PSMA PET

The goal is to provide more accurate diagnostic tools and optimized diagnostic workflows for clinically suspected prostate cancer patients with prior negative biopsies, improving early detection rates for csPCa and reducing missed diagnoses.

Brief Summary: This prospective, multicenter study aims to discover, develop, and validate a plasma exosomal RNA-based signature as a rule-out test for predicting bone metastasis in prostate cancer, using baseline treatment-naïve PSMA PET as the gold standard. The study is designed in four sequential phases: Phase 1 (Discovery, n=250): High-throughput sequencing of plasma exosomal RNAs to identify differentially expressed candidate RNAs. Phase 2 (Model Development, n=300): Digital droplet PCR (ddPCR) analysis of candidates in an independent cohort to construct and lock the final multi-RNA predictive signature using appropriate machine learning methods. Phase 3 (Internal Validation, n=300): Independent validation of the locked signature in a consecutive cohort reflecting natural disease prevalence. Phase 4 (External Validation, n=150): Final independent validation in a multi-center cohort enriched for bone metastasis. Primary Outcome: To evaluate the diagnostic performance of the signature as a rule-out test for PSMA PET-defined bone metastasis. The primary performance metrics are: Sensitivity, with a prespecified target of ≥95% (to ensure minimal false negatives). Specificity at the threshold that achieves the ≥95% sensitivity. A specificity of ≥30% will be considered supportive of clinical utility. A specificity of ≥30% (or a lower bound of the 95% confidence interval exceeding 20%) will be considered supportive of clinical utility. Need: Current biomarkers lack sensitivity and specificity for early detection of bone metastasis. More importantly, existing tools lack adequate negative predictive value to safely rule out bone metastasis in low-risk patients, leading to over-imaging or delayed detection. There is an urgent need for a non-invasive rule-out test to safely defer PSMA PET/CT in very-low-risk patients. Plasma exosomal RNAs offer a promising liquid biopsy approach, but prospective multicenter studies with rigorous validation are lacking. Secondary Outcomes: 1. Secondary metrics include negative predictive value (NPV), positive predictive value (PPV), area under the ROC curve (AUC), calibration, and decision curve analysis. 2. Correlation between exosomal RNA levels and number of bone metastatic lesions (PSMA PET). 3. Association with PSA, PSMA PET SUVmax, and MRI findings. 4. Tissue-plasma correlation to confirm tumor origin (exploratory). 5. Mechanistic exploration of key candidates via in vitro/in vivo assays (exploratory). 6. Subgroup analyses by hormone sensitivity, metastatic pattern, Gleason grade (exploratory). Inclusion Criteria: 1. Histologically confirmed prostate cancer scheduled for baseline PSMA PET. 2. PSMA PET performed prior to any prostate cancer-related treatment. 3. Blood samples collected prior to any treatment AND prior to prostate biopsy. 4. Willing to undergo prostate biopsy if clinically indicated (after blood collection). 5. Written informed consent. 6. Age ≥18 years. Exclusion Criteria: 1. Any prior prostate cancer treatment before baseline PSMA PET. 2. Blood samples collected after prostate biopsy. 3. Other active malignancy within past two years (excluding non-melanoma skin cancer). 4. Inadequate blood sample quality or quantity. 5. Severe comorbidities interfering with study conduct.

This prospective, multicenter study aims to evaluate the clinical utility of serial PSMA PET for therapy monitoring in patients with newly diagnosed clinically significant prostate cancer. Clinically significant prostate cancer is defined as Gleason score ≥7.Patients will undergo baseline PSMA PET/CT prior to any treatment. A second PSMA PET/CT will be performed either at PSA recurrence (PSA rise ≥2 ng/mL above nadir after radiotherapy or biochemical progression per PCWG3 criteria) or at a fixed time window of 12-24 months after treatment completion for those without biochemical recurrence. Primary Outcome: 1\. Absolute and relative change in SUVmax from baseline to follow-up PSMA PET, correlated with treatment response categories (complete response, partial response, stable disease, progressive disease) defined by a composite reference standard (PSA kinetics, conventional imaging, clinical outcomes). \[Time Frame: Baseline and follow-up (up to 24 months)\] Secondary Outcomes: 1. Absolute and relative change in the number of PSMA-avid lesions (primary tumor, nodal, bone metastases) as a supportive exploratory endpoint. 2. Proportion of patients with treatment strategy change following serial PSMA PET. 3. Agreement between PSMA PET response (≥30% decrease in SUVmax) and PSA50 response (≥50% PSA decline) using Cohen's kappa. 4. Agreement between PSMA PET response and PSA90 response (≥90% PSA decline). 5. Prognostic value of baseline and follow-up PSMA PET parameters for progression-free survival (PFS). 6. Prognostic value of baseline and follow-up PSMA PET parameters for time to castration resistance (ADT-treated patients only). 7. Subgroup analyses by treatment type (radiotherapy, ADT, chemotherapy), baseline disease burden (oligometastatic vs. polymetastatic), and Gleason grade group (≤7 vs. ≥8). 8. Inter-reader agreement for PSMA-avid lesion counts. \[Time Frame: Up to 2 years, except inter-reader agreement at baseline\] Need: Current treatment response evaluation relies on PSA changes and conventional imaging, which lack sensitivity and accuracy for early assessment. PSMA PET has demonstrated superior sensitivity for detecting prostate cancer lesions, but its role in longitudinal therapy monitoring remains undefined, with no specific regulatory approval for this indication. Prospective data on serial PSMA PET to guide treatment decisions in patients with clinically significant prostate cancer (Gleason score ≥7) are urgently needed. Inclusion Criteria: 1. Newly diagnosed, histologically confirmed clinically significant prostate cancer with Gleason score ≥7. 2. Planned curative-intent or systemic therapy. 3. Baseline PSMA PET performed prior to any treatment. 4. Age ≥18 years. 5. Written informed consent. Exclusion Criteria: 1. Prior prostate cancer treatment before baseline PSMA PET. 2. Contraindication to PSMA PET imaging. 3. Other active malignancy within past two years (excluding non-melanoma skin cancer). 4. Unable to comply with follow-up schedule.

The primary research purpose is to evaluate the diagnostic efficacy of 68Ga-PSMA PET in metastatic lesions of locally advanced and advanced renal cell carcinoma, and to compare with that of enhanced CT. The second purpose is to evaluate whether 68Ga-PSMA PET can change the treatment decision of patients with locally advanced and advanced renal cell carcinoma

This is an open label, longitudinal Phase 3 study of prostate specific membrane antigen (PSMA) positron emission tomography (PET) combined with magnetic resonance imaging (MRI) compared to standard of care (SOC) for the detection of prostate cancer (PCa).