ICRU Report 78, Prescribing, Recording, and Reporting Proton-Beam Therapy


Proton therapy is a rapidly expanding modality and the number of new facilities is rapidly increasing. The advantage of proton beams relative to conventional photon beams for radiation therapy lies in their superior dose distributions. The efficacy of proton therapy is well established for several tumor categories. The present report provides information necessary to standardize techniques and procedures and to harmonize the clinical descriptions of proton treatments with those of other modalities. The concepts and recommendations in other ICRU reports concerning radiation therapy are extended to proton therapy.

The topics covered here include the rationale for and the history of proton therapy, radiation biology, proton-beam delivery and properties, dosimetry, geometric and dose-volume terms, treatment planning, uncertainties in dose delivery, motion management, quality assurance, prescribing and recording and reporting treatment. In addition, six clinical examples of proton beam therapy are provided to illustrate the application of the recommendations contained in this Report.

Recommendations in the Report include the use of a generic RBE (relative biological effectiveness) value of 1.1 and the adoption of the IAEA TRS (Technical Report Series) 398 code of practice as the standard proton dosimetry protocol. The concept of RBE-weighted absorbed dose (DRBE, the product of proton absorbed dose, D, and proton RBE) is introduced to estimate the photon dose that would produce the same therapeutic effect as the proton absorbed dose, D, given under identical conditions.

As the present report describes in some detail the radiobiological, physical, technical, treatment planning and clinical aspects of proton beam therapy, it should be a useful reference for current practitioners and should also provide new and potential users, as well as other interested readers, with the basic background to enable them to understand the techniques involved in proton therapy.