Low-Field NMR Relaxometry for Intraoperative Tumour Margin Assessment in Breast-Conserving Surgery

• Main Authors: Valeria Bitonto, Maria Rosaria Ruggiero, Alessandra Pittaro, Isabella Castellano, Riccardo Bussone, Lionel M. Broche, David J. Lurie, Silvio Aime, Simona Baroni, Simonetta Geninatti Crich
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Cancers
• Subjects: low-field NMR relaxometry; breast cancer; margin assessment; breast-conserving surgery; cross-membrane water exchange
• Online Access: https://www.mdpi.com/2072-6694/13/16/4141

As conserving surgery is routinely applied for the treatment of early-stage breast cancer, the need for new technology to improve intraoperative margin assessment has become increasingly important. In this study, the potential of fast field-cycling ¹H-NMR relaxometry as a new diagnostic tool was evaluated. The technique allows the determination of the tissue proton relaxation rates (<i>R</i>₁), as a function of the applied magnetic field, which are affected by the changes in the composition of the mammary gland tissue occurring during the development of neoplasia. The study involved 104 small tissue samples obtained from surgical specimens destined for histopathology. It was found that a good accuracy in margin assessment, i.e., a sensitivity of 92% and a specificity of 85%, can be achieved by using two quantifiers, namely (i) the slope of the line joining the <i>R</i>₁ values measured at 0.02 and 1 MHz and (ii) the sum of the <i>R</i>₁ values measured at 0.39 and 1 MHz. The method is fast, and it does not rely on the expertise of a pathologist or cytologist. The obtained results suggest that a simplified, low-cost, automated instrument might compete well with the currently available tools in margin assessment.