Year: 2025 | Month: December | Volume: 12 | Issue: 12 | Pages: 331-337
DOI: https://doi.org/10.52403/ijrr.20251238
Surface Dose Enhancement Using a Silicon Rubber–Tungsten (SR-W) Bolus: RED, Absorbed Dose, and PDD Analysis for LINAC-Based Radiotherapy
Gita Nubuwwah Harahap1, Eko Hidayanto1, Ngurah Ayu Ketut Umiati1, Adnan Cindyana1, Tri Setiyo Utami1
1Department of Physics, Faculty of Science and Mathematics, Diponegoro University, Semarang, Indonesia
Corresponding Author: Gita Nubuwwah Harahap
ABSTRACT
This study investigates the dosimetric performance of a Silicon Rubber–Tungsten (SR–W) composite bolus designed for external beam radiotherapy using 6‑MV and 10‑MV photon energies. The bolus was manufactured by integrating 6 wt% tungsten powder into an RTV‑52 silicone matrix and fabricated in five thickness variations (2–10 mm). Relative electron density (RED) was quantified from CT-derived Hounsfield Unit conversion, while absorbed dose and percentage depth dose (PDD) were measured in a solid‑water phantom using a Farmer-type ionization chamber under standardized LINAC conditions. The RED remained stable and tissue‑equivalent for 2–8 mm (1.043–1.047), while the 10‑mm sample showed increased density (1.102) attributable to enhanced effective electron density. The incorporation of tungsten significantly improved dose build‑up, yielding higher absorbed dose and PDD values, with optimal enhancement observed at 16–18 mm for 6 MV and 18–20 mm for 10 MV, without introducing excessive attenuation. These findings demonstrate that the SR–W bolus provides reliable surface‑dose amplification and consistent dosimetric behavior, indicating strong potential for clinical implementation in megavoltage LINAC radiotherapy.
Keywords: Silicon Rubber–Tungsten bolus; Relative Electron Density; Absorbed dose; Percentage Depth Dose; LINAC radiotherapy.
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