OR35-2 Endoscopic ultrasound outperforms CT/MRI and somatostatin receptor scintigraphy for pancreatic lesion detection in Multiple Endocrine Neoplasia Type 1 patients

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR35-Neoplasia of Endocrine Tissues
Bench to Bedside
Monday, June 17, 2013: 11:15 AM-12:45 PM
Presentation Start Time: 11:30 AM
Room 122 (Moscone Center)
Sophie J van Asselt*1, Adrienne H Brouwers2, Hendrik M van Dullemen2, Eric J van der Jagt2, Alfons H Bongaerts2, Ido P Kema2, Klaas P Koopmans3, Gerlof D Valk4, Henri JLM Timmers5, Wouter W. de Herder6, Richard Abraham Feelders6, Paul Fockens7, Wim J Sluiter2, Elisabeth G de Vries2 and Thera P Links2
1University of Groningen, University Medical Center Groningen, Netherlands, 2University of Groningen, University Medical Center Groningen, Groningen, Netherlands, 3Martini Hospital, Groningen, Netherlands, 4UMC Utrecht, Utrecht, Netherlands, 5Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, 6Erasmus MC, Rotterdam, Netherlands, 7Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
Background: In Multiple Endocrine Neoplasia type 1 (MEN1), pancreatic neuroendocrine tumors are the leading MEN1-related cause of death. Therefore, early detection is warranted. Currently in MEN1, it is unknown which technique is best for detection of pancreatic neuroendocrine tumors. In this head-to-head comparison study, we aimed to evaluate the value of endoscopic ultrasound (EUS) and of 11C-5-hydroxytryptophan positron emission tomography (11C-5-HTP PET) versus the recommended screening techniques to detect pancreatic lesions in MEN1 patients.

Patients and methods: We conducted a cross-sectional study in 41 patients in a tertiary university medical center. Patients with a germline MEN1 mutation or with one MEN1-manifestation and a mutation carrier as 1st grade family member, were eligible. Patients with MEN1 screening consisting of somatostatin receptor scintigraphy (SRS) within 6 months, abdominal computed tomography (CT) or magnetic resonance imaging (MRI) as well as the circulating tumor markers chromogranin A, gastrin, pancreatic polypeptide and glucagon within 4 months, were included. Patients underwent linear EUS and 11C-5-HTP PET. For all imaging techniques, positivity for pancreatic lesions was calculated at the level of individual  patients and of individual lesions. The sum of positives of the four imaging techniques served as a composite reference standard. EUS and 11C-5-HTP PET were compared with standard imaging using Mc Nemar’s test for comparison.

Results: In 35 patients (85%), a total number of 107 pancreatic lesions were detected: EUS found 101 pancreatic lesions in 34 patients, 11C-5-HTP PET 35 lesions in 19 patients, and CT/MRI+ SRS 32 lesions in 18 patients. Compared to CT/MRI+ SRS, EUS was superior at a patient- and lesion-based level (P < 0.001), and for lesions > 1 cm (P < 0.01). 11C-5-HTP PET performed similar as CT/MRI+ SRS, and better compared to SRS alone (13 lesions in 12 patients) both at a patient- and lesion-based level (P < 0.05). Eighteen of the 35 (51%) patients with pancreatic lesions on imaging had elevated tumor marker(s), and of these 44% had marginally elevated levels (< 2-fold the upper limit of normal).

Conclusion: EUS is superior to CT/MRI+ SRS for pancreatic lesion detection in MEN1 patients. In this setting 11C-5-HTP PET is not useful. Our data suggest that tumor markers are probably not useful in the screening setting. We recommend EUS as first choice technique for pancreas imaging in MEN1 patients.

Disclosure: RAF: Clinical Researcher, Novartis Pharmaceuticals, Speaker, Novartis Pharmaceuticals. Nothing to Disclose: SJV, AHB, HMV, EJV, AHB, IPK, KPK, GDV, HJT, WWD, PF, WJS, EGD, TPL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: Dutch Cancer Society Grant (2008-4188)