Evaluation of contrast-enhanced computed tomographic colonography in detection of local recurrent colorectal cancer

Prospective Trial Evaluating the Surgical Anastomosis at One-Year Colorectal Cancer Surveillance: CT Colonography Versus Optical Colonoscopy and Implications for Patient Care

OBJECTIVE

The aim of this study was to compare the accuracy of CT colonography versus optical colonoscopy for neoplastic involvement at the surgical anastomosis 1 year after curative-intent colorectal cancer resection.

DESIGN, SETTING, PATIENTS, AND INTERVENTIONS

Two hundred one patients (mean age, 58.6 years; 117 men, 84 women) underwent same-day contrast-enhanced CT colonography and colonoscopy approximately 1 year (mean, 12.1 months; median, 11.9 months) after colorectal cancer resection as part of a prospective, multicenter trial. All patients enrolled were without clinical evidence of disease and considered low risk for recurrence (stage I-III).

MAIN OUTCOME MEASURES

Suspected neoplastic lesions within 5 cm of the colonic anastomosis were recorded at CT colonography, with subsequent colonoscopy performed for the same, with segmental unblinding of colonography findings. Anastomotic region biopsy or polypectomy was performed at the endoscopist's discretion.

RESULTS

None of the 201 patients had intraluminal anastomotic cancer recurrence or advanced neoplasia (or metachronous cancers). CT colonography detected extramural perianastomotic recurrence in 2 patients (1.0%); neither was detected at colonoscopy. Only 2 patients (1.0%; 2/201) were called positive at CT colonography for intraluminal anastomotic nondiminutive lesions (7- to 8-mm polyps), which were confirmed at colonoscopy but nonneoplastic at histopathology. At optical colonoscopy, the anastomosis was deemed abnormal and/or biopsied in 10.0% (20/201), yielding only 1 nondiminutive benign neoplasm (7-mm tubular adenoma).

LIMITATIONS

The lack of luminal cancer recurrence in our lower-risk cohort precludes assessment of sensitivity for detection, rendering the study underpowered in this regard. Potential cost savings of combined CT/CT colonography over the standard CT/colonoscopy approach were not assessed.

CONCLUSIONS

Relevant intraluminal anastomotic pathology appears to be very uncommon 1 year after colorectal cancer resection in lower-risk cohorts. Unlike colonoscopy, diagnostic contrast-enhanced CT colonography effectively evaluates both the intra- and extraluminal aspects of the anastomosis. See Video Abstract at http://links.lww.com/DCR/A471.

Early detection of colorectal cancer recurrence in patients undergoing surgery with curative intent: current status and challenges

Despite advances in neoadjuvant and adjuvant therapy, attention to proper surgical technique, and improved pathological staging for both the primary and metastatic lesions, almost half of all colorectal cancer patients will develop recurrent disease. More concerning, this includes ~25% of patients with theoretically curable node-negative, non-metastatic Stage I and II disease. Given the annual incidence of colorectal cancer, approximately 150,000 new patients are candidates each year for follow-up surveillance. When combined with the greater population already enrolled in a surveillance protocol, this translates to a tremendous number of patients at risk for recurrence. It is therefore imperative that strategies aim for detection of recurrence as early as possible to allow initiation of treatment that may still result in cure. Yet, controversy exists regarding the optimal surveillance strategy (high-intensity vs. traditional), ideal testing regimen, and overall effectiveness. While benefits may involve earlier detection of recurrence, psychological welfare improvement, and greater overall survival, this must be weighed against the potential disadvantages including more invasive tests, higher rates of reoperation, and increased costs. In this review, we will examine the current options available and challenges surrounding colorectal cancer surveillance and early detection of recurrence.

CT colonography in patients who have undergone sigmoid colostomy: a feasibility study

OBJECTIVE

The purpose of this study was to evaluate the technical feasibility of CT colonography of patients who have undergone sigmoid colostomy after abdominoperineal resection.

MATERIALS AND METHODS

Seven men and 11 women (mean age, 57.2 ± 14.5 [SD] years) who had undergone abdominoperineal resection with sigmoid colostomy for rectal cancer were included. Colonic cleansing and fecal tagging were performed with magnesium citrate and 5% weight/volume barium. A conventional small rectal catheter with a retention balloon was introduced into the colonic stoma. An inflated balloon (15-25 mL) was positioned several centimeters beneath the skin. The interposed tissue acted as the mechanism for preventing balloon expulsion during colonic insufflation with carbon dioxide. Unenhanced right decubitus and contrast-enhanced supine images were obtained. Air-fluid leak, balloon expulsion, complications, and colonic distention evaluated on a 4-point scale in which 1 was the worst and 4 the best and mucosal coverage were assessed.

