Long-term efficacy of microwave hyperthermia combined with chemoradiotherapy in treatment of nasopharyngeal carcinoma with cervical lymph node metastases.

OBJECTIVE The long-term efficacy of microwave hyperthermia combined with chemoradiotherapy in treating nasopharyngeal carcinoma (NPC) with metastatic foci in cervical lymph nodes was evaluated. METHODS A total of 154 cases of N2 or N3 stage NPC were randomized into two groups: hyperthermia group (76 cases) and control group (78 cases). Both received cisplatin chemotherapy and radiotherapy. In addition, the hyperthermia group further received microwave hyperthermia to the metastatic cervical nodes with different patterns (before or after radiotherapy), heating temperatures (T90 < 43° and T90 ≥ 43°) and hyperthermia episodes (< 4 times, 4-10 times and > 10 times). RESULTS The 3-month and 5-year complete response (CR) rates of cervical lymph nodes in the hyperthermia group were significantly higher than those in the control group. The 5-year disease-free survival (DFS) rate and the 3-year / 5-year overall survival rate in the hyperthermia group were also significantly higher. There was no significant difference in 5-year metastatic rates. In the hyperthermia group, the 3-month and 5-year CR rates of T90 < 43° treatment were significantly lower than with T90 ≥ 43° treatment. The CR rate was highest when the hyperthermia was performed 4-10 times. There were no significant differences in 3-month and 5-year CR rates between hyperthermia before or after radiotherapy treatment. CONCLUSION Microwave hyperthermia combined with chemoradiotherapy can increase local control, DFS and 3, 5-year overall survival rates of patients with N2 ~ N3 stage NPC. The heating temperature should be over 43° with hyperthermia repeated 4-10 times.