Stereotactic Body Radiotherapy for Early-Stage Multiple Primary Lung Cancers

Outcomes of patients with early-stage multiple primary lung cancers (MPLC) were reviewed from a prospective database at a high-volume institution. Compared to patients receiving a single course of stereotactic body radiotherapy (SBRT), MPLC patients receiving multiple courses of SBRT or receiving surgery followed by SBRT had no significant detriment in survival, freedom from disease progression, or toxicity. Background: Patients with multiple primary lung cancers increasingly receive multiple courses of stereotactic body radiotherapy (SBRT). We aimed to clarify the efficacy and safety of such treatments. Patients and Methods: We reviewed a prospective lung SBRT database of patients treated for stage I non-small-cell lung cancer between June 2004 and December 2015. Results: A total of 374 patients received a single course of SBRT, 14 received synchronous SBRT, 48 received metachronous SBRT alone, and 108 received surgery and metachronous SBRT. Median follow-up was 37.0 months for survivors. Patients who received a single course had a 3-year overall survival (OS) of 54.2% (95% confidence interval [CI], 48.8-59.3), 3-year freedom from progression (FFP) of 67.3% (95% CI, 60.9-72.9), and grade 3 or higher toxicity of 3.5%. Compared to single-course patients, patients receiving metachronous SBRT alone and patients receiving surgery and metachronous SBRT had improved OS (79.7% [95% CI, 64.4-88.9%], P < .0001 and 95.4% [95% CI, 89.2-98.0%], P <.0001, respectively) and FFP (85.8% [95% CI, 70.7-93.5], P = .03 and 95.4% [95% CI, 89.2-98.0%], P < .0001, respectively). Patients receiving synchronous SBRT had similar OS (46.4% [95% CI, 19.369.9%], P = .75) and similar FFP (57.5% [95% CI, 25.3-80.0%], P = .17) as single-course patients. There were no significant differences in rates of grade 3 or higher toxicity or of grade 1 or higher toxicity between single-course patients and the other groups. Conclusion: Patients who received either synchronous or metachronous SBRT had no significant detriment in OS or toxicity compared to single-course patients. This supports the use of SBRT in patients with multiple primary lung cancers. (C) 2018 Elsevier Inc. All rights reserved.