The 2015 PTCOG annual meeting will be held in beautiful downtown San Diego, California. The theme for our 2015 conference will be The Modern Era of Particle Beam Therapy: Widening the Therapeutic Window for Better Patient Outcomes. As in the past, the conference will begin with the Educational Workshops taking place May 18–20th and be followed by the Scientific Meetings taking place May 21st–23rd. The conference will feature plenary sessions, workshops, poster presentations and an extensive exhibition hall. Participants will also have an opportunity to visit the newly opened Scripps Proton Therapy Center and celebrate “San Diego style” at the Thursday evening Gala.