Expanding the role of PSMA PET in active surveillance

Abstract

Introduction Accurate grading at the time of diagnosis is fundamental to risk stratification and treatment decision making, particularly for men being considered for Active Surveillance (AS). With the introduction of prostate-specific membrane antigen (PSMA) positron emission tomography (PET) there has been considerable improvement in sensitivity and specificity for the detection and staging of clinically significant prostate cancer. Our study aims to determine the role of PSMA PET/CT in men with newly diagnosed low or favourable intermediate risk prostate cancer to better select men for AS. Method This is a retrospective single centre study performed from January 2019 and October 2022. This study includes men identified from electronic medical record system who had undergone a PSMA PET/CT following newly diagnosed low or favourable-intermediate risk prostate cancer. Primary outcome was to assess the change in management for men being considered for AS following PSMA PET/CT results on the basis of PSMA PET characteristics. Results In total, there were 11 of 30 men (36.67%) who were assigned management by AS and 19 of 30 men (63.33%) who had definitive treatment. 15 of the 19 men that needed treatment had concerning features on PSMA PET/CT results. Of the 15 men with concerning features on PSMA PET, 9 (60%) men were found to have adverse pathological features on final prostatectomy features. Conclusion This retrospective study suggests that PSMA PET/CT has potential to influence the management of men with newly diagnosed prostate cancer that would otherwise be appropriate for active surveillance.

The Role of PSMA PET Imaging in the Classification of the Risk of Prostate Cancer Patients: A Systematic Review on the Insights to Guide an Active Surveillance Approach

“…After reviewing the titles and abstracts, 1766 of them were excluded for different reasons: 534 because the reported data were not within the field of interest of this review, 126 were systematic reviews, 110 were care series or case reports, 974 were conference abstracts, 12 were editorials, nine were study protocols, and one study had the same cohort as another paper. Consequently, eight studies addressing the role of PSMA PET/CT in the clinical setting of AS were selected and the full texts were retrieved [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. No additional studies were found after analyzing the reference lists of these articles ( Figure 1 ).…”

“…Among the total number of studies included in the systematic review, three were retrospective [ 22 , 23 , 26 ], whereas five had a prospective design [ 20 , 21 , 24 , 25 , 27 ]. In terms of radiopharmaceuticals used, five studies were performed using [ 68 Ga]Ga-PSMA-11 [ 20 , 21 , 23 , 24 , 27 ], a single study with [ 18 F]F-PSMA-1007 [ 22 ], a study with both [ 68 Ga]Ga-PSMA-11 and [ 18 F]F-DCFPyL [ 26 ], while in one study, the tracer used was not specified and referred to as a general [ 68 Ga]Ga-PSMA [ 25 ], although different papers published by the same group used [ 68 Ga]Ga-PSMA-11. Moreover, six studies were performed using a PET/CT tomograph [ 21 , 23 , 24 , 25 , 26 , 27 ] and two studies used PET/MRI [ 20 , 22 ].…”

“…In terms of radiopharmaceuticals used, five studies were performed using [ 68 Ga]Ga-PSMA-11 [ 20 , 21 , 23 , 24 , 27 ], a single study with [ 18 F]F-PSMA-1007 [ 22 ], a study with both [ 68 Ga]Ga-PSMA-11 and [ 18 F]F-DCFPyL [ 26 ], while in one study, the tracer used was not specified and referred to as a general [ 68 Ga]Ga-PSMA [ 25 ], although different papers published by the same group used [ 68 Ga]Ga-PSMA-11. Moreover, six studies were performed using a PET/CT tomograph [ 21 , 23 , 24 , 25 , 26 , 27 ] and two studies used PET/MRI [ 20 , 22 ]. The main characteristics of the studies and their results are briefly presented in Table 1 and Table 2 .…”

“…Jain et al [ 26 ] assessed the role of PSMA PET/CT in AS in men newly diagnosed with low or favorable intermediate-risk PCa, including 30 patients submitted to both [ 68 Ga]Ga-PSMA-11 and [ 18 F]F-DCFPyL. In the 15 subjects with GG 1 disease at biopsy, seven were assigned to AS and all of them had mildly expressing lesions upon PSMA imaging.…”

“…Interestingly, PSMA PET/CT and targeted biopsies yielded upgrading most frequently in patients with negative MRI and, in patients with additional PSMA-targeted biopsies, upgrading was most frequently found in those with a higher PSMA density and a negative MRI [ 25 ]. Additionally, it has been reported that PSMA PET/CT was able to change the management approach of patients suitable for AS with low or favorable intermediate-risk PCa, resulting in the diversion of management to intervention based on some concerning imaging features such as the presence of MRI occult lesions, marked PSMA uptake, and extraprostatic extension [ 26 ]. Nevertheless, the combination of these two imaging modalities into PSMA PET/MRI revealed high diagnostic accuracy in the staging of PCa and the ability to change clinical treatment decisions in a significant number of patients, including a switch to the AS approach [ 20 ].…”