Prospective evaluation of serial CT findings in detection of local recurrence of rectal carcinoma

Local tumor recurrence following 'curative' surgery for rectal carcinoma remains a difficult problem. In most patients, diagnosis is made when they have pelvic pain and elevation of CEA, and at that time only palliative treatment can usually be given. Computed tomography (CT) is the best method for confirming tumor recurrence. However, when an isolated presacral mass is seen, there is difficulty in distinguishing postoperative fibrosis from local recurrence by only a single CT study. In 26 of 31 patients (83.9%), local recurrence was detected within two years after surgical treatment. From these observations, we performed baseline CT of the pelvis within 2-4 months after surgery, followed by serial CT at 6-month intervals. There are 13 patients for whom at least two serial CT scans were obtained. In two of these 13, local recurrence was detected after the third and fourth CT, respectively, and in one of them total pelvic exenteration could be performed. In the other eleven patients, presacral mass or streaky densities were demonstrated by baseline CT, and these configurations became smaller and sharper. However, it was difficult to distinguish these fibrous masses from local recurrence by a single CT examination. Therefore, serial CT is recommended for the early detection of local pelvic recurrence. (author)