Phase 1/2 Study Finds 2.24 Gy the Maximum Tolerable Level for Treating Non-small Cell Lung Cancer

Using helical tomotherapy, Belgium researchers employed radiation dose escalation to evaluate the toxicity of radiation therapy combined with chemotherapy in treating patients with inoperable, locally advanced, stage III non-small cell lung cancer.

With 34 participants, the phase 1/2 study assessed the maximum tolerated dose (MTD) of radiation that could be administered concurrently with docetaxel and cisplatin, starting at 2 Gy and increasing 6 percent per dose cohort, according to the article “Toxicity Report of a Phase 1/2 Dose-escalation Study in Patients With Inoperable, Locally Advanced Non-small Cell Lung Cancer With Helical Tomotherapy and Concurrent Chemotherapy,” published in the Nov. 13, 2009 issue of Cancer.

No differences in toxicity were observed between dose cohorts until the fraction size reached 2.36, stated Samuel Bral, M.D., et al. The overall incidence of acute grade 3 toxicity was 24 percent for esophageal and 3 percent for pulmonary, with overall late lung toxicity at 21 percent.

“The use of HT to 67.2 Gy with concurrent cisplatin/docetaxel was feasible and resulted in acceptable toxicity,” concluded the authors. “A full phase 2 study has been initiated to establish the true local response rate at the MTD of 2.24 Gy per fraction.”