Evaluation of the Lens-absorbed Dose of the Scattered Radiation Generated During Tomotherapy IMRT to the H&N Cancer Patient

Abstract

This paper uses a glass dosimeter to evaluate the lens-absorbed close of scattered radiation generated in tomotherapy intensity modulated radiation therapy (WIRT). The head and neck portion of the rando phantom was subjected to a CT scan. The tomotherapy plan was designed to ensure delivery of the prescribed total 70 Gy day 2.2 Gy. With the lens portion of the glass dosimeter, a 5mm bolus was subjected to the scattered radiation treatment, and the dose was measured in each of the three megavoltage CT (MVCT) modes. The result is multiplied by 30 times and was determined once as the mean value. The measurement at the MVCT Coarse mode is RT mode 10.797 mGy, that for the Normal mode is 13.360 mGy, for the Fine mode is a maximum of 22.872 mGy, and for the treatment mode is 895.830 mGy. A small amount of scattered radiation in the MVCT is measured in the lens scattered radiation, but scattered radiation during treatment was measured to be near 1 Gy on the lens. Compared to a one-time radiation treatment of 2.2 Gy, the survey showed something unexpected in that it was half the value of that research to the patient. Therefore, will be aware of how much of an influence there will be on sensitive organs, such as the lens by scattered radiation generated during intensity modulated radiation therapy.