使用血管分析於3D能量都卜勒超音波之乳房腫瘤化學治療評估

Abstract

對於女性來說，乳癌是一種常見且為主要死因的疾病。癌症病人通常會接受化學治療來防止癌細胞的擴散，然而伴隨化療的副作用也對病人造成很大的傷害。化療結果的提早預測不僅能幫助決定是否改變治療藥劑以避免不必要的療程對病人造成的無謂傷害，也能用於評估病人是否有接受手術的必要。一般而言，化療的結果是利用化療後的剩餘腫瘤大小來做評估。然而腫瘤血管化也是一種有潛力的預後指標。過去已有許多研究廣泛地使用血管指標(vascularization index)來做化療結果的評估，但由於此指標對於血管型態以及機能的描述不夠充分，以至於其實驗結果可信度較低。在這篇論文中，我們使用三維都卜勒超音波(3-D power Doppler ultrasound)來檢閱血管的資訊。由於掃描區域的偏移，我們使用影像套合的技術來將化療前後的血管對齊。位於影像交集區域內的血管會被擷取出來並細線化以利血管特徵的計算。為了補足型態及機能上的描述不足，我們將追蹤十七種用於描述型態及曲度變化的血管特徵，且其變化率將被用於化療結果的預測。本實驗將用接受前置化療的32位癌症病人來檢驗所提出的系統，其中包括10位陰性以及22位陽性病例。準確性、敏感性、專一性、陽性以及陰性預測值分別為84.4 (27/32)、86.4 (19/22)、80.0 (8/10)、90.5 (19/21)以及72.2 (8/11)。ROC曲線的Az值則為0.91。結果顯示出血管的變化與化療的結果是高度相關，且新提出的系統能成功地區分化療結果為有效或無效。

Breast cancer is a common disease and a major cause of death for women. Cancer patients often receive chemotherapy to stop the proliferation of cancer cells, but the side effects of chemotherapy also injure them greatly. The early prediction of therapy results not only helps to decide whether the change of treatment is needed to prevent damage that unnecessary therapy course brings to the patients, but also is useful in evaluating the need of surgical treatment. In general, the therapy result is predicted by the residual tumor size, yet the tumor vascularity is also a potential prognostic indicator. Research in the past has broadly used the vascularization index to evaluate the response of chemotherapy. But the lack of morphological and functional description of this indicator makes the experiment results have lower reliability. In this paper, we used 3-D power Doppler to observe vessel information. Due to the departure of the scanned region, the image registration technique is applied to align the vessels. The vessels in the intersected region will be extracted and skeletonized to facilitate the quantification of vessel features. To complement the insufficiency of morphological and functional description, seventeen vascular features depicting changes in morphology and tortuosity are traced and the change ratio will be used to predict the therapy response. The proposed system was examined on 32 breast cancer patients that underwent neoadjuvant chemotherapy, including 10 negative-response and 22 positive-response cases. The accuracy, sensitivity, specificity, positive and negative predictive values were 84.4 (27/32), 86.4 (19/22), 80.0 (8/10), 90.5 (19/21) and 72.2 (8/11), respectively. The Az value of the ROC curve was 0.91. The results showed a high correlation between the change of vessels and response to chemotherapy and the proposed system can differentiate the therapy results into negative or positive responses.