【摘要】：目前，肺癌放射治療通常采用螺旋CT在患者自由呼吸狀態(tài)下行定位掃描，每層掃描時(shí)間遠(yuǎn)小于一個(gè)呼吸周期所需時(shí)間，由此所采集到的圖像只是腫瘤在某一呼吸周期中一個(gè)隨機(jī)時(shí)相點(diǎn)的影像，既不能反映腫瘤在靜止?fàn)顟B(tài)下的情況，也不能準(zhǔn)確反映腫瘤在呼吸周期中的運(yùn)動(dòng)范圍。由此圖像進(jìn)行計(jì)劃設(shè)計(jì)，不但增大了正常組織的受量，同時(shí)也增加了腫瘤漏照的可能。 本論文對30例肺癌患者同時(shí)采用統(tǒng)一體位固定裝置行常規(guī)CT掃描與4DCT掃描，對所得到的的圖像按照ICRU62號(hào)報(bào)告規(guī)定進(jìn)行以下處理：對常規(guī)CT定位圖像進(jìn)行GTV的勾畫；在4DCT10各呼吸時(shí)相圖像上分別勾畫取平均值IGTV，用4DCT圖像中的最大密度投影圖像進(jìn)行GTVMIP勾畫；用平靜呼氣末時(shí)相和平靜吸氣末時(shí)相的融合圖像進(jìn)行GTV0+50勾畫，按照不同的外放形成PTV后進(jìn)行計(jì)劃設(shè)計(jì)，將此計(jì)劃投影到4DCT各時(shí)相上去，，進(jìn)行劑量學(xué)分析。同時(shí)，對基于最大密度投影圖像和平靜呼氣末時(shí)相和平靜吸氣末時(shí)相的融合圖像所設(shè)計(jì)的和資料計(jì)劃進(jìn)行劑量學(xué)比較。 體積比較顯示：GTV與IGTV比較無統(tǒng)計(jì)學(xué)差異，GTVMIP和GTV0+50與IGTV比較均有統(tǒng)計(jì)學(xué)差異，GTVMIP和GTV0+50比較無統(tǒng)計(jì)學(xué)差異。 劑量學(xué)比較顯示：基于常規(guī)CT的治療計(jì)劃對上肺癌患無統(tǒng)計(jì)學(xué)差異，中下肺均有統(tǒng)計(jì)學(xué)差異；基于MIP的治療計(jì)劃和基于雙時(shí)相融合圖像的治療計(jì)劃對所有肺癌患者均有統(tǒng)計(jì)學(xué)差異。所有的治療計(jì)劃對全肺劑量學(xué)比較均有統(tǒng)計(jì)學(xué)差異。 應(yīng)用4DCT進(jìn)行肺癌的放射治療，在不增加正常組織受量的前提下，提高靶區(qū)覆蓋率，可以獲得更好的局部控制率。
[Abstract]:At present, radiotherapy for lung cancer usually uses spiral CT to localize the patient's free breathing state, and the scanning time per layer is much less than that required for a respiratory cycle. The obtained images are only a random time-point image of the tumor in a certain respiratory cycle, which can neither reflect the static state of the tumor nor accurately reflect the range of motion of the tumor in the respiratory cycle. The planning of the image not only increases the amount of normal tissue, but also increases the possibility of tumor leakage. In this paper, 30 patients with lung cancer were scanned by conventional CT scanning and 4DCT scanning with unified posture fixation device at the same time. According to the ICRU62 report, the obtained images were processed as follows: the conventional CT localization images were sketched by GTV; The average value of IGTV, was sketched on the images of each breathing phase of 4DCT10, and the maximum density projection image of 4DCT image was used for GTVMIP sketching. The fusion images of calm end-breath phase and calm inspiratory end-phase were used to sketch GTV0 50. After PTV was formed according to different explants, the plan was projected to each phase of 4DCT, and dosimetric analysis was carried out. At the same time, the dosimetric comparison of the fusion images based on the maximum density projection image and the calm end-breath phase and the calm end-inspiratory phase was carried out. The volume comparison showed that there was no significant difference between GTV and IGTV, GTVMIP and GTV0 50 were statistically different from IGTV, but there was no significant difference between GTVMIP and GTV0 50. The dosimetric comparison showed that there was no significant difference in the treatment plan based on conventional CT for patients with upper lung cancer, but there was significant difference between the middle and lower lungs. There were significant differences between MIP-based treatment plan and dual-phase fusion image-based treatment plan for all patients with lung cancer. All treatment plans were statistically different in whole lung dosimetry. The radiotherapy of lung cancer with 4DCT can obtain better local control rate by increasing the coverage of target area without increasing the amount of normal tissue.
【學(xué)位授予單位】：清華大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：R734.2;R730.55

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本文編號(hào)：2493685