Usefulness of 3-Dimensional-Printed Breast Surgical Guides for Undetectable Ductal Carcinoma In Situ on Ultrasonography: A Report of 2 Cases

Abstract

Tumor localization is challenging in the context of ductal carcinoma in situ (DCIS) treated with breast-conserving surgery. Conventional localization methods are generally performed under the guidance of ultrasonography or mammography and are rarely performed with magnetic resonance imaging (MRI), which is more sensitive than the aforementioned modalities in detecting DCIS. Here, we report the application of MRI-based individualized 3-dimensional (3D)-printed breast surgical guides (BSGs) for patients with breast cancer. We successfully resected indeterminate and suspicious lesions that were only detected using preoperative MRI, and the final histopathologic results confirmed DCIS with clear resection margins. MRI guidance combined with 3D-printed BSGs can be used for DCIS localization, especially for lesions easily detectable using MRI only.

Keywords: Breast neoplasms; Carcinoma, ductal; Magnetic resonance imaging; Printing, three-dimensional.

Figure 1. Enhanced breast magnetic resonance imaging (A) revealing an irregular enhancing mass in the 11 o'clock position, 6.1 cm from the nipple, with a diameter of 2.8 cm, in the right breast which was concordant with biopsy-confirmed malignancy. (B) an indeterminate mass in the central portion of the right breast, 3.0 cm from the nipple, with a diameter of 0.6 cm (C) and another indeterminate mass at 6 o'clock of the left breast, 3.6 cm from the nipple, with a diameter of 0.6 cm were detected.

Figure 2. Preoperative ultrasonography did not reveal the magnetic resonance imaging–detected indeterminate masses (A) right 10 o'clock, (B) left 4 o'clock in either breast.

Figure 3. Data obtained from supine magnetic resonance imaging were analyzed, and the tumors, including the right breast biopsy-confirmed cancer (A, D: red arrow) and the indeterminate tumors in the right breast (B, D: yellow arrow), left breast (C, D: green arrow), and normal tissues, were divided. The final histopathologic diagnosis of the 11 o'clock specimen from the right breast was invasive ductal carcinoma. Furthermore, the tumor in the central portion of the right breast was a DCIS, and the tumor in the left breast was a DCIS with lobular carcinoma in situ.

DCIS = ductal carcinoma in situ.

Figure 4. Patient-specific hybrid-type breast surgical guides (BSGs) containing the blue dye injection columns, which can indicate the tumor extent requiring removal, are modeled (A). The following specifications were used for modeling the BSGs to ensure an accurate display of the tumor resection boundaries: 1) they were made to precisely fit the breast skin surface, 2) a hole was provided to fit the nipple, and 3) guidelines to prevent rotation of the BSGs and indicate their placement relative to the opposite nipple and the suprasternal notch were included (B, C). The tumor resection boundaries were drawn onto the breast skin surface designed to match tumor shape (D).

BSG = breast surgical guide.