磁振溫度影像導引平台於高能聚焦超音波乳房腫瘤熱治療之研究

Abstract

根據衛福部公佈的資料顯示，世界上大約一年有超過五十萬人死於乳癌，而且位居女性癌症發生率第一名，並且罹患的比例也逐年的增加，目前只能藉由定期的檢查，期望能夠及早發現並早期治療，以降低死亡率。高能聚焦超音波（High-intensity Focused Ultrasound，HIFU）熱治療為近年來於腫瘤治療中最被重視與發展之非侵入式技術之一，此方法主要是使用高能聚焦超音波加熱腫瘤的部位，透過熱效應來殺死癌細胞，但運用高能聚焦超音波治療癌症必須藉由精確的醫學影像進行定位，本研究目的是開發出一磁振造影溫度量測平台以協助高能聚焦超音波於乳癌之治療，其功能主要是提供即時的溫度監控與資訊回饋，並做為高能聚焦超音波定位之導引工具，以利提升燒灼乳癌腫瘤之精準度。本研究進行了六種實驗，三種演算法進行溫度量測之比較、磁振影像溫度量測與光纖溫度計量測實驗、假體與離體的實驗、單線圈與雙通道線圈實驗、MRI的參數不同實驗、MRI成像技術不同的實驗。從實驗結果中可以發現，本平台重建出的溫度與光纖溫度計的誤差均在 ± 1 ℃左右，並且各實驗中在非燒灼點的部位的標準差均小於 1 ℃，各實驗均顯示本研究之溫度量測平台的可靠性。

Breast cancer incidence rate is ranked as the number 1 in female cancers. Breast cancer cases increase in the past decade and progress to a younger population in Taiwan and world-wide. Traditional breast cancer treatment methods include lumpectomy, mastectomy, radiotherapy or chemotherapy, which are either invasive or having unpleasant side effects. Thus, how to provide an accurate, effective and comfortable treatment has become the most challenging topic in breast cancer therapy. High-intensity focused ultrasound (HIFU) thermal ablation has long been proven to be a non-invasive modality for cancer therapy. With MRI guidance, HIFU could provide high accuracy in tumor localization and thermal ablation. In this research, we aimed to establish an MRI-guided platform to facilitate the use of HIFU on treating breast tumor. We designed several experiments, like comparison with three algorithms, comparison between MR-temperature mapping and fiber-optical thermometer, temperature mapping with different MRI parameters, MR-temperature mapping with single and dual channel RF coil, MR-temperature mapping with echo planar imaging, MR-temperature mapping with breast phantom. Our current results show that the temperature differences between the fiber-optical thermometer and MR temperature mapping are only ± 1 ℃. Moreover, the standard deviations of areas without HIFU heating are all smaller than 1 ℃, which have demonstrated our platform’s feasibilities.