Effects of furosemide and tracer selection on urinary activity and peri-bladder artefacts in PSMA PET/CT: a single-centre retrospective study

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 68Ga-PSMA-11 as tracer, with (cohort G+) or without 10mg intravenous furosemide (G−) concurrent with tracer, or 18F-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 18F-DCFPyL compared to 68Ga-PSMA-11 PET/CT. Effective reduction of urinary activity may be reached through forced diuresis using 10mg intravenous furosemide, which is especially advantageous in 18F-DCFPyL PET/CT.

PSMA Targeted Molecular Imaging and Radioligand Therapy for Prostate Cancer: Optimal Patient and Treatment Issues

“…The primary endpoint was prostate-specific antigen (PSA) response defined by a reduction of at least 50% from baseline. Primary endpoints have been achieved ( 177 Lu-PSMA-617 group vs. cabazitaxel group, PSA responses; 66 vs. 37% by intention to treat; difference 29% (95% CI: 16–42; p < 0·0001; and 66 vs. 44% by treatment received; difference 23% [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]; p = 0·001)). However, the study results require careful interpretation because the primary endpoint of the study was at least a 50% reduction in PSA; in addition, the dose of 20 mg/m 2 cabazitaxel was lower than the 25 mg/m 2 in the TROPIC [ 7 ] and CARD trials [ 50 ].…”

“…68 Ga-PSMA-11 shows high accumulation in prostate cancer, but it should be discontinued in the diagnosis of perineural recurrence due to urinary excretion [17]. This point is reported to be reduced by the administration of furosemide, hydration, and urination [18][19][20]. If a Ge/Ga generator is available, it is relatively easy to create, but the short half-life of 68 Ga [21] makes it unsuitable for delivery.…”

“…In general, agents using 18F have a longer half-life than 68 Ga agents, making them suitable for image evaluation at later time points and mass production. 18 F is generally synthesized in cyclotrons and has a longer half-life than 68 Ga [21], which may be superior in production and supply, but production facilities are limited due to the need for huge cyclotrons. 18 F-PSMA-1007 is characterized by biliary excretion and low urinary excretion, which is considered an advantage in the evaluation of local lesions [22].…”

“…18 F is generally synthesized in cyclotrons and has a longer half-life than 68 Ga [21], which may be superior in production and supply, but production facilities are limited due to the need for huge cyclotrons. 18 F-PSMA-1007 is characterized by biliary excretion and low urinary excretion, which is considered an advantage in the evaluation of local lesions [22]. However, it is highly concentrated in the liver, which may mask liver metastatic lesions, and may not be suitable for patients with severe hepatic dysfunction [23].…”

“…The indications are the same as for 68 Ga-PSMA-11, which is approved for the diagnosis of recurrence after radical therapy, staging of localized prostate cancer, and metastatic prostate cancer. It is excreted from the urine and liver, but its accumulation in the liver is reported to be milder than that of 18 F-PSMA-1007, and it may be safer than 18 F-PSMA-1007 in patients with hepatic dysfunction [23]. PSMA-PET has a lot of evidence for primary staging evaluation in localized intermediateand high-risk prostate cancer and diagnosis of biochemical recurrence (BCR) after radical prostatectomy (RP) or radiotherapy, but there are many challenges for diagnosis in metastatic prostate cancer and CRPC.…”