Head-to-head comparison of [۹۹mTc]Tc-MDP and [۹۹mTc]Tc-PSMA whole-body SPECT/CT in prostate cancer patients

Intoduction: Due to high expenses and lack of wide availability of [۶۸Ga]Ga-PSMA PET/CT scan, we aimed to evaluate [۹۹mTc]Tc-MDP and [۹۹mTc]Tc-PSMA scan findings in a cluster of prostate cancer patients.Methods: This prospective cross-sectional study was conducted from March ۲۰۲۱ to March ۲۰۲۲ at Shahid Hashemi Nejad hospital in Tehran, Iran. In this study, prostate cancer patients with intermediate to high-risk or patients with PSA rise during follow-up were selected for undergoing both [۹۹mTc]Tc-MDP bone scintigraphy and [۹۹mTc]Tc-PSMA scan. The scans were performed with a maximum ۲-week interval. The images were evaluated for presence, number and locations of abnormal lesions. CT findings were used as an anatomical comparator; however, CT was not considered a true reference standard.Results: ۲۰ patients were evaluated. ۶۳ bone lesions on CT scan, ۶۹ lesions on [۹۹mTc]Tc-MDP bone scan, ۲۳ lesions on [۹۹mTc]Tc-PSMA SPECT/CT and ۱۶ lesions on [۹۹mTc]Tc-PSMA planar images, were visualized. ۵۶.۳%, ۳۱.۱% and ۳۱.۱% of patients had positive conventional bone scan, [۹۹mTc]Tc-PSMA SPECT/CT and planar [۹۹mTc]Tc-PSMA images. Mean number of lesions on these modalities were ۴.۳۱±۶.۸۵, ۱.۴۳±۳.۷۵ and ۱.۰۰±۲.۳۰, respectively. Sensitivity rates of these three modalities were ۱۰۰%, ۵۵.۶% and ۵۵.۶% while specificity was ۱۰۰% for all of these modalities. Mean number of bone lesions on [۹۹mTc]Tc-MDP bone scintigraphy and [۹۹mTc]Tc-PSMA SPECT/CT showed significant difference (p=۰.۰۲۷).Conclusion: In this cohort, [۹۹mTc]Tc-MDP whole-body SPECT/CT scintigraphy identified a greater number of skeletal lesions than [۹۹mTc]Tc-PSMA SPECT/CT. however, because a composite reference standard was unavailable, these findings should be interpreted as differences in lesion detection rather than definitive evidence of superior diagnostic performance. Larger prospective multicenter studies are warranted.

کلیدواژه ها:

Bone scan ، [۹۹mTc]Tc-MDP ، [۹۹mTc]Tc-PSMA ، SPECT/CT ، prostate cancer ، Bone metastasis