Is Hypofractionated (Chemo) radiation Delivered With Helical Tomotherapy a Feasible Option to Escalate the Dose in Locally- Advanced Inoperable NSCLC?: Results From a Phase 2 Trial

Purpose/Objective(s): To assess treatment outcome, and toxicity after a moderately escalated hypofractionated radiation therapy delivered with helical tomotherapy (HT) in locally advanced stage III inoperable nonsmall cell lung cancer (NSCLC) combined with sequential or concurrent chemotherapy. Materials/Methods: Sixty-one eligible patients were treated with combined platinum-based chemotherapy associated with a moderately escalated hypofractionated radiation course delivered with HT. The treatment schedule consisted of 30 daily fractions of 2.28 Gy each administered in 6 weeks, corresponding to a normalized total dose at 2 Gy per fraction (NTD2) of 70 Gy, applying a/b ratio of 10. The target was considered the gross tumor volume and the clinically proven nodal regions, without elective nodal irradiation. Overall survival and local control were assessed as well as acute and late toxicity using National Cancer Institute Common Terminology Criteria and Adverse Events (CTCAE) version 3.0. Results: No Grade 4 acute and late toxicity was reported. Acute Grade 3 treatment-related pneumonitis was detected in 12% of patients. Two patients, both receiving the concurrent schedule, developed a Grade 3 acute esophagitis. The overall incidence of late Grade 3 lung toxicity was 7%. No patients experienced a Grade 3 late esophageal toxicity. After a median follow-up of 25 months (range, 6-40 months), 2-year local control and overall survival rates were 65% and 53% for all patients, 36% of whom were stage IIIB. The same features for patients who received concurrent chemoradiation were 72% and 56%, respectively. Conclusions: Our findings shows that a moderately hypofractionated radiation course delivered with HT is a feasible treatment option for patients with inoperable locally advanced NSCLC receiving chemotherapy (sequentially or concurrently). Hypofractionated radiation therapy with a dedicated technique allows safely dose escalation, minimizing the effect of tumor repopulation that may occur with prolonged treatment time