Accuracy of CT colonography in the preoperative staging of colon cancer: a prospective study of 217 patients

Abstract

Aim The purpose of the present study was to evaluate the accuracy of computed tomography colonography (CTC) in the preoperative localization and TN staging of colon cancer. CTC can be an effective technique for preoperative evaluation of colon cancer and could facilitate the selection of high‐risk patients who may benefit from neoadjuvant chemotherapy. Method This was a prospective observational study conducted at a single tertiary‐care centre. It involved 217 patients (225 tumours) who had colon cancer and underwent preoperative CTC and elective colectomy. The radiologist determined the TNM stage using postprocessing software with multiplanar images and virtual colonoscopy. The following criteria were analysed for every colon tumour: location, size and signs of direct colon wall invasion. The histopathological findings of the surgical colectomy specimens served as the reference standard for local staging. Results CTC detected all tumours and achieved an exact location in 208 cases (92.4%). CTC findings changed the surgical plan in 31 patients (14.3%) following colonoscopy. The accuracy in differentiating T3/T4 vs T1/T2 tumours was 87.1%, with a sensitivity and specificity of 88.5% and 84.1%, respectively (kappa = 0.71). For high‐risk tumours (T3 ≥ 5 mm and T4), CTC showed an accuracy, sensitivity and specificity of 82.7%, 86% and 80%, respectively (kappa = 0.65). The accuracy of N‐stage evaluation was 69.3%, the sensitivity 74% and the specificity 67.1% (kappa = 0.37). Conclusion CTC provides accurate information for the assessment of tumour localization and T staging, allowing better surgical planning and also allows the selection of locally advanced tumours that may benefit from new treatments such as neoadjuvant chemotherapy.

Tumor and nodal staging of colon cancer: accuracy of preoperative computed tomography at a Swedish high-volume center

“…A more recent study by Maupoey Ibanez et al. (15) showed an 87% accuracy of differentiating T1/T2 from T3/T4 stage (κ = 0.7) and an N-stage accuracy of 69% (κ = 0.37). The current main use of CTC is as an alternative to conventional colonoscopy in cases of obstructive colorectal cancer (3).…”

Utility of CT colonography and/or PET‐CT preoperatively in obstructing left‐sided colorectal cancers – a systematic review

“…13,15,25,28 Ibanez et al found that it could accurately differentiate tumours confined to the colon wall (T1/T2) from higher staged tumours (T3/T4). 11,12,19,20,28 In locally advanced tumours, there may be a role for neoadjuvant chemotherapy.…”

“…[16][17][18] Five studies used the term 'obstructing tumours' but failed to define it. [19][20][21][22][23] Three studies used the term 'obstructive tumour' as defined as incomplete colonoscopy or where the colonoscope failed to observe the proximal colon. [24][25][26] Two studies used 'stenosing' cancers, tumours or masses in their description, but both failed to define this term.…”

“…Nine of the 17 included CTC studies reported whether the surgical management was changed due to the findings of CTC. 11,13,15,16,18,20,25,28,30 The surgical plan was changed in 2.4-14.3% of patients after the use of CTC. Changes to surgical resection due to findings of synchronous proximal CRC included subtotal colectomy and ileorectal anastomosis rather than sigmoid colectomy (n = 1), 16 left hemicolectomy rather than a sigmoid colectomy alone (n = 2), 13,16 subtotal colectomy rather than a left hemicolectomy (n = 5), 13,18,28 Sigmoid resection and right hemicolectomy instead of sigmoid resection alone for CRC (n = 1).…”

Using structured templates or free text style in reporting CT staging on colon cancer: a national survey

“…Computed tomography (CT) is a widely used method for reporting colon cancer. It is currently the national standard, with a sufficient ability to distinguish between small and advanced colon tumors (1,2). Upon suspicion of colon cancer, patients will be offered a CT scan with the purpose of locating possible distant metastases and assess the characteristics of the tumor (3).…”