【摘要】：目的:為提高放療精度,建立CT-電子密度轉換曲線,確定對放射治療計劃劑量計算的影響。方法:利用CT電子密度模體,對模擬定位CT機的CT值進行檢測。比較人體不同組織的CT值,建立CT-電子密度轉換曲線。根據各組織的相對電子密度對組織不均勻性劑量進行校正,并分析照射劑量MU數值的變化。結果:在同一定位掃描參數下,不同位置的等效密度組織CT值均有變化:高密度組織CT值變化較大,近床面的等效密度組織CT值變化均大于遠床面的等效密度組織。不同的CT-電子密度轉換曲線其MU數值相差均20%,調強放療(intensity modulated radiation therapy,IMRT)較大,三維適形放射治療(3-dimensional conformal radiation therapy,3DCRT)和調強放療各偏差值相同。結論:對治療計劃系統(tǒng)數據進行采集錄入時,應正確合理地輸入一條CT-電子密度轉換曲線,以保證治療計劃劑量計算的精度。
[Abstract]:Objective: to improve the accuracy of radiotherapy, to establish CT-electron density conversion curve and to determine the effect on dose calculation of radiotherapy plan. Methods: using CT electron density motif, the CT value of simulated location CT machine was detected. The CT values of different tissues were compared and the CT-electron density conversion curve was established. The inhomogeneity dose of tissue was corrected according to the relative electron density of each tissue, and the change of MU value of irradiation dose was analyzed. Results: under the same scanning parameters, the CT values of the equivalent density tissue in different locations were all changed: the CT value of the high-density tissue changed greatly, and the CT value of the near-bed tissue was larger than that of the far-bed tissue. The difference of MU values in different CT-electron density conversion curves was 20. The difference of MU values in intensity modulated radiotherapy (IMRT) was larger than that in intensity modulated radiotherapy (IMRT). The deviations of three dimensional conformal radiotherapy (3-dimensional conformal radiation therapeutic therapy) and intensity modulated radiotherapy (IMRT) were the same. Conclusion: a CT-electron density conversion curve should be inputted correctly and reasonably when collecting and inputting the data of the treatment plan system in order to ensure the accuracy of the dose calculation of the treatment plan.
【作者單位】： 解放軍89醫(yī)院腫瘤放療科;武警后勤學院附屬醫(yī)院;
【分類號】：R730.55
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本文編號：2136331