PT - JOURNAL ARTICLE AU - Christoph Rischpler AU - Anna Schlitter AU - Michael Herz AU - Behrooz Yousefi AU - Alexander Von Werder AU - Robert Tauber AU - Tobias Maurer AU - Simon Robinson AU - Cesare Orlandi AU - Stephan Nekolla AU - Markus Schwaiger AU - Matthias Eiber TI - <strong>First experience using LMI1195 PET in patients with the suspicion of pheochromocytoma or paraganglioma</strong> DP - 2018 May 01 TA - Journal of Nuclear Medicine PG - 51--51 VI - 59 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/59/supplement_1/51.short 4100 - http://jnm.snmjournals.org/content/59/supplement_1/51.full SO - J Nucl Med2018 May 01; 59 AB - 51Objectives: Pheochromocytoma (PHEO) or paraganglioma (PARA) are known to overexpress the norepinephrine transporter (NET). NET can be imaged by PET using N-[3-bromo-4-(3-(18)F-fluoro-propoxy)-benzyl]-guanidine [LMI1195], a novel, F-18-labeled radiotracer which has only been evaluated in healthy volunteers so far. The aim of this study was to investigate the potential of LMI1195 in patients (pts) with the suspicion of primary or recurrent PHEO or PARA. Methods: In total 21 LMI1195 PET/CT scans were performed in 20 pts: Suspicion of primary PHEO or PARA was based on symptoms and/or pathological lab results in 9, on therapy-refractory hypertension in 4 and on incidental finding in morphological imaging in 1 patient. 6 pts underwent restaging after initial resection of PHEO or PARA. PET imaging was acquired 65±24 minutes p.i. after a mean injected activity of 256±33 MBq (effective dose: 6.7±0.9 mSv) using a state-of-the art PET/CT-scanner (Siemens Biograph mCT). Any medication potentially interfering with LMI1195 accumulation was discontinued prior to the scan according to the EANM guidelines for MIBG imaging. Results: No short-term adverse events occurred after LMI1195 application. Highest tracer accumulation (SUVmean) was observed in the thyroid (23±7), bladder (12±15), pancreas (13±4), kidneys (11±4), stomach (10±4), salivary glands (8±2) and left ventricle (7±2). Healthy adrenal gland tissue showed mean SUVmax and SUVmean of 13±4 and 8±2, respectively. Primary PHEO, primary PARA, recurrent PHEO and recurrent PARA were suspected by PET/CT in 8, 1, 2 and 4 pts, respectively. In the remaining 5 patients, there was no abnormality on PET/CT. LMI1195 showed intense uptake with mean SUVmax/SUVmean of 25±19/12±9 and 12±2/9±2 in PHEO and PARA, respectively. Histological verification was performed in 8 pts with PHEO. True positive and negative PET/CTs were histologically confirmed in 5 patients ((PHEO (n=4) and PARA (n=1)) and 3 pts (adenoma (n=2) and Conn’s syndrome (n=1)), respectively. In 1 patient (high suspicion of multiple PARAs) follow-up imaging confirmed previous findings. Image quality of LMI1195 PET was clearly superior to a usual MIBG SPECT scan despite a 50% shorter imaging time and a comparable radiation exposure. Conclusions: LMI1195, a novel F-18-labeled PET-tracer, is highly effective in detecting tumors of the adrenal medulla or the sympathetic trunk. High uptake in lesions and superb image quality promote its use as alternative to MIBG. Further potential applications (e.g. assessment of the sympathetic innervation of the heart) should be evaluated.