A Comparative Analysis of Virtual ۲D VMAT-Based SFRT and ۳D Lattice Radiotherapy: Evaluation of Dosimetric and Therapeutic Outcomes

Background: Spatially Fractionated Radiotherapy (SFRT) can be implemented using Volumetric-Modulated Arc Therapy (VMAT) in either two-dimensional (۲D) or three-dimensional (۳D) configurations.Objective: This study aimed to compare the dosimetric and clinical outcomes of two VMAT-based SFRT techniques for large lung tumors.Material and Methods: In this experimental study, SFRT plans were designed for each patient using cylindrical and spherical grid targets. Single-fraction prescription doses of ۱۵ and ۲۰ Gy were delivered to the grid target isocenters using ۶ MV Flattening-filter-free (FFF) photon beams.Results: The ۲D SFRT plan demonstrated higher Gross Tumor Volume (GTV) mean dose, GTV Equivalent Uniform Dose (EUD), and Valley-to-peak Dose ratio (VPDR) compared to the ۳D lattice plan. However, the ۳D Lattice Radiotherapy (۳D-LRT) technique provided a better therapeutic ratio and more uniform valley-peak dose distribution. Both plans demonstrated therapeutic ratios greater than one with minimal Normal Tissue Complication Probability (NTCP). Conclusion: Both ۲D and ۳D lattice VMAT-based SFRT techniques effectively delivered high radiation doses with steep dose gradients within the GTV, minimizing normal tissue exposure and reducing the risk of complications.

کلیدواژه ها:

Spatially Fractionated Radiotherapy ، Volumetric-Modulated Arc Therapy ، Lattice Radiotherapy ، Grid Target ، Lung Neoplasms ، Treatment outcome ، Dose Fractionation ، Radiation