高強度聚焦超音波應用於甲狀腺腫瘤熱治療之研究

High Intensity Focused Ultrasound For Thyroid Tumor Thermal Therapy

陳威佑(Wei-You Chen)

指導教授 ： 林文澧

共同指導教授 ： 陳永耀(Yung-Yaw Chen)

國立臺灣大學/工學院/醫學工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02180

摘要

本研究的目的是在探討聚焦型超音波在不傷害甲狀腺以外的正常組織及不引起皮膚燒灼的條件下，治療甲狀腺腫瘤的可能性以及作妥善的術前規劃評估。單一晶片超音波換能器應用在模擬及體外實驗之中，其開口直徑3.5公分、曲率半徑5.5公分，頻率4MHz。模擬中探討不同的輸入功率、表面冷卻、加熱及冷卻時間來估算焦斑形成的大小，以及皮膚及前場溫升的情況。此外，為了更進一步避免皮膚燒灼及縮短焦斑長度，模擬中也將探討不同換能器的直徑及曲率半徑對聲強分佈及焦斑形成長度的影響。結果顯示，低於10W的輸入功率及高於10秒的加熱時間可以控制焦斑長度在約1公分之內，在此參數之下，40秒的冷卻時間足夠讓皮膚及前場的溫度回降。而在設計換能器方面，直徑4.375公分，曲率半徑3.5公分的換能器在降低皮膚溫度及縮短焦斑長度上的確有明顯的效果。本研究結果確認了聚焦型超音波應用在甲狀腺腫瘤治療上的可能性。以模擬及體外實驗結果所建議的參數將可讓焦斑集中在目標區域中而不傷害區域外的組織。

關鍵字

超音波 ； 熱治療 ； 甲狀腺

並列摘要

The purpose of this study is to investigate the feasibility of using high intensity focused ultrasound(HIFU) to treat thyroid nodules tissue without overheating surrounding normal tissues or inducing skin burn . A single element transducer (diameter 3.5cm、radius of curvature 5.5cm and frequency 4MHz) was used in simulation and in-vitro experiment study . Various input power、precooling、water temperature、sonication time and cooling interval among sonications were investigated to evaluate the lesion formation and temperature elevation. Furthermore, the intensity and thermal dosage distribution of different parameters ultrasound transducer was studied for the purpose of avoiding skin burn and shortening the lesion length. Results indicate that the input power lower than 10W and heating time longer than 10 seconds can produce a lesion within 1cm , 40 seconds cooling time is sufficient to cool down the temperature in front of the lesion. A diameter 4.375cm and radius of curvature 3.5cm transducer is suitable to produce a short lesion with low skin temperature elevation. The simulation and experiment study confirmed the feasibility of using HIFU to treat thyroid nodules , a target area can be treated safely without overheating the surrounding normal tissues by the input power and heating time suggested by the simulation and the in-vitro experiments.

並列關鍵字

HIFU ； ultrasound ； therapy ； thyroid

參考文獻

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