- 學位論文
建立個別病人於介入性肝臟動脈栓塞治療之劑量評 估系統
Establishing An Individual Dosing System For Patients Undergoing Interventional Transcatheter Arterial Embolization
摘要
使用透視攝影及數位減贅攝影進行影像導引介入性血管攝影檢查，因為容易達到病灶且相對風險小，可治療許多疾病，在醫療輻射暴露越來越廣泛使用，然而卻存在確定性效應並潛在誘發癌症機率效應的風險。國際組織也對於介入性的放射手術有閾值劑量上的建議，和皮膚劑量的限值，並希望記錄追蹤個別病人的醫療輻射暴露量。 本研究利用自顯色膠片和量測為基礎的蒙地卡羅程式BEAMnrcMP，建立一套個別病人於介入性血管攝影，進行肝動脈血管栓篩治療的劑量評估系統。我們研究自顯色膠片特性，並將量測病人劑量分布結果輸入蒙地卡羅，得到三維劑量分布對應於電腦斷層影像。分叢技術可透過歸類屬性相近的資料點，進行資料區分，我們進而使用K-means分叢法於電腦斷層影像，區分不同器官，計算器官組織劑量。 成功建立個別病人於肝動脈栓塞器官組織劑量評估系統，未來可將此系統運用在不同的介入性手術或心導管造成的劑量評估及追蹤。
並列摘要
Less invasive imaging-guided vascular interventions with fluoroscopy and digital subtraction angiography have recently become widespread and have been successfully used for treating various diseases. However, interventional fluoroscopy procedures may present deterministic and stochastic radiation risks. The International Commission on Radiological Protection (ICRP) and the Food and Drug Administration have requested identifying procedures that may involve patient doses greater than the recommended thresholds. The International Atomic Energy Agency (IAEA) announced a new project to track radiation exposure from medical diagnostic procedures. In this study, radiochromic dosimetric media, known as self-developing films, and measurement-based Monte Carlo simulations were used to establish an interventional radiology dosing system for individual patients undergoing interventional transcatheter arterial embolization. We investigated the characteristics of gafchromic films, and successfully inputed dose distribution of the measured films from clinical situation to Monte Carlo simulation. A 3D dose map incorporated into CT images was established. Then k-mean clustering method played the role based on the cluster analysis with the nearest mean for the local segmentation. We furthermore utilized the K-mean clustering to achieve the organ segmentation, and calculated the organ doses. The organ doses for individual patients were evaluated using this dosing system. This system could be applied very well to other fluoroscopic or interventional procedures for patient dose management.