Reliability of Magseed® marking before neoadjuvant systemic therapy with subsequent contrast-enhanced mammography in patients with non-palpable breast cancer lesions after treatment: the MAGMA study

• Published in: Breast cancer research and treatment 2024-11, Vol.208 (1), p.133-143
• Main Authors: Bravo, Eva Iglesias, Martínez, Antonio Mariscal, Alvà, Helena Peris, Sancho, Diego Riol, López, José Carlos Antela, Sánchez, Joel Aranda, Casa, Pilar Escobar, de las Heras, Cristina Gómez, Venegas, María Antonia Fernández, Vidal, Eduarda García, Begines, Elisabeth Delgado, Mur, Carmen García, Vicente, Isabel, Casamayor, Carmen, Cruz, Silvia, Barrado, Anabel García
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biopsy; Breast cancer; Breast carcinoma; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - pathology; Breast Neoplasms - surgery; Breast Neoplasms - therapy; Contrast Media - administration & dosage; Female; Humans; Lesions; Lumpectomy; Mammography; Mammography - methods; Medicine; Medicine & Public Health; Middle Aged; Neoadjuvant Therapy - methods; Neoplasm, Residual - diagnostic imaging; Neoplasm, Residual - pathology; Oncology; Patients; Prospective Studies; Radiology; Reproducibility of Results; Solid tumors; Surgery; Tumors
• ISSN: 0167-6806; 1573-7217; 1573-7217
• DOI: 10.1007/s10549-024-07407-6

Purpose To assess the reliability of excising residual breast cancer lesions after neoadjuvant systemic therapy (NAST) using a previously localized paramagnetic seed (Magseed®) and the subsequent use of contrast-enhanced spectral mammography (CESM) to evaluate response. Methods Observational, prospective, multicenter study including adult women (> 18 years) with invasive breast carcinoma undergoing NAST between January 2022 and February 2023 with non-palpable tumor lesions at surgery. Radiologists marked tumors with Magseed® during biopsy before NAST, and surgeons excised tumors guided by the Sentimag® magnetometer. CESMs were performed before and after NAST to evaluate tumor response (Response Evaluation Criteria for Solid Tumors [RECIST]). We considered intraoperative, surgical, and CESM-related variables and histological response. Results We analyzed 109 patients (median [IQR] age of 55.0 [46.0, 65.0] years). Magseed® was retrieved from breast tumors in all surgeries (100%; 95% CI 95.47–100.0%) with no displacement and was identified by radiology in 106 patients (97.24%), a median (IQR) of 176.5 (150.0, 216.3) days after marking. Most surgeries (94.49%) were conservative; they lasted a median (IQR) of 22.5 (14.75, 40.0) min (95% CI 23.59–30.11 min). Most dissected tumor margins (93.57%) were negative, and few patients (5.51%) needed reintervention. Magseed® was identified using CESM in all patients (100%); RECIST responses correlated with histopathological evaluations of dissected tumors using the Miller–Payne response grade ( p