TY - JOUR T1 - Variability of tumor-SUV using EARL-accredited PET scanners JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1198 LP - 1198 VL - 60 IS - supplement 1 AU - Danielle Koopman AU - Pieter Jager AU - Cornelis Slump AU - Siert Knollema AU - Jorn Dalen Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1198.abstract N2 - 1198Objectives: For reliable response evaluation with PET and to allow multi-center trials, a high SUV-reproducibility is crucial, in particular when using different PET scanners. We evaluated the variability of tumor-SUV in whole-body FDG-PET scans from patients with cancer, using both conventional and digital EARL-accredited PET systems. Methods: We performed a prospective side-by-side PET-comparison study in 50 patients with suspected or proven cancer, referred for whole-body FDG-PET/CT. Patients were scanned on both a conventional scanner (cPET, Ingenuity TF PET/CT, Philips) and a scanner with digital-detector technology (dPET, Vereos PET/CT, Philips). Both scanners are EARL-accredited. The PET scanning order was randomized and EARL-compatible reconstructions were applied. Per patient SUVmax, SUVmean and lesion diameter were measured in up to 5 lesions. The relative difference in tumor-SUV between cPET and dPET was calculated by ΔSUV = (SUVdPET-SUVcPET)/((SUVdPET+SUVcPET)[asterisk]0.5). Furthermore, we calculated the repeatability coefficient using RC=1.96[asterisk] SD ΔSUV, reflecting the 95% limit of repeatability for ΔSUV. Results: We included 151 lesions with an average size of 17±13 mm. On cPET, the average SUVmean and SUVmax were 4.9±3.3 and 7.8±6.1, respectively. On dPET, these parameters were 5.4±3.6 and 8.5±6.7 (p<0.001), respectively. Average ΔSUVmean and ΔSUVmax were 9.9%±17% and 9.8%±19% respectively (p=0.80). We found differences between lesions from -43% to +44% (range 87%) for ΔSUVmean, and from -32% to +58% (range 90%) for ΔSUVmax. Repeatability coefficients were 33% (ΔSUVmean) and 37% (ΔSUVmax). Conclusions: Even in EARL-accredited PET scanners, tumor-SUVs can vary considerably. Readers should be aware of this. ER -