Intravaginal high-dose-rate brachytherapy for stage I endometrial cancer: a randomized study of two dose-per-fraction levels.
OBJECTIVE
To compare two different fractionation schedules for postoperative vaginal high-dose-rate (HDR) irradiation in endometrial carcinomas.


METHODS
In a complete geographic series of 290 low-risk endometrial carcinomas, the efficacy and side effects of two different fractionation schedules for postoperative vaginal irradiation were evaluated. The patients were treated during the years 1989-2003. The tumors were in International Federation of Gynecology and Obstetrics Stages IA-IB and Grades 1-2. The HDR MicroSelectron afterloading equipment (iridium-192) was used. Perspex vaginal applicators with diameters of 20-30 mm were used, and the dose was specified at 5 mm from the surface of the applicator. Six fractions were given, and the overall treatment time was 8 days. The size of the dose per fraction was randomly set to 2.5 Gy (total dose of 15.0 Gy) or 5.0 Gy (total dose of 30.0 Gy). One hundred forty-four patients were treated with the 2.5-Gy fraction and 146 patients with the 5.0-Gy fraction.


RESULTS
The overall locoregional recurrence rate of the complete series was 1.4% and the rate of vaginal recurrences 0.7%. There was no difference between the two randomized groups. The vaginal shortening measured by colpometry was not significant (p = 0.159) in the 2.5-Gy group (mean, 0.3 cm) but was highly significant (p < 0.000001) in the 5.0-Gy group (mean 2.1 cm) after 5 years. Mucosal atrophy and bleedings were significantly more frequent in the 5.0-Gy group. Symptoms noted in the 2.5-Gy group were not different from what could be expected in a normal group of postmenopausal women.


CONCLUSIONS
The fractionation schedule recommended for postoperative vaginal irradiation in low-risk endometrial carcinoma is six fractions of 2.5 Gy when the HDR technique is used.
Sorbe
Bengt
B
Department of Gynecological Oncology, Orebro University Hospital, Orebro, Sweden. bengt.sorbe@orebroll.se
Straumits
Andris
A
Karlsson
Leif
L
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D018269:Carcinoma, Endometrioid / Q000473:pathology / Q000532:radiotherapy*; D019583:Dose Fractionation, Radiation; D016889:Endometrial Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies