Intraoperative radiation therapy in the management of gynecologic and genitourinary malignancies

Abstract

Women with locally advanced primary or recurrent gynecologic malignancies have a poor prognosis. The doses of external radiation necessary to treat gross or microscopic recurrent disease in patients previously irradiated exceed the doses tolerated by normal tissue [1,3-5]. IORT has been added to the treatment armamentarium in this group of patients to maximize local control and minimize the radiation exposure to dose-limiting surrounding structures. In addition, IORT may improve the long-term local control and the overall survival rates in women with pelvic sidewall or para-aortic nodal recurrence [1,4,5]. The most encouraging results are seen in cases of microscopic residual disease following surgical debulking [4,6]. In gynecologic malignancies, IORT has served to reiterate the importance of optimal surgical resection. Higher 5-year disease-free and overall survival rates have been documented in women who have microscopic residual disease, compared with those who have gross residual disease [1,3-6]. IORT in the management of GU malignancies has not been used extensively. In RCC, where surgery alone often results in suboptimal treatment results, IORT seems to be well tolerated and controls local disease [2,27,29,30]. Because of the chemoresistant nature of RCC, IORT may play an important role in the future in the management of locally advanced and recurrent RCC. In bladder cancer, IORT had been used in combination with chemotherapy and EBRT, as part of bladder-sparing protocols. The data suggest that IORT in this patient population is also well tolerated, and may become more widely used as less radical surgical procedures gain clinical importance. IORT in the treatment of prostate and testicular cancers has not been used frequently, given the highly efficacious treatment modalities currently available to treat these malignancies. A review of institutional experiences with IORT may allow the establishment of guidelines for patient selection. These criteria, in turn, may be useful in the design of clinical trials. The construction, execution, and evaluation of clinical trials are mandatory to adequately assess the role of IORT in the treatment of patients with gynecologic and GU malignancies.