聚焦型超音波應用於乳癌熱手術之研究

Investigation of Focused Ultrasound Thermal Surgery for Breast Tumors

鄭茲元(Tze-Yuan Cheng)

指導教授 ： 林文澧

國立臺灣大學/工學院/醫學工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.01391

摘要

基於非侵入式的優點，超音波熱手術是乳癌治療的理想方式，然而依據以往的臨床經驗，治療時間過長以及肋骨過熱，一直是亟待改善的問題。為此，本研究以分離聚焦型換能器為主體，建構一組以腫瘤目標為旋轉中心的治療系統，並提出一套與之相輔的加熱策略。該策略將換能器以45 度的入射角配置，並運用換能器三種互補性的聚焦模式，由數個分散的路徑對目標進行切換加熱，期望能達到提升治療效率，並且減輕肋骨過熱的目標。由電腦模擬的結果顯示，對於中心距離肋骨界面2cm 以上的目標，該策略可在不加入冷卻時間，以及肋骨溫度低於50°C 的前提下，完成8立方公分腫瘤目標的加熱，所形成的熱劑量分布趨於完整而集中，有效地改善了乳癌熱手術的治療品質。此外，本研究藉由活體外組織的燒灼實驗，也確認了加熱策略在軟組織中所形成的焦斑形態，以及骨組織界面的溫升程度，皆與模擬的結果相接近。

關鍵字

聚焦型超音波 ； 熱手術 ； 乳癌 ； 治療規劃

並列摘要

Because of less invasiveness, focused ultrasound has become apromising tool for localized tumor therapy. Clinical tests of breast tumorablation, however, have shown that the main problems are long treatment time and rib heating. In this study, a target rotating system based on split-focused ultrasound transducer is constructed, and an appropriate heating strategy is designed to cooperate with the system. The transducer is oriented in an angle of 45 degrees to heat the target via temporal switching from separate paths. The aims of the strategy are to increase the therapeutic efficiency and to alleviate rib heating. For targets with a distance more than 2cm from the rib,the results of simulation demonstrated that the strategy could accomplish heating of target with volume 8cm3 without cooling-time interval,and the temperature of the rib was maintain below 50°c during heating process.The distribution of thermal dose tended to be intact and dense after the treatment.Furthermore,the simulation results were also examined by phantom experiments.Both the heating pattern and measured temperature rise of bones matched the simulation results well.

並列關鍵字

Focused Ultrasound ； Thermal Surgery ； Breast Tumors ； Treatment Planning

參考文獻

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