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

Purpose 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 [Ga-68]Ga-PSMA-11 PET/CT, [Ga-68]Ga-NODAGA-zoledronate ([Ga-68]Ga-NODAGA(ZOL)) PET/CT, and [Tc-99m]Tc-MDP bone scan in the assessment of bone metastases in patients with advanced PCa. Methods We prospectively recruited two cohorts of patients (staging and re-staging cohorts) with advanced prostate cancer. The staging cohort was treatment-naive PCa patients who showed skeletal metastases on bone scan. These patients were subsequently imaged with [Ga-68]Ga-PSMA-11 PET/CT and [Ga-68]Ga-NODAGA(ZOL) 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 [Ga-68]Ga-PSMA-11 PET/CT and [Ga-68]Ga-NODAGA(ZOL) PET/CT. We performed a per-patient and per-lesion analysis of skeletal metastases in both cohorts and made a comparison between scan findings. Results Eighteen patients were included with a median age of 68 years (range = 48-80) and a median Gleason score of 8. There were ten patients in the staging cohort with a median PSA of 119.26 ng/mL (range = 4.63-18,948.00) and eight patients in the re-staging cohort with a median PSA of 48.56 ng/mL (range = 6.51-3175.00). In the staging cohort, skeletal metastases detected by [Ga-68]Ga-PSMA-11 PET/CT, [Ga-68]Ga-NODAGA(ZOL) PET/CT, and bone scan were 322, 288, and 261, respectively, p = 0.578. In the re-staging cohort, [Ga-68]Ga-PSMA-11 PET/CT and [Ga-68]Ga-NODAGA(ZOL) PET/CT detected 152 and 191 skeletal metastases, respectively, p = 0.529. In two patients with negative [Ga-68]Ga-PSMA-11 PET/CT findings, [Ga-68]Ga-NODAGA(ZOL) detected one skeletal metastasis in one patient and 12 skeletal metastases in the other. Conclusion In patients with advanced prostate cancer, [Ga-68]Ga-PSMA-11 PET/CT may detect more lesions than [Ga-68]Ga-NODAGA(ZOL) PET/CT and [Tc-99m]Tc-MDP bone scan for the staging of skeletal metastases. In patients who experience PSA progression on PSMA-based radioligand therapy, [Ga-68]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, [Ga-68]Ga-NODAGA(ZOL) PET/CT may detect more lesions than [Ga-68]Ga-PSMA-11 PET/CT.

Automated summary

This study compared the lesion detection rate of [Ga-68]Ga-PSMA-11 PET/CT, [Ga-68]Ga-NODAGA(ZOL) PET/CT, and [Tc-99m]Tc-MDP bone scan in assessing bone metastases in patients with advanced prostate cancer. The results showed that in the staging of skeletal metastases, [Ga-68]Ga-PSMA-11 PET/CT may detect more lesions than [Ga-68]Ga-NODAGA(ZOL) PET/CT and [Tc-99m]Tc-MDP bone scan.