[醫(yī)藥]腫瘤質(zhì)子治療原理及臨床應(yīng)用-在線瀏覽
2024-09-27 01:15本頁(yè)面
【正文】 the dose limit of surrounding normal tissues. However, the monly used external radiation sources, such as electrons and photons, have certain limitations. Electrons are limited to treat superficial tumour, and photons are used for deepsited target. Because the depth dose curve of photons follow the exponential law, which means that a considerable amount radiation dose delivered to surrounding normal tissue and cause early or late side effects. Protons have a special depth dose curve, so called bragg peak. It has a finite range, and is energy depended. This makes the radiation dose uniform across the target volume, a zero dose beyond tumour and a lower dose proximal tumour than photons. Therefore, the clinical benefits are very obvious. Tumour control probability can be improved by increasing radiation dose in tumour, while without increasing side effect. Several clinical cases were used for illustration of dose distribution of proton therapy, and the principles of proton treatment planning were discussed. The clinical results were reviewed briefly. The clinical indication and potential technical development were also discussed. Key words: oncology, radiotherapy, proton 一、 質(zhì)子治療原理光子（X射線）和電子線是最常用的對(duì)腫瘤實(shí)施體外照射的放射源。文中簡(jiǎn)單探討了質(zhì)子治療計(jì)劃技術(shù)，使用幾個(gè)病例來(lái)說(shuō)明質(zhì)子束劑量分布的特點(diǎn)。質(zhì)子射束由于其特殊的深度劑量分布，博拉格峰，使腫瘤內(nèi)劑量分布均一，腫瘤后方劑量為零，腫瘤前方劑量低于光子；而且，博拉格峰的位置是能量依賴的，能夠精確的調(diào)整到需要的位置。腫瘤質(zhì)子治療原理及臨床應(yīng)用穆向魁山東淄博萬(wàn)杰質(zhì)子治療中心山東，淄博，255213論文摘要： 放射治療的目的是給予腫瘤致死放射劑量，而同時(shí)給予腫瘤周?chē)＝M織最小的放射劑量以避免放射損傷。然而，通常使用的體外射線源，電子線和X線，都有一定的限制：電子線限于治療表淺腫瘤；X線治療可用于深部腫瘤，但是由于光子隨穿透深度指數(shù)衰減，使腫瘤周?chē)＝M織受到大量照射，引起早期或晚期并發(fā)癥。因此，使用質(zhì)子治療可以提高腫瘤劑量來(lái)提高腫瘤局部控制率，而且由于正常組織沒(méi)有或少照射而避免的并發(fā)癥的發(fā)生?；仡櫡治隽私陙?lái)的臨床資料，并探討了質(zhì)子治療的適應(yīng)癥和未來(lái)技術(shù)發(fā)展的方向等問(wèn)題。電子線由于穿透能力有限，只能用于治療表淺部位腫瘤。三維適形治療（3DCRT）使用多個(gè)射束交叉照射腫瘤，劑量分布與腫瘤形狀適形，正常組織得到一定保護(hù)；調(diào)強(qiáng)放療（IMXT）使劑量分布適形度進(jìn)一步提高，但是周?chē)艽篌w積的正常組織受到了中、低劑量輻射。質(zhì)子與光子和電子線得主要不同之處是質(zhì)子深度劑量曲線的末端形成博拉格峰。Bragg峰的深度是能量依賴的，因此通過(guò)調(diào)節(jié)質(zhì)子射束能量，并且按不同腫瘤大小恰當(dāng)?shù)財(cái)U(kuò)展峰的寬度，可使高劑量量區(qū)集中在不同深度和大小的腫瘤部位(圖1)。質(zhì)子治療可以降低活動(dòng)骨髓、耳蝸、心臟、腎臟等等危及器官的吸收劑量，所以可以聯(lián)合使用強(qiáng)效化療方案，可以降低聯(lián)合使用順鉑造成的聽(tīng)力受損或腎功衰竭的危險(xiǎn)，可以降低聯(lián)合或續(xù)貫使用阿霉素化療方案造成的嚴(yán)重心肌病變的危險(xiǎn)。圖 1
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