A prospective intra-individual comparison of [68Ga]Ga-PSMA-11 PET/CT, [68Ga]Ga-NODAGAZOL PET/CT, and [99mTc]Tc-MDP bone scintigraphy for radionuclide imaging of prostate cancer skeletal metastases

Abstract

Prostate cancer (PCa) commonly metastasizes to the bones. There are several radionuclide techniques for imaging PCa skeletal metastases. We aimed to compare the lesion detection rate of [68Ga]Ga-PSMA-11 PET/CT, [68Ga]Ga-NODAGA-zoledronate ([68Ga]Ga-NODAGAZOL) PET/CT, and [99mTc]Tc-MDP bone scan in the assessment of bone metastases in patients with advanced PCa. We prospectively recruited two cohorts of patients (staging and re-staging cohorts) with advanced prostate cancer. The staging cohort was treatment-naïve PCa patients who showed skeletal metastases on bone scan. These patients were subsequently imaged with [68Ga]Ga-PSMA-11 PET/CT and [68Ga]Ga-NODAGAZOL PET/CT. Re-staging cohort was patients who were previously treated with PSMA-based radioligand therapy and were experiencing PSA progression. The re-staging cohort was imaged with [68Ga]Ga-PSMA-11 PET/CT and [68Ga]Ga-NODAGAZOL PET/CT. We performed a per-patient and per-lesion analysis of skeletal metastases in both cohorts and made a comparison between scan findings. Eighteen patients were included with a median age of 68years (range = 48-80) and a median Gleason score of 8. There were ten patients in the staging cohort with a median PSA of 119.26ng/mL (range = 4.63-18,948.00) and eight patients in the re-staging cohort with a median PSA of 48.56ng/mL (range = 6.51-3175.00). In the staging cohort, skeletal metastases detected by [68Ga]Ga-PSMA-11 PET/CT, [68Ga]Ga-NODAGAZOL PET/CT, and bone scan were 322, 288, and 261, respectively, p= 0.578. In the re-staging cohort, [68Ga]Ga-PSMA-11 PET/CT and [68Ga]Ga-NODAGAZOL PET/CT detected 152 and 191 skeletal metastases, respectively, p= 0.529. In two patients with negative [68Ga]Ga-PSMA-11 PET/CT findings, [68Ga]Ga-NODAGAZOL detected one skeletal metastasis in one patient and 12 skeletal metastases in the other. In patients with advanced prostate cancer, [68Ga]Ga-PSMA-11 PET/CT may detect more lesions than [68Ga]Ga-NODAGAZOL PET/CT and [99mTc]Tc-MDP bone scan for the staging of skeletal metastases. In patients who experience PSA progression on PSMA-based radioligand therapy, [68Ga]Ga-NODAGA PET/CT is a more suitable imaging modality for the detection of skeletal lesions not expressing PSMA. In the setting of re-staging, [68Ga]Ga-NODAGAZOL PET/CT may detect more lesions than [68Ga]Ga-PSMA-11 PET/CT.