Document Type : Original Article(s)
Authors
- Aparna Dode 1
- Srikanth Guduru 2
- Rohith Singareddy 3
- Madhusudhana Sresty N.V.N. 4
- Deleep Kumar Gudipudi 3
1 Department of Physics, University college of science, Osmania University Hyderabad, Telangana, India
2 Department of Radiation physics, Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
3 Department of Radiation Oncology, Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
4 Department of Radiation Physics, Basavatarakam Indo-American Cancer Hospital and Research Institute, Hyderabad, Telangana, India
Abstract
Background: Stereotactic radiosurgery (SRS) relies on precise, highly conformal radiation with sharp dose falloff to protect adjacent normal brain tissue. Differences in multileaf collimator (MLC) configuration and planning system algorithms can affect dosimetric performance and delivery efficiency, supporting the need for comparative assessment of current techniques. The present study aimed to compare the dosimetric parameters and treatment efficiency of SRS plans using RapidArc with an HD120 MLC against volumetric modulated arc therapy (VMAT) using the Agility-MLC in patients diagnosed with a single brain metastasis.
Method: In this retrospective dosimetric study of 12 patients who received single‑fraction 22 Gy SRS for single brain metastasis, paired treatment plans were generated for each case: (i) a RapidArc plan in Eclipse with an HD120‑MLC and (ii) a VMAT plan in Monaco with an Agility‑MLC. Target coverage, conformity index, homogeneity index, gradient index (GI), and organ‑at‑risk (OAR) doses were compared alongside efficiency indicators monitor units (MUs) and beam‑on time (BOT). Paired t‑tests performed in SPSS v28.0 by international business machines (IBM) determined statistical significance, with P < 0.05 considered significant.
Results: Both techniques achieved acceptable target coverage and met OAR constraints. RapidArc showed significantly improved gross tumor volume (GTV) homogeneity (P = 0.00047), lower GI (P = 0.04238), and lower normal brain volume receiving at least 12Gy (V12Gy, P = 0.005). VMAT plans required fewer MUs (P = 0.011) and had shorter BOT (P = 0.04), indicating improved efficiency. No significant differences were observed in maximum doses to the brainstem, optic apparatus, and cochlea.
Conclusion: Both RapidArc and VMAT delivered clinically acceptable SRS plans. In our patient population RapidArc offered superior homogeneity and better sparing of normal brain tissue.
Highlights
Aparna Dode (google scholar)
Deleep Kumar Gudipudi (google scholar)
Keywords
Main Subjects
Please cite this article as: Guduru S, Singareddy R, Madhusudhana Sresty NVN , Gudipudi DK, Dode A. Dosimetric Evaluation of Two Linac-Based Stereotactic Radiosurgery Approaches in the Management of Single Brain Metastasis. Middle East J Cancer. 2026; 17(3): p-p. doi: 10.30476/mejc.2026.107219.2286.
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