Diffusion-Weighted MRI in the Evaluation of Early-Stage Breast Cancer Treated with a Short Preoperative Radiotherapy: Preliminary Results. Issue 1 (7th February 2023)

• Record Type: Journal Article
• Authors: Hottat, Nathalie; Jani, Jacques; Badr, Dominique; Ridder, Mark De; Nazac, André; Houte, Katherina Vanden; Lecomte, Sophie; Cannie, Mieke
• Is Part Of: Journal of the Belgian Society of Radiology. Volume 107:Issue 1(2023)
• Publication Date: 2023-02-07
• Subjects: apparent diffusion coefficient -- diffusion-weighted MRI -- early-stage breast cancer -- Ki-67 index -- neoadjuvant radiotherapy; Radiology -- Periodicals; Periodicals; 616.0757
• DOI: 10.5334/jbsr.2815
• Languages: English
• ISSNs: 2514-8281

Abstract

Objective: To assess tumor response with diffusion-weighted MRI (DW-MRI) after a short preoperative radiotherapy in early-stage breast cancer (BCa). Materials and Methods: This was a prospective, single-center pilot study. 3T-MRI were performed before and after radiotherapy. The longest diameter (LD) and the apparent diffusion coefficient (ADC) value of a region of interest (ROI) of the tumors were recorded. Histopathology and immunohistochemistry, including the Ki-67 index of the core biopsy and of the surgical specimen, were the reference standards. Results: Nineteen patients with 22 early-stage BCa were included. The mean ROI ADC value was 1.093 ± 0.278 × 10 -3 mm 2 /s before radiotherapy and 1.490 ± 0.429 × 10 -3 mm 2 /s (p-value < 0.001) after radiotherapy. The Ki-67 index was 9.2 ± 9.1% at the percutaneous biopsy before radiotherapy and 4.9 ± 7.5% (p-value = 0.005) after radiotherapy at the surgical specimen. After neoadjuvant radiotherapy, a 4.7% decrease in LD and a 36.3% increase in ROI-ADC of the tumors were measured at MRI and a 46.7% decrease in Ki-67 index was observed at histology of the surgical specimen in comparison with the percutaneous core biopsy. Conclusion: In early-stage BCa, a significant increase in ROI-ADC at DWI and a significant decrease in Ki-67 index were observed after a short preoperative radiotherapy, suggesting early tumor response.