Relationships between thermal dose parameters and the efficacy of definitive chemoradiotherapy plus regional hyperthermia in the treatment of locally advanced cervical cancer: data from a multicentre randomised clinical trial

Purpose: To evaluate the contribution of the thermal dose parameters during regional hyperthermia (HT) treatment to the clinical outcomes in patients with cervical carcinoma (CC) who received chemoradiotherapy (CRT) plus HT.Materials and methods: Data from a multicentre randomised clinical trial of concurrent CRT+HT vs. CRT alone were used to evaluate the efficacy and safety of this combination therapy in the CC patients. The intrarectal temperatures of patients undergoing HT were recorded. The complete thermal data of 47 (92%) of the 51 patients in the CRT+HT group were available for the thermal analysis. Thus, 47 patients who received CRT+HT were included in the present study.Results: Among the patients who received CRT+HT, a higher CEM43T90 (1min) value (a thermal dose parameter) was significantly associated with better local relapse-free survival in both univariate (p=0.024) and multivariate (p=0.0097) analyses. The disease-free survival of the patients with higher CEM43T90 (1min) values tended to be better in comparison to patients with lower CEM43T90 (<1min) value (p=0.071). A complete response tended to be associated with the CEM43T90 (p=0.056). Disease-free survival, local relapse-free survival and complete response rate for patients with higher CEM43T90 (1) were significantly better than those for patients with CRT alone (p=0.036, p=0.036 and p=0.048).Conclusions: Dose-effect relationships between thermal dose parameters and clinical outcomes were confirmed in the CC patients treated with a combination of CRT+HT. This study also confirmed that HT with lower CEM43T90 is insufficient to achieve a significant hyperthermic sensitisation to CRT.