On the impact of improved dose calculation accuracy in clinical treatment planning for superficial high-dose-rate brachytherapy of extensive scalp lesions

Giulio Rossi; Vasiliki Peppa; Mark Gainey; Michael Kollefrath; Tanja Sprave; Panagiotis Papagiannis; Dimos Baltas

doi:10.1016/j.phro.2024.100673

On the impact of improved dose calculation accuracy in clinical treatment planning for superficial high-dose-rate brachytherapy of extensive scalp lesions

Phys Imaging Radiat Oncol. 2024 Nov 16:32:100673. doi: 10.1016/j.phro.2024.100673. eCollection 2024 Oct.

Authors

Giulio Rossi¹, Vasiliki Peppa², Mark Gainey¹, Michael Kollefrath¹, Tanja Sprave³, Panagiotis Papagiannis², Dimos Baltas¹

Affiliations

¹ Division of Medical Physics, Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, German Cancer Consortium (DKTK), Partner Site DKTK, Freiburg, Germany.
² Medical Physics Laboratory, Medical School, National and Kapodistrian University of Athens, Greece.
³ Department of Radiation Oncology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, German Cancer Consortium (DKTK), Partner Site DKTK, Freiburg, Germany.

Abstract

TG-43-based dose calculations disregard tissue heterogeneities and finite scatter conditions, prompting the introduction of model-based dose calculation algorithms (MBDCAs) to improve accuracy in high-dose-rate (HDR) brachytherapy. This study evaluated the effectiveness of MBDCAs over TG-43 in HDR ¹⁹²Ir brachytherapy of extended scalp lesions. Treatment planning dose calculations were compared with Monte Carlo (MC) data. TG-43 exhibited a dose overestimation ranging from 10% to 23% as the distance from the implant increased, while a better agreement from 2% to 6% was observed between the MBDCA and MC, supporting the adoption of MBDCAs for dose calculations in broad scalp lesions.

Keywords: HDR 192Ir mold brachytherapy; MBDCA; MC simulation; TG-43.