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Session: Professional General ePoster Viewing [Return to Session]

Implementation, Utilization, and Time Analysis of An Optional Physics Pre-Planning Check

B Juneja1*, L Kim1, (1) MD Anderson Cancer Center at Cooper, Camden, NJ


PO-GePV-P-6 (Sunday, 7/25/2021)   [Eastern Time (GMT-4)]

Purpose: TG-100 gives examples of checks that should be performed before treatment-planning, not afterwards as is commonly done. We have implemented a "physics pre-plan check," an optional check, performed at dosimetrist request, of 36 items that affect dose-calculation or plan-optimization with the intent of catching errors that would require repeating those steps. In this study, we report on utilization and time required for this additional check.

Methods: For 3487 patients between February 2017 and February 2021, we recorded if and when a pre-plan check was requested and whether the check was performed. We calculated hours spent between contour completion and plan completion with and without pre-plan check.

Results: Pre-plan checks were requested for 663 (19.0%) patients, but requests steadily declined over time from 43.9% in 2017 to 6.7% in 2021. 5.4% of checks were requested after planning but prior to plan documentation/upload. The likelihood of a request had a high positive correlation (0.899) with days remaining to the first fraction. Of the requested checks, 575 (86.7%) were completed. The remaining requests were eventually canceled by the dosimetrist. The median time from request to check completion was 2.3 hours. For canceled requests, the median time from request to cancellation was 5.6 hours. On average, a pre-plan check added 3.6 hours overall to the planning process. Plans without checks were completed in 9 hours compared to 12.6 hours for plans with checks (p-value: 9.014E-7).

Conclusion: Our institutional experience is that the wait for a physics pre-plan check generally exceeded the expected time savings from catching an error early, and our dosimetry staff has mostly opted to forgo it. To retain the benefits of pre-plan checks, we developed a tool to automate the checking of 14 items and developed a checklist for the remainder for the dosimetrist to use without requiring a physicist.



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