Staging computed tomography in upper GI malignancy. A survey of the 5 cancer networks covered by the South West Cancer Intelligence Service

How useful is preoperative imaging for tumor, node, metastasis (TNM) staging of gastric cancer? A meta-analysis

BACKGROUND

Surgery is the fundamental curative option for gastric cancer patients. Imaging scans are routinely prescribed in an attempt to stage the disease prior to surgery. Consequently, the correlation between radiology exams and pathology is crucial for appropriate treatment planning.

METHODS

Systematic searches were conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 1998 to December 1, 2009. We calculated the accuracy, overstaging rate, understaging rate, Kappa statistic, sensitivity, and specificity for abdominal ultrasound (AUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) with respect to the gold standard (pathology). We also compared the performance of CT by detector number and image type. A meta-analysis was performed.

RESULTS

For pre-operative T staging MRI scans had better performance accuracy than CT and AUS; CT scanners using ≥ 4 detectors and multi-planar reformatted (MPR) images had higher staging performances than scanners with <4 detectors and axial images only. For pre-operative N staging PET had the lowest sensitivity, but the highest specificity among modalities; CT performance did not significantly differ by detector number or addition of MPR images. For pre-operative M staging performance did not significantly differ by modality, detector number, or MPR images.

CONCLUSIONS

The agreement between pre-operative TNM staging by imaging scans and post-operative staging by pathology is not perfect and may affect treatment decisions. Operator dependence and heterogeneity of data may account for the variations in staging performance. Physicians should consider this discrepancy when creating their treatment plans.

Pancreas-protocol imaging at a high-volume center leads to improved preoperative staging of pancreatic ductal adenocarcinoma

BACKGROUND

High-quality preoperative cross-sectional imaging is vital to accurately stage patients with pancreatic ductal adenocarcinoma (PDAC). We hypothesized that imaging performed at a high-volume pancreatic cancer center with pancreatic imaging protocols more accurately stages patients compared with pre-referral imaging.

METHODS

We retrospectively reviewed data from all patients with PDAC who presented to the surgical oncology clinic at our institution between June 2005 and August 2009. Detailed preoperative imaging, staging, and operative data were collected for each patient.

RESULTS

A total of 230 patients with PDAC were identified, of which 169 had pre-referral imaging. Patients were selectively reimaged at our institution based on the quality and timing of imaging at the outside facility: 108 (47%) patients were deemed resectable, 54 (23.5%) were deemed borderline-resectable, and 68 (29.5%) were deemed unresectable. Of the resectable patients, 99 opted for resection. Eighty-two of those 99 patients underwent preoperative imaging at our institution, and of these 27% had unresectable disease at the time of surgery compared with 47% of patients who only had pre-referral imaging (p = 0.14). Reimaging altered staging and changed management in 56% of patients. Among that group were 55 patients, categorized as resectable on pre-referral imaging, who on repeat imaging were deemed to be borderline resectable (n = 27) or unresectable (n = 28).

CONCLUSIONS

Pancreas-protocol imaging at a high-volume center improves preoperative staging and alters management in a significant proportion of patients with PDAC who undergo pre-referral imaging. Thus, repeat imaging with pancreas protocols and dedicated radiologists is justified at high-volume centers.