| Authors | Keyhandokht Karimi Shahri,Najmeh Mohammadi |
|---|---|
| Journal | Biomedical Physics and Engineering Express |
| Page number | 1-14 |
| Serial number | 11 |
| Volume number | 4 |
| Paper Type | Full Paper |
| Published At | 2025 |
| Journal Type | Typographic |
| Journal Country | Iran, Islamic Republic Of |
| Journal Index | Scopus |
Abstract
Thisstudyaimedtoinvestigatetheeffectoftissuecalcificationonthedosedistributionoflow-energy brachytherapyseedsusedinthetreatmentofprostateandbreasttumors.Toachievethis,simulations of theIR-125Iand131Cs-1seedswereconductedusingtheMCNPXMonteCarlo(MC)code. Brachytherapydosimetricparameters,suchasthedoserateconstant (L)andradialdosefunction(g (r)), werecalculated inwaterfollowingtheTG-43U1protocolandvalidatedbycomparingtheresults withdatareportedinotherliterature.Thefindingsrevealedsignificantuncertaintyintheg(r)for calcifiedtissue oftheprostate, adipose,andglandularbreastcomparedtonormaltissue.Theg(r)value showedanotableincreaseinthevicinityoftheseeds(within1cmfromthecenteroftheseeds), followedbyadecrease.Thistrendwasobservedinallthreetissues.Thehigherthepercentageof calcification inthetissue, themorepronouncedthechanges.Theg(r)increasedbyafactorof266and 102forIR-125I,and131Cs-1seeds,respectively, inthe100%calcifiedprostate.Thetrendofg(r) changesalignedwiththetrendofchangesinthemassattenuationcoefficientscalculatedforthetissues at different calcification percentages. Anexponentialfunction(Aexp(-r/t))wasderivedtopredictg(r) acrossvariouscalcificationpercentages.Additionally, theinsightsgainedfromthisstudymayapplyto othersofttissues