Asymptomatic Rectal Perforation After Radiation for Rectal Cancer: A Diagnostic Dilemma and Role of MRI
By: Dr. Praveen Kammar
Authors: Suman Kumar Ankati, Reena Engineer, Prachi Patil, Vikas Ostwal, Avanish Saklani
Journal: Annals of Case Reports and Images
Category: Colorectal Surgeries
Start: January 26, 2019
Source : https://www.scitemed.com/article/288/scitemed-acri-2019-00095
DOI : 10.24983/scitemed.acri.2019.00095
Radiation-induced rectal perforation during the treatment of locally advanced rectal cancer (LARC) is very rare. Symptomatic perforation is diagnosed clinically and requires urgent intervention. However, asymptomatic perforation may be found incidentally on imaging and this can be easily confused with residual/progressive disease.
Magnetic resonance imaging (MRI) may help in correct diagnosis and choosing the right line of treatment. Case 1: A 32-year-old gentleman was operated in another centre for upper rectal adenocarcinoma (T3, N0) without adjuvant therapy. He was treated with chemoradiation therapy for anastomotic site recurrence after nine months.
He was referred to our centre for residual presacral disease on computerized tomography. However, MRI of the pelvis showed the mass to be heterogeneous with air pockets on T2 sequence and a fistulous communication between rectal lumen and mass. This indicated complete resolution of recurrence with a perforation at the previous colorectal anastomotic site. Case 2: A 33-year-old lady with mid rectal adenocarcinoma was treated with short course of radiotherapy and systemic chemotherapy at our centre.
On reassessment using MRI, local progression was suspected. But, on careful review of MRI, a tumour site perforation was found, which was communicating with mesorectal fat. She underwent surgery for primary disease and this finding was confirmed intra-operatively.
In conclusion, differentiating rectal perforation from recurrence or progressive disease during radiation for LARC is difficult due to lack of specific imaging characteristics. However, the presence of breach in the rectal wall and fistulous communication between mass and rectal lumen on MRI are confirmatory findings of perforation and thus help in choosing the right treatment.