Short-term temperature effect on the HRMAS spectra of human brain tumor biopsies and their pattern recognition analysis

• Published in: Magma (New York, N.Y.) N.Y.), 2010-09, Vol.23 (4), p.203-215
• Main Authors: Valverde-Saubí, Daniel, Candiota, Ana Paula, Molins, Maria Antònia, Feliz, Miguel, Godino, Óscar, Dávila, Myriam, Acebes, Juan José, Arús, Carles
• Format: Article
• Language: English
• Subjects: Biomarkers, Tumor - analysis; Biomedical Engineering and Bioengineering; Biopsy; Brain; Brain Neoplasms - chemistry; Brain Neoplasms - metabolism; Brain Neoplasms - pathology; Brain tumors; Computer Appl. in Life Sciences; Discriminant Analysis; Health Informatics; Histopathology; Humans; Imaging; Linear Models; Lipids; Magnetic Resonance Spectroscopy; Medical imaging; Medicine; Medicine & Public Health; NMR; Nuclear magnetic resonance; Pattern recognition; Principal Component Analysis; Principal components analysis; Radiology; Research Article; Solid State Physics; Temperature; Temperature effects; Time Factors; Tumors
• ISSN: 0968-5243; 1352-8661
• DOI: 10.1007/s10334-010-0218-7

Object To investigate the effect of temperature (0 versus 37°C) in the high-resolution magic angle spinning spectroscopy (HRMAS) pattern of human brain tumor biopsies and its influence in recognition-based tumor type prediction. This proof-of-principle study addressed the bilateral discrimination between meningioma (MM) and glioblastoma multiforme (GBM) cases. Materials and methods Forty-three tumor biopsy samples were collected (20 MM and 23 GBM), kept frozen and later analyzed at 0°C and 37°C by HRMAS. Post-HRMAS histopathology was used to validate the tumor type. Time-course experiments (100 min) at both temperatures were carried out to monitor HRMAS pattern changes. Principal component analysis and linear discriminant analysis were used for classifier development with a training set of 20 biopsies. Results Temperature-dependent, spectral pattern changes mostly affected mobile lipids and choline-containing compounds resonances and were essentially reversible. Incubation of 3 MM and 3 GBM at 37°C during 100 minutes produced irreversible pattern changes below 13% in a few resonances. Classification performance of an independent test set of 7 biopsies was 100% for the pulse-and-acquire, CPMG at echo times (TE) of 30 ms and 144 ms and Hahn Echo at TE 30 ms at 0°C and 37°C. The performance for Hahn Echo spectra at 136 ms was 83.3% at 0°C and 100% at 37°C. Conclusion The spectral pattern of mobile lipids changes reversibly with temperature. HRMAS demonstrated potential for automated brain tumor biopsy classification. No advantage was obtained when acquiring spectra at 37°C with respect to 0°C in most of the conditions used for the discrimination addressed.