The role of radiotherapy in the management of pelvic recurrence of rectal cancer.

Unresectable pelvic recurrence from carcinoma of the rectum becomes invariably symptomatic. While radiotherapy remains the most common antineoplastic modality used for palliation of symptoms, the optimal radiation dose and fractionation remains undefined. A systematic review of the literature was performed to determine the most effective dose fractionation schedule for the relief of symptoms in patients with pelvic recurrence. An expert panel reviewed and interpreted the data, with a special focus on indications, effectiveness, optimal dose fractionation, and toxicity of radiotherapy in this context. Only retrospective data (level V evidence) were available on this issue and were reviewed. Pain relief was the major indication for treatment, although bleeding and mucous discharge were also seen as indications for radiotherapy. Initial pain relief appeared to be achievable in 70-90% of patients. The median duration of pain relief was approximately three months, 23-50% of patients had symptom control at six months. The value of "local control" as a meaningful additional endpoint was discussed. There were no significant differences observable in initial symptom response and the proportion maintaining a response at six months, within the range of doses employed, comparing "lower" versus "higher" doses (using 45-50 Gy as the dividing dose). Toxicity was usually evaluated qualitatively and was deemed acceptable. The expert panel agreed that pelvic radiotherapy has a definite value in the relief of symptoms in patients with pelvic recurrence from rectal carcinoma. The optimal dose fractionation in this context could not be determined in view of the quality of the data available. Well designed, randomized studies with clinically relevant study arms and endpoints are necessary to define an optimal dose fractionation against which alternative strategies can be compared.