Beyond considerations of cost-effectiveness, clinical practice guidelines (CPG) can reduce practice variations and thus improve the quality of care. However, despite the proliferation of implemented CPG and their wide diffusion thanks to Internet-based technologies, physicians' compliance with formal standards is weak. Developed according to a document-based paradigm, OncoDoc proposes an original framework for implementing CPG. Domain knowledge has been encoded as a decision tree whose branches are both exclusive and exhaustive. This generic knowledge is operationalized at the point of care by the interactive building, through hypertextual navigation, of a patient-based clinical context leading to specific therapeutic recommendations. OncoDoc has first been applied to the management of breast cancer patients and demonstrated within a full-scale experimentation in a clinical setting a compliance of 80 per cent.