BACKGROUND: Controversy surrounds the appropriate therapy for T1 glottic cancer. Both transoral endolaryngeal resection and radiation offer excellent local control and voice quality; some lesions are best addressed with resection and others with radiation. METHODS: The American College of Radiology (ACR) Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed by a multidisciplinary expert panel. The guideline development includes an analysis of current literature from peer reviewed journals and the well-established "modified Delphi" consensus methodology to rate the appropriateness of treatment. Where evidence is not definitive, expert opinion informed recommendations. RESULTS: The ACR Expert Panel on Radiation Oncology - Head and Neck Cancer developed consensus recommendations for treatment of T1 glottic cancer. Treatment planning is complex and decisions nuanced. CONCLUSION: Best treatment for a particular cancer cannot be defined without consideration of the lesion's location, extent, depth of invasion, and quality of surgical exposure during direct laryngoscopy.