The pelvis after surgery for rectal carcinoma: serial CT observations with emphasis on nonneoplastic features

Abstract

Ten asymptomatic patients who had undergone resection of rectal carcinoma were evaluated prospectively by at least three serial computed tomographic (CT) examina tions of the pelvis within 24 months of surgery. Of the seven patients who had undergone abdominoperineal resection, five were found to have a presacral mass due to normal postoperative changes within the first 4 months. The mass showed a variable diminution between 4 and 9 months after operation and developed a more distinct outline, partial separation from the sacrum, or a change in configuration to a thin transverse sliver. These changes indicate the possibility of CT differentiation of a normal postoperative mass from local recurrence. In the other five patients, no post operative mass was observed. In one patient CT demonstrated a solitary 1.5 cm lymph node metastasis. This patient was asymptomatic and had a normal carcinoembryonic antigen level. From these observations, a baseline CT study of the pelvis within 2-4 months of resection of rectal carcinoma, followed by serial CT examinations at about 6-month intervals is recommended for the detection of early asymptomatic pelvic recurrence and to facilitate differentiation from persistent postoperative changes. Received February 23, 1983; accepted after revision July 13, 1983. The clarity with which CT can demonstrate pelvic anatomy suggests that it may be capable of detecting small recurrences before the development of symptoms.This potential led us to institute a prospective study involving serial CT exami nations of the pelvis in asymptomatic patients after resection of rectal carcinoma.In several of the patients in this study, a nonneoplastic mass in the presacral operative bed was detected by CT. Authors previously have noted the difficulty of distinguishing such a mass after abdominoperineal (AP) resection from local pelvic recurrence on the basis of a single CT study [6,8]. We describe the AJR 141:959-964,

Consensus statement on the multidisciplinary management of patients with recurrent and primary rectal cancer beyond total mesorectal excision planes

“…Radiological detection of locally recurrent disease can be challenging. A soft tissue mass may persist in the pelvis for 24 months or more following surgery in the absence of recurrence, and this appearance is enhanced by previous radiotherapy or pelvic sepsis due to postoperative anastomotic leakage. Recurrence may be suspected by changes detected over serial scans, and CT‐guided biopsy of accessible suspicious areas may be possible.…”

The Role of Positron Emission Tomography in the Management of Recurrent Colorectal Cancer: A Review

“…Computer tomography imaging often is sup- plemented with information from MRI and/or endoluminal ultrasound scans in addition to clinical examination and endoscopy. Initially it was reported that MRI had a greater ability to differentiate between scar and tumor recurrence than CT [42][43][44][45][46] ; however, more recent results have raised doubts about these findings. 47,48 CT and MRI are both accurate at detecting pelvic masses after colorectal surgery, but they often are unreliable in distinguishing between scar and tumor recurrence.…”

CT of radiatioe-indeced injury of the gastrointestinal tract spectrum of findings with barium studies correlation

“…The mass is usually located in the midline and homogeneous in density on CT, and does not increase in size with time. The CT criteria that suggest recurrent cancer include invasion of adjacent structures, increased size, heterogeneity of the contents of the mass, asymmetry, associated lymphadenopathy and peritoneal carcinomatosis [9]. In this regard, imaging techniques can provide useful information, and particularly CT imaging, which allows a complete assessment of the pelvis, including clinically inaccessible areas.…”