摘要
於骨髓移植前之全身照射中，體內劑量的均勻性和敏感器官的劑量控制是最重要的兩個部分，而體內劑量的均勻性容易受到體表輪廓的不平整和組織非均勻性的影響。本實驗的主要目的便是藉由組織補償物米的全身性補償以克服體表輪廓的不平整及組織缺陷的影響，改善側面全身照射體內劑量的差異，並設法降低肺部組織劑量。在假體佈點之前，先量測放射線於治療距離處的相關物理特性，根據所量得的物理特性進行體內劑量的計算。並進行不同條件下的照射與假體內熱發光劑量計佈點，以瞭解這些照射條件下體內劑量的均勻性。並使用三度空間治療計畫計算體內劑量分佈，分析比較之。

實驗結果發現藉由補償物的補償可改善體內劑量的差異，藉由0.5公分鉛合金的肺部補償更可以使中平面各點與指定點劑量的差異控制在10%以內。而根據三度空間治療計畫系統所計算出來的結果可以發現軟組織幾乎都被100%等劑量曲線所包圍，而肺部組織則都被包圍於100%和110%的等劑量曲線，與熱發光劑量計的量測結果相當吻合。因此此方法不僅可以達到體內劑量的均勻性，並使病人達到最大的舒適感。

Abstract
During total body irradiation therapy, the dose uniform in total body and the dose control of some important organ are very important. The dose uniform in body can be easily affected by the convex of contour. The aim of this experiment is to overcome the convex of contour by adding the rice as tissue compensator to improve the uniform in body. We also tried to decrease the dose of lung by adding the compensator of lead. Before measuring the dose distribution in rando phantom, we measured the relative physical characteristic at treatment distance to calculate the dose in body. Then we placed the TLD at mid-plane of rando phantom and irradiated at different condition to find out the dose distribution in body in these conditions. At last, we used the 3-D planning system to calculate the dose distribution in body and compared with the measuring result of TLD.

From the result of experiment, we can find that it can improve the dose uniform in body by adding the rice as a tissue compensator. Besides, we can control the dose of mid-plane different from the precision dose within 10%. And from the calculating result of 3-D planning system, we can find that the soft tissue is almost surrounded by the iso-dose curve of 100% and lung tissue is surrounded by the iso-dose curve of 100% and 110%. These results are good fit to the measuring results of TLD.

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