Yonekura Y, Tsujii H, Hopewell J W, López P Ortiz, Cosset J-M, Paganetti H, Montelius A, Schardt D, Jones B, Nakamura T
Ann ICRP. 2014 Dec