In the post-radiation patient, late vascular sequelae and fibrosis predispose women to poor tissue healing, such that small tissue injuries could theoretically evolve into much larger ones such as fistulae. We sought to determine if a correlation exists between invasive procedures such as post-treatment biopsies and the subsequent development of gynecologic fistulae.

A retrospective review was performed evaluating all patients treated for cervical cancer at our institution between 1997 and 2010. Biopsies or pelvic surgeries were included if performed within the radiated field, and evaluated in a multivariate predictive model for development of gynecologic fistulae.

Out of 325 total patients, 27 patients with fistulae were identified (8.2%). 14 fistulae (51.9%) were considered toxicity-related, 6 (22.2%) resulted from primary disease, and 7 (25.9%) were attributable to recurrent disease. Eighty-nine patients underwent an invasive procedure (55 biopsies and 34 pelvic surgeries). Recurrent and/or residual cancer was found in 28 (31.5%) specimens, and of the 61 patients who underwent an invasive procedure and were not found to have evidence of recurrent disease, 9 (14.8%) subsequently developed a fistula at a median 3.08 months. An elevated dose of radiation to the rectum (OR 1.001 for dose >72 Gy, p=0.0005), advancing tumor stage (OR 5.38 for stage III, OR 10.47 for stage IV, p=0.0288), and a post-radiation biopsy (OR 5.27, p=0.013) were significantly associated with fistula development.

Performing a biopsy in an irradiated field is associated with a relatively low yield and significantly contributes to the risk for fistula development.