Author: Dr. Sheaka Alobaidli, Anju K V, Dr. Chiranjib Konar, Sreejesh MS, Dr. Vijayaprabhu N, Dr. Deepti Sharma, Dr. Hanuman Prasad Yadav 👨🔬
Affiliation: Amity Institute of Applied Sciences, Kuwait Cancer Control Center, Institute of Liver and Biliary Sciences, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER), Amity institute of Applied Sciences, Amity University, Institute of Liver and Biliary Sciences(ILBS) 🌍
Purpose:
The accuracy of dose delivery in stereotactic body radiotherapy (SBRT) is critical for effectively treating hepatocellular carcinoma (HCC). This study aims to develop patient-specific 3D-printed heterogeneous phantom to verify dose distributions for SBRT treating HCC.
Methods:
The phantom structure was fabricated using a 3D printing technique with Polylactic acid (PLA) filament . The tissue compartments were filled with substances mimicking their respective electron densities. CT images of the phantom were obtained and analyzed to compare its electron density values with those reported in the literature for human tissues. The dose calculations for volumetric-modulated arc therapy (VMAT) plans targeting HCC were performed using the Monaco Treatment Planning System (TPS). These plans were delivered on an Elekta Versa HD linear accelerator (Elekta Medical Systems India Pvt. Ltd., UK). Gafchromic EBT3 film and 0.015 cc ionization chamber measured the dose delivered during treatment. Additionally, Gamma comparison was performed using the PTW Octavius system (PTW, Freiburg, Germany).
Results:
The electron density values for the OARs closely matched those reported in the literature .The dose discrepancies measured with the ion chamber were 0.36% at the isocenter, 0.67% in the liver, and 1.43% in the heart for the VMAT plans. The film analysis showed a gamma pass rate of 99.5% for 3%/3 mm and 97.1% for 2%/2 mm criteria across the treatment plans. The Octavius system achieved a gamma pass rate of 98.3% for 3%/3 mm and 95.4% for 2%/2 mm criteria across the treatment plans.
Conclusion:
The 3D-printed heterogeneous abdomen phantom is a cost-effective, user-friendly and that mimics the exact shape of the human body, enhancing its realism and clinical relevance while advancing patient-specific dose verification for SBRT in HCC. It enhances quality assurance by providing realistic, reproducible simulations, improving precision and safety in treatment planning and delivery.