Stereotactic body radiotherapy for second pulmonary nodules after operation for an initial lung cancer

Abstract

Objective: A second lung cancer is occasionally observed in patients who underwent surgical resection of the index lung cancer. The purpose of this study is to evaluate stereotactic body radiation ther- apy for second lung cancer. Methods: Fifty-one medically inoperable patients who underwent stereotactic body radiation ther- apy for second lung cancer were the subjects: 31 cases of multiple primary lung cancer and 20 of pulmonarymetastasis fromthe index cancer. Clinical stagewas T1a in 27 patients, T1b in 13 patients and T2a in 11 patients, and 70% of subjects had impaired respiratory function. Histology of second lung cancer was adenocarcinoma in 16 patients, squamous cell carcinoma in 9 patients and not as- sessed in 25 patients. The interval between index cancer operation and stereotactic body radiation therapy was 31 months (range: 4-171). The total stereotactic body radiation therapy doses were 48 Gy in 4 fractions or 60 Gy in 10 fractions. Results: With the median follow-up of 36 months, 3-year overall survival rates were 62% with the median survival time of 46 months. Cause-specific survival was 73% at 3 years. Overall survival for multiple primary lung cancer and pulmonary metastasis was quite similar: 62 and 61% at 3 years, respectively. Three-year overall survival was 77% for T1a and 43% for T1b or T2a. Grade 2 pul- monary toxicities occurred in five patients and one patient died of Grade 5 pneumonitis. Conclusions: Even though the subjects were medically inoperable, the survival outcomes of stereo- tactic body radiation therapy were favorable. Furthermore, having acceptable toxicity, stereotactic body radiation therapy is feasible and could be an option for multiple primary lung cancer and pul- monary metastasis after surgical resection for the index cancer.