atelectasis. With regard to radiodermatitis, 7 patients had G1 skin pigmentation and 2 patients had G1 induration or G1 atrophy. No other vascular, cardiac, esophageal or neurologic toxicities were encountered. Conclusions: We believe that stereotactic body radiation therapy for primary lung cancer in octogenarians is safe and minimally invasive. Author Disclosure: T. Ishihara: None. K. Yamada: None. M. Tanahashi: None. H. Niwa: None. T. Matsui: None. K. Yokomura: None. R. Sasaki: None.