Exploratory analysis of 64CuCl2 PET-CT imaging in carcinoma prostate and its comparison with 68Ga-PSMA-11 and 18F-FDG PET-CT

Abstract

Aim Exploratory analysis of 64CuCl2 PET-CT imaging in patients of carcinoma prostate and its head-to-head comparison with 68Ga-PSMA-11 and 18F-FDG PET-CT. Methods In this prospective study, 50 patients of biopsy-proven carcinoma prostate belonging to the entire spectrum of disease were evaluated, out of which 21 patients were for initial staging and 29 were for restaging/response evaluation. Both 64CuCl2 (early and delayed) and 68Ga-PSMA-11 PET-CT were undertaken in all patients and 18F-FDG PET-CT was done in patients whenever possible. All scans were done within a period of 2 weeks, without any interim therapeutic intervention. 64CuCl2 PET-CT was acquired at 1 and 3 h. We evaluated the physiological uptake of 64CuCl2, correlated the uptake in primary with disease parameters like Gleason score and serum PSA levels, and compared the detection rates for primary and metastatic disease with 68Ga-PSMA-11 and 18F-FDG PET-CT. Results The detection rates of primary disease were same for both 64CuCl2 and 68Ga-PSMA-11 PET-CT and both agents performed similarly in detecting extra-prostatic disease. There was no statistically significant correlation observed between the uptake of 64CuCl2 in the primary lesion with disease parameters. With regard to the evaluation of metastatic disease, the detection rate of 64CuCl2 PET-CT was 86% for lymph nodes, 77.3% for skeletal metastases and 80.6% for soft tissue metastases while 68Ga-PSMA-11 PET-CT performed better with detection rates were 98%, 99% and 85.4%, respectively. In 17 patients where 18F-FDG PET-CT was available, 64CuCl2 PET-CT detected more metastatic disease than 18F-FDG PET-CT. Conclusion 64CuCl2 PET-CT did not show any additional advantage over 68Ga-PSMA-11 PET-CT in evaluation of local disease or for the assessment of metastatic disease. When compared to 68Ga-PSMA-11 PET-CT, the absence of urinary bladder and ureteric activity allows better contrast for evaluating local disease, but it does not translate into increased disease detection.