Peroperative transperineal brachytherapy for recurrent pelvic malignancies

Recurrent pelvic malignancies represent often a challenge to the therapist due to the limited efficacy of most classical treatment especially in case of prior radiation or lateral extension. Moreover, a surgical resection such as a total pelvic exenteration is only recommended for central recurrence due to the severe mutilation. An innovative approach combining transperineal brachytherapy (BT) with rigid templates and peroperative BT with plastic tubes was developed for the treatment of pelvic recurrence. Plastic tubes were placed during surgery using hollow perineal needles. The laparotomy offers the possibility of a perfect visualisation of the target area to be implanted. Furthermore, a debulking of the tumor mass is possible, limiting the residual volume to be treated. One week after surgery, the loading with 192iridium wires is performed after simulation and dosimetry CTscan. Computed dosimetry is obtained by means of orthogonal radiographs and isodoses are superimposed on the CTslices. Since december 1994, 3 patients were treated for a pelvic relapse of a cervix cancer (2pts) and a sigmoidal cancer (1ppt) to test the feasibility of this approach. Two patients had an history of pelvic irradiation. The third patient was treated with an implant after 40 Gy external beam radiotherapy. A total dose of 60 to 80 Gy was delivered with this technique to a volume ranging from 15 to 24 cm3. One patient had an acute urethritis and another developed a vesicovaginal fistula after a biopsy performed for a slight irregularity of the vaginal mucosa in the highly irradiated area. One relapse in the implanted area is reported within this period of observation. Additional follow up and experience is required to assess the real efficacy of this method. Nevertheless, this approach offers a good alternative for patients relapsing in the pelvis especially in already irradiated area with a good acute and late tolerance and a satisfactory implantation technique