Preoperative imaging for resectable periampullary cancer: clinicopathologic implications of reported radiographic findings.

BACKGROUND

High-resolution, multiphase, computed tomography (CT) is a standard preoperative test prior to pancreatectomy, yet the clinical significance of routinely reported findings remains unknown.

METHODS

We identified patients who underwent a pancreaticoduodenectomy for a periampullary adenocarcinoma (PA) over the previous 5 years and had a pancreas protocol CT at our institution. Clinicopathologic implications of reported CT findings were evaluated.

RESULTS

There were 155 pancreatic ductal adenocarcinomas (PDA) and 47 non-pancreatic PAs. No mass was visualized on CT in 6 % of PDAs and 23 % of non-pancreatic PA. A size discrepancy of ≥1 cm between radiographic and pathologic tumor diameters was observed in 40 % of PAs, with CT underestimating the size in most instances (75 %). Radiographically enlarged lymph nodes were not associated with true lymph node metastases in PDAs (70 % lymph node positive cases were enlarged on CT vs 74 % lymph node negative, p = 0.5), but were associated with a preoperatively placed biliary endoprosthesis (63 % with endoprosthesis were enlarged vs 37 % no endoprosthesis, p = 0.013). Major visceral vessel involvement on CT was not associated with a vascular resection (3 % with CT vessel involvement vs 2 % without, p = 0.8) or a positive uncinate resection margin (24 vs 20 %, respectively, p = 0.6).

DISCUSSION

While dedicated pancreas protocol CT provides unprecedented detail, the test may lead to overinterpretation of the extent of disease in some instances. A radiographic suggestion of enlarged lymph nodes and vascular involvement does not necessarily preclude exploration with curative intent. CTs with local disease should be reported in an objective template and carefully reviewed by a multidisciplinary group of surgeons, radiologists, and oncologists to avoid missing an opportunity for neoadjuvant therapy or cure by resection.