Treatment planning strategies for stereotactic Radiosurgery in managing Multiple brain metastases -An Institutional Experience.

Authors

Priya Jacob

Abstract

Managing multiple brain metastases poses a significant challenge in neuro-oncology. The Cyber Knife system, a robotic radiosurgery device, has become a crucial treatment modality due to its precision and efficacy. This study investigates treatment planning strategies for Cyber Knife stereotactic radiosurgery (SRS) in patients with multiple brain metastases1,2. We evaluated the treatment plans of 10 patients who underwent SRS using the Cyber Knife system. The primary objective was to assess the efficacy and precision of the treatment planning strategies employed. The study highlights the importance of individualized treatment plans based on the number, size, and location of metastases, as well as the patient's overall health and prognosis. Advanced imaging modalities, such as MRI and PET-CT, play a critical role in accurate target delineation. The findings aim to optimize treatment outcomes, minimize adverse effects, and improve the quality of life for patients with multiple brain metastases. Purpose of this study is to assess the delivery efficiency, plan quality, and dosimetry of planned treatment volume (PTV) and normal brain tissue in Cyber Knife planning approaches for multiple brain metastases (MBM).In our clinic, 10 cancer patients with multiple cranial metastases (2 to 6 tumors) were treated with Cyber Knife. The prescription dose was 20 Gy in a single fraction. Dosimetric properties were evaluated, with the new Conformity Index (nCI) and Gradient Index (GI) being 1.14 ± 0.09 and 3.96 ± 0.16, respectively, and the Homogeneity Index (HI) being 1.10 ± 0.05. For combined PTV, Dmin (Gy) was 18.95 ± 0.21, Dmax (Gy) was 22.21 ± 0.24, D2% (Gy) was 22.07 ± 0.05, and D98% (Gy) was 19.91 ± 0.3. For normal brain tissue, the dosimetric parameters evaluated were V12Gy (cm³) at 4.98 ± 0.59, V10Gy (cm³) at 7.77 ± 0.39, V5Gy (cm³) at 22.99 ± 1.44, and V3Gy (cm³) at 86.71 ± 3.27. The maximum doses (Gy) to organs at risk (OARs) were 0.12 ± 0.04 for lenses, 3.01 ± 0.31 for the brainstem, and 2.71 ± 0.29 for optic nerves.

Keywords

Cyber Knife, Iris, gradient index, conformity index, Stereotactic radiosurgery.

Treatment planning strategies for stereotactic Radiosurgery in managing Multiple brain metastases -An Institutional Experience.. Priya Jacob. 2024. IJIRCT, Volume 10, Issue 2. Pages 1-7. https://www.ijirct.org/viewPaper.php?paperId=2503101