18F-PSMA-1007 PET/CT Performance on Risk Stratification Discrimination and Distant Metastases Prediction in Newly Diagnosed Prostate Cancer

Abstract

ObjectiveTo evaluate the prediction performance of 18F-PSMA-1007 PET/CT and clinicopathologic characteristics on prostate cancer (PCa) risk stratification and distant metastatic prediction.Materials and MethodsA retrospective analysis was performed on 101 consecutively patients with biopsy or radical prostatectomy proved PCa who underwent 18F-PSMA-1007 PET/CT. The semi-quantitative analysis provided minimum, maximum and mean standardized uptake (SUVmin, SUVmax and SUVmean) of PCa. Association between clinicopathologic characteristics (total prostate-specific antigen, tPSA and Gleason Score, GS) and PET/CT indexes were analyzed. The diagnostic performance of distant metastatic on PET/CT parameters, tPSA and GS was evaluated using logistic regression analyses. A path analysis was conducted to evaluate the mediating effect of tPSA level on the relation between semi-quantitative parameters of primary tumors and metastatic lesions.ResultsThe PET/CT parameters were all higher in high risk stratification subgroups (tPSA>20 ng/mL, GS ≥ 8, and tPSA>20 ng/mL and/or GS ≥ 8, respectively) with high sensitivity (86.89%, 90.16% and 83.61%, respectively). The SUVmax, tPSA and GS could effectively predict distant metastatic with high sensitivity of SUVmax (90.50%) compared with tPSA (57.14%) and GS (55.61%). With a cutoff value of 29.01ng/mL for tPSA, the detection rate of distant metastasis between low and high prediction tPSA group had statistical differences (50.00% vs. 76.60%, respectively; P = 0.006) which was not found on guideline tPSA level (P>0.05). 6/15 (40%) patients tPSA between 20ng/mL to 29.01ng/mL without distant metastases may change the risk stratification. Finally, tPSA had a partial mediating effect on SUVmax of primary tumors and metastases lesions.ConclusionThe 18F-PSMA-1007 PET/CT SUVmax has a higher sensitivity and can be an “imaging biomarker” for primary PCa risk stratification. The prediction tPSA level (29.01 ng/mL) is more conducive to the assessment of distant metastasis and avoid unnecessary biopsy.

Evaluation of a radiomics nomogram derived from Fluoride-18 PSMA-1007 PET/CT for risk stratification in newly diagnosed prostate cancer

“…Thus, to reduce unnecessary prostate biopsies for tumor malignancy prediction, radiomics signatures provide a more objective and independent prediction scheme.Prior study found that the detection rate of distant metastasis for 18 F-PSMA PET/CT was higher between the PSA ≥ 30ng/mL and PSA ≥ 20ng/mL cohorts. The PET/CT parameter SUVmax difference between primary tumors and metastatic lesions in metastatic PCa patients with a higher prediction PSA level (i.e., > 29.01) ( 4 ). Therefore, benefiting populations in a nomogram based on PSA, metastatic status, and radiomics score may be more likely to be represented in patients with higher PSA.…”

“…All participants included in the data analysis were evaluated using 18 F-PSMA-1007 PET/CT and had PSA values measured within 4 weeks prior to the imaging scan. Diagnosis of PCa proven through histological examination served as a reference for PET imaging analyses ( 4 , 24 ). Patients were excluded from the analysis if they 1) had received local or systemic treatment, 2) lacked histological examination proven diagnosis or PSA value, and 3) had incomplete imaging data.…”

“…PET data sets were reconstructed using time-of-flight with three iterations. Whole-body PET scans were performed in three-dimensional mode (emission time: 90 s per bed position, scanned for a total of 7–10 beds) as our prior study ( 4 ).…”

“…Prostate cancer (PCa) is one of the leading causes of death in men worldwide, and its biological behavior is highly heterogeneous, directly affecting patient prognosis and treatment options ( 1 – 4 ). During prostate screening, elevated prostate-specific antigen (PSA) levels indicate an increased risk of PCa; however, PSA is organ-specific but not tumor-specific, and the specificity of PSA in reflecting disease severity remains debatable ( 5 ).…”

18F-Prostate-Specific Membrane Antigen and 18F-Fluorodeoxyglucose PET/CT Unmasked the Characteristics of Prostate Lymphoma: A Case Report and Literature Review

“…Thus, PSMA is a promising and specific target for prostate adenocarcinoma imaging. In the past years, PSMA PET/CT has extremely improved the management of prostate adenocarcinoma when compared with conventional imaging, especially in the aspect of detecting metastatic spread and micrometastases ( 5 , 6 ). Furthermore, as a molecular imaging examination, the expression level of PSMA on PET/CT is positively correlated with tumor stage and grade ( 7 ), which could help urologists identify patients who may need more intensive treatment and tailor treatment regimes.…”