Comparing radiotherapy with or without intracavitary hyperthermia in the treatment of primary nasopharyngeal carcinoma: a retrospective analysis

Aims and background. A retrospective study was performed to evaluate the contribution of intracavitary hyperthermia in patients with nasopharyngeal carcinoma who received radiation therapy. Methods and study design. Patients with nasopharyngeal carcinoma were treated with radiotherapy alone or with radiotherapy plus hyperthermia of the primary tumor. All patients were treated in a uniform fashion by definitive-intent radiotherapy in both groups. In the radiotherapy plus hyperthermia group, patients were treated with microwave heating hyperthermia delivered twice a week in combination with radiation. Results. Between November 1992 to September 1994, 225 patients were recruited, with 98 patients matched to the criteria of either treatment group (49 in the radiotherapy and 49 in the radiotherapy plus hyperthermia group). Ninety-eight patients were included in the treatment response and 87 patients in the survival analysis according to the intent-to-treat principle (11 patients were lost to follow-up). Overall survival did not show a significant difference between the two groups (81 vs 86 months of median survival time, respectively, P = 0.068). However, there were significant differences not only in progression-free survival (median months, 60 vs 100, respectively, P = 0.036), but also in local progression-free survival (median months, 54 vs 111, respectively, P = 0.029) between the radiotherapy and radiotherapy plus hyperthermia groups. No statistical difference was noted in the cumulative incidence of grade 3 adverse events or late radiation morbidity during follow-up between the two study groups. Conclusions. The retrospective study showed that hyperthermia combined with radiation therapy can improve progression-free survival and local progression-free survival, although no increase in overall survival was observed. Thus, the inclusion of hyperthermia in the treatment of nasopharyngeal carcinoma using radiation offers no survival benefit but may help to improve the current standard of care consisting of radiation and chemotherapy.