756 Rectal balloon for CT of rectal cancer clinical applications and methods

Abstract

CT plays an important role for the pre-surgical evaluation of rectal cancer, both for staging versus RT and for planning the operation. Pelvic scans provide the surgeon with a complete, readable map of the anatomy. The aim of the study is to optimise the protocol for CT of rectal cancer. The luminal distension of visceral wall has been obtained in a clean, well tolerable way by using a balloon catheter filled with water. The catheter is positioned in the rectum at the level of the neoplastic lesion. It consists of a 20 cm long latex balloon 6 cm in diameter, assembled over 12F double-way polyethylene catheter: one to inflate the balloon, the second for a guidewire, both for giving stiffness to the system, to advance it and to make the catheter radiopaque to evaluate the correct positioning by CT Fluoroscopy or Scout View. The balloon in gently injected with water, monitoring the degree of distension on minimal discomfort complained by the patient. Optimal distension is usually obtained by injecting 100–200 ml of water. The patient decubit is determined by the position of the lesion leaving it sloping. The scans are performed by a General Electric Pro Speed. After the exam without contrast, 80 ml bolus of lopamidol 370 is injected in 60′. CT with the rectal balloon allows a precise evaluation of a series of parameters important for the pre-surgical staging: the distance between anal sphincters and tumor, extension of the tumor and the invasion of perirectal fat and surrounding structures, lymphnodes metastases. The execution of this exam is simple and clean. Rectal distension is well tolerated by patients, without complaints as when entire colon is involved. Avoiding the injection of contrast material in the colon, the CT doesn’t interfere with other exams that can be executed on the same day. The quality of images allows a high diagnostic accuracy.