Search

Small intestine injury causes long-term suffering and high mortality. Five of 187of our patients had developed serious small intestine injury. Four patients had corrective surgery. Three patients died. All were women. Subsequently, all patients who received definitive pelvic irradiation had small intestine roentgenograms to determine itslocation and mobility. Female patients, thin patients, and elderly patients had larger amounts of small intestine in the whole pelvis, a deeper cul de sac, and a greater incidence of relatively immobile small intestine. Patients with relativelyimmobile small intestine in the treatment field may be predisposed to injury. There wasno relationship of the incidence of relatively immobile small intestine to prior pelvicsurgery. We used the findings from the small intestine roentgenograms to modify indiviually the radiotherapy regimen so as to minimize the risk for small intestine injury. Patients were placed in the prone position to displace the small intestineout of the treatment fields used for booster dose irradiation. The treatment field wasmodified to exclude the small intestine. The total tumor dose delivered was determinedby expectations for curve vs. complications. To date, none of the patients in this study group has developed small intestine injury. Cadaver studies showed the feasibility of elective shortening of the pelvic cul de sac. The small intestine can be displacedaway from the bladder, prostate, or cervix.

Between 1975 and 1977, 74 patients had roentgenographic studies of the small intestine to determine the anatomic relationship of the small intestine to the pelvic portal and to the booster portal. Digital examination, contrast cystography and ultrasound B scans were used to delineate the prostate carcinoma. The small intestine was observed to be at the level of the superior extent of the prostate carcinoma in 19 patients and overlapped the prostate carcinoma in 10 patients. Booster portal size was determined by consideration for tumor control, cure and complication. Therapeutic efforts to reduce tumor size prior to booster irradiation included hormone therapy and whole pelvic irradiation. A “shrinking” field could then be used in patients at risk for small intestine injury. Recognition of the relative position of the terminal Ileum to the pelvic portal was important for patients who undergo surgery after irradiation. Inadvertent injury can be avoided. Since initiation of this study no patient has developed small intestine injury. Tumor control rates remain constant.