Clinical analysis of combination of (252)Cf neutron intracavitary brachytherapy and external beam radiotherapy for 110 cervical cancer patients

Abstract

To evaluate the curative effect and complication of (252)Cf brachytherapy on cervical cancer. From Nov 2002 to Nov 2007, 110 cervical cancer patients were treated by combination of (252)Cf neutron intracavitary brachytherapy and external beam radiotherapy. There were 2 cases of stage Ib, 5 stage IIa, 57 stage IIb, 2 stage IIIa, 41 stage IIIb, 2 stage IVa, and 1 stage IVb. The whole pelvic cavity was irradiated with 8 MV X-ray, 1.8 Gy/fraction, 4 - 5 times per week. The total dose of external beam radiotherapy was 40 - 50 Gy (the center of whole pelvic field was blocked by 4 cm in width after 20 - 30 Gy). (252)Cf neutron intracavitary brachytherapy was delivered at 6 - 8 Gy(i)/fraction, and the total dose of reference point A was 30-51 Gy(i). The median dose was 42 Gy(i). The overall 3-year survival rate of all patients was 79.2%, and the local control rate was 90.0%. In particular, the 3-year survival rate was 1/2 for stage I, 84.3% for stage II, 53.7% for stage III. The difference between stage II and stage III was statistically significant (P < 0.05). The 3-year survival in cervical lesions larger than or equal to 4 cm and those less than 4 cm was 68.1% and 71.2%, respectively (P > 0.05). The 3-year survival rate of patients with and without anemia was 42.4% and 78.2%, respectively (P < 0.05). The 3-year survival rate of patients with squamous cell carcinoma and adenocarcinoma was 78.5% and 76.9%, respectively (P > 0.05). The late radiation complications of rectum and bladder was 11.8% (13/110) and 2.7% (3/110), respectively. It is concluded that (252)Cf is a better source for intracavitary brachytherapy. According to our initial experience, (252)Cf has advantages of a high local control rate, especially to bulky tumor and adenocarcinoma.