【摘要】：調(diào)強(qiáng)放射治療(IMRT)是目前先進(jìn)的放射治療技術(shù)之一,在我國應(yīng)用比較廣泛,在IMRT提高腫瘤治療效果和患者生命質(zhì)量的同時(shí),國外也報(bào)道了IMRT由于放療劑量錯(cuò)誤而導(dǎo)致的放療事故,國際原子能機(jī)構(gòu)(IAEA)等國際組織對IMRT實(shí)施劑量的準(zhǔn)確度給予了更嚴(yán)格的要求。因此,做好IMRT執(zhí)行前的質(zhì)量控制(QC)劑量驗(yàn)證工作,具有重要的實(shí)際意義。 IMRT劑量驗(yàn)證新型工具——一維矩陣探測器,具有使用方便、高效等優(yōu)點(diǎn),已成為當(dāng)前領(lǐng)域研究的熱點(diǎn),但在國內(nèi)對其質(zhì)量控制研究工作報(bào)道較少。因此,本研究選取一種二維電離室矩陣探測器作為研究對象,首先研究其在光子束下較全面的劑量學(xué)特性,包括測量重復(fù)性、長期穩(wěn)定性、劑量率依賴性、劑量響應(yīng)線性和電離室間響應(yīng)一致性等,建立起質(zhì)量控制檢測方法,其次將二維矩陣探測器與參考電離室進(jìn)行劑量測量比對,最后將二維矩陣探測器在IMRT劑量驗(yàn)證中進(jìn)行應(yīng)用。 二維矩陣探測器在不同能量(60Coγ,6MV、10MV和15MVX)射線下測量重復(fù)性0.3%,在60Co丫射線下半年測量穩(wěn)定性0.5%,表明其具有良好的測量可信度;在不同能量X射線下,加速器出束10-250cGy和60Coγ射線下測量,矩陣電離室線性0.5%;在劑量率為100MU/min～600MU/min下測量最大偏差為1.3%,顯示矩陣劑量率依賴性較�。痪仃嚥煌婋x室劑量響應(yīng)偏差1%；矩陣電離室與參考電離室測量比對顯示,測量偏差≤0.57%;矩陣電離室與參考電離室在4cm×4cm～20cm×20cm不同方形野下測量輸出因子結(jié)果基本一致；分析兩種應(yīng)用二維矩陣探測器進(jìn)行劑量驗(yàn)證的方法,發(fā)現(xiàn)機(jī)架角0°計(jì)劃與非0°計(jì)劃(實(shí)際照射)驗(yàn)證劑量分布與計(jì)劃劑量分布符合較為理想。 以上實(shí)驗(yàn)結(jié)果表明,二維矩陣探測器具有良好的劑量學(xué)特性,是放療技術(shù)質(zhì)量控制的有力工具。通過實(shí)驗(yàn)建立一套包括校準(zhǔn)、比對的質(zhì)量控制方法，，為以后對IMRT質(zhì)量控制劑量驗(yàn)證設(shè)備進(jìn)行質(zhì)量控制打下基礎(chǔ)。實(shí)施機(jī)架角非0°計(jì)劃照射更貼近實(shí)際照射情況,建議采取非0°劑量驗(yàn)證方法進(jìn)行IMRT劑量驗(yàn)證。
[Abstract]:Intensity modulated radiotherapy (IMRT) is one of the advanced radiotherapy techniques, which is widely used in China. While IMRT improves the effect of tumor treatment and the quality of life of patients, Foreign countries have also reported the radiation accident caused by the wrong dose of IMRT. The International Atomic Energy Agency (IAEA) and other international organizations have imposed more stringent requirements on the accuracy of the dose of IMRT. Therefore, it is of great practical significance to do the quality control (QC) dose verification before IMRT execution. One-dimensional matrix detector, a new tool for IMRT dose verification, has become a hot spot in current research field because of its advantages of convenience and high efficiency. However, there are few reports on its quality control in China. Therefore, a two-dimensional ionization chamber matrix detector is chosen as the research object. Firstly, the dosimetric characteristics of the detector under photon beam are studied, including repeatability, long-term stability and dose-rate dependence. The method of quality control detection is established based on the linearity of dose response and the consistency between ionization chamber and so on. Secondly, the two dimensional matrix detector is compared with the reference ionization chamber. Finally, the two-dimensional matrix detector is applied to the IMRT dose verification. The repeatability of the two-dimensional matrix detector was 0.3 at different energy (60Co 緯, 6MV 10MV and 15MVX), and the stability was 0.5 in the second half of the 60Co ray, which showed that it had good reliability. Under different energy X-ray, the matrix ionization chamber was measured under 10-250cGy and 60Co 緯 rays, and the maximum deviation was 1.3 when the dose rate was 100MU/min~600MU/min, which showed that the matrix dose-rate dependence was small. The dose response deviation of different ionization chambers is 1. The comparison of matrix ionization chamber and reference ionization chamber shows that the measurement deviation is less than 0.57.The results of matrix ionization chamber and reference ionization chamber are basically consistent under different square fields of 4cm 脳 4cm~20cm 脳 20cm. Two methods of dose verification using 2-D matrix detector are analyzed. It is found that the verification dose distribution and the planned dose distribution of the frame angle 0 擄plan and non-0 擄plan (actual irradiation) are in good agreement with each other. The experimental results show that the two-dimensional matrix detector has good dosimetry characteristics and is a powerful tool for quality control of radiotherapy technology. A set of quality control methods including calibration and comparison were established through experiments, which laid a foundation for the quality control of IMRT quality control dose verification equipment in the future. The implementation of frame angle non-0 擄planned irradiation is closer to the actual irradiation situation. It is suggested that the method of non-0 擄dose verification should be adopted for IMRT dose verification.
【學(xué)位授予單位】：中國疾病預(yù)防控制中心
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：R730.55

【參考文獻(xiàn)】

中國期刊全文數(shù)據(jù)庫 前6條

1 李齊林;鄧小武;陳立新;;二維半導(dǎo)體探測器陣列的方向性響應(yīng)和在調(diào)強(qiáng)放射治療合成劑量驗(yàn)證中的應(yīng)用研究(英文)[J];癌癥;2010年06期

2 汪琪;翟振宇;王靜;何俠;蔣明華;葉峰;;利用二維電離室矩陣驗(yàn)證鼻咽癌調(diào)強(qiáng)放射治療的劑量分布[J];腫瘤學(xué)雜志;2011年01期

3 陳開強(qiáng);柏朋剛;張秀春;李奇欣;;鼻咽癌調(diào)強(qiáng)放療劑量驗(yàn)證的探討[J];中國醫(yī)療設(shè)備;2010年02期

4 任健;高峰;王艷菊;;二維電離室點(diǎn)矩陣Matrixx在調(diào)強(qiáng)驗(yàn)證中的應(yīng)用[J];醫(yī)療裝備;2011年02期

5 袁一楓;李軍;譚飛;葛和平;茅冬俊;;二維電離室矩陣在IMRT中的劑量學(xué)驗(yàn)證[J];醫(yī)療裝備;2011年08期

6 吳昊;蔣t

本文編號：2351699