A team from Leeds, England, evaluated the role of pre-operative magnetic resonance imaging (MRI) in the management of rectal cancer.
They assessed whether body coil MRI could pre-operatively stage mural penetration, nodal status, and circumferential resection margin (CRM) involvement of rectal cancer.
Between 1995 and 1997, MRI using a body coil was performed in consecutive patients with primary rectal carcinomas.
The patients were divided into two groups.
In the first, 67 subjects underwent surgery without long-course neo-adjuvant therapy. Predicted tumor stage was compared to the histology of the specimen.
In the second group, 21 patients (with MRI evidence of advanced disease) underwent long-course neo-adjuvant therapy followed by repeat MRI prior to surgery. The second scan assessed response to treatment and likelihood of CRM involvement at subsequent surgery.
The accuracy of pre-operative staging in the group who did not receive neo-adjuvant therapy was as follows: ‘T' stage - 54%, ‘N' stage - 77%, involvement of CRM by tumor - 97%.
|Body coil MRI predicts potential for circumferential resection margin involvement of rectal cancer.|
Amongst the individuals who did receive the long-course neo-adjuvant therapy, the second MRI scan was 95% accurate in predicting CRM involvement by tumor.
Author I. D. Botterill, of the General Infirmary at Leeds, said on behalf of colleagues, "In this study, pre-operative rectal cancer staging with MRI and a body coil lacks accuracy in predicting mural penetration and nodal involvement.
"However, body coil MRI can accurately predict the potential for CRM involvement."
"This technique may help determine which patients require long-course neo-adjuvant therapy," it was concluded.