發(fā)布時(shí)間：2019-02-19 15:37

【摘要】：放射治療正呈現(xiàn)出以下兩個(gè)主要研究方向:1.放射治療分割劑量及治療方案的優(yōu)化改進(jìn)。2.改善放射劑量在體內(nèi)的分布。這兩個(gè)方面都必須基于對(duì)治療效果的準(zhǔn)確預(yù)評(píng)價(jià),即對(duì)腫瘤及危及器官放射生物學(xué)行為的準(zhǔn)確判斷。臨床對(duì)于治療結(jié)果的判斷主要采用劑量體積直方圖,而該圖的技術(shù)缺陷也很明顯,首先,對(duì)于統(tǒng)計(jì)值相同,劑量分布不同的計(jì)劃,無(wú)法比較其放射生物學(xué)響應(yīng)。其次,描述計(jì)劃時(shí),只能用分布圖上幾個(gè)參考點(diǎn)上的劑量來(lái)描述。最后,對(duì)于不同分割量,相同總劑量的計(jì)劃無(wú)法比較。 論文在Niemierko研究的基礎(chǔ)上,考慮了腫瘤細(xì)胞在放射治療過(guò)程中的增殖效應(yīng),在原等效均勻劑量數(shù)學(xué)模型的基礎(chǔ)上,加入了潛在倍增時(shí)間這一變量,改進(jìn)了模型,使得不同分割劑量、不同劑量梯度分布、不同分次照射間隔時(shí)間的治療計(jì)劃之間有了比較的途徑和參照,克服了劑量體積直方圖的弱點(diǎn)。 在不同參數(shù)的變化下,通過(guò)對(duì)1995年版、1999年版及含潛在倍增時(shí)間的等效均勻劑量的變化趨勢(shì)及程度的比較,確定了各個(gè)參數(shù)在這個(gè)模型中的權(quán)重和各模型之間的區(qū)別與聯(lián)系、各個(gè)模型的特點(diǎn)及其適宜的應(yīng)用領(lǐng)域與條件。 對(duì)40例肺部接受放射治療患者的肺部等效均勻劑量及傳統(tǒng)的體積劑量參數(shù)的統(tǒng)計(jì)對(duì)比,進(jìn)一步研究了等效均勻劑量在正常組織所受放射性損傷方面評(píng)估的參考價(jià)值,并提出了研究肺部放射性損傷時(shí)的建議a值。研究結(jié)果表明等效均勻劑量可以克服不同計(jì)劃圖像、不同分次肺部組織生物學(xué)效應(yīng)評(píng)估困難,并可以很好地預(yù)測(cè)放射性損傷,具有一定的臨床應(yīng)用價(jià)值。 對(duì)6例大分割劑量治療計(jì)劃與三維適形照射計(jì)劃的99版及含潛在倍增時(shí)間的等效均勻劑量的對(duì)比,分析了等效均勻劑量模型在研究大分割照射、不同分次照射、不同間隔時(shí)間照射時(shí)對(duì)于腫瘤放射生物學(xué)效應(yīng)的評(píng)估價(jià)值。研究表明等效均勻劑量、尤其是含潛在倍增時(shí)間的等效均勻劑量能非常敏感地反映出細(xì)胞倍增效應(yīng)對(duì)于腫瘤組織放射治療結(jié)果的影響,具有一定的臨床應(yīng)用價(jià)值。 論文最后提出了進(jìn)一步改進(jìn)等效均勻劑量數(shù)學(xué)模型的建議,考慮將潛在倍增時(shí)間轉(zhuǎn)化為總放射劑量的一個(gè)函數(shù),將正常組織修復(fù)因子融入到等效均勻劑量模型中,使得模型更加完善,能夠?yàn)榕R床提供更準(zhǔn)確的預(yù)測(cè)。
[Abstract]:Radiotherapy is showing the following two main research directions: 1. Optimization and improvement of fractionation dose and treatment scheme for radiotherapy. 2. To improve the distribution of radiation dose in vivo. These two aspects must be based on the accurate pre-evaluation of the therapeutic effect, that is, the accurate judgment of the radiobiological behavior of the tumor and the organ endangering it. Dose volume histogram is the main method to judge the therapeutic results in clinic, and its technical defects are also obvious. First of all, it is impossible to compare the radiobiological response for the plan with the same statistical value and different dose distribution. Second, the plan can only be described in terms of doses at several reference points on the map. Finally, the plan for the same total dose cannot be compared with different partitioning doses. On the basis of Niemierko study, the proliferation effect of tumor cells during radiotherapy was considered. On the basis of the original equivalent uniform dose mathematical model, the variable of potential doubling time was added to improve the model. The treatment plan with different dose distribution, different dose gradient distribution and different interval time of irradiation has a comparison approach and reference, which overcomes the weakness of dose volume histogram. Under the change of different parameters, the weight of each parameter in this model and the difference and relation between each model are determined by comparing the change trend and degree of the equivalent uniform dose with the 1995 edition, the 1999 edition and the potential doubling time. The characteristics of each model and its suitable application fields and conditions. The statistical comparison of the lung equivalent uniform dose and the traditional volume dose parameters of 40 patients receiving radiation therapy was carried out, and the reference value of evaluating the radiation damage to normal tissues was further studied. The suggested a value for the study of lung radiation injury is also proposed. The results show that the equivalent uniform dose can overcome the difficulty of evaluating the biological effects of lung tissue in different planning images and different grades of lung tissue, and can predict the radiation injury well, which has certain clinical application value. In this paper, we compared the 99 version of large segmented dose treatment plan with that of three-dimensional conformal radiation plan and the equivalent uniform dose with potential doubling time, and analyzed that the model of equivalent uniform dose was used to study the large segmented irradiation and the different times of irradiation. Evaluation of radiobiological effects of different intervals of irradiation on tumors. It has been shown that the effect of cell doubling effect on the radiotherapy results of tumor tissue can be reflected sensitively by the equivalent uniform dose, especially with the potential doubling time, which has certain clinical application value. At the end of the paper, some suggestions are put forward to further improve the mathematical model of equivalent uniform dose. We consider converting the potential doubling time into a function of total radiation dose, and incorporate the normal tissue repair factor into the equivalent uniform dose model. Make the model more perfect, can provide more accurate prediction for clinical.
【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】：2010
【分類(lèi)號(hào)】：R311

【共引文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 董令儀;超分割放射治療宮頸癌與其細(xì)胞凋亡相關(guān)基因表達(dá)關(guān)系的研究[D];廣西醫(yī)科大學(xué);2008年

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本文編號(hào)：2426634