分析影像導引定位系統對治療等中心點位移準確度的研究

在放射治療過程中，患者的治療等中心點位置準確度是影響精確治療的關鍵因素。每日治療時的擺位誤差主要可分為系統誤差(systematic error)與隨機誤差(random error)。本研究主要分為兩個主要部分：一、利用假體模擬臨床治療過程，來驗證影像導引定位系統治療等中心點是否準確，此部分主要為表現系統誤差。二、以2006年11月至2007年2月間，採用影像導引放射治療技術(Image-Guided Radiotherapy, IGRT)的18位頭頸部患者與22位胸腹部患者的資料來分析治療等中心點位移是否準確，此部分主要為表現隨機誤差。研究測量結果，分析擺位誤差與三維各軸的平均位移誤差。所測得假體X、Y、Z三軸的平均位移分別為0.6 mm、0.3 mm、0.6 mm。頭頸部患者平均位移誤差分別為0.9 mm、1.1 mm、0.9 mm。Σ值分別為0.9 mm、1.1 mm、0.9 mm。σ值分別為0.6 mm、0.7 mm、0.5 mm；胸腹部患者平均位移誤差分別為1.7 mm、2.3 mm、1.8 mm。Σ值分別為1.5 mm、1.9 mm、2.1 mm。σ值分別為0.7 mm、0.9 mm、1.5 mm。結果顯示整體Σ值和σ值皆能小於2.3 mm，說明治療等中心點的位移誤差皆在擺位誤差內，結果證明本科影像導引定位系統對於治療等中心點均保持一定程度的準確度與再現性。

關鍵字

影像導引放射治療技術；擺位誤差；系統誤差；隨機誤差

並列摘要

In the process of radiotherapy, the radiotherapy isocenter accuracy of a patient is the key factor affecting the precision of therapy. Setup errors could majorly be divided into systematic error and random error in daily treatment. The study could majorly be divided into two main parts: The first, Will make use of phantom to imitate clinical treatment process, to identify whether the isocenter of the ExacTrac X-ray positioning system radiotherapy was accurate or not, this part mainly measures a systematic error. The second, We investigated 18 head and neck cases with 22 chest and abdomen cases who underwent Image-Guided Radiotherapy (IGRT) between November 2006 and February 2007. Radiotherapy isocenter shift was accurate or not, this part mainly measures a random error. The results showed analyze the setup errors data with mean translation in X(LR), Y(SI) and Z(AP) directions in isocenter. Measure the phantom mean translation in X (LR), Y(SI) and Z(AP) directions were 0.6 mm, 0.3 mm, 0.6 mm. The head and neck cases mean translation in X (LR), Y (SI) and Z (AP) directions were 0.9 mm, 1.1 mm and 0.9 mm, respectively. The standard deviations of systematic error (Σ) were 0.9 mm, 1.1 mm and 0.9 mm, respectively, and that of the (σ) were 0.6mm, 0.7mm, 0.5mm, respectively. The chest and abdomen cases mean translation in X(LR), Y(SI) and Z(AP) directions were 1.7 mm, 2.3 mm, and 1.8 mm, respectively. The standard deviations of systematic error (Σ) were 1.5 mm, 1.9 mm, and 2.1 mm, respectively, and that of the (σ) were 0.7 mm, 0.9 mm, 1.5 mm, respectively. Results showed whole Σ value and σ to be worth all ability small in 2.3 mm, find the shift error margin of the radiotherapy isocenter in the setup errors. The results revealed the positioning system of the ExacTrac X-ray to all keep the accuracy and the reposition with certain degree to the radiotherapy isocenter.

並列關鍵字

ExacTrac X-ray positioning system ； setup error ； systematic error ； random error

國際替代計量

分析影像導引定位系統對治療等中心點位移準確度的研究

全文下載

主題瀏覽