Purpose: To improve the treatment results of locally advanced non-small cell lung cancer (NSCLC), we have been conducting a clinical trial using regional hyperthermia combined with radiotherapy.
Methods and materials: Between 1985 and 1990, 19 patients were treated. All cases except one were regarded as initially unresectable. There were 10 Stage IIIA cases and nine Stage IIIB cases. In 10 cases thermoradiotherapy was used definitively, and in the other nine cases preoperatively. Radiotherapy was administered with conventional fractionation. Total dose ranged from 42 to 80 Gy (mean 62.9 Gy) for definitive treatment cases, and 38 to 47 Gy (mean 40.6 Gy) for preoperative cases. Radiofrequency (RF) capacitive hyperthermia was administered twice weekly, immediately after radiotherapy. Total sessions of hyperthermia ranged from 5 to 16 times (mean 9.0) for definitive treatment cases and 3 to 8 times (mean 6.7) for preoperative cases.
Results: The results of thermoradiotherapy group (HTRT group) were compared with our historical control group (RT group); initially unresectable Stage III NSCLC irradiated definitively with 50 Gy or more (26 cases), or became resectable after radiotherapy and operated (4 cases). As for initial response, there were 5 complete responses (CRs), 13 partial responses (PRs), and 1 no change (NC) (CR rate 26%, response rate 95%) in the HTRT group, whereas there were no CR, 21 PRs, and 9 NCs in the RT group (CR rate 0%, p < 0.005, response rate 70%, p < 0.05). Overall 3-year local relapse-free survival and survival rate for the HTRT group was 73% and 37%, respectively, and 20% and 6.7%, respectively, for the RT group (p < 0.01, p < 0.01). The rate of death from uncontrolled primary disease for the HTRT group was significantly lower than for the RT group (21% vs. 53%, p < 0.03).
Conclusion: Although the number of cases is rather small, thermoradiotherapy in the treatment of locally advanced NSCLC is promising in raising resectability, local control, and, thus, long-term survival.