Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy
Microdosimetry plays a critical role in particle therapy by quantifying energy deposition within microscopic domains to assess biological effects. This study evaluates the influence of different microdosimetric functions (MFs) and domain geometries (DGs) on relative biological effectiveness (RBE) pr...
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| Format: | Article |
| Language: | English |
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MDPI AG
2025-06-01
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| Series: | Radiation |
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| Online Access: | https://www.mdpi.com/2673-592X/5/2/21 |
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| author | Shannon Hartzell Keith M. Furutani Alessio Parisi Tatsuhiko Sato Yuki Kase Christian Deglow Thomas Friedrich Chris J. Beltran |
| author_facet | Shannon Hartzell Keith M. Furutani Alessio Parisi Tatsuhiko Sato Yuki Kase Christian Deglow Thomas Friedrich Chris J. Beltran |
| author_sort | Shannon Hartzell |
| collection | DOAJ |
| description | Microdosimetry plays a critical role in particle therapy by quantifying energy deposition within microscopic domains to assess biological effects. This study evaluates the influence of different microdosimetric functions (MFs) and domain geometries (DGs) on relative biological effectiveness (RBE) predictions in carbon ion radiotherapy. Specifically, we compare the analytical microdosimetric function (AMF), calculated for spherical domains and implemented in PHITS, with the Kiefer–Chatterjee (KC) track structure model, which is conventionally applied to cylindrical geometries. To enable a direct comparison, we also introduce a novel implementation of the KC model for spherical domains. Using both models, specific energy distributions were calculated across a range of domain sizes and geometries. These distributions were input into the modified microdosimetric kinetic model (mMKM) to calculate RBE for the HSG cell line and compared against published in vitro data. The results show that both microdosimetric function and domain geometry significantly affect microdosimetric spectra and the resulting RBE, with deviations exceeding 10% when fixed mMKM parameters are used. Parameter optimization within the mMKM enables alignment across models. Our findings emphasize that microdosimetric function and domain geometry selection must be explicitly accounted for in microdosimetry-based RBE modeling, and that model parameters must be tuned accordingly to ensure consistent and biologically accurate predictions. |
| format | Article |
| id | doaj-art-0dab0be9542a41e3978ffbac5f0e25e9 |
| institution | DOAJ |
| issn | 2673-592X |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Radiation |
| spelling | doaj-art-0dab0be9542a41e3978ffbac5f0e25e92025-08-20T03:16:38ZengMDPI AGRadiation2673-592X2025-06-01522110.3390/radiation5020021Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion RadiotherapyShannon Hartzell0Keith M. Furutani1Alessio Parisi2Tatsuhiko Sato3Yuki Kase4Christian Deglow5Thomas Friedrich6Chris J. Beltran7Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USADepartment of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USADepartment of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USANuclear Science and Engineering Center, Japan Atomic Energy Agency, Tokai 319-1195, JapanB Dot Medical Inc., Edogawa-ku 143-0003, JapanGSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, GermanyGSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, GermanyDepartment of Radiation Oncology, Mayo Clinic, Jacksonville, FL 32224, USAMicrodosimetry plays a critical role in particle therapy by quantifying energy deposition within microscopic domains to assess biological effects. This study evaluates the influence of different microdosimetric functions (MFs) and domain geometries (DGs) on relative biological effectiveness (RBE) predictions in carbon ion radiotherapy. Specifically, we compare the analytical microdosimetric function (AMF), calculated for spherical domains and implemented in PHITS, with the Kiefer–Chatterjee (KC) track structure model, which is conventionally applied to cylindrical geometries. To enable a direct comparison, we also introduce a novel implementation of the KC model for spherical domains. Using both models, specific energy distributions were calculated across a range of domain sizes and geometries. These distributions were input into the modified microdosimetric kinetic model (mMKM) to calculate RBE for the HSG cell line and compared against published in vitro data. The results show that both microdosimetric function and domain geometry significantly affect microdosimetric spectra and the resulting RBE, with deviations exceeding 10% when fixed mMKM parameters are used. Parameter optimization within the mMKM enables alignment across models. Our findings emphasize that microdosimetric function and domain geometry selection must be explicitly accounted for in microdosimetry-based RBE modeling, and that model parameters must be tuned accordingly to ensure consistent and biologically accurate predictions.https://www.mdpi.com/2673-592X/5/2/21microdosimetryrelative biological effectivenesscarbon ion radiotherapymicrodosimetric kinetic modelmodified MKMKiefer–Chatterjee |
| spellingShingle | Shannon Hartzell Keith M. Furutani Alessio Parisi Tatsuhiko Sato Yuki Kase Christian Deglow Thomas Friedrich Chris J. Beltran Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy Radiation microdosimetry relative biological effectiveness carbon ion radiotherapy microdosimetric kinetic model modified MKM Kiefer–Chatterjee |
| title | Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy |
| title_full | Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy |
| title_fullStr | Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy |
| title_full_unstemmed | Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy |
| title_short | Impact of Microdosimetric Modeling on Computation of Relative Biological Effectiveness for Carbon Ion Radiotherapy |
| title_sort | impact of microdosimetric modeling on computation of relative biological effectiveness for carbon ion radiotherapy |
| topic | microdosimetry relative biological effectiveness carbon ion radiotherapy microdosimetric kinetic model modified MKM Kiefer–Chatterjee |
| url | https://www.mdpi.com/2673-592X/5/2/21 |
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