Preface

This Report is the result of a long collaboration between the IAEA and the ICRU, in an attempt to standardize the reporting of ion beam radiotherapy using concepts previously developed by the ICRU for reporting other therapies but with special emphasis on the use and reporting of RBE-weighted quantities.

Such harmonization will facilitate the comparison of therapeutic results obtained with ions not only between centers using this approach but also with centers using other modern forms of radiation therapy, such as proton and intensity modulated radiation therapy with photon beams.

A first meeting on the topic of Relative Biological Effectiveness in Ion Beam Therapy, jointly sponsored by the IAEA and the ICRU, was held in Vienna, in June 2004. The meeting dealt primarily with the review of experimental measurements of RBE and approaches to the clinical use of the concept of RBE based on experimental findings, theoretical models and previous clinical experience with fast neutrons and ions. A report was published by the IAEA within the Technical Report Series (TRS 461) in 2008.

As a follow-up to the 2004 meeting in Vienna and the report produced on the RBE of ions, the ICRU and IAEA jointly organized a second meeting on ion beam therapy to further discuss the fundamental issues that have to be understood and resolved in order to reach an agreement for reporting. This meeting took place in Columbus, Ohio, 18–20 March 2006 and was organized by R. Gahbauer and hosted by the A. James Cancer Hospital. This second meeting aimed at initiating further discussions for the development of a set of recommendations for international harmonization of the reporting of ion-beam therapy. The dose distribution and the method of reporting are influenced by the beam delivery technique, dosimetry, method of RBE determination, treatment planning, medical judgment and intent of the prescription. These issues were presented and discussed at the Columbus meeting by worldwide experts in the field and were published jointly by the ICRU and IAEA in an IAEA Technical Document on Dose Reporting in Ion Beam Therapy (TDOC-1560) in 2006. During the meeting, a decision was made to form an ICRU report committee, to prepare the underlying report.

This first report committee was jointly chaired by Hirohiko Tsujii and William Chu. Dr. Tsujii, for many years was the clinical director of the Heavy Ion Medical Accelerator at the National Institute of Radiological Sciences (NIRS), the first dedicated clinical facility for light ion therapy. Dr. Chu was part of the team of researchers at the Lawrence Berkeley National Laboratory, which pioneered radiotherapy with ion beams between the 1970s and 1990s. The first official committee meeting took place in 2007.

While much had been done, the report was far behind schedule. The ICRU decided in 2015 to finalize the Report with a smaller sub-group of the committee, chaired by Oliver Jäkel, head of the Medical Physics Team at the Heidelberg Ion Beam Therapy Unit (HIT). The present Report provides a thorough discussion of the use of carbon ions in a therapeutic clinical setting. Consensus recommendations are provided for the recording and reporting of treatments.

In addition to material from the committee members, important material for the clinical examples was contributed by M. Uhl from the Heidelberg Ion Beam Therapy Center at the University Medical Center, Heidelberg, Germany.

We also want to acknowledge the contribution of two young academics, who strongly supported Oliver Jäkel with proofreading, formatting, and generation of the literature database: Mrs. Johanna Winter and Mr. Tom Russ, both from German Cancer Research Center, Heidelberg.

Oliver Jäkel and Paul DeLuca