Novel Biomarkers for Differentiating Between Recurrent Brain Tumor and Radiation Necrosis

Abstract Differentiating between recurrent brain tumors and radiation necrosis remains a significant challenge in neuro-oncology, given the overlapping radiological characteristics of these conditions. Misdiagnosis can lead to incorrect treatment, making the development of accurate diagnostic tools essential. This review focuses on novel biomarkers identified through advanced imaging modalities such as Magnetic Resonance Spectroscopy (MRS), Magnetic Resonance Perfusion (MRP), and Positron Emission Tomography (PET). MRS has demonstrated high diagnostic accuracy, with a choline/NAA ratio of 2.0 or higher predicting tumor recurrence with 85% accuracy. MRP, with relative cerebral blood volume (rCBV) measurements, shows a sensitivity of 82% and specificity of 88% for distinguishing between tumor recurrence and necrosis. PET imaging, using radiopharmaceuticals like [11C]methionine, achieves a sensitivity of 87%, making it superior in detecting metabolic differences between tumor recurrence and necrosis. Hybrid PET/MRI systems further enhance diagnostic precision by combining metabolic and structural data. Emerging biomarkers, such as circulating microRNAs and genomic markers, offer non-invasive options for monitoring tumor recurrence. Future advancements integrating radiomics and artificial intelligence (AI) are expected to improve diagnostic accuracy, making these techniques more reliable and accessible in clinical settings. Keywords: Brain Tumor, Radiation Necrosis, Biomarkers, Neuroimaging, PET, MRI, MR Spectroscopy