Radiotherapy planning at rectal cancer

Radiotherapy can be applied more effectively on rectal cancer like other cancers as a result of tecnological advances in radiation oncology. Nowadays, the current approach is conformal tecniques. The target volume and critical organs at risk should be identified according to international criteria by making the best patient simulation. Three-dimensional treatment with multiple fields purposed for rectal cancer radiotherapy. Three fields often used as one posterior and two lateral fields. Four field "box" technique or other techniques are identified according to target volume differences. 45-50.4 Gy radiotherapy at convantional fractionation is required for treatment of microscopic disease. 5.4 Gy boost dose added to tumour or tumour bed by keeping the small bowel outside the high dose volume after 45 Gy radiotherapy to pelvis. The effect of the dose above 50.4 Gy is not clear for local control. The results of new studies should be expected for dose escalation and the use of advanced radiotherapy techniques.