16 Cervix Carcinoma

Cervix Cancer 315

In the early 1950s, Fletcher developed a system for radium that combined a rigid metallic intrauterine tandem with cylindrical colpostats; the latter are positioned against the cervix, perpendicular to the axis of the vagina (35). Subsequently, this system was modified by Delclos and Suit for manual afterloading and then for remote afterloading (Fletcher-Suit-Delclos applicator (22)). Later, a European version was proposed by Horiot (54) to be adapted to the use of cesium sources and different afterloading machines. The intrauterine tandem is available in a variety of curvatures. The length can be adjusted by positioning an adjustable flange. The cylindrical colpostats are 2 cm in diameter but can be enlarged by the addition of caps to 2.5 or 3.0 cm diameter (Fig 14.7). Tungsten shielding is integrated into the anterior and posterior part of the standard colpostats to reduce the dose to bladder and rectum. The tandem and colpostats are selected to conform to the tumor volume and topography and the individual patient’s anatomy. The position of the applicator is maintained by vaginal packing which is also used to reduce the dose to the bladder and rectum. Because the Fletcher-Suit-Delclos applicator allows independent positioning of the uterine tandem and ovoids, source positions can be readily adapted to different anatomical and pathological situations (4,35,54). 7.4 “Stockholm” based techniques (8,115) The classical “Stockholm method” was based on a flexible intrauterine tube and a flat box (plate) in the vagina pushed by an individual packing device against the cervix. The tube and the box were implanted independently of each other. Therefore no fixed geometry was present. The rigid uterine tandem with a ring applicator was developed during the 1960ies as an afterloading device (115), first for Cesium-137 sources, and then also for Iridium-192. Fig 14.8: Stockholm based Technique

Fig 14.8A: Classical metallic ring applicator set (A) which is available for an Iridium and a Cesium source. The different lengths and angles of the intrauterine tube are demonstrated (B). The ring is available in different diameters (26, 30, 34 mm diameter source-source position) and the intrauterine tube in different lengths (20, 40, 60, 80 mm) (B). Acrylic caps cover the ring tube to reduce the dose to the vaginal mucosa. The ring and the intrauterine tube are fixed to each other with a screw. A rectal retractor is also shown which can be additionally used (Nucletron ®).