TY - JOUR T1 - First experience using F-18-flubrobenguane PET imaging in patients with the suspicion of pheochromocytoma or paraganglioma JF - Journal of Nuclear Medicine JO - J Nucl Med DO - 10.2967/jnumed.120.248021 SP - jnumed.120.248021 AU - Lukas Kessler AU - Anna Melissa Schlitter AU - Markus Kroenke AU - Alexander von Werder AU - Robert Tauber AU - Tobias Maurer AU - Simon P Robinson AU - Cesare Orlandi AU - Michael Herz AU - Behrooz H Yousefi AU - Stephan G. Nekolla AU - Markus Schwaiger AU - Matthias Eiber AU - Christoph Rischpler Y1 - 2020/08/01 UR - http://jnm.snmjournals.org/content/early/2020/08/27/jnumed.120.248021.abstract N2 - Rationale: Pheochromocytomas and paragangliomas are a rare tumor entity originating from adreno-medullary chromaffin cells in the adrenal medulla or in sympathetic, paravertebral ganglia outside the medulla. Especially small lesions are difficult to detect by conventional CT or MR imaging and even by SPECT imaging with currently available radiotracers (e.g. MIBG). The novel PET-radiotracer F-18-flubrobenguane could change the diagnostic paradigm in suspected pheochromocytomas and paragangliomas due to its homology to MIBG and the general advantages of PET-imaging. Aim of this retrospective analysis was to evaluate F-18-flubrobenguane in pheochromocytomas and paragangliomas and to investigate the biodistribution in patients. Methods: 24 Patients with suspected pheochromocytoma and paraganglioma underwent PET/CT or PET/MRI at 63±24 min p.i. after injection of 256±33 MBq F-18-flubrobenguane. SUVmean and SUVmax values of organs were measured with spherical volume-of-interests. Threshold segmented volume-of-interests were used to measure SUVmean/max of the tumor lesions. One reader evaluated all cross-sectional imaging datasets (CT or MRI) separately as well as the PET hybrid datasets and reported lesion number and size. A three point-scale indicating the diagnostic certainty for a positive lesion was assigned. Results: F-18-flubrobenguane showed a reproducible, stable biodistribution with highest values of SUVmax/mean in the thyroid gland (30.3±2.2/22.5±1.6), pancreas (12.2±0.8/9.5±0.7), tumor lesions (16.8±1.7/10.1±1.1) and the lowest SUVmax/mean values in muscle (1.1±0.06/0.7±0.04) and lung (2.5±0.17/1.85±0.13). In a subgroup analysis both pheochromocytoma and paraganglioma lesions showed a significantly higher average SUVmean compared to healthy adrenal glands (11.9±2.0 vs 9.9±1.5 vs 3.7±0.2). In total 47 lesions were detected. The reader reported more and smaller lesions with higher certainty in PET hybrid imaging compared to conventional imaging, however, statistical significance was not reached. 61% (14/23) of the 23 (23/47, 49%) lesions smaller than 1 cm were found on hybrid imaging only. Conclusion: Our preliminary data suggest F-18-flubrobenguane PET as a new effective staging tool in patients with suspected pheochromocytoma and paraganglioma. Major advantages are the fast acquisition and high spatial resolution of PET imaging and intense uptake in tumor lesions facilitating lesion detection. Further studies are warranted to define its role particularly in comparison to standard diagnostic procedures such as MRI or I-123-MIBG SPECT/CT. ER -