Radiotherapy for hilar or mediastinal lymph node metastases after definitive treatment with stereotactic body radiotherapy or surgery for stage I non-small cell lung cancer.

ABSTRACT

PURPOSE: Management of regional lymph node (LN) recurrence is an important issue in definitive treatment of non-small cell lung cancer (NSCLC). We evaluated clinical outcomes of conventional radiotherapy for hilar or mediastinal LN metastases developing after stereotactic body radiotherapy (SBRT) or surgery for stage I NSCLC. METHODS AND MATERIALS Between 2004 and 2008, 26 patients with hilar or mediastinal LN metastases without local recurrence and distant metastasis after SBRT (n = 14) or surgery (n = 12) were treated with conventional radiotherapy. Twelve of the 14 post-SBRT patients (86%) were judged medically inoperable at the time of SBRT. All patients were treated to the hilum and mediastinum with conventional daily fractions of 2.0 Gy (n = 25) or 2.4 Gy (n = 1). The median total dose for treating metastatic LN was 60 Gy (range, 54-66 Gy) for the post-SBRT patients and 65 Gy (range, 60-66 Gy) for the post-surgery patients. Only 1 of the 14 post-SBRT patients and 8 of the 12 post-surgery patients received chemotherapy. RESULTS: For all 26 patients, the overall and cause-specific survival rates at 3 years from radiation for LN metastases were 36% and 51%, respectively (14% and 39%, respectively, for the 14 post-SBRT patients and both 64% for the 12 post-surgery patients). Three of the SBRT patients were alive at 35 to 43 months with (n = 2) or without (n = 1) further recurrence, and 4 of the post-surgery patients were alive at 36 to 62 months with (n = 2) or without (n = 2) further recurrence. The incidence of ≥grade 2 pulmonary toxicity was 49% at 1 year (53% for post-SBRT patients and 44% for post-surgery patients). A grade 5 pulmonary toxicity was observed in 1 of the post-SBRT patients. CONCLUSIONS: Conventional radiotherapy could successfully salvage LN relapses after SBRT as well as after surgery in 7 of 26 patients. Radiotherapy in this setting appears reasonably well tolerated.