It is with great enthusiasm that I present to you the inaugural issue of the International Journal of Particle Therapy (IJPT), the official journal of the Particle Therapy Cooperative Group (PTCOG). PTCOG has informally existed since the mid 1980s. As worldwide interest in particle therapy has grown so have the PTCOG annual meetings, with attendees including medical physicists, engineers, radiation oncologists, radiation biologists, dosimetrists, radiation therapists, facility administrators and vendors from around the world. More than 400 participants enrolled in the PTCOG 52 educational course and over 600 registered for the scientific meeting held in Essen, Germany, in 2013. The governing body of PTCOG is the Steering Committee, which includes 46 members from 46 radiation therapy institutions across 15 nations, two elected officers, the Chair (Eugen Hug, MD, Medical Director and Chief Medical Operator of ProCure Proton Therapy Centers) and the Secretary (Martin Jermanns, Vice Director of the Paul Scherrer Institute), and an executive committee. At the PTCOG 51 meeting in Seoul, Korea in May of 2012, the need for a peer-reviewed journal was discussed, and at PTCOG 52, the executive and steering committees agreed upon the creation of such a journal.

The purpose of the IJPT will be to provide a preferred venue for disseminating the most up-to-date information on the clinical, physical, and biological research in proton, light-ion, and heavy charged-particle therapy. Articles will explore topics such as proton and ion radiobiology, physics, delivery techniques, treatment planning, beam scanning, quality assurance, clinical outcomes, radiation safety, facility design and startup, and social and economic issues impacting particle therapy. IJPT will offer an avenue for education, much needed with the rapid and widely distributed growth in particle therapy across the world. We hope also to create a venue to voice considered opinions on particle therapy's role within the medical community as well as larger socioeconomic issues of interest to practitioners of particle therapy.

This inaugural issue presents the proceedings from PTCOG 52 and 4 peer-reviewed articles. Subsequent issues will contain offerings dealing with the physics and biology of particle therapy, clinical outcomes, treatment planning studies, technical notes, operational topics, and socioeconomic issues, some with a focus on a particular disease site or subject. The 2014 Summer issue will focus on the role of particle therapy in pediatric malignancies.

It is our hope that this journal will provide the optimum venue for information exchange regarding particle therapy, and we welcome participation through submissions, letters, and editorial service from all interested in the promise and progress of particle therapy.

Acknowledgments

I thank Dr. William Mendenhall for his service as operating editor, and Jessica Kirwan and Judy Tran for their editorial review of all of the articles published in the inaugural issue as well as operation of the IJPT editorial office.