Dual-purpose MAGIC gel bolus: Bridging bolus application and 3D polymer gel dosimetry in external beam radiotherapy
Radiation Physics and Chemistry, cilt.249, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 249
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.radphyschem.2026.114240
- Dergi Adı: Radiation Physics and Chemistry
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: 3D dose verification, External beam radiotherapy, MAGIC gel dosimeter, Patient-specific bolus, Radiotherapy quality assurance
- Ankara Üniversitesi Adresli: Evet
Özet
This paper details the development and dosimetric validation of an innovative dual-function MAGIC-based gel bolus intended to serve concurrently as a tissue-equivalent bolus and to evaluate its potential as a volumetric 3D dosimeter in external beam radiation. The gel bolus was prepared with a normoxic MAGIC formulation and evaluated with calibration irradiations within the 0–1000 cGy dose range utilizing 6-MV photon beams. The performance of the novel dual-function MAGIC-based gel bolus was evaluated against two clinically validated dosimetry systems: EBT4 radiochromic film (2D) and TLD-100 thermoluminescent dosimeters (point-dose). Magnetic resonance imaging and spin-spin relaxation rate (R2) analysis were employed to derive dose-response curves for the gel, whereas flatbed scanning (for optical density) and thermoluminescent dosimeter readouts were utilized for EBT4 and TLD-100, respectively. The gel bolus showed a robust linear dose-response relationship (R2 = 0.996) throughout the entire calibration range. Phantom measurements carried out on an anthropomorphic leg phantom demonstrated strong agreement between the gel bolus and TPS-calculated doses, especially within the high-dose target area (800 cGy). EBT4 films presented significant linearity (R2 = 0.994), while TLD-100 chips exhibited linear behavior but deviated in the low-dose region, consistent with established limitations of point-dose systems. The findings reveal that the formulated gel bolus achieves clinically acceptable accuracy (deviating strictly within the recommended ±5% tolerance limit) and presents the distinct benefit of facilitating both bolus application and volumetric dosimetric evaluation within a single medium. The dual-function capability of the gel bolus positions it as an important tool to enhance treatment accuracy and quality assurance in modern radiotherapy.