Authors: Devendra Gupta, Abhay Mundra
Abstract: Brain tumor segmentation is a critical task in medical imaging, supporting accurate diagnosis, treatment planning, and continuous monitoring of tumor progression. Over the years, a variety of segmentation strategies have been proposed, each offering distinct advantages and limitations. Early traditional approaches—including thresholding, edge-based detection, and region-growing methods—are computationally efficient and simple to implement, but they often perform poorly in the presence of noise, intensity inhomogeneity, and complex or ambiguous tumor boundaries. Statistical and model-driven techniques, such as clustering methods and deformable models, improve adaptability to anatomical variability but typically require careful parameter selection and may involve higher computational cost. In recent years, machine learning and deep learning methods have transformed brain tumor segmentation, particularly through the use of Convolutional Neural Networks (CNNs) and U-Net-based architectures, which have demonstrated strong accuracy and robustness across large and diverse MRI datasets. More recently, hybrid methods that combine classical image processing with deep learning have gained attention for improving efficiency, interpretability, and generalization. This review summarizes the evolution of brain tumor segmentation methods, compares major categories of approaches, and discusses current challenges and promising future research directions.
