- What is the cost-effectiveness of PET imaging using PSMA labelled with gallium-68 (68Ga) or fluorine-18 (18F) in patients with suspected or confirmed metastatic or biochemically recurrent prostate cancer?
- What is the diagnostic accuracy of PET imaging using PSMA labelled with 68Ga or 18F in patients with suspected or confirmed metastatic or biochemically recurrent prostate cancer?
- What are the evidence-based guidelines regarding the use of PET imaging using prostate-specific membrane antigen (PSMA) labelled with 68Ga or fluorine-18 18F in patients with suspected or confirmed metastatic or biochemically recurrent prostate cancer?
Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) imaging for patients with biochemical recurrence of prostate cancer was evaluated as a cost-effective alternative to usual care imaging in one well-conducted economic analysis. The applicability of this study to the Canadian healthcare setting was not clear and the study was limited by the sources of clinical and cost data inputs. Evidence identified on the diagnostic accuracy of PSMA PET imaging consisted of 197 relevant primary studies compiled in 16 systematic reviews included in this report. This large body of evidence was evaluated by 11 of the included systematic reviews as having significant risk of bias, most commonly associated with the diagnostic reference standard. Additionally, four systematic reviews found evidence of possible publication bias in favour of positive results within the primary study evidence. Despite high heterogeneity and a lack of consistent diagnostic performance outcomes between primary studies, a consensus that PSMA PET provided useful diagnostic performance for recurrent prostate cancer was reported by the systematic reviews. Evidence was also identified from four systematic reviews that suggested that PSMA PET provided greater diagnostic accuracy than radiolabeled choline-based PET. There was also consensus that PSMA PET diagnostic accuracy decreased with decreasing prostate-specific antigen (PSA) levels in biochemical recurrence, as observed with other PET radiolabeled tracers. One meta-analysis also reported statistically superior disease detection of PSMA PET as compared to radiolabeled choline PET imaging in patients with lower PSA levels. The authors of the majority of systematic reviews concluded that larger prospective comparative trials with a suitable and consistent reference standard are required to accurately determine diagnostic accuracy of PSMA PET and thereby its optimal role in diagnosing patients with recurrence of prostate cancer. One set of guidelines from the US had a relevant recommendation, based on expert opinion, that PET/CT including PSMA PET imaging may be used for patients with biochemical recurrence of prostate cancer as an alternative to conventional imaging.