Authors' objectives: To search for and summarise evidence on the effectiveness of PET using 68Ga-PSMA and other PET tracers in the investigation of recurrent prostate cancer.

Authors' results and conclusions: There is evidence from two systematic reviews which show that 68Ga-PSMA PET has a higher sensitivity and specificity than other imaging modalities. However, these studies may be at risk of bias, primarily due to the small population sizes studied. The lack of studies directly comparing the diagnostic accuracy of tracers makes comparisons of their effectiveness difficult. Formal statistical comparison of diagnostic accuracy is therefore not possible. One prospective study published subsequent to the systematic reviews reports very high sensitivity (98.8%, 95% confidence interval 95.7 to 99.8%) and specificity (100.0%, 95% confidence interval 83.4 to 100.0%) for 68Ga-PSMA PET in identifying prostate cancer recurrence. Although no studies exist of head-to-head comparisons of the diagnostic accuracy of 68Ga-PSMA PET to other imaging techniques, several studies consistently showed higher detection rates with 68Ga-PSMA PET than with any of the comparators investigated (choline-based PET/CT, or conventional imaging such as CT and MRI). Clinical utility outcomes for PSMA-based PET were reported by one systematic review (ten relevant studies included) and nine studies (919 patients in total) that were published subsequent to the systematic review, all using 68Ga-PSMA. All these studies demonstrated that the findings of 68Ga-PSMA PET can influence subsequent treatment planning, although the percentage of patients affected varied widely between studies. Data on the effectiveness of 18F-PSMA PET/CT is only available from three retrospective case series. These only reported detection rates for positive lesions, and did not include any data on verification of test results. Reported detection rates ranged from 75 to 95%. No published primary or secondary research on the cost effectiveness of PSMA-based PET for the investigation of recurrent prostate cancer were identified.

Authors' recommendations: The adoption of 68Ga-PSMA PET for the diagnosis of recurrent prostate cancer is partially supported by the evidence. The use of 68Ga-PSMA PET provides a high degree of diagnostic accuracy on which to base management decisions as compared with conventional tracers. However, evidence comparing 68Ga-PSMA PET to other tracers is limited, and estimating the cost of using 68Ga-PSMA PET for the investigation of possible recurrent prostate cancer is complex and uncertain. Therefore, 68Ga-PSMA PET is recommended if the service can be delivered at no greater cost than current standard care. The adoption of 18F-PSMA PET for the diagnosis of recurrent prostate cancer is not supported by the evidence.

Authors' methods: The Evidence Appraisal Report is based on a literature search (strategy available on request) for published clinical and economic evidence on the health technology of interest. It is not a full systematic review but aims to identify the best available evidence on the health technology of interest. Researchers critically evaluate and synthesise this evidence. We include the following clinical evidence in order of priority: systematic reviews; randomised trials; non-randomised trials. We only include evidence for “lower priority” evidence where outcomes are not reported by a “higher priority” source. We also search for economic evaluations or original research that can form the basis of an assessment of costs/cost comparison. We carry out various levels of economic evaluation, according to the evidence that is available to inform this.

Authors' identified further research: Large, prospective, comparative multicentre studies are recommended to evaluate the impact on patient management and outcomes of PSMA-based PET tracers compared to currently-used imaging modalities. Such studies should also define the cost effectiveness of this investigation and help clarify the indications and point in the care pathway when 68Ga-PSMA PET should be considered. Further research on the diagnostic accuracy and clinical performance of 18F-PSMA PET should also be undertaken.

Project Status: Completed

Year Published: 2019

URL for published report: https://www.healthtechnology.wales/reports-guidance/fluorine-or-gallium-prostate-specific-membrane-antigen-positron-emission-tomography-radiotracers/

English language abstract: An English language summary is available

Publication Type: Rapid Review

Country: Wales, United Kingdom

Organisation Name: Health Technology Wales

Contact Address: Floor 3, 2 Capital Quarter, Tyndall Street, Cardiff, CF10 4BZ

Contact Name: Susan Myles, PhD

Contact Email: healthtechnology@wales.nhs.uk

Copyright: Health Technology Wales