Abstract P4-13-12: Impact of an image fusion technique for preoperative planning in breast conserving surgery in patients with non -mass enhancement on MRI

Abstract

Abstract [Objective] The potential benefit of preoperative MRI is still being controversial and international guidelines do not recommend MRI for routine preoperative assessment. However, when breast conserving surgery (BCS) is considered for non-mass enhancement (NME), an area of enhancement without an associated space occupying mass or focus, biopsy-proven malignancy, the precise localization in surgical position is required. Although breast ultrasound (US) plays an adjunctive role in evaluation of MRI findings in preoperative planning for BCS, the US morphology least likely to have an US correlation was NME, not a mass enhancement or a focus, and the identification rate of NME in second look US was heterogeneous. Recently, real-time virtual sonography (RVS), which coordinates US with MRI that uses an image fusion technique by using magnet position tracking system, has been introduced in breast imaging. The purpose of this study was to evaluate the effect of preoperative planning using RVS on BCS in patients with NME. [Methods] We enrolled 12 consecutive patients who had lesions with NME that exceeded the US hypoechoic area, in which it was particularly difficult to evaluate the tumor margin. During preoperative planning before BCS, RVS was used to delineate the enhancing area on the breast surface after additional supine breast MRI was performed. We analyzed both the surgical margin positivity rate and the reoperation rate. [Results] The preoperative diagnosis by core needle biopsy were 7 DCIS and 5 invasive ductal carcinoma. NME distribution types were 5 segmental, 4 branching-ductal and 3 regional. The median diameters of the NME and hypo-echoic lesions were 24 mm (range: 12-39 mm) and 8.0 mm (range: 4.9-18 mm), respectively (p = 0.0002). After RVS-derived skin marking was performed on the surface of the affected breast, 7 lumpectomy and 5 quadrantectomy were conducted. The surgical margins were positive in 2 (17%) patients. The patients with positive margins were found to have ductal carcinoma in situ. None of the patients required additional resection. [Conclusion] Although further prospective studies are required, the findings of our preliminary study suggest that preoperative planning using RVS for BCS in patients with NME could improve both a surgical margin positive rate and a reoperation rate. Citation Format: Shogo Nakano, Kimihito Fujii, Yukako Mouri, Junko Kousaka, Takahito Ando, Mirai Ido, Manami Goto, Yukie Ito, Hirona Banno, Kenjiro Suzuki. Impact of an image fusion technique for preoperative planning in breast conserving surgery in patients with non -mass enhancement on MRI [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-12.