Tani Natsumi Hirano, Koreeda Yuki, Nawata Aya, Fujisaki Akitaka, Hayashida Yoshiko, Shimajiri Shohei, Nakayama Toshiyuki, Hisaoka Masanori, Inoue Yuzuru, Hirata Keiji, Tashima Yuko, Tanaka Fumihiro, Aoki Takatoshi
Department of Radiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
Department of Surgery 1, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
Magn Reson Med Sci. 2025 Jan 1;24(1):112-121. doi: 10.2463/mrms.mp.2023-0127. Epub 2024 Feb 7.
Adipocytes around aggressive breast cancer (BC) are less lipid different from naive adipocytes (cancer-associated adipocytes, CAAs), and peritumoral edema caused by the release of cytokines from CAAs can conduce to decrease the peritumoral fat proportion. The purpose of this study was to correlate peritumoral fat content identified by using iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) with lymph node metastasis (LNM) and recurrence-free survival (RFS) in BC patients and to compare with T2-weighted (T2WI) and diffusion-weighted images (DWI) analyses.
This retrospective study consisted of 85 patients who were diagnosed with invasive carcinoma of breast and underwent breast MRI, including IDEAL before surgery. The scan time of fat fraction (FF) map imaging using IDEAL was 33s. Four regions of interest (ROIs), which are 5 mm from the tumor edge, and one ROI in the mammary fat of the healthy side were set on the FF map. Then average peritumoral FF values (TFF), average FF values on the healthy side (HFF), and peritumoral fat ratio (PTFR, which is defined as TFF/HFF) were calculated. Tumor apparent diffusion coefficient (ADC) values were measured on ADC map obtained by DWI. Peritumoral edema was classified into three grades based on the degree of signal intensity around the tumor on T2WI (T2 edema).
The results of stepwise logistic regression analysis for four variables (TFF, PTFR, T2 edema, and ADC value) indicated that TFF and T2 edema were significant factors of LNM (P < 0.01). RFS was significantly associated with TFF (P = 0.016), and 47 of 49 (95.9%) patients with TFF more than 85.5% were alive without recurrence.
Peritumoral fat content identified by using IDEAL is associated with LNM and RFS and may therefore be a useful prognostic biomarker for BC.
侵袭性乳腺癌（BC）周围的脂肪细胞与原始脂肪细胞（癌症相关脂肪细胞，CAA）的脂质差异较小，且CAA释放的细胞因子引起的瘤周水肿可导致瘤周脂肪比例降低。本研究的目的是将使用水脂迭代分解与回波不对称和最小二乘估计（IDEAL）识别的瘤周脂肪含量与BC患者的淋巴结转移（LNM）和无复发生存期（RFS）相关联，并与T2加权（T2WI）和扩散加权图像（DWI）分析进行比较。
这项回顾性研究包括85例被诊断为乳腺浸润性癌并接受乳腺MRI检查的患者，包括术前的IDEAL检查。使用IDEAL进行脂肪分数（FF）图成像的扫描时间为33秒。在FF图上设置距肿瘤边缘5毫米的四个感兴趣区域（ROI），以及健康侧乳腺脂肪中的一个ROI。然后计算瘤周平均FF值（TFF）、健康侧平均FF值（HFF）和瘤周脂肪比率（PTFR，定义为TFF/HFF）。在通过DWI获得的ADC图上测量肿瘤表观扩散系数（ADC）值。根据T2WI上肿瘤周围信号强度的程度将瘤周水肿分为三个等级（T2水肿）。
对四个变量（TFF、PTFR、T2水肿和ADC值）进行的逐步逻辑回归分析结果表明，TFF和T2水肿是LNM的显著因素（P<0.01）。RFS与TFF显著相关（P = 0.016），49例TFF超过85.5%的患者中有47例（95.9%）无复发存活。
使用IDEAL识别的瘤周脂肪含量与LNM和RFS相关，因此可能是BC的一种有用的预后生物标志物。
