Jacob Gersh, PhD, DABR AAPM Talk

Product catalog summary

Introduction
This document outlines the daily quality assurance (QA) procedures for the CyberKnife system using the QA BeamChecker+ device. It includes disclosures about the speaker's affiliations and the current clinical use of the Varian TrueBeam system.

Daily QA Procedures
The daily QA tasks focus on photon output, energy constancy, flatness and symmetry, and both MV and kV imaging, all performed with the gantry mount.

Weekly QA Procedures
Weekly checks include electron output and energy constancy, electron checks, EDW, and RapidArc, with some tasks performed using the couch-placed setup.

Monthly QA Procedures
Monthly procedures involve respiratory gating checks using the gantry mount.

Patient-Specific QA
These involve electron cut-out measurements using the couch-placed setup.

Features of the QA BeamChecker+
The QA BeamChecker+ is highlighted for its robustness, simple hardware and software interfaces, wireless capability, scalable database, stable readings, and excellent support. It provides easy out-of-tolerance notifications and has very few problems.

LINAC Output Verification
Verification ensures that the machine isocenter matches the room isocenter, with room lasers providing demarcation. It involves alignment crosshairs and optical SSD, and can be delivered as an automated clinical beam.

Current Output Verification Methods
These methods require manual manipulation of the robot, non-clinical mode beam delivery, manual corrections for temperature and pressure, and manual numeric entry for baseline comparison. Setup uncertainty is noted, especially following Iris QA.

Alignment and Plan Preparation
The document describes the use of milled inlays for precise fit, crosshair for rough alignment, and fiducial markers for alignment and offset calculation using TLS. Plan preparation involves scanning from the superior to the cutting board to the blue casing, defining fiducial marker locations in the TPS, and placing five single beams for output verification.

Conclusion
The document concludes with a thank you note, emphasizing the importance of these QA procedures in maintaining the accuracy and reliability of the CyberKnife system.

Catalog excerpts

Daily QA of the CyberKnife using the QA BeamChecker+ Gibbs Cancer Center & Research Institute

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Speaker is the owner of Spectrum Medical Physics, LLC, a company which has contracts with; - Standard Imaging, Inc - Siemens Healthcare USA c Gibbs Cancer Center SPECTRUM & Research Institute Medical Physics, LLC SPECTRUM Medical Physics, LLC

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Current Clinical Use Varian TrueBeam • Daily — Photon Output (Gantry Mount) — Photon Energy Constancy (Gantry Mount) — Photon Flatness and Symmetry (Gantry Mount) — MV Imaging (Gantry Mount) — kV Imaging (Gantry Mount) • Weekly — Electron Output (Couch-Placed) — Electron Energy Constancy (Couch-Placed) — Electron (Couch-Placed) — EDW (Gantry Mount) — RapidArc (Gantry Mount) • Monthly — Respiratory Gating (Gantry Mount) • Patient-Specific — Electron Cut-out Measurements (Couch-Placed) Gibbs Cancer Center SPECTRUM & Research Institute Medical Physics, LLC

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Gibbs Cancer Center & Research Institute Lovable Aspects of the QABC+ • Robust • Simple Hardware Interface • Simple Software Interface • Simple-to-traverse database • Easily Scalable as clinic changes • Stable readings • Easy out-of-tolerance notifications • Very few problems • Excellent Support

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• Machine Isocenter matches the Room Isocenter • Room Lasers provide demarcation of machine isocenter • Alignment crosshair • Optical SSD • Can be delivered as an automated clinical beam Gibbs Cancer Center SPECTRUM & Research Institute Medical Physics, LLC

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Output Verification (Current Methods) Requires manual manipulation of the robot Beam delivered in a non-clinical mode Requires manual correction for temperature and pressure Requires manual numeric entry for baseline comparison Setup uncertainty associated with setup following Iris QA Gibbs Cancer Center & Research Institute

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Output Verification (Current Methods) Machine Isocenter matches the Room Isocenter Room Lasers provide demarcation of machine isocenter Alignment crosshair (Sort of) Optical SSD Can be delivered as an automated clinical beam

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• Crosshair used for "rough alignment" • Four fiducial markers for alignment and offset calculation using TLS Gibbs Cancer Center & Research Institute

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