Real-Time Molecular Diagnosis and Margin Definition of Tumors Based on a Novel Laser-Based Mass Spectrometry Technology

We assessed on dog sarcoma the performances of a newly developed technology, for fast ex-vivo diagnostic of tumors in the perspective to target in the future noninvasive in-vivo real-time diagnostic and excision margin definition intraoperatively, named Spidermass. The instrument is based on Mass Spectrometry (MS) molecular analysis through a laser microprobe operating under ambient condition using resonant excitation of endogenous water molecules Specificity of the molecular profiles generated with the instrument was evaluated using multivariate analysis for tumor typing or grading. Classification models based on cancer/normal, cancer/normal/necrotic, tumor grade, and cancer subtype showed at minimum of 97.63% correct classification. Specific markers of normal, cancer and necrotic regions were identified by tandem MS and validated by MS Imaging. Margins detection capabilities was studied, and compared to MS imaging and histological staining. Our results confirmed the high accuracy of the technology to differentiate between histological areas or sarcoma subtypes in real-time.