Carcinoma Rectum :MRI

Discussion by Dr MGK Murthy, Dr GA PrasadMR- useful to assist staging & identify ­ patients who may benefit from preoperative chemotherapy–radiation therapy, and in surgical planning.Currently, surgical resection with stage-appropriate neoadjuvant combined-modality therapy is the mainstay in the treatment of rectal cancer.Total mesorectal excision (TME) has reduced the prevalence of local recurrence from 38% to less than 10%. TME is surgical en bloc resection of the primary tumor and the mesorec ­tum by means of dissection along the mesorectal fascial plane or the circumferential resection margin (CRM) . Even with TME, however, the presence of a tumor or malignant node within 1 mm of the CRM remains an important pre­disposing factor for local recurrence.Randomized trials have shown that combined preoperative radiation therapy –TME reduces the prevalence of local recurrence from 8% to 2% and is superior to postoperative radia­tion therapy alone. Also lone radiation therapy yields little survival benefit and results in significant morbidity when used to treat stage T1 –T2 or favorable-risk early stage T3 tumors (5 mm invasion outside the muscularis propria).Key sequences -Orthogonal,  sagittal and coronal high-resolution T2-weighted imagesof the primary tumor; the mesorectal fascia, peri ­toneal reflection, other pelvic viscera; and superior rectal and pel­vic sidewall lymph nodes. Diffusion-weighted imaging– helpful for iden...
Source: Sumer's Radiology Site - Category: Radiology Authors: Source Type: blogs