RESULTS

Examinations were performed uneventfully for all but one patient, who had temporary air and fluid leakage. The mean amount of carbon dioxide used was 2.64 ± 0.64 L. In the right decubitus position, the mean distention grade of each colonic segment was 2.7 ± 1.1 (sigmoid), 3.4 ± 0.6 (descending), 3.6 ± 0.5 (transverse), 3.6 ± 0.5 (ascending), and 3.7 ± 0.5 (cecum). In the supine position the mean grades were 2.7 ± 1.2, 3.1 ± 0.7, 3.7 ± 0.5, 3.7 ± 0.5, and 3.8 ± 0.4. Four patients (22.2%) had segments not adequately visualized in either position owing to luminal collapse; all of these segments were in the sigmoid colon. Three patients (16.7%) had areas submerged under fecal matter in both positions, but these areas were evaluable because of fecal tagging or IV contrast enhancement.

CONCLUSION

CT colonographic examination through a sigmoid stoma was technically feasible with currently available instruments, but further improvements in technique are needed.

Colon distension and scan protocol for CT-colonography: an overview

This article reviews two important aspects of CT-colonography, namely colonic distension and scan parameters. Adequate distension should be obtained to visualize the complete colonic lumen and optimal scan parameters should be used to prevent unnecessary radiation burden. For optimal distension, automatic carbon dioxide insufflation should be performed, preferably via a thin, flexible catheter. Hyoscine butylbromide is - when available - the preferred spasmolytic agent because of the positive effect on insufflation and pain/burden and its low costs. Scans in two positions are required for adequate distension and high polyp sensitivity and decubitus position may be used as an alternative for patients unable to lie in prone position. The great intrinsic contrast between air or tagging and polyps allows the use of low radiation dose. Low-dose protocol without intravenous contrast should be used when extracolonic findings are deemed unimportant. In patients suspected for colorectal cancer, normal abdominal CT scan protocols and intravenous contrast should be used in supine position for the evaluation of extracolonic findings. Dose reduction can be obtained by lowering the tube current and/or voltage. Tube current modulation reduces the radiation dose (except in obese patients), and should be used when available. Iterative reconstructions is a promising dose reducing tool and dual-energy CT is currently evaluated for its applications in CT-colonography. This review also provides our institution's insufflation procedure and scan parameters.

CT colonography for combined colonic and extracolonic surveillance after curative resection of colorectal cancer

PURPOSE

To determine the accuracy of contrast material-enhanced computed tomographic (CT) colonography for postoperative surveillance in colorectal cancer patients without clinical or laboratory evidence of disease recurrence.

MATERIALS AND METHODS

The Institutional Review Board approved this HIPAA-compliant study and waived informed consent. Between January 2006 and December 2007, 742 consecutive patients without clinical or laboratory evidence of recurrence following curative-intent colorectal cancer surgery underwent contrast-enhanced CT colonography. Of these, 548 patients who had subsequent colonoscopy and pathologic confirmation of colonic lesions (reference standard) were included in the colonic analysis. All 742 patients were included in the extracolonic analysis. Sensitivity and specificity of CT colonography for nonanastomotic colonic lesions at least 6 mm in size and anastomotic lesions of any size, including performance according to lesion histologic type, were determined. Diagnostic yields of contrast-enhanced CT colonography for colonic cancers and for extracolonic recurrences were obtained.

RESULTS

CT colonography depicted all six metachronous cancers and one anastomotic recurrence within the colon in six patients (0.8%; 95% confidence interval [CI]: 0.3%, 1.8%]), for per-patient and per-lesion sensitivities of 100% (95% CIs: 64.3%, 100% and 67.8%, 100%, respectively). All cancer lesions within the colon were amenable to additional curative treatment. CT colonography per-patient and per-lesion sensitivity was 81.8% (95% CI: 60.9%, 93.3%) and 80.8% (95% CI: 64.3%, 97.2%), respectively, for advanced neoplasia and 80.0% (95% CI: 68.6%, 88.1%) and 78.5% (95% CI: 68.3%, 88.7%), respectively, for all adenomatous lesions. Negative predictive values for adenocarcinoma, advanced neoplasia, and all adenomatous lesions were 100%, 99.1%, and 97.0%, respectively. CT colonography specificity was 93.1% (95% CI: 90.4%, 95.2%). Contrast-enhanced CT colonography enabled detection of extracolonic recurrences in an additional 11 patients (1.5%; 95% CI: 0.8%, 2.7%).

CONCLUSION

Contrast-enhanced CT colonography is an accurate and practical surveillance tool following colorectal cancer surgery in patients without clinical or laboratory evidence of recurrence, allowing for simultaneous less-invasive evaluation of both colon and extracolonic organs.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100385/-/DC1.

