Comparison of 2 common radiation therapy techniques for definitive treatment of small cell lung cancer

Purpose: Two choices are widely used for radiation delivery, 3-dimensional conformal radiation therapy (3DCRT) and intensity modulated radiation therapy (IMRT). No randomized comparisons have been conducted in the setting of lung cancer, but theoretical concerns suggest that IMRT may negatively impact disease control. We analyzed a large cohort of limited-stage small-cell lung cancer (LS-SCLC) patients treated before and after institutional conversion from 3DCRT to IMRT to compare outcomes. Methods and Materials Patients with LS-SCLC treated with definitive radiation at our institution between 2000 and 2009 were retrospectively reviewed. Both multivariable Cox regression and propensity score matching were used to compare oncologic outcomes of 3DCRT and IMRT in the context of other clinically relevant covariables. Acute and chronic toxicities associated with the 2 techniques were compared using Fisher exact and log-rank tests, respectively. Results A total of 223 patients were treated during the study period, with 119 receiving 3DCRT and 104 receiving IMRT. Their median age was 64 years (range, 39-90 years). Median follow-up times for 3DCRT and IMRT were 27 months (range, 2-147 months) and 22 months (range, 4-83 months), respectively. Radiation modality was not associated with differences in overall survival or disease-free survival in either multivariable or propensity score-matched analyses. IMRT patients required significantly fewer percutaneous feeding tube placements (5% vs 17%, respectively, P=.005). Conclusions IMRT was not associated with worse oncologic outcomes than those of 3DCRT. IMRT was associated with a lower rate of esophagitis-related percutaneous feeding tube placements.