title: The value of preoperative imaging in small bowel neuroendocrine tumors.
abstract: BACKGROUND
  Neuroendocrine tumors of the small bowel (SBNETs) are a rare but important subgroup of malignancies. Since 30 % of SBNETs present with metastatic disease, often with an occult primary, preoperative imaging is critical for determining who will benefit most from abdominal exploration. We set out to evaluate the usefulness of the two most commonly performed imaging modalities in predicting the extent of disease found at exploration in patients with SBNETs.
  
  
  METHODS
  A retrospective chart review was performed on patients with SBNETs resected at 1 institution. Data from preoperative computed tomography (CT) scans were reviewed to determine whether the primary tumor, nodal, or liver metastases were seen, then compared with intraoperative findings. Results of preoperative somatostatin receptor scintigraphy (SRS) were similarly examined.
  
  
  RESULTS
  A total of 62 patients with SBNETs were included. Of these patients, 42 of 62 (68 %) had distant metastases and 48 of 62 (77 %) had nodal metastases at exploration. A total of 56 patients had preoperative CT scans and 47 had SRS. Using CT, a primary tumor was localized to the small bowel in 27 of 56 (48 %) and nodal metastases seen in 33 of 56 (79 %) of cases. SRS found intra-abdominal uptake in 35 of 47 cases (74 %).
  
  
  CONCLUSIONS
  CT and SRS are complementary in making the diagnosis of SBNET, with CT giving more precise anatomical detail, while SRS helps to confirm that lesions are NETs and is useful for identifying occult extrahepatic sites of metastatic disease. However, 10-15 % of SBNETs were not identified by either test preoperatively, and therefore surgical exploration still plays an important role in making the diagnosis in these patients.
authors.affiliation: Division of Surgical Oncology and Endocrine Surgery, Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City, IA, USA.
authors.forename: Fadi S
authors.initials: FS
authors.lastname: Dahdaleh
authors.forename: Allison
authors.initials: A
authors.lastname: Lorenzen
authors.forename: Maheen
authors.initials: M
authors.lastname: Rajput
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Carr
authors.forename: Junlin
authors.initials: J
authors.lastname: Liao
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Menda
authors.forename: Thomas M
authors.initials: TM
authors.lastname: O'Dorisio
authors.forename: James R
authors.initials: JR
authors.lastname: Howe
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007205:Indium Radioisotopes; D007414:Intestinal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D007421:Intestine, Small; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000556:secondary; D004369:Pentetic Acid / Q000031:analogs & derivatives; D011300:Preoperative Care; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: C452379:DTPA pentetreotide; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D004369:Pentetic Acid