{"title":"Feasibility of the analytical dose calculation method for Au-198 brachytherapy","authors":"","doi":"10.1016/j.ejmp.2024.104501","DOIUrl":null,"url":null,"abstract":"<div><h3>Purpose</h3><p>A dose calculation algorithm Computed Tomography (CT)-based analytical dose calculation method (CT<sub>anly</sub>), which can correct for subject inhomogeneity and size-dependent scatter doses, was applied to the <sup>198</sup>Au seed. In this study, we evaluated the effectiveness of the CT<sub>anly</sub> method by comparing the gold standard Monte Carlo (MC) method and the conventional TG43 method on two virtual phantoms and patient CT images simulating oral cancer.</p></div><div><h3>Methods</h3><p>As virtual phantoms, a water phantom and a heterogeneous phantom with soft tissue inserted cubic fat, lung, and bone were used. A 2-mm-thick lead plate was also inserted into the heterogeneous phantom as a dose attenuator. Virtual <sup>198</sup>Au seeds and a 2-mm-thick lead plate were placed on the patient CT images. Dose distributions obtained via the TG43 and CT<sub>anly</sub> methods were compared with those of the MC by gamma analysis with 2%/2-mm thresholds. The computation durations were also compared.</p></div><div><h3>Results</h3><p>In the water phantom, dose distributions comparable to those obtained via the MC method were obtained regardless of the algorithm. For the inhomogeneity phantom and patient case, the CT<sub>anly</sub> method showed an improvement in the gamma passing rate and dose distributions similar to those of the MC method were obtained. The computation time, which was days with the MC method, was reduced to minutes with the CT<sub>anly</sub> method.</p></div><div><h3>Conclusions</h3><p>The CT<sub>anly</sub> method is effective for <sup>198</sup>Au seed dose calculations and takes a shorter time to obtain the dose distributions than the MC method.</p></div>","PeriodicalId":56092,"journal":{"name":"Physica Medica-European Journal of Medical Physics","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1120179724002461/pdfft?md5=1085468ddc0be672af09430479818c3a&pid=1-s2.0-S1120179724002461-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physica Medica-European Journal of Medical Physics","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1120179724002461","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
引用次数: 0
Abstract
Purpose
A dose calculation algorithm Computed Tomography (CT)-based analytical dose calculation method (CTanly), which can correct for subject inhomogeneity and size-dependent scatter doses, was applied to the 198Au seed. In this study, we evaluated the effectiveness of the CTanly method by comparing the gold standard Monte Carlo (MC) method and the conventional TG43 method on two virtual phantoms and patient CT images simulating oral cancer.
Methods
As virtual phantoms, a water phantom and a heterogeneous phantom with soft tissue inserted cubic fat, lung, and bone were used. A 2-mm-thick lead plate was also inserted into the heterogeneous phantom as a dose attenuator. Virtual 198Au seeds and a 2-mm-thick lead plate were placed on the patient CT images. Dose distributions obtained via the TG43 and CTanly methods were compared with those of the MC by gamma analysis with 2%/2-mm thresholds. The computation durations were also compared.
Results
In the water phantom, dose distributions comparable to those obtained via the MC method were obtained regardless of the algorithm. For the inhomogeneity phantom and patient case, the CTanly method showed an improvement in the gamma passing rate and dose distributions similar to those of the MC method were obtained. The computation time, which was days with the MC method, was reduced to minutes with the CTanly method.
Conclusions
The CTanly method is effective for 198Au seed dose calculations and takes a shorter time to obtain the dose distributions than the MC method.
期刊介绍:
Physica Medica, European Journal of Medical Physics, publishing with Elsevier from 2007, provides an international forum for research and reviews on the following main topics:
Medical Imaging
Radiation Therapy
Radiation Protection
Measuring Systems and Signal Processing
Education and training in Medical Physics
Professional issues in Medical Physics.