Effects of furosemide and tracer selection on urinary activity and peri-bladder artefacts in PSMA PET/CT: a single-centre retrospective study
Maarten L. Donswijk, Maurits Wondergem, Berlinda J. de Wit–van der Veen, Natascha M. Bruin, Pim J. van Leeuwen, Henk G. van der Poel, Marcel P. M. Stokkel, Wouter V. Vogel
Abstract
Abstract Background High urinary activity in urinary bladder and ureters may hamper interpretation of prostate cancer and regional nodal metastases in prostate-specific membrane antigen (PSMA) PET/CT. The goal of this study was to assess effects of furosemide and choice of tracer on urinary activity in the bladder and ureters, as well as on occurrence of peri-bladder artefacts in PET/CT. Methods Four cohorts with a total of 202 men staged with PSMA PET/CT for prostate cancer received either 68 Ga-PSMA-11 as tracer, with (cohort G+) or without 10mg intravenous furosemide (G−) concurrent with tracer, or 18 F-DCFPyL with (F+) or without furosemide (F−). SUVmax of bladder and ureters, presence, type, and severity of peri-bladder artefacts were compared between cohorts. The influence of furosemide and choice of tracer was determined while taking differences in biodistribution time into account. Results Median SUVmax bladder was 43,5; 14,8; 61,7 and 22,8 in cohorts G−, G+, F− and F+, respectively, resulting in significant overall ( p < 0.001) and between cohort differences ( p adjusted < 0.001 to 0.003) except between G− and F+. Median SUVmax ureter was 6.4; 4.5; 8.1 and 6.0 in cohorts G−, G+, F− and F+, respectively, resulting in significant overall ( p < 0.001) and between cohort differences for G+ : F− and F− : F+ ( p < 0.001, respectively, 0.019). Significant effects of furosemide and choice of tracer on SUVmax bladder ( p < 0.001 resp. p = 0.001) and of furosemide on SUVmax ureter ( p < 0.001) were found, whereas differences in biodistribution time had not impacted these results significantly. Peri-bladder artefacts were present in 42/202 (21%) patients and were significantly more frequent in the F− cohort, respectively, less frequent in the G+ cohort ( p = 0.001 resp. p < 0.001). Peri-bladder artefacts had a direct positive correlation with SUVmax bladder ( p = 0.033). Conclusions Increased urinary activity and higher incidence of peri-bladder artefacts were found in 18 F-DCFPyL compared to 68 Ga-PSMA-11 PET/CT. Effective reduction of urinary activity may be reached through forced diuresis using 10mg intravenous furosemide, which is especially advantageous in 18 F-DCFPyL PET/CT.