Matched-Pair Comparison of ¹⁸F-DCFPyL PET/CT and ¹⁸F-PSMA-1007 PET/CT in 240 Prostate Cancer Patients: Interreader Agreement and Lesion Detection Rate of Suspected Lesions

Abstract

IntroductionTens of different Prostate Specific Membrane Antigen (PSMA) targeting radiopharmaceuticals for both imaging and therapy have been synthesized. Although variability in biodistribution and affinity for binding to the PSMA receptor between different PSMA targeting radiopharmaceuticals are known, little is known about the clinical implications of those variabilities. Therefore, in this study differences in interreader agreement and detection rate between two regularly used 18 F-labeled PSMA-receptor targeting radiopharmaceuticals [ 18 F]-DCFPyL and [ 18 F]-PSMA-1007 were analyzed. Material and methods One hundred and twenty consecutive patients scanned with [ 18 F]-PSMA-1007 were match-paired with 120 patients scanned with [ 18 F]-DCFPyL. All 240 PET/CTs were reviewed by two readers and scored according to PSMA-RADS reading criteria for PSMA PET/CT. Inter-reader agreement and detection rate of suspected lesions were scored for different anatomical locations including prostate/prostatic fossa, lymph nodes, bone, and other locations. ResultsLarge equality between [ 18 F]-DCFPyL and [ 18 F]-PSMA-1007 was found; however, some clinically relevant and statistically significant differences were observed. [ 18 F]-PSMA-1007 detected suspected prostatic/prostatic fossa lesions in a higher proportion of patients and especially in the subcohort of patients scanned for biochemical recurrence. [ 18 F]-DCFPyL and [ 18 F]-PSMA-1007 showed equal ability for detection of suspected lymph nodes, although inter-reader agreement for [ 18 F]-DCFPyL was higher. [ 18 F]-DCFPyL showed less equivocal skeletal lesions and higher inter-reader agreement for skeletal lesions.The majority of equivocal lesions found with PSMA-1007 (at least were determined to be aof nonmetastatic origin. ConclusionClinically relevant differences, which may account for diagnostic dilemmas, were observed between of [ 18 F]-DCFPyL and [ 18 F]-PSMA-1007. Those findings encourage further studies, as they may have consequences for selection of the proper PSMA targeting radiopharmaceutical.

Prospective intra-individual blinded comparison of [18F]PSMA-1007 and [68 Ga]Ga-PSMA-11 PET/CT imaging in patients with confirmed prostate cancer

“…However this information may still play an important role in pre-operative surgical planning, choice of treatment modality (radiotherapy may be preferred over exenterative surgery for T4 disease), guiding the extent of radiotherapy treatment (extension of local tumour volume delineation to cover adjacent in ltrated bladder, rectum and/or elective treatment of pelvic lymph nodes (21,22), and the use of androgen deprivation therapy (23). These imaging ndings are consistent with most literature, including a matched pair comparison of 240 scans with [ 18 F]PSMA-1007 vs F-DCFPyl identi ed suspected prostate/prostatic fossa lesions in a higher proportion of [ 18 F]PSMA-1007 scans, particularly for the indication of biochemical recurrence (24). Also in the setting of biochemical recurrence, [ 18 F]PSMA-1007 has previously been shown to be at least as accurate as [ 68 Ga]Ga-PSMA-11 (14,15,25).…”

Molecular Imaging in Primary Staging of Prostate Cancer Patients: Current Aspects and Future Trends

“…In this regard, some new PSMA molecules labeled with other radioisotopes, such as 18 F, were developed [ 107 ]. Fluoride-18 is a cyclotron-generating radioisotope that has more favorable characteristics than 68 Ga, including production in larger quantities, transportation to satellite centers, longer physical half-life, delayed imaging, theoretically better spatial resolution [ 108 , 109 , 110 ], and possibly detection of smaller lesions due to lower positron energy [ 107 , 111 ]. Also, [ 18 F]PSMA-1007 has biliary excretion.…”

“…Except for [ 18 F]PSMA-1007, there are other clinically available 18 F-labeled PSMA agents ([ 18 F]DCFPyL and [ 18 F]DCFBC) [ 113 , 114 , 115 , 116 ]. Despite some differences, which may influence our preference for clinical use, all seem equally effective for imaging of PCa [ 111 , 112 , 117 ]. Very recently, [ 18 F]FDCFPyL was also approved by FDA for staging and re-staging of PCa.…”

“…Very recently, [ 18 F]FDCFPyL was also approved by FDA for staging and re-staging of PCa. Yet, there is no clear recommendation regarding which tracer should be selected [ 111 ].…”

Head-to-Head Comparison of 68Ga-PSMA-11 PET/CT and Multiparametric MRI for Pelvic Lymph Node Staging Prior to Radical Prostatectomy in Patients With Intermediate to High-Risk Prostate Cancer: A Meta-Analysis

“…Among them, 68 Ga-PSMA-11 and 18 F-DCFPyL have been consecutively approved by the FDA for patients with primary and recurrent PCa ( 9 , 10 ). Nevertheless, although 18 F-based tracers offer important advantages such as higher production capacity, longer physical half-life, and minimal radiotracer accumulation in the bladder ( 11 – 13 ); up until now, 68 Ga-PSMA-11 is still worldwide the most commonly used and provides the absolute majority of evidence in the literature for PSMA imaging. Importantly, many accuracy studies and two previous meta-analyses have reported favorable diagnostic performance of 68 Ga-PSMA-11 PET/CT for the detection of pelvic lymph node metastases (PLNMs) in intermediate to high-risk PCa ( 14 – 17 ).…”