Hye Jin Kim MD, Presenter: Nothing to Disclose

Seong Ho Park MD, Abstract Co-Author: Nothing to Disclose

Seung Soo Lee MD, Abstract Co-Author: Nothing to Disclose

Ah Young Kim MD, Abstract Co-Author: Nothing to Disclose

Hyun Kwon Ha MD, Abstract Co-Author: Nothing to Disclose

To retrospectively determine the diagnostic yield of CT colonography (CTC) in postoperative colorectal cancer (CRC) patients without apparent clinical evidence of recurrence/metastasis.

Over a two-year period, 747 consecutive patients (421 men, 326 women; mean age, 59 years) who had undergone curative surgery for CRC and were referred for abdominopelvic CT for routine surveillance without apparent clinical evidence of recurrence/metastasis, underwent CTC. Time interval between the surgery to CTC ranged from 6 to 59 months (mean time, 28 months). CTC was performed after fecal tagging with 5% w/v barium, colonic purgation with magnesium citrate and bisacodyl, and intravenous contrast enhancement. Colon was examined with primary 3D review. Any types and sizes of morphologic abnormalities in the anastomosis were reported, whereas lesions ≥6 mm were only reported in the non-anastomotic sites. Extracolic abnormalities were evaluated on 2D images. Diagnostic yield and positive predictive value (PPV) were obtained.

Anastomotic abnormalities were identified at CTC in 35 (4.7 %) of 747 patients. Concordant lesions were identified in 16 of 22 patients who underwent subsequent optical colonoscopy (OC), resulting in PPV of 72.7%. Inflammatory/granulation polyp was the most common anastomotic abnormality seen in 15 patients, whereas recurrent cancer was noted in one patient. In the non-anastomotic sites, ≥6 mm lesions were identified at CTC in 88 (11.8 %) of 747 patients. Concordant lesions were identified in 45 of 69 who underwent subsequent OC, resulting in PPV of 65.2%. Of those, metachronous neoplastic lesions and cancers were present in 38 and 5 patients, respectively. Metachronous cancers measured 8 to 17 mm. Distant metastasis was found in 17 (2.3 %) of 747 patients.

CTC detected a considerable number of unsuspected additional cancer lesions compared to abdominopelvic CT in postoperative CRC patients, demonstrating 35.3% (6/17) increased detection of patients with cancer lesions. Prospective studies to determine its cost-effectiveness, influence on patient survival, and combined use with OC in postoperative surveillance are warranted.

CTC detects a considerable number of unsuspected additional cancer lesions compared to abdominopelvic CT in postoperative CRC patients and has a potential to be an effective tool for surveillance.

Kim, H, Park, S, Lee, S, Kim, A, Ha, H, CT Colonographic Surveillance after Curative Resection for Colorectal Cancer: Experience in 747 Patients.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6016910.html