OncoAgent turns esophageal radiotherapy guideline text into 3D target volumes zero-shot, reaching CTV Dice 0.842 with no significant difference from fully supervised nnU-Net
The study introduces OncoAgent, a guideline-aware AI agent framework in which a large language model parses free-text clinical guidelines into an executable tool-call plan, generating three-dimensional target volumes without any expert-annotated training data; on planning CT from 40 mid-thoracic esophageal cancer patients (32 for training, 8 for testing), it achieved zero-shot CTV Dice of 0.842 and PTV Dice of 0.880, with no statistically significant difference from the fully supervised nnU-Net (GTV Prior) at 0.862 and 0.893 on primary metrics, and it was rated higher than that supervised baseline by blinded physicians on guideline compliance, modification effort, and clinical acceptability.