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Evaluation of C-RAD Catalyst HD for SRS

S Kamath*, Z Chen , Yale New Haven Hospital, New Haven, CT


(Wednesday, 8/1/2018) 10:00 AM - 10:30 AM

Room: Exhibit Hall | Forum 6

Purpose: Stereotactic radiosurgery with open face mask provides for improved patient comfort, while also being amenable to use of optical surface imaging technology for setup and continually monitoring patient motion during treatment. In this work, we evaluate the accuracy of a 3-camera optical surface imaging system (C-RAD Catalyst HD SRS module) for radiosurgery.

Methods: For accuracy testing, we used a head phantom with an open face mask that allows for skin monitoring. We used a precision metallic rotational platform capable of holding and rotating the phantom up to 90 degrees in each direction to simulate couch rotations. The platform was covered to avoid metallic reflections. We performed the following tests: 1. Assess ability of Catalyst HD to maintain phantom surface visibility with gantry rotations (camera obscuration) 2. Continuous monitoring of the phantom at five applied rotation angles, each with gantry upright as well as with one side camera blocked at a time. 3. Couch translational motion accuracy testing.

Results: 1. The phantom surface does not disappear at any gantry angles with couch at zero rotation position. 2. The RMS and standard deviations of displayed shifts from actuals were less than 0.5 mm in all directions over a sequence of positions that included the five rotation angles for approximately equal duration. The platform is not mathematically perfect. This and other measurement uncertainties were not quantified. However, they contribute to the measured deviations. 3. The RMS and standard deviation of displayed shifts from actuals were less than 0.2 mm for translation test when imaged with a marker.

Conclusion: With sub-millimeter display and real-time monitoring capability for non-coplanar treatments, Catalyst HD SRS module is a useful tool for radiosurgery. Cross validation for monitoring accuracy with an imaging system will be performed to further assess suitability of clinical implementation for stereotactic radiosurgery.

Funding Support, Disclosures, and Conflict of Interest: Equipment support for this study has been provided by C-RAD


Stereotactic Radiosurgery, Surface Matching


Not Applicable / None Entered.

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