[Computed tomographic evaluation of thickness of perirectal fascia in rectal cancer treated by preoperative radiotherapy--diagnostic value for prediction of local recurrence].

Perirectal fascia was examined by computed tomography before and after preoperative radiotherapy in thirty-six patients with rectal cancer. CT measurement showed that perirectal fascia tend to increase in thickness during preoperative radiotherapy in proportion to tumor extension into perirectal fat tissue. The fascial thickening more than 7 mm after preoperative radiotherapy was suggestive of local recurrence to develop. Preoperative or intraoperative boost irradiation would be recommended for such high-risk patients.