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Patient Release Criteria for Eye Plaque Procedures

G Nelson

G Nelson1*, (1) University Utah, Salt Lake City, UT


TU-RPM-GePD-TT-4 (Tuesday, August 1, 2017) 3:45 PM - 4:15 PM Room: Therapy ePoster Theater

Purpose: To evaluate current recommendations regarding lead eye patches used for COMS Eye Plaque patients, determine the recommendations' effectiveness, and consider improved recommendations.

Methods: Existing regulations and recommendations regarding lead eye patches were reviewed. Three years worth of Eye Plaque patient data was acquired. Dose to another individual was calculated using the equation provided in NUREG-1556, Vol 9, Rev 2, Appendix U, Supplement B, for each case. A multivariate linear regression analysis was done looking at many planning parameters and the resulting dose from the NRC equation. Another multivariate regression analysis was performed using only the two most significant parameters.

Results: The two most significant parameters were the prescribed treatment depth and the number of seeds. In the both multivariate regression analyses prescribed treatment depth was by far the most significant factor on the dose to others (p-value < 2.3x10⁻⁶⁹). The patient plans were then plotted viewing prescribed treatment depth verses calculated dose to others. A best fit line was plotted (R=0.9694) and then used to determine what prescribed treatment depth would reach the patient release limitation of 0.5rem. Only prescribed depths greater than over 12mm would reach the release limit.

Conclusion: Eye plaque procedures are only recommended for tumors with a thickness of 1cm or less. Such treatments will always result in a dose to another individual being less than the dose limitations outlined by the NRC. This is independent of the time of the implant, but is dependent on the treatment dose and the treatment depth. This study demonstrates that for all standard eye plaque treatments patients are capable of being released without the need for a lead eye patch.

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