XXXX ion radiotherapy in Japan: an assessment of 20 years of clinical experience.

@entity5 @entity1 @entity505 @entity788
UNASSIGNED: Charged particle therapy is generally regarded as cutting-edge technology in oncology. Many proton therapy centres are active in the USA, Europe, and Asia, but only a few centres use heavy ions, even though these ions are much more effective than x-rays owing to the special radiobiological properties of densely ionising radiation. The National Institute of Radiological Sciences (NIRS) Chiba, Japan, has been treating @entity5 with high-energy @entity505 ions since 1994. So far, more than 8000 @entity1 have had this treatment at NIRS, and the centre thus has by far the greatest experience in @entity505 ion treatment worldwide. A panel of radiation oncologists, radiobiologists, and medical physicists from the USA and Europe recently completed peer review of the @entity505 ion therapy at NIRS. The review panel had access to the latest developments in treatment planning and beam delivery and to all updated clinical data produced at NIRS. A detailed comparison with the most advanced results obtained with x-rays or protons in Europe and the USA was then possible. In addition to those @entity5 for which @entity505 ions are known to produce excellent results, such as bone and soft-tissue sarcoma of the skull base, head and neck, and pelvis, promising data were obtained for other @entity5 , such as locally recurrent @entity5 and @entity788 . The most serious impediment to the worldwide spread of heavy ion therapy centres is the high initial capital cost. The 20 years of clinical experience at NIRS can help guide strategic decisions on the design and construction of new heavy ion therapy centres.
