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 treatingnasopharyngeal carcinoma (NPC) with metastatic foci in cervical lymph nodes was evaluated.
Methods: A totalof 154 cases of N2 or N3 stage NPC were randomized into two groups: hyperthermia group (76 cases) and controlgroup (78 cases). Both received cisplatin chemotherapy and radiotherapy. In addition, the hyperthermia groupfurther received microwave hyperthermia to the metastatic cervical nodes with different patterns (before or afterradiotherapy), heating temperatures (T90 < 43°C and T90 ≥ 43°C) and hyperthermia episodes (< 4 times, 4-10times and > 10 times).
Results: The 3-month and 5-year complete response (CR) rates of cervical lymph nodesin the hyperthermia group were significantly higher than those in the control group. The 5-year disease-freesurvival (DFS) rate and the 3-year / 5-year overall survival rate in the hyperthermia group were also significantlyhigher. There was no significant difference in 5-year metastatic rates. In the hyperthermia group, the 3-monthand 5-year CR rates of T90 < 43°C treatment were significantly lower than with T90 ≥ 43°C treatment. TheCR rate was highest when the hyperthermia was performed 4-10 times. There were no significant differencesin 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-yearoverall survival rates of patients with N2 ~ N3 stage NPC. The heating temperature should be over 43°C withhyperthermia repeated 4-10 times.