In order to lower unacceptably high local failure rates after surgery
reported as curative for rectal cancer, perioperative radiotherapy has
been extensively investigated, The collected information from a numbe
r of controlled trials indicates that the proportion of local recurren
ces is reduced to less than half when radiotherapy at moderately high
doses is given preoperatively, This reduction in local failure rates i
s not seen after postoperative radiotherapy, even if higher doses have
been used, Possibly, there is also a slight positive influence on sur
vival from preoperative radiotherapy, Improved survival has been seen
also in trials using postoperative radiotherapy, but then only when co
mbined with chemotherapy. With proper dose planning, sufficiently high
doses can be given preoperatively with little if any increase in post
operative mortality, Thus, although published knowledge is still rathe
r limited, a properly planned preoperative radiotherapy seems to infli
ct small bowel and other complication rates, that are less than when r
adiotherapy of similar efficacy against the tumour is given postoperat
ively.