CO2TOLMS has now become one of the most used therapeutic strategies for early intermediate glottic cancer and long-term outcome data from large series is now available. Through this data there is an evolving understanding of which sites within larynx carry a higher risk of failure after primary treatment with CO2TOMLS, providing additional prognostic information in adjunct to standard TNM staging. New developments in diagnostic methods such as microvascular enhancement techniques and magnetic resonance imaging are now also allowing for a better delineation of tumor extension and the identification of the involvement of such high-risk areas in both primary and recurrent disease, providing valuable information to support treatment decision and help delineate reasonable limits of this technique. This symposium will present the current long-term outcome data for CO2TOLMS in early-intermediate glottic cancer. Current insights into diagnostic and prognostic possibilities and the implication for daily practice will also be discussed and illustrated in case presentations.