Raman Spectroscopy Compared to Flow Cytometry

The assessment of measurable residual disease (MRD) is a frequent practice in the management of acute lymphoblastic leukemia (ALL). The detection of MRD is associated with an increased risk of relapse and adverse prognosis in all patient groups diagnosed with ALL. The three approved methods for MRD measurement are flow cytometry, polymerase chain reaction (PCR) of specific mutations, and next-generation sequencing (NGS). Of these, flow cytometry is the most used method in clinical practice. However, it has a sensitivity level that detects one leukemic cell in 10,000 normal cells, along with other disadvantages such as the need for a panel of fluorescent antibodies for MRD detection, and its measurement is not standardized in many centers. New determination techniques may be necessary for MRD evaluation. Raman spectroscopy is proposed as a potential technique for MRD measurement, which is based on the inelastic scattering of light that occurs when it interacts with matter, causing optical scattering, where a portion of the radiation changes its wavelength (by Raman effect). By analyzing the inelastically scattered light, we can obtain a Raman spectrum formed by the intensity of the scattered light as a function of its vibration frequency, thus obtaining information about the biochemical composition of a biological sample. Objectives: MAIN OBJECTIVE: To evaluate the presence of MRD in patients with ALL by comparing a standard evaluation method using flow cytometry with a new proposed method using Raman spectroscopy. SPECIFIC OBJECTIVES: * To assess the presence of MRD using flow cytometry in patients with ALL. * To assess the presence of MRD using Raman spectroscopy in patients with ALL. * To perform a comparison between the MRD measurement techniques by determining sensitivity, specificity, positive predictive value, and negative predictive value. * To establish the validation of using Raman spectroscopy as a method for MRD evaluation. Study Design: An observational, cross-sectional, comparative, and diagnostic test study will be conducted on bone marrow aspirate samples from adult and pediatric ALL patients to evaluate the presence of MRD using Raman spectroscopy, comparing the results of this technique with those obtained using flow cytometry. As a diagnostic test study, sensitivity, specificity, positive predictive value, and negative predictive value will be evaluated. The study will be conducted on adult and pediatric patients diagnosed with acute lymphoblastic leukemia treated at the hemato-oncology department of the UMAE No. 1 National Medical Center Bajio and the UMAE Hospital Gynecology-Pediatrics No. 48. Inclusion Criteria: Patients diagnosed with ALL for whom MRD determination is clinically necessary will be included in the study. Their results will be evaluated using the gold standard, flow cytometry, and compared with results obtained through Raman spectroscopy.