Quantitative characterization of 18F-PSMA-1007 and [68Ga]Ga-PSMA-11 PET-CT Imaging in Suspected Prostate Cancer: A Single-centre Experience

Objectives: We record quantitative differences between 18 F-prostate specific membrane antigen ( 18 F-PSMA)-1007 and [ 68 Ga]Ga-PSMA-11 positron emission tomography (PET) prostate scans at our centre to investigate if significant differences exist between suspected lesion and lesion/ background parameters studied.We also assess the potential impact of such differences on tracer interchangeability when supply is constrained.Methods: Sixty-one [ 68 Ga]Ga-PSMA-11 and seventy-two 18 F-PSMA-1007 patients were analysed in two cohorts, each comprising 200 lesions.Clinical reports were used to determine maximum standard uptake values (SUV max ) was recorded for suspected lesions (T).Similarly, normalisations of mean standardized uptake (SUV mean ) and standardized uptake value-peak (SUV peak ) using lean body mass (SUV lbm ) and body surface area (SUV bsa ) were estimated.SUV mean of liver backgrounds (B) was recorded to estimate T/B ratios.Metabolic tumour volume and total lesion PSMA (TL-PSMA) were investigated as functional volume surrogates.The Mann-Whitney U test was used to identify significant differences between the [ 68 Ga]Ga-PSMA-11 and 18 F-PSMA-1007 distributions.Results: Significant differences were observed for lesion SUV max (p=0.0004),SUV peak (p=0.0017),SUV mean (p=0.0007),SUV lbm (p=0.0002), and SUV bsa (p=0.0005) in lesions with higher [ 68 Ga]Ga-PSMA-11 SUV.Similarly, significant differences were observed in liver SUV max (p