Abstract P3-04-08: Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size

Abstract Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size Yinan Ji＊1, Geyi Liao＊1, Ningbing Luo2, Yi Jiang1, Xiaoming Liao1, Wei Tang1, Huawei Yang 1. 1Department of Breast Surgery, 2Department of Radiology, Guangxi Medical University Tumor Hospital, Nanning, China Correspondence to: Dr. Huawei Yang, Department of Breast Surgery, Guangxi Medical University Cancer Hospital, 71 Hedi Road, Nanning, Guangxi Zhuang Autonomous Region 530021, P.R. China Email: Lordyhw@163.com ＊Contributed equally Background: Breast cancer is the malignant tumor with the highest incidence among women in China, seriously endangering women’s health. After breast cancer is diagnosed, surgery is one of the primary treatments. Assessing the extent of breast cancer is vitally important to formulate the best surgical option, obtain clear margins while minimizing the volume of removed tissue, and improve the treatment outcome and patient’s quality of life. Currently, breast surgery relies heavily on Breast MRI (bMRI) for preoperative assessment. However, bMRI may overestimate the tumor sizes. bMRI is contraindicated in patients with claustrophobia, metal implants, and allergy to gadolinium contrast medium. In addition, bMRI is generally expensive and time-consuming. Some patients find bMRI less favorable for cost and time concerns. Cone Beam Breast CT (CBBCT) is a new modality using Cone Beam CT technology and iodinated contrast media for true 3D high-resolution imaging of the breast. Our previous studies have proved the feasibility of CBBCT in the preoperative assessment of breast cancer. A large-scale study has been done to further examine the clinical significance of CBBCT in pre-operative assessment compared with bMRI. Methods: 273 female primary breast cancer patients were included in this study. The maximal diameters of the tumors were measured in CBBCT and bMRI images by an experienced radiologist. The differences between the image-measured size and surgical pathology size (gold standard) were calculated as ΔDCT and ΔDMR. ΔD ˃ 5mm was considered an overestimation and ΔD ˂-5mm was considered an underestimation. The absolute values of ΔDCT and ΔDMR were also calculated as ΔDCT_abs and ΔDMR_abs. A Student t-test was used to compare the statistical differences between ΔDCT_abs and ΔDMR_abs. Among ΔDCT_abs and ΔDMR_abs, a 5mm cut-off value was used to determine the concordance between image and pathology. The concordance rates of CBBCT-Pathology and bMRI-Pathology were tested with the χ2 method. Factors that may affect the accuracy of tumor size measurement were analyzed. Results: Overall there were no statistically significant differences between ΔDCT_abs and ΔDMR_abs. (0.58±0.68cm vs. 0.65±0.68cm; t=1.653, P=0.100). Using 5mm as the cut-off value of concordance, there was no significant difference in the CBBCT-Pathology and bMRI-Pathology concordance rates (64.8% vs. 60.1%, χ2 =1.320, P=0.251). The overestimation rate of CBBCT was significantly lower than that of bMRI (11.4% vs. 19.4%, χ2=6.810, P=0.009). But there was no significant difference in the underestimation rates (23.8% vs. 20.5%, χ2=0.860, P=0.354). ΔDCT_abs is significantly smaller than ΔDMR_abs among the invasive ductal carcinoma group (P=0.017), the premenopausal group (P=0.004), and the small tumor size (≤2cm) group (P=0.003). ΔDCT_abs and ΔDMR_abs.have no significant differences among the lymph node metastasis group, multi-lesion group, and enhancement type group (P > 0.05). Conclusions: CBBCT is concordant with surgical pathology in breast tumor size measurement and provides more accurate tumor size estimation compared with bMRI. CBBCT can be used as a valuable modality for pre-operative assessment. Citation Format: YINAN JI, Geyi Liao, Ningbing Luo, Yi Jiang, Xiaoming Liao, Wei Tang, Huawei Yang. Comparison Of Cone Beam Breast CT And Breast MRI In Preoperative Assessment Of Primary Breast Cancer Tumor Size [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-04-08.