MRI in predicting curative resection of rectal cancer: Defining a “window of opportunity” for laparoscopic surgery

Over the past three years, our experience has been that, in addition to clinical and sigmoidoscopic examination, serial magnetic resonance imaging can be of value after chemoradiotherapy in documenting an ongoing response beyond the conventional four to six weeks interval before surgery. 2 In 30 consecutive patients with locally advanced rectal cancer, we repeated magnetic resonance scans at four weekly intervals to optimise the timing of surgery at maximal response, the median time for which was 12 weeks (range 8 to 15 weeks).