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Introduction of Efficient Workflow of In-Vivo Dosimetry Based On TOYOTA Production System

T Matsunaga*, J Suzuki , H Takahashi , K Hamajima , M Niwa , T Okuda , TOYOTA Memorial Hospital, Toyota, Aichi, Japan


(Sunday, 7/14/2019)  

Room: ePoster Forums

Purpose: AAPM TG-100 recommends the creation and evaluation of risk-based radiation therapy process that consider the impact on patients. In radiation therapy, daily positional error or anatomical changes of patient may lead to serious errors. However, evaluating them daily (In-vivo dosimetry: IVD) is not commonly done in many hospitals in Japan because it increases human and time costs. The process map made in our hospital doesn’t include IVD as a standard process, so this is inadequate as a safe radiation therapy process. TOYOTA Production System (TPS) is the source of Lean and aims to improve efficiency leading to safety and quality. We introduced an efficient IVD based on the concept of TPS and evaluated its effectiveness.

Methods: ADAPTIVO (Standard Imaging Inc.) was used for IVD. In vivo mode for evaluating the exit dose of the EPID during treatment, and Adaptive mode that performs deformable image registration, dose calculation, and evaluates dose distribution using CBCT images for IGRT were used for analysis of ADAPTIVO. The implementation rate of IVD and the time required were evaluated.

Results: IVD was implemented in 79.1% of patients after introduction of ADAPTIVO. In cases where the result was failed, review of the patient setup or judgment of the replan were considered. Since all analysis are performed automatically, the time required for confirming the result of IVD was about only 15 minutes per day. It was possible to introduce IVD without increasing personnel and without affecting patients and other processes.

Conclusion: IVD was introduced at a low cost in our hospital, and it became possible to carry out radiation therapy with a safer system.


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TH- External beam- photons: adaptive therapy

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