Takahashi Shota, Fujimoto Hiroshi, Nasu Katsuhiro, Nakaguchi Toshiya, Ienaga Naoto, Kuroda Yoshihiro
Degree Programs in System and Information Engineering, University of Tsukuba, 1-1-1 Tennodai, Tsukuba City, Ibaraki, 305-8573, Japan.
Department of General Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana Chuo-ku, Chiba City, Chiba, 260-0856, Japan.
Int J Comput Assist Radiol Surg. 2025 Apr;20(4):817-824. doi: 10.1007/s11548-024-03288-8. Epub 2024 Dec 16.
In image-guided surgery for breast cancer, the representation of the breast deformation between planning and surgery plays a key role. The breast deforms significantly and behaves as a fluid with some constraints. Concretely, the deep fat layer in the breast deforms fluidly due to its incomplete fixation to the chest wall, while the anchoring structures by fascia avoid excessive deformation. In this study, we propose a method to simulate the semi-fluid deformation of the breast, considering the fluidic properties of the adipose tissue under the constraints of the anchoring structures.
The proposed method prioritizes anatomical features of the breast, enhancing tissue mobility near the chest wall and modeling the anchoring structure of the fascia along the inframammary fold. To simulate semi-fluid deformation, constraint force from anchoring structure is applied to prone-positioned breast model, using a finite element method.
The results of the evaluation indicate a tumor center registration error of 11.87 ± 4.05 mm. Additionally, we verified how semi-fluid representation affects the registration error. The tumor's Hausdorff distance decreased from 12.89 ± 6.24 mm to 11.50 ± 4.38 mm with considering semi-fluidity.
The results showed that the use of semi-fluid representation tends to reduce registration errors. Therefore, it was suggested that the proposed method could improve the accuracy of breast posture conversion.
在乳腺癌的图像引导手术中，规划与手术之间乳房变形的呈现起着关键作用。乳房会发生显著变形，其行为类似于具有一定约束的流体。具体而言，乳房中的深层脂肪层由于其与胸壁的固定不完全而呈流体状变形，而筋膜的锚固结构可避免过度变形。在本研究中，我们提出一种方法来模拟乳房的半流体变形，该方法考虑了在锚固结构约束下脂肪组织的流体特性。
所提出的方法优先考虑乳房的解剖特征，增强胸壁附近组织的移动性，并沿乳房下皱襞对筋膜的锚固结构进行建模。为了模拟半流体变形，使用有限元方法将来自锚固结构的约束力应用于俯卧位乳房模型。
评估结果表明肿瘤中心配准误差为11.87±4.05毫米。此外，我们验证了半流体表示如何影响配准误差。考虑半流体特性时，肿瘤的豪斯多夫距离从12.89±6.24毫米降至11.50±4.38毫米。
结果表明，使用半流体表示往往会减少配准误差。因此，建议所提出的方法可以提高乳房姿态转换的准确性。
