^68Gallium-labelled PSMA-PET/CT as a diagnostic and clinical decision-making tool in Asian prostate cancer patients following prostatectomy

Objective:Prostatecancers(PCa)inAsianindividualsaremolecularlydistinctfromthosefoundintheirCaucasiancounterparts.ThereisnoriskstratificationtoolforAsianmenwithrapidbiochemicalrecurrence(BCR)followingradicalprostatectomy(RadP).Thisstudyaimstoassessthedetectionrateof^68Ga-prostate-specificmembraneantigen-positronemissiontomography/computedtomography(PSMA-PET/CT)fordiagnosisofclinicalrecurrenceandasatreatmentdecisionmakingtoolinAsianpatientswithBCRpost-RadP.Methods:^68GaPSMA-PETandCTbodywith/withoutbonescan[conventionalworkup(CWU)]wereperformedin55AsianpatientswithBCRwithin36monthspost-RadP.Twoblindedreviewersassessedtheimages.Detectionratesof^68GaPSMAPET/CTwereevaluated,andimpactonmanagementwasreviewedbycomparisonwithCWU.Results:MediantimetoBCRpost-RadPwas8.1months.Detectionratefor^68GaPSMA-PET/CTwas80%(44/55).Apositivescanwassignificantlyassociatedwithincreasingprostate-specificantigen(PSA)level[oddsratio(OR)=1.13(95%CI1.05–1.30),P=0.017],butnotwithhigherGleasongradeorshorterPSAdoublingtime.ComparedtoCWU,68GaPSMA-PET/CTdetectedanadditional106lesionsin33/44patientswithapositivescan,resultinginachangeinmanagementin25/44(56.8%)patients:10tohormonaltherapy(HT)andwholepelvisradiotherapy(RT)inadditiontobedRT,and15topalliativeHTalone.Conclusions:Inthepresentreport,wedemonstratedthediagnosticandtreatmentdecisionutilityof^68GaPSMA-PET/CTinAsianmenwithrapidBCR.DetectionofsmallvolumenodalandsystemicrecurrencesatlowPSAlevels(<1.0ng/mL)highlightstheroleofthetoolinassigningpatientstotreatmentintensificationwithHT-RTorpalliativeHTinpolymetastaticdisease.