Intravaginal brachytherapy for patients with endometrial cancer after surgery-review of technical developments

Abstract

The use of intravaginal brachytherapy as a post-operative procedure to reduce the incidence of reccurence of carcinoma of the endometrium is well known. We analysed 3 differents methods of intravaginal brachytherapy: conventional brachytherapy Ra-226, LDR after-loading technic Cez 137 and HDR after-loading brachytherapy lrydium 192. In the period 1953–1986 in Gynaecological Radiotherapy Department in Poznań, brachytherapy with vaginal applicators containing 30 mg radium, filtrated by 2 mm Pb, were used after total hysterectomy. The given dose was 3000 mgh in 100 hours of one insertion. Since 1986 Caesium 137 in one oblong applicator has been used to fill the vagina. Usualy four sources were employed and treatment time was about 24 hours. On the basis of the radiological verification in two planes, the doses were calculated at 0,5 cm from the applicator surface and at the contact point of the contrast image of the Foley catheter placed in the bladder neck. Dose in the rectum was calculated at the distance shown by a marker situated in the rectum. The patients were treated to the total dose of 30 Gy. From 1995 HDR after-loading inreasingly replaced LDR after-loading in intravaginal brachytherapy. With iridium 192 the overall dose was applied in three fractions-each 6 Gy calculated at 0,5 cm from the surface of the oblong applicator. Complications were graded with EORTC\RTOG criteria.