淋巴閃爍造影對乳癌淋巴轉移的應用與影像探討

Application of Lymphoscintigraphy and Imaging of Sentinel Lymph Node Metastasis in Breast Cancer

淋巴系統是腫瘤細胞轉移的路徑之一。淋巴閃爍攝影（Lymphoscintigraphy）主要用於顯示淋巴分佈並定位離腫瘤最近的前哨淋巴結，提供乳房手術時進行前哨淋巴結切片（Sentinel Lymph Node Biopsy, SLNB），檢測是否有淋巴轉移，對乳癌進行分期。淋巴閃爍攝影，經由皮下注射藥物Tc-99mPhytate於乳暈或腫瘤周圍後，利用核醫伽碼造影機偵測出前哨淋巴結位置，待淋巴顯影後於病人皮膚上標示淋巴結位置。病人所受到的輻射劑量很少，遠低於原子能委員會規定的限值，無須擔憂。研究指出，使用SLNB作為早期乳癌的前哨淋巴結定位是高度可靠的方法。

The lymphatic system is one of the major routes by which tumor cell metastases occur. Lymphoscintigraphy is used for mapping the distribution of lymph nodes and locating the sentinel lymph nodes nearest to a tumor. This facilitates sentinel lymph node biopsies (SLNB) during breast cancer surgery, which enable the detection of lymph node metastases and aid in breast cancer staging. In lymphoscintigraphy, Tc-99m phytate is injected subcutaneously around the areola or tumor, and the locations of the sentinel lymph nodes are detected using a gamma camera. Once the lymph nodes have been imaged, their positions are marked on the skin of the patient. The radiation dose received by patients during lymphoscintigraphy is minimal, well below the limit stipulated by the Nuclear Safety Commission of Taiwan, and is therefore not a cause for concern. SLNB is a highly reliable method for locating sentinel lymph nodes in early breast cancer.