FACTORS ASSOCIATED WITH SEVERE ACUTE ESOPHAGITIS FROM HYPERFRACTIONATED RADIOTHERAPY WITH CONCURRENT CHEMOTHERAPY FOR LIMITED-STAGE SMALL-CELL LUNG CANCER

Purpose: To describe incidence and identify factors associated with development of severe acute esophagitis during hyperfractionated radiotherapy with concurrent chemotherapy (BID-CRT) in patients with limited-stage small-cell lung cancer (SCLC). Methods and Materials: Retrospective cohort analysis of patient-, tumor-, and treatment-related variables was performed to identify factors associated with Radiation Therapy Oncology Group (RTOG) Grade 3 acute esophagitis. Twice-daily chemoradiotherapy (BID-CRT) involved 45 Gy at 1.5 Gy per fraction, treated twice daily with concurrent platinum-based chemotherapy. Logistic regression analyses were used to identify factors associated with esophagitis. Results: Between June 1999 and June 2007,48 patients underwent curative intent BID-CRT for SCLC and were included in the analysis. Median radiotherapy dose was 45 Gy (range, 42-51 Gy) delivered with a median 4 cycles of chemotherapy (range, 2-6). RTOG Grade 3 acute esophagitis developed in 11 patients. No patient developed Grade 4 or 5 esophagitis. Simple logistic regression analyses demonstrated a highly significant association between Grade 3 acute esophagitis and mean esophageal dose (p = 0.002) as well as relative volume dosimetric area under curve (RV-AUC;p = 0.004). Using multiple regression analysis, RV-AUC was identified as the only factor associated with Grade 3 esophagitis (p = 0.004). The most strongly associated dosimetric volume was the V15 (Grade 3 esophagitis rates of 15% vs. 64% for V15 <60% versus >= 60%, respectively). Conclusions: RV-AUC is the factor most associated with development of Grade 3 acute esophagitis in limited stage SCLC patients receiving BID-CRT. (C) 2009 Elsevier Inc.