22 Penis Cancer

Penis Cancer 483

7.2

Interstitial brachytherapy

7.2.1 Classical method After many decades of radium-needle implants, the first modern technique was described by the IGR group of Pierquin and Chassagne during the sixties. (5,10,14,27) This classical procedure is based on the use of hypodermic needles manually afterloaded with iridium wires. After healing of the previous circumcision, the implant is performed under general or spinal anaesthesia. A Foley catheter is inserted to determine the exact position of the urethra to avoid implantation of the urethra by the needles. The urinary catheter stays in place during the whole irradiation. After precise evaluation of the target volume, hypodermic needles are implanted through the glans, perpendicularly to the axis of the penis. The lengths of the needles and the distance in between are adapted to the target volume respecting the rules of the Paris System. During the placement of the needles, two lucite plaques are prepared in the operating room itself. These handmade templates are adapted to each implant. Size, shape and distance of perforations in the template are pre-determined according to the position of the needles. The needles are introduced into the corresponding holes of the plaques (Fig 21.4). In order to maintain these two templates in parallel to each other, plaster strips are inserted around them between the needles.

Fig 21.4 : Pierquin-Chassagne applicator. Finally, a sponge, which is perforated to slide over the penis, is fastened in place in the prepubic area to immobilize the penis and to keep the radioactive material away from the testis. This interstitial technique using hypodermic needles has become classical. Its merits have been proven by the good results obtained from hundreds of patients treated with this method. Nevertheless, this is a protracted and detailed technique, not always easy to administer and it involves risks of sepsis. The preparation of the plates of plexiglas and the application of the plaster strips are potential sources of infection. Strict parallelism of the needles is not always possible and is difficult to maintain throughout treatment. Distortion of the apparatus can occur, resulting in loss of parallelism of the radioactive lines. Such

distortion can also cause discomfort and pain. An improved system was therefore developed.