An audit and evaluation of bladder movements during radical radiotherapy.

With the introduction of the conformal approach for radical radiotherapy for prostate cancer, there has been renewed interest in the movement of the prostate and other pelvic organs during the course of radical pelvic radiotherapy. Many patients reviewed during a course of radical radiotherapy for bladder carcinoma have urinary flow symptoms, which may suggest impaired bladder emptying. There is concern, therefore, that the bladder volume may increase during such treatment, leading to inadequate coverage of the bladder by the planning target volume. We used serial CT scans to assess bladder size in 20 patients during the course of radical bladder radiotherapy. Our results showed that there was little variation in the left to right direction and, in 12 of the 20 patients studied, the anteriorposterior (AP) movement was < 1 cm. The bladder dome rose out of the treatment field in two patients during the course of therapy. However, in 16 patients, the target volume was encompassed as planned throughout.