Long-term outcomes of intracavitary hyperthermia in combination with radiotherapy for locally advanced uterine cervical cancer / 中华放射肿瘤学杂志

Objective To evaluate the long-term clinical efficacy and toxicities of combined intracavitary hyperthermia and radiotherapy fur 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-my 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℃. 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,intraeavity 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% vemus32.3% forstage Ⅲ (χ2=7.06,P=0.007) . The 10-year survival was46.5% versus42.6% 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 in5 patients(3.9% ) in RT group and I 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.

Simulation of SAR and temperature distribution for tumor RF thermotherapy with double-frequencies and double-plates / 生物医学工程学杂志

The model establishment and numerical simulation of specific absorption rate (SAR) and the unsteady-state temperature distribution for radio frequency (RF) thermotherapy with double-frequencies and double-plates are presented in this paper. The model can correctly reflect the attenuation of electromagnetic wave in the biotissue. The variation of perfusion with temperature and the lower perfusion in tumor tissue are fully considered in the simulation of unsteady-state temperature profiles. Also presented are detailed analyses and discussions on the characteristics of SAR and temperature profiles, and the effects of the plates location and power as well as of the perfusion on the depth of effective treatment.

Study of a new microwave applicator for hyperthermia treatment of uterocervical cancer / 生物医学工程学杂志

A new microwave applicator for intracavitary hyperthermia treatment of uterocervical cancer has been designed and tested. Compared with the traditional microwave applicators, the exposed inner conductor of this applicator is replaced by a cone-helical antenna with the reflect shade. We confirm that the heat pattern of the applicator is shifted towards the tip in muscle tissue equivalent phantom material. The result indicates that this new applicator may play an important role in clinical use for treatment.

Development of thermal dosimeter for hyperthermia / 医疗卫生装备

To realize temperature real-time control in microwave heat treatment, this paper presents a new type of thermal dosimeter on hyperthermia. The sign of temperature is extracted by mini-thermal-electronic-couple transducer, amplification circuit and main magnifier. The bond of temperature controlling and thermal therapy is achieved, the experimental prototype of thermal dosimeter equipment is developed and clinical experiment scheme is designed. The whole system is simple in structure, high in efficiency and reliability.