Performance of Ga-68 PSMA PET/CT for diagnosis and grading of local prostate cancer

Abstract

Background We aimed to evaluate the utility of prostate-specific membrane antigen (PSMA) PET/CT for the detection of local disease within the prostate. Methods This is a retrospective review of a single-center experience evaluating intraprostatic detection rates compared with final histopathology in a radical prostatectomy (RP) population. Seventy-two patients had PSMA PET/CT scan performed as part of their primary staging. Intraprostatic PSMA PET/CT avidity was assessed. PSMA PET/CT uptake was retrospectively correlated with patient characteristics including final histopathology, MRI Prostate Imaging Reporting and Data System (PI-RADS) score, clinical tumor stage, prostate-specific antigen (PSA) level, and patient age. Results The sensitivity of PSMA PET/CT for the detection of RP-confirmed prostate cancer was 81.2%. Much higher sensitivity was found within certain subpopulations. The patient characteristics that most strongly correlated with focal intraprostatic PSMA PET/CT uptake were patient age (Kendall's tau coefficient τ b = 0.24, p < 0.05) and clinical T stage (τ b = 0.21, p < 0.05). The International Society of Urological Pathology (ISUP) grade group from final RP was predicted by standardized uptake value (SUV max ) and to a lesser extent PSA and the maximal dimension of PET-avid lesions. SUV max monotonically increased with ISUP grade group. If SUV max was above 10 g/mL, the final RP histopathology had a relative risk of 2.3 (95% CI 1.3–4.1) of being ISUP grade group 5. Conclusion This trial provides early evidence that PSMA PET/CT assists in the grading of prostate cancer and suggests that the imaging modality is particularly accurate in subpopulations including the elderly and those with palpable disease.

Could 68Ga-PSMA PET/CT Evaluation Reduce the Number of Scheduled Prostate Biopsies in Men Enrolled in Active Surveillance Protocols?

“…Recently, 68Ga-PSMA-PET/CT has been suggested to improve the clinical stadiation of high-risk PCa and disease recurrence [ 7 ]; at the same time, PSMA PET/CT has been proposed for the diagnosis of primary intraprostatic cancer [ 15 ]. The presence of focal uptake on PSMA-PET/CT, the standardised uptake value (SUVmax) and the maximal dimensions of PET-avid lesions have been correlated with the presence of csPCa [ 20 , 21 ]. There is a range of proposed cutoffs to detect csPCa from SUVmax 3.15 to up SUVmax 9.1 [ 22 , 23 ]; the concordance between preoperative PSMA PET/TC evaluation (SUVmax, dimension of the lesion), and definitive prostate specimen ranges from 81.2% (24) to 96% [ 24 , 25 , 26 , 27 , 28 ].…”

Association of serum prostate-specific antigen (PSA) level and circulating tumor cell-based PSA mRNA in prostate cancer

“…However, it does not accurately represent the molecular state of the tumor cells or their biological characteristics. 1 , 2 , 3 , 4 , 5 Serum PSA is often measured as high in men without PCa or low in advanced PCa. Many other biological markers have been studied to compensate for this and PSA mRNA has been proposed as a novel marker.…”

“…However, it does not accurately evaluate the biological characteristics of prostate cancer cells, and there is a need to develop better biological markers to assess the progression of prostate cancer. 1 , 2 , 3 , 4 , 5 In particular, as the treatment for metastatic PCa is diversified, there is increased interest in the development of biomarkers to predict treatment responsiveness.…”

Multiparametric Magnetic Resonance Imaging of the Prostate and Prostate-specific Membrane Positron Emission Tomography Prior to Prostate Biopsy (MP4 Study)

“…Initial utilisation primarily focused upon its role in the detection of disease recurrence following the curative-intent treatment of the primary cancer by surgery or radiotherapy, and also as a tool for primary staging [1] , [2] , [3] . More recently, PSMA PET has an evolving role as a diagnostic tool to characterise prostate cancer within the gland [4] , [5] , [6] , [7] , [8] . Several provocative studies have indicated the potential for PSMA imaging in conjunction with multiparametric magnetic resonance imaging (MRI) of the prostate to triage those men who could be potentially reassured and monitored, rather than proceed to diagnostic biopsy [6] , [7] , [9] .…”