Long-term outcomes of intracavitary hyperthermia in combination with radiotherapy for locally advanced uterine cervical cancer

Objective: To evaluate the long-term clinical efficacy and toxicities of combined intracavitary hyperthermia and radiotherapy for locally advanced uterine cervical cancer. Methods: 310 patients with locally advanced uterine cervical cancer were assigned into intracavitary hyperthermia + radiotherapy group(TRT, 181 patients) and external-beam radiotherapy + traditional intracavitary radiation group (RT,129 patients). The external-beam radiotherapy were given with 60Co γ-ray or 6-8 MV X-ray in traditional fractionation. In TRT group, radiotherapy was 40 Gy using the anterior-posterior pelvic fields and additional 20-25 Gy using the lateral fields. Hyperthermia was delivered by the 915 MHz microwave hyperthermia device within 15-60 min after external radiotherapy for 10-12 times(40 min each time, 1-2 times per week). The temperature of tumor surface was 46-47 degree C. In the RT group, the external-beam radiotherapy of 40 Gy was delivered using the anterior-posterior pelvic fields. The intracavity radiotherapy of radium was delivered before 1989, with 50 mg radium in the vagina and 30 mg in uterine cavity for 24 hours, weekly for 3 times to a total dose of 7200 mg·h. After 1989, intracavity radiotherapy of 192Ir was delivered to a total dose of 30-36 Gy to point A in 5-6 Gy fractions, 2 fractions per week. Results: The 5-year survival of patients in TRT group and RT group was 67.4% versus 52.1% for stage II disease (χ2=7.55, P=0.006), and 60.0% versus 32.3% for stage III (χ2=7.06, P=0.007). The 10-year survival was 46.5% versus 42.6% for stage II (χ2=3.90, P=0.058), and 43.7% versus 20.6% for stage III (χ2=17.28, P=0.000). Cox regression analysis showed that the tumor stage(P=0.023) and intracavitary hyperthermia (P=0.019) were prognostic factors. According to the RTOG criteria, the rate of mild to moderate late side effects of rectum and bladder in TRT and RT group was 17.7% and 33.1%, respectively (χ2=9.18, P=0.002). Rectovaginal fistula was developed in 5 patients (3.9%) in RT group and 1 patient (0.6%) in TRT group (χ2= 4.38,P=0.036). Conclusions: The long-term survival of patients with stage III uterine cervical cancer is better of TRT group than RT group. The TRT is well tolerated and the late toxicity rate is obviously low. it is necessary to carry out large randomized clinical trials to confirm these outcomes. (authors)