以多次位移增加2D-ARRAY解析度來比較不同部位之放射治療計畫

Increase 2D-ARRAY resolution by multiple acquisition to compare radiation treatment plan in different regions

郭丞(Cheng Kuo)

指導教授 ： 張寶樹

高雄醫學大學/健康科學院/醫學影像暨放射科學系碩士在職專班/碩士(2016年)

摘要

研究目的：利用現有單位上的測量儀器，進行臨床上放射治療計畫的劑量驗證，並參考2005年E. Spezi利用多次位移的方式，以增加PTW 2D-ARRAY seven29的空間解析度，並實際帶入不同部位的放射治療計畫，以比較此測量方式對不同部位之效果與不同位移次數下對於空間解係度的差異。
材料與方法：放射治療計畫分別為頭頸部與骨盆腔各10組，利用多次位移2D-ARRAY的測量位置以完整覆蓋其二維平面，並且實際測量放射治療計畫的劑量分佈。利用Matlab軟體以加馬指標(gamma index，GI)的方式比較測得的數據與放射治療計畫，探討不同部位以多次位移2D-ARRAY的方式做測量之效果差異。
結果：位移1次、2次、4次和8次的GI平均值分別為0.54、0.47、0.46和0.46，表示隨著位移次數變多實際測量的劑量分佈與放射治療計畫的差異變小，並透過成對樣本t檢定檢查後具有統計學上的意義(p值＜0.05)。
結論：因為2D-ARRAY的游離腔彼此間有間隔，本研究透過多次位移方式是證實可以有效增加空間解析度。但本研究的放射治療計畫與測量對象皆為2D-ARRAY和固態水假體，所以並無預想頭頸部會因為具有許多竇腔(sinus)造成較多誤差的情形發生，反而是頭頸部在放射治療計畫中具有較多的小照野，經過多次位移後更能夠將數據完整的收集。

關鍵字

強度調控放射治療 ； 多次位移 ； 2D array

並列摘要

Purposes︰The use of measuring instruments on the department to verify the clinical radiation treatment plan and reference 2005 Spezi use multiple acquisition(MA) to increase the PTW 2D-ARRAY seven29 spatial resolution, and actually implement different body regions radiation treatment plan to compare spatial resolution in different body regions and different MA sequences by multiple acquisition.
Methods and materials︰Radiation treatment plan divided into two groups , each divided into 10 samples of H&N and pelvic. The use of multiple acquisition by 2D-ARRAY to complete coverage of its two-dimensional plane, and the measurement of dose distribution in the treatment plans. Then use of Matlab software to compare the measured data with radiation treatment plan by Gamma Index (GI) , to discus the effect in different body regions by multiple acquisition sequences.
Result︰Acquisition once, twice, four times and eight times the average GI were 0.54,0.47,0.46 and 0.46 , respectively. It means that the difference between measured data and radiation treatment plan become smaller when more multiple acquisition sequences. It is a significance statistically(p value <0.05) by paired sample t test.
Conclusion︰Because between 2D-ARRAY ion chambers have spaced from each other, the study through multiple acquisition is proven to be effective way to increase spatial resolution. However, the study object are 2D-ARRAY and solid water phantom in measured object and radiation treatment plan , so do not expect because of the H&N have many sinuses cause more errors occur, but is in the H&N radiation treatment plan has more small segments , after repeated acquisiton can be more complete data collection.

並列關鍵字

IMRT ； multiple acquisition ； 2D array

參考文獻

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