Contrast-enhanced CT colonography with 64-slice MDCT compared to endoscopic colonoscopy in the follow-up of patients after colorectal cancer resection

BACKGROUND

Seventy percent of newly diagnosed colorectal cancer cases are potential candidates for curative surgery, but after resection, in 30%, the tumor will recur. Postoperative follow-up includes endoscopic colonoscopy (EC) and computed tomography (CT). There have been only a few publications on the use of contrast-enhanced CT colonography (CECTC) in the follow-up of these patients.

METHODS

Twenty-nine consecutive patients after resection of colorectal cancer underwent CECTC and EC on the same day. CECTC studies were reviewed for identification of strictures, recurrence, polyps and metastases.

RESULTS

The anastomosis was identified in 96% of patients on CECTC and in 82% on endoscopic colonoscopy. One stricture was identified by both techniques. One extraluminal recurrence was depicted only on CECTC. Sensitivity in detecting polyps was per polyp 93% and per patient 100%.

CONCLUSION

CECTC performed on a 64-slice multidetector CT is reliable in imaging the postoperative colon for the follow-up of patients after resection of colorectal cancer.

CT colonography for follow-up after surgery for colorectal cancer

OBJECTIVE

The purpose of this article is to discuss the CT colonography (CTC) findings and the role of CTC for follow-up after curative surgery for colorectal cancer.

CONCLUSION

Contrast-enhanced CTC can be effective for surveillance for colorectal cancer recurrence after curative surgery because it enables simultaneous evaluation of distant abdominal metastasis, pericolic recurrence, intraluminal recurrence, and metachronous lesions. The appearances of anastomotic recurrences at CTC overlap with those of more common inflammatory polyps and rare benign ulcers.

Update on Colorectal Cancer Imaging

Colorectal cancer remains a leading cancer killer worldwide. The disease is both curable and preventable, and yet the importance of widespread screening is only now starting to be appreciated. This article reviews the variety of diagnostic tests, imaging procedures and endoscopic examinations available to detect colorectal cancer and polyps in their early stage and also presents details on various screening options. The critical role of the radiologist is elaborated on including accurate assessment of the tumor extent within the bowel wall and beyond and the detection of lymph node and distant metastases. Staging with CT, MR imaging, endorectal ultrasound, and positron emission tomography are of paramount importance in determining the most appropriate therapy and the risk of tumor recurrence and overall prognosis.

CT colonography: surveillance in patients with a history of colorectal cancer

Colorectal cancer is a leading cause of morbidity and mortality in the United States. It is also a disease that is preventable if precursor adenomatous polys are removed. Once a diagnosis of colorectal cancer is made, surgical resection is the only means of cure. The ability to resect colorectal cancer for cure is largely dependent upon the stage of tumor at presentation. Once a patient has been treated for colorectal cancer with surgery and in some cases neo-adjuvant or adjuvant therapy, they will present for follow-up. Surveillance is performed on these patients in order to detect local recurrence that if detected early can be surgically resected for cure. Surveillance also allows detection of distant metastatic disease that may in some cases also be cured with resection. Finally, surveillance of the remaining colon is important to detect the development of new or metachronous adenomatoid polyps that if left in place could develop into new colon cancers. Imaging can play a part in patient surveillance to detect recurrent disease at extracolonic sites as well as the development of new colonic lesions. CT colonography is a promising tool for surveillance in patients with a history of colorectal cancer.

Clinical value of CT three-dimensional imaging in diagnosing gastrointestinal tract diseases

AIM: To discuss the clinical value of CT three-dimensional (3-D) imaging in diagnosing gastrointestinal tract diseases.

METHODS: Three-D imaging findings of 52 patients were retrospectively analyzed. Three-D imaging methods included shaded surface display (SSD), volume rendering (VR), virtual endoscopy (VE) and multiplanar reformatting (MPR). The diagnosis results of CT 3-D were evaluated by comparison with those of endoscopy and/or surgical finding.

RESULTS: Fifty-two patients with gastrointestinal tract diseases were diagnosed by CT 3-D imaging, of whom 50 cases were correctly diagnosed and 2 were misdiagnosed. There were 33 cases of gastric diseases (27 with carcinoma, 5 with peptic ulcer and 1 with leiomyoma) and 19 large intestinal diseases (10 with colon carcinoma, 2 with carcinoma of the rectum, 5 with colon polypus and 2 with tuberculosis of the ileocecal junction). Twenty-two cases with prominent lesions (9 with subsequent hollow lesions), 20 with stenosis of cavity (8 with concomitant prominent lesions) and 10 with hollow lesions (5 with concomitant prominent lesions) were shown in 3-D images. The minimal lesion shown was 1.0 cm × 0.8 cm × 0.5 cm.

CONCLUSION: CT 3-D imaging, a non-invasive examination without pain, can display clearly and directly the lesions of gastrointestinal tract with accurate location and high diagnosis accuracy. It is an important complementary technique to endoscopy.