Speaker
Description
Tongue cancer accounts for nearly 20,000 new cases projected for 2026, with a higher incidence in men [1]. Both teletherapy and brachytherapy are established treatment options. In this work, Monte Carlo simulations were used to investigate and compare the dosimetric characteristics of these two approaches. The absorbed dose in the adult male mesh-type virtual anthropomorphic phantom [2], was estimated for teletherapy and brachytherapy scenarios using computational simulations using the TOPAS Monte Carlo transport code [3]. The generated files were subsequently analyzed using the 3D Slicer software [4], enabling the extraction of dose-volume histograms and the dosimetric parameters of interest. The $^{198}\mathrm{Au}$ brachytherapy sources were modeled in Blender [5], based on literature specifications [6]. The comparative analysis indicated that, in the brachytherapy treatment, there was a reduction in absorbed dose to the parotid gland and thyroid compared to teletherapy, while the ocular structures presented higher dose deposition. The lower exposure of the glands is attributed to the steep dose fall-off in tissues adjacent to the target volume, a characteristic behavior of brachytherapy. In contrast, the higher dose observed in the eyes may be explained by the absence of field conformality, unlike teletherapy, which reduces the exposure of structures located outside the primary field. The simulated scenarios showed that brachytherapy delivers lower doses to adjacent organs, while teletherapy has the advantage of geometric beam conformality, allowing the protection of radiation-sensitive structures through the collimation of treatment fields.
[1] Siegel et al 2026 CA Cancer J Clin 76 1
[2] Kim et al 2020 Ann ICRP 49 13–201
[3] Faddegon et al 2020 Phys Med 72 114–121
[4] Fedorov et al 2012 Magn Reson Imaging 30 1323–1341
[5] Blender Foundation 2018 Blender
[6] Ozaki et al 2017 J Radiat Res 58 523–528