Residual, inoperable or recurrent colorectal cancer. Interaction of surgery and radiotherapy.

For irradiation of inoperable, residual or recurrent colorectal cancers, doses of 4,500 to 5,000 rads can achieve short-term palliation; doses must be increased to 6,000 to 7,000 rads or more, however, if long-term control of disease or possible cure is desired. The ability to achieve those dose levels safely depends on close interaction between the surgeon, the radiation oncologist and the diagnostic radiologist in defining and displacing normal and tumor tissues. Methods used at Massachusetts General Hospital from March 1976 to August 1979 are defined. They include the use of operative clips and pelvic reconstruction, diagnostic computed tomography and ultrasound, radiotherapy optimization including shrinking field techniques, radiation with bladder distention and single intraoperative boost doses given in combination with external beam.