Large fraction radiotherapy plus misonidazole for treatment of advanced lung cancer: report of a phase I/II trial.

From August 1978 through December 1979, 51 patients with advanced non-oat cell carcinoma of the lung were enrolled in a Phase I/II trial sponsored by the Radiation Therapy Oncology Group (RTOG) employing misonidazole (a 2-nitroimidazole) as a hypoxic cell sensitizer and radiation. The purpose of this study was to test drug and radiation tolerance and to assess the short term efficacy of this unconventional treatment. Tumor doses of 600 rad wer given twice weekly for three weeks for a total of 3600 rad, preceded four to six hours by misonidazole in a dose of 2 gm/m2 or 1.75 gm/m2, administered orally. Forty-nine patients were evaluable. Serious toxicity from this treatment was rare. Grade 2 or 3 peripheral neuro-toxicity occurred in eight of 24 patients (33%) with drug doses of 2 gm/m2 and in four of 26 patients (15%) who received 1.75 gm/m2. Grade 3 or 4 central nervous system toxicity occurred in two patients. Two patients developed serious late radiation complications: one patient had a transverse myelitis that appeared one year following delivery of 3600 rad to the spinal cord; a second patient developed a tracheoesophageal fistula and pericarditis eight months following treatment. Objective responses were reported in 67% of patients (complete in 18%); 70% of the patients died with a median survival time of nine months. Of 32 patients eligible for 12 month follow-up, 34% survived more than one year. Patterns of relapse after initial treatment and comparison with results from other RTOG trials using conventional fractionation are discussed.