Task: Answer Verification
Input (English): Question: Are rigid sigmoidoscopy and MRI interchangeable in determining the position of rectal cancers?
Answer: 1) MRI and sigmoidoscopy are not interchangeable in determining the distance from anus to tumour simply by correcting for the length of the anal canal. It has not been determined if measurements from MRI or sigmoidoscopy are more accurate, but current evidence concerning the effect of neoadjuvant irradiation at different positions in the rectum is based upon rigid sigmoidoscopy. 2) The gain in tumour free distance above the anus induced by neoadjuvant treatment is small. Facilitation of sphincter-saving surgery should not be an argument for neoadjuvant treatment.
Output (English): no