The Internet has totally changed the way information is published and shared in medicine. With web 2.0 and semantic web technologies, web applications allow now collaborative information editing in a way that can be reused by machines. These new tools could be used to in local health networks to promote the editing and sharing of medical knowledge between practitioners. Oncolor, a French oncology network, has edited 144 decision guidelines. These local guidelines rely upon national French guidelines and are built and updated collaboratively by medical experts. To improve working conditions, the need of an online collaborative tool has been expressed. This paper presents ONCOLOGIK, a semantic wiki approach for local oncology guideline editing. Semantic wikis allow online collaborative work and manage semantic annotations which can be reused automatically to bring new services. Applied to oncology guidelines, semantic technologies improve the guideline management and provide additional services such as targeted queries to external bibliographical resources.