Results following treatment to doses of 92.4 or 102.9 Gy on a phase I dose escalation study for non-small cell lung cancer.

Background And Purpose: The University of Michigan lung dose escalation study has increased the dose of external beam radiation for non-small cell lung cancer based on the volume of normal lung irradiated. The results of patients treated to either 92.4 or 102.9 Gy are reported.

Materials And Methods: Seventeen patients have completed treatment to 92.4 or 102.9 Gy and have been followed for at least 6 months. The treatment planning goal was to minimize the effective volume (V(eff)) of total lung irradiated as computed using the Kutcher-Burman DVH reduction scheme. Dose was escalated independently within each of five V(eff) bins. Toxicity, freedom from local progression (FFLP), overall survival (OS) and cause specific survival (CSS) are reported.

Results: Thirteen patients were Stage I, one was Stage II and three were Stage III. V(eff) ranged from 0.06 to 0.21. The median pretreatment FEV(1) was 1.24 L or 44% of predicted. Median follow-up for survivors was 37.9 months. No patient had significant pulmonary toxicity. One patient each had grades 2 and 3 esophagitis. Median percent change in FEV1 was -11%. Two- and three-year actuarial FFLP and OS rates for the entire group were 68 and 58% and 51 and 26%, respectively. For Stage I patients, the 2 and 3 year FFLP, OS and CSS rates were 82 and 68%, 54 and 33%, 76 and 48% respectively.

Conclusions: These results suggest that doses of radiation of 92.4 and 102.9 Gy can be delivered safely to limited lung volumes with minimal toxicity.