Purpose: To evaluate the feasibility and toxicity of three-times-daily radiotherapy (3tdRT), preceded by induction chemotherapy (iCT), in stage IIIA-IIIB non-small cell lung cancer (NSCLC).
Patients and methods: iCT consisted of three cycles of cisplatin and gemcitabine. Surgery was considered for stage IIIA patients responsive to iCT; definitive or postoperative 3tdRT was planned. Doses of 54.4 Gy and 64.6 Gy in postoperative and definitive treatments, respectively, were delivered in three daily fractions.
Results: From February 1998 to October 2000, 37 patients received 3tdRT as definitive (n = 18) or postoperative treatment (n = 19). Toxicity was limited to RTOG grade 2 (25 patients, 67.6%) and grade 3 (four patients, 10.8%) acute esophagitis; no grade 3 late esophagitis occurred. Late lung toxicity was represented by one grade 3 pneumonitis. No correlation emerged between acute esophageal toxicity and irradiated esophageal volume or disease- and treatment-related factors. A significant correlation was found for stage (IIIA vs. IIIB; p = 0.03) and a trend for the N-class (N2 vs. N3; p = 0.08).
Conclusion: In this experience of 3tdRT preceded by iCT, the low toxicity profile confirmed the feasibility of this combination. The limited statistical power does not permit a definition of predictors for radiation-induced esophagitis incidence and severity; additional studies are required to clarify the impact of volumetric and dosimetric parameters. Failure patterns and survival results are warranted to confirm the efficacy of this approach in locally advanced NSCLC.