Dosimetric and Treatment Delivery Efficiency Comparison of Two Ring-gantry Linear Accelerator Platforms for Liver Stereotactic Body Radiotherapy
Srikanth Guduru, Rohith Singareddy, N. V. N. Madhusudhana Sresty, Deleep Kumar Gudipudi, Aparna DodeAbstract
Purpose:
The purpose of this study was to compare the dosimetric performance and treatment delivery efficiency of two ring-gantry linear accelerator platforms, Helical Tomotherapy and Halcyon, in stereotactic body radiation therapy (SBRT) for liver metastasis.
Materials and Methods:
A retrospective dosimetric analysis was conducted on 16 patients with solitary liver metastasis. For each patient, SBRT plans were generated using the Accuray treatment planning system (TPS) (Tomotherapy) and Eclipse TPS (Halcyon). Plan evaluation included conformity, homogeneity, and gradient indices, along with target coverage and organs at risk (OAR) dose–volume parameters, in accordance with Radiation Therapy Oncology Group-1112 (RTOG-1112) guidelines. Treatment efficiency was assessed using monitor units (MU) and beam-on time (BOT). Statistical analysis was performed using paired
Results:
Both platforms achieved acceptable target coverage and OAR constraints. Conformity index and gradient index were comparable. Halcyon showed improved planning target volume homogeneity, lower normal liver V15 Gy, reduced OAR doses, and significantly lower MU and BOT (
Conclusion:
Both Tomotherapy and Halcyon are capable of generating high-quality liver SBRT plans with comparable target coverage. However, Halcyon demonstrated improved normal tissue sparing and enhanced treatment efficiency.