title: Simultaneous (68)Ga-DOTA-TOC PET/MRI with gadoxetate disodium in patients with neuroendocrine tumor.
abstract: OBJECTIVE
  To evaluate a simultaneous PET/MRI approach to imaging patients with neuroendocrine tumor using a combination of (68)Ga-DOTA-TOC as a PET contrast agent and gadoxetate disodium as a hepatobiliary MRI contrast agent.
  
  
  METHODS
  Ten patients with neuroendocrine tumor with known or suspected hepatic disease were imaged using a (68)Ga-DOTA-TOC PET/CT immediately followed by a 3.0T time-of-flight PET/MRI, using a combined whole body and liver specific imaging. The presence of lesions and DOTA-TOC avidity were assessed on CT, PET from PET/CT, diffusion weighted imaging, hepatobiliary phase imaging (HBP), and PET from PET/MRI. Maximum standardized uptake values (SUVmax) in hepatic lesions and nodal metastases were compared between PET/CT and PET/MRI, as were detection rates using each imaging approach.
  
  
  RESULTS
  A total of 101 hepatic lesions were identified, 47 of which were DOTA-TOC avid and able to be individually measured on both PET/CT and PET/MRI. HBP imaging had a higher sensitivity for detection of hepatic lesions compared to CT or PET (99% vs. 46% and 64%, respectively; p values <0.001). There was a strong correlation between SUVmax of liver lesions obtained with PET/CT compared to PET/MR imaging (Pearson's correlation = 0.91). For nodal disease, CT had a higher sensitivity compared to whole body MRI (p = 0.015), although PET acquired from PET/MRI detected slightly more lesions compared to PET from PET/CT.
  
  
  CONCLUSIONS
  A simultaneous PET/MRI using both (68)Ga-DOTA-TOC and gadoxetate disodium was successful in whole body staging of patients with neuroendocrine tumor. HBP imaging had an increased detection rate for hepatic metastases.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, 505 Parnassus Avenue - 0628, San Francisco, CA, 94143-0628, USA, thomas.hope@ucsf.edu.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hope
authors.forename: Miguel Hernandez
authors.initials: MH
authors.lastname: Pampaloni
authors.forename: Eric
authors.initials: E
authors.lastname: Nakakura
authors.forename: Henry
authors.initials: H
authors.lastname: VanBrocklin
authors.forename: James
authors.initials: J
authors.lastname: Slater
authors.forename: Salma
authors.initials: S
authors.lastname: Jivan
authors.forename: Carina Mari
authors.initials: CM
authors.lastname: Aparici
authors.forename: Judy
authors.initials: J
authors.lastname: Yee
authors.forename: Emily
authors.initials: E
authors.lastname: Bergsland
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D005710:Gallium Radioisotopes; D006801:Humans; D007089:Image Enhancement; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D018358:Neuroendocrine Tumors / Q000175:diagnosis*; D015282:Octreotide / Q000031:analogs & derivatives*; D009942:Organometallic Compounds; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D051598:Whole Body Imaging
chemical_list: D003287:Contrast Media; C499142:Ga(III)-DOTATOC; D005710:Gallium Radioisotopes; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA; D015282:Octreotide