Dose Enhancement Due to Injection of 79Au, 64Ga, 26Fe and 22Ti Nanoparticles into Tumor During HDR- 192Ir Brachytherapy Treatment: Monte Carlo Study

[摘要] BackgroundandObjective:Onthebaseofphotoninteractionswithmaterial,increaseofatomicnumberanddecreaseofemittedphotonenergyincreasesphotoelectricabsorption.Inthecurrentstudy,thedoseenhancementfactor(DEF)ofloadedtumorwithnanoparticles(NPs)wasstudiedusing192IrHDRbrachytherapysource.SubjectsandMethods:MonteCarlocalculationswereperformedwithMCNP4CcodetodeterminetheDEFfrom192Irsource.TheNPs-watermixturemodelwassimulated.UniformdistributionofNPsintothetumorvolumelocated1.5cmfromcenterofsourcecenteredinthewaterphantomwith7,18and30mgr/grconcentrationsof79Au,64Ga,26Feand22Ti,wasconsidered.Result:DEFof1.049,1.122,1.201and1.033,1.083and1.136wereestimatedfor79Auand64Gdwithconcentrationsof7,18and30mgr/gr,respectively.Increasingoftumordoseswasnotsignificantduetoloadingof26Feand22Ti.Increasetheradialdistanceofsourcefromthetumor(from1.5to5cm)increasestheDEF(upto22.3%).Conclusion:Ourdatapredicatethatloadingoftumorwithhigh-ZNPssuchasgoldNPsincreasetheabsorbeddoseoftumorirradiatedto192IrHDRbrachytherapysourceduetoincreaseofphotoelectricinteractions.IncreaseofatomicnumberandconcentrationofNPsandradialdistanceoftumorfromthesourceincreaseDEF.LoadingofthetumorvolumewithNPsduringradiationtherapyimprovestherapeuticratio.

[学科分类] 基础医学