Application of 68Ga-DOTA-TATE PET/CT in metastatic neuroendocrine tumor of gastrointestinal origin

Georgios Z. Papadakisa, Samira M. Sadowskibc, Ulas Bagcid, Corina Milloe

Warren Grant Magnuson Clinical Center (CC), National Institutes of Health (NIH), Bethesda, USA; National Cancer Institute, National Institutes of Health, Bethesda, USA; University Hospitals of Geneva, Geneva, Switzerland; University of Central Florida, Orlando, USA; Clinical Center, National Institutes of Health, Bethesda, USA

aRadiology and Imaging Sciences, Warren Grant Magnuson Clinical Center (Georgios Z. Papadakis); bEndocrine Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, USA (Samira M. Sadowski); cEndocrine and Thoracic Surgery, University Hospitals of Geneva, Geneva, Switzerland (Samira M. Sadowski); dCenter for Research in Computer Vision, Electrical and Computer Science Department, University of Central Florida, Orlando, USA (Ulas Bagci); ePET Department, Clinical Center, National Institutes of Health, Bethesda, USA (Corina Millo)

Correspondence to: Georgios Z. Papadakis, MD, MPH, Department of Radiology & Imaging Sciences, Warrant Grant Magnuson Clinical Center, National Institutes of Health, 10 Center Drive, Room 1C370, Bethesda, MD, 20892-1182 USA, Tel.: +1 301 827 1827, e-mail: papadakisg@cc.nih.gov, gzpapadakis@gmail.com
Received 6 July 2016; accepted 31 July 2016; published online 6 September 2016
DOI: http://dx.doi.org/10.20524/aog.2016.0082

Ann Gastroenterol 2017; 30 (1): 130

A 65-year-old man underwent an abdominal ultrasound of acute abdominal pain, showing an incidental. Subsequently, a magnetic resonance imaging (MRI) scan of the abdomen revealed additional liver lesions, hyper-intense on T2-weighted images. Needle biopsy of the largest lesion showed a well-differentiated neuroendocrine tumor (NET) of gastrointestinal origin. The patient underwent a whole-body positron emission tomography–computed tomography (PET/CT) scan using 68Ga-DOTATATE (somatostatin [SST]-analog) for accurate disease staging, which showed approximately 16 tracer-avid liver lesions. The hottest lesion (SUVmax: 52.4) was inferior to the medial segment of the left lobe (Fig. 1A: red arrow) corresponding to the largest lesion seen on MRI (Fig. 1B: arrow). A prominent tracer-avid lesion (SUVmax: 72.8) was seen in the terminal ileum/ileocecal junction (Fig. 1A: black arrow; Fig. 1C, D: white arrows) strongly suggesting the location of the primary tumor. In addition, two 68Ga-DOTATATE-positive mesenteric lymph nodes were seen in the abdomen and left inferior pelvis (Fig. 1A: green arrows; SUVmax: 62.3 & 25.4, respectively) (Fig. 1D: yellow arrow). The patient underwent exploratory laparotomy with radio-guided (using a gamma probe post 68Ga-DOTATATE injection) excision of the tumors from the small bowel, the mesenteric lymph nodes and the liver lesions. Subsequently pathological evaluation of all excised specimens revealed primary grade-I NET in the terminal ileum with metastases to the liver and mesenteric lymph nodes.

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Figure 1 (A) Whole-body maximum intensity projection (MIP)Β 68Ga-DOTATATE positron emission tomography (PET) image. (B) Axial T2-weighted magnetic resonance image of the upper abdomen. (C) Axial fused 68Ga-DOTATATE PET/CT image of the pelvis. (D) Coronal-fused 68Ga-DOTATATE PET/CT image of the abdomen and pelvis

Since the majority of NETs overexpress SST receptors, they can be effectively targeted and localized using radiolabeled SST analogs [1,2]. In the presented case 68Ga-DOTATATE PET/CT accurately showed the extent of the disease and confidently revealed the location of the primary tumor, demonstrating the utility of PET/CT using 68Ga-DOTA-conjugated peptides in the accurate management of patients with gastro-entero-pancreatic NETs [3].

References

1. Hofman MS, Lau WF, Hicks RJ, Somatostatin receptor imaging with 68Ga DOTATATE PET/CT: clinical utility, normal patterns, pearls, and pitfalls in interpretationRadiographics 2015; 35: 500-516.

2. Papadakis GZ, Bagci U, Sadowski SM, Patronas NJ, Stratakis CA, Ectopic ACTH and CRH Co-secreting tumor localized by 68Ga-DOTA-TATE PET/CTClin Nucl Med 2015; 40: 576-578.

3. Baumann T, Rottenburger C, Nicolas G, Wild D, Gastroenteropancreatic neuroendocrine tumours (GEP-NET) - Imaging and stagingBest Pract Res Clin Endocrinol Metab 2016; 30: 45-57.

Notes

Conflict of Interest: None