ESTRO 2024 - Abstract Book

S765

Clinical - CNS

ESTRO 2024

Keywords: intraoperative radiotherapy, brain metastasis

621

Digital Poster

Stereotactic Spine Irradiation Program at MD Anderson Cancer Center: A Comprehensive Overview

Gizem Cifter, Dennis Mackin, Shane Krafft, Eun Young Han, Yana Zlateva, Jihong Wang, Yao Ding, Jing Li, Amol Ghia, Tina Briere

MD Anderson Cancer Center, Radiation Physics, Houston, USA

Purpose/Objective:

Purpose: Stereotactic spine radiosurgery (SSRS) stands as the favored approach for managing metastatic spine tumors. It delivers high doses in one to five fractions, maintaining a sharp dose gradient between the tumor target and adjacent organs. During SSRS delivery, proper dosing is crucial to prevent weakened tumor control and avoid severe toxicity to nearby organs. Reliable immobilization techniques as well as integration of sophisticated image guided technologies are key to reducing setup and motion errors. In response to these challenges, we have crafted a streamlined SSRS delivery procedure and clinical workflow optimized for treating metastatic spine tumors.

Material/Methods:

Methods: Our procedure has four major components: (1) CT and MR Simulation, (2) Customizable immobilization using the Klarity System, (3) Volume definition and planning, (4) Treatment with integrated imaging modalities.

A team of therapists, a physicist and a physician are present during CT simulation. The appropriate immobilization devices are selected, and tailored devices are designed (Figure 1, 2). The physicist's responsibility is to advise on the most suitable immobilization, while the physician validates the target location and isocenter. MR-simulation may be performed immediately after the CT simulation. This back-to-back arrangement is essential to guarantee consistent patient positioning during both simulations, leveraging the same custom-made immobilization tools. For patient immobilization we use the Klarity SBRT System, which has interchangeable accessories allowing for standardized yet adaptable setups. This system employs a full-length carbon fiber base plate that is indexed to make setups intuitive and reproducible. All accessories are available in MRI compatible versions. Simulations are conducted with the patient in a supine position, with their arms either raised ("up") or lowered ("down"). The "arms up" configuration utilizes a vacuum cushion and a wingspan baseplate, whereas the "arms down" positioning supports the arms with straps, with the patient resting on just the base plate and headrest. We further enhance stability using a custom-designed belly belt and knee bridge, accompanied by a compact vacuum bag. To maximize comfort and stability, we also incorporate foot positioners and knee cushions.