Background and purpose: This lecture is given on behalf of my former Lyon Sud Radiotherapy department (Dr P. Romestaing) and of the Radiotherapy Department of Centre Antoine-Lacassagne in Nice (Dr A. Courdi) without which it would have been impossible to produce any original clinical data. The major benefit from radiotherapy (RXT) in oncology can be summarized with 3 'C': cure-cost effectiveness-conservative treatment.
Patients and methods: Rectal cancer illustrates the hypothesis that radiotherapy can increase the chance of conservative treatment (with sphincter preservation SP). Sphincter preservation is a complex process, and only randomized trials can be used to see if preoperative treatment can increase SP.
Results: Different phase III trials have shown that: preoperative RXT is superior to postop RX (local control--toxicity--SP), preoperative RXT with immediate surgery does not increase SP, preoperative RXT with delayed surgery increases SP, concurrent chemotherapy with RXT has not yet proven to increase SP, important dose escalation (90 Gy) with contact X-ray RXT increases complete clinical tumor response and SP.
Conclusions: The surgeon is the key person for the cure of rectal cancer and mainly responsible for the decision of sphincter preservation. The experience gained with contact X-ray therapy stresses the importance of a complete clinical tumor response before surgery to increase the chance of sphincter preservation. 'High dose small volume' RXT is a key factor to achieve such a complete clinical tumor response.