Published online May 7, 2017. doi: 10.3748/wjg.v23.i17.3092
Peer-review started: October 26, 2016
First decision: December 19, 2016
Revised: January 30, 2017
Accepted: March 31, 2017
Article in press: March 31, 2017
Published online: May 7, 2017
Processing time: 194 Days and 17.3 Hours
To establish the ability of magnetic resonance (MR) and computer tomography (CT) to predict pathologic dimensions of pancreatic neuroendocrine tumors (PanNET) in a caseload of a tertiary referral center.
Patients submitted to surgery for PanNET at the Surgical Unit of the Pancreas Institute with at least 1 preoperative imaging examination (MR or CT scan) from January 2005 to December 2015 were included and data retrospectively collected. Exclusion criteria were: multifocal lesions, genetic syndromes, microadenomas or mixed tumors, metastatic disease and neoadjuvant therapy. Bland-Altman (BA) and Mountain-Plot (MP) statistics were used to compare size measured by each modality with the pathology size. Passing-Bablok (PB) regression analysis was used to check the agreement between MR and CT.
Our study population consisted of 292 patients. Seventy-nine (27.1%) were functioning PanNET. The mean biases were 0.17 ± 7.99 mm, 1 ± 8.51 mm and 0.23 ± 9 mm, 1.2 ± 9.8 mm for MR and CT, considering the overall population and the subgroup of non-functioning- PanNET, respectively. Limits of agreement (LOA) included the vast majority of observations, indicating a good agreement between imaging and pathology. The MP further confirmed this finding and showed that the two methods are unbiased with respect to each other. Considering ≤ 2 cm non-functioning-PanNET, no statistical significance was found in the size estimation rate of MR and CT (P = 0.433). PBR analysis did not reveal significant differences between MR, CT and pathology.
MR and CT scan are accurate and interchangeable imaging techniques in predicting pathologic dimensions of PanNET.
Core tip: Radiological tumor size estimation of pancreatic neuroendocrine tumors is of utmost importance for therapeutic decision-making, especially for non-functioning ones. This study showed that both magnetic resonance and computer tomography are accurate and interchangeable in predicting pathologic tumor size.