Room: Exhibit Hall | Forum 5
Purpose: Prostate cancer (PCa) is the second most common malignant tumor in men worldwide. 68Ga-PSMA is highly specific for PCa and 68Ga-PSMA-ligand can help delay systemic therapy of PCa. In these retrospective analyses we evaluated the biodistribution of 68Ga-PSMA in ten patients with metastatic prostate cancer who underwent PET/CT imaging in terms of SUVmax.
Methods: Ten 68Ga PET/CT scans for patients with end-stage prostate cancer were studied. All patients received 5 mCi of 68Ga-PSMA. All patients signed a written informed consent form for the purpose of anonymized evaluation and publication of their data. Scans were total body, attenuation and scatter corrected with 168 ×168 matrix size for reconstruction. The fusion of images was performed with the Symbia-T fusion software. RadiAnt software was used to measure SUVmax in desired reign of interests (ROIs). Bone, lung, kidney, liver, spleen, heart, bladder, lacrimal gland, salivary gland, bone metastases, lymph nodes, and cist were included for SUVmax assessment.
Results: We measured the SUVmax values for the organs that are considered as the target of normal biodistribution for 68Ga-PSMA, bone metastases, lymph nodes, and cists if any. our results showed that the 68Ga-PSMA uptake in metastases and lymph nodes is much higher than other organs (from about 5 to about 40 times higher uptake in metastases sites). However, high uptake in kidney, bladder, salivary gland, and spleen should be taken into account for dosimetric consequences.
Conclusion: The results of this study provide promising horizons for treatment planning with this theranostic agent. Since diagnosis and treatment with PSMA-based agents is not FDA-approved yet, there is still demand further study about PSMA-agents. The study that will demonstrate if there is a relation between absorbed dose and SUVmax is in progress for our subjects.