Large Language Models for Intelligent RDF Knowledge Graph Construction: Results from Medical Ontology Mapping

Apostolos MavridisStergios TegosChristos AnastasiouMaria PapoutsoglouGeorgios Meditskos^*

• Aristotle University of Thessaloniki, Thessaloniki, Greece

The exponential growth of digital data, particularly in specialized domains like healthcare, necessitates advanced knowledge representation and integration techniques. RDF knowledge graphs offer a powerful solution, yet their creation and maintenance, especially for complex medical ontologies like SNOMED CT, remain challenging. Traditional methods often struggle with the scale, heterogeneity, and semantic complexity of medical data. This paper introduces a methodology leveraging the contextual understanding and reasoning capabilities of LLMs to automate and enhance medical ontology mapping for RDF knowledge graph construction. We conduct a comprehensive comparative analysis of six systems-GPT-4o, Claude 3.5 Sonnet v2, Gemini 1.5 Pro, Llama 3.3 70B, DeepSeek R1 and BERTMap-using a novel evaluation framework that combines quantitative metrics (precision, recall, F1-score) with qualitative assessments of semantic accuracy. Our approach integrates a data preprocessing pipeline with an LLM-powered semantic mapping engine, utilizing BioBERT embeddings and ChromaDB vector database for efficient concept retrieval. Experimental results on a dataset of 108 medical terms demonstrate the superior performance of modern LLMs, particularly GPT-4o, achieving a precision of 93.75% and an F1-score of 96.26%. These findings highlight the potential of LLMs in bridging the gap between structured medical data and semantic knowledge representation, towards more accurate and interoperable medical knowledge graphs.