[Role of adjuvant radiotherapy in the treatment of rectal carcinoma].
Radiotherapy (RT) either pre or postoperative is widely accepted as the standard adjuvant treatment in rectal carcinoma invading the perirectal tissues. The main effect of RT was to decrease the incidence of local recurrence by 30%-50%; there was however no evidence of any impact on survival. With preoperative RT a large range of doses was tested; a dose of 35 Gy or more with fractions of 1.8-2.0 Gy five times per week (or a biologically equivalent regimen) is required to affect the local recurrence rate; with postoperative RT a more uniform dose of 45-50 Gy in 5 five weeks was used. Wether RT is better to be given pre or postoperatively has been the object of a continuing debate. The preoperative option seems at present preferable: the main advantages of this option are the lower morbidity and the possible increase of sphincter saving surgery; the availability of the intrarectal imaging modalities made the clinical staging very reliable, eliminating the major concern of preoperative RT represented by the possible overtreatment of early intraparietal tumours. For tumours located in the range of applicability of intrarectal US or MR (extraperitoneal rectum) preoperative RT should be considered the first choice adjuvant treatment. For tumours located in the intraperitoneal part of the rectum postoperative RT, on the basis of pathological staging, is probably preferable. Two randomized trials reported an improvement of the overall survival when postoperative RT was given concomitantly with 5 Fluorouracil but at the expense of a higher morbidity and a lower compliance. The most promising approach to be explored seems therefore the concomitant combination of preoperative RT and 5 Fluorouracil. Future studies should also define the more effective modality of this combination and wether 5 Fluorouracil has to be given alone or combined with other drugs.
Cionini
L
L
Dip. to di Oncologia, Divisione di Radioterapia, Università degli Studi di Pisa.
Mussari
S
S
Panichi
M
M
Galardi
A
A
D006801:Humans; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery