The firefly algorithm (FA) is a nature-inspired metaheuristic increasingly applied to medical image segmentation because of its flexible search mechanism and optimization capability. This paper systematically reviews FA-based approaches for medical image segmentation and related image-analysis tasks published between 2010 and 2026. A structured search of Scopus, PubMed, IEEE Xplore, Web of Science, and Google Scholar was conducted using predefined eligibility criteria. The included studies were categorized into multilevel thresholding, entropy-based segmentation, clustering-assisted methods, adaptive and chaotic FA variants, and hybrids with deep learning and other metaheuristics. Major appl... More >