{
  "abstract": "Background\n\nAAPM TG-43-based dose calculations for intracranial cesium-131 (¹³¹Cs) brachytherapy ignore patient-specific heterogeneities, which can affect dose accuracy. This study investigates the dosimetric impact of these heterogeneity effects using Monte Carlo (MC) simulations and patient-specific imaging data.Purpose\n\nTo quantify the impact of tissue heterogeneity on dose distributions in intracranial brachytherapy using ¹³¹Cs sources and to evaluate the accuracy of AAPM TG-43-based treatment planning system (TPS) calculations.Methods\n\nTG-43 dosimetric parameters for the ¹³¹Cs source were independently characterized and benchmarked against published consensus data. MC simulations using MCNP were performed in both homogeneous water phantoms and heterogeneous voxelized lattice phantoms derived from CT DICOM RT data. Single and multiple-seed configurations were investigated. TPS and MC dose distributions were compared using dose-volume histogram (DVH) metrics such as (V₆₀, V₁₀₀, D2cc, and mean dose), isodose distributions, dose difference maps, and local and global dose difference analyzes. Spatial agreement was quantified using gamma analysis.Results\n\nStrong agreement was observed between TPS and MC calculations in homogeneous media. However, heterogeneous patient-specific MC simulations revealed systematic differences in DVH metrics for the target volume and organs at risk, including the skull and skin. Local dose differences revealed pronounced deviations near high-density bony regions, where dose enhancement effects were observed, while global dose difference analyzes demonstrated an overall dosimetric bias. Gamma pass rates decreased in heterogeneous regions, consistent with these spatial dose discrepancies. Compared with the MC simulations, the TG-43-based TPS overestimated the mean dose to the target by approximately 23.63±4.97% , V₆₀ and V₁₀₀ by approximately 24.42±4.97% , and 23.75±4.97% , respectively, and the mean dose to the skin by approximately 73.60±4.97% , while underestimating the mean dose to the skull by 220.90±4.97% .Conclusion\n\nAlthough the TG-43 formalism provides accurate dose estimates in homogeneous media, it introduces clinically meaningful local and global dosimetric deviations in heterogeneous intracranial environments. Careful consideration is required when reporting doses to the target and OARs, particularly given the potential for substantially higher doses to the irradiated skull in certain cases (up to 3.2-fold in this study), as well as the possibility of target underdosage within the high-risk clinical target volume (HR-CTV). Patient-specific MC modeling highlights the importance of incorporating tissue heterogeneity into intracranial brachytherapy dose calculations to improve dosimetric accuracy and optimize treatment planning.",
  "abstract_shown": true,
  "affiliations": [
    "University of Minnesota, Minneapolis, Minnesota, USA.",
    "East Carolina University, Greenville, North Carolina, USA.",
    "University of Texas MD Anderson Cancer Center, Houston, Texas, USA.",
    "Kathmandu University, Nepal.",
    "Loyola University Medical Center, Maywood, Illinois, USA."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Tirthraj Adhikari",
      "orcid": "0009-0007-5305-0879"
    },
    {
      "affs": [
        1
      ],
      "name": "Jae W Jung"
    },
    {
      "affs": [
        2
      ],
      "name": "Sherif M Gadoue"
    },
    {
      "affs": [
        3
      ],
      "name": "Puja Sharma"
    },
    {
      "affs": [
        4
      ],
      "name": "Tomas Montegegro"
    },
    {
      "affs": [
        0
      ],
      "name": "Farhad Jafari"
    },
    {
      "affs": [
        0
      ],
      "name": "Clara Ferreira"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2brhmtm6fdjxr.bib",
  "cited_by": 0,
  "doi": "10.1002/acm2.70872",
  "fulltext_url": "https://europepmc.org/articles/PMC13720234",
  "id": "2brhmtm6fdjxr",
  "issns": [
    "1526-9914"
  ],
  "landing_url": "https://europepmc.org/article/MED/42958620",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Research Article"
    ],
    [
      "openalex",
      "3108|Advanced Radiotherapy Techniques"
    ]
  ],
  "openalex": "W7224842983",
  "pdf_url": "https://europepmc.org/articles/PMC13720234?pdf=render",
  "pmcid": "PMC13720234",
  "pmid": "42958620",
  "published": "2026-10-29",
  "publisher": "Wiley",
  "ris": "https://research.draconitic.com/paper/2brhmtm6fdjxr.ris",
  "sources": [
    {
      "first_seen": "2026-11-01T00:20:36Z",
      "native_id": "MED:42958620",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42958620"
    },
    {
      "first_seen": "2026-11-03T12:21:10Z",
      "native_id": "PMC13720234",
      "source": "pmc",
      "url": "https://doi.org/10.1002/acm2.70872"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3108|Advanced Radiotherapy Techniques",
      "subfield": "applied-instrumentation"
    }
  ],
  "title": "Impact of tissue heterogeneity on intracranial Cesium-131 brachytherapy dosimetry: A patient-specific Monte Carlo Study.",
  "title_text": "Impact of tissue heterogeneity on intracranial Cesium-131 brachytherapy dosimetry: A patient-specific Monte Carlo Study.",
  "type": "peer-reviewed",
  "updated_at": "2026-11-03T12:21:10Z",
  "url": "https://research.draconitic.com/paper/2brhmtm6fdjxr",
  "venue": "Journal of applied clinical medical physics",
  "versions": []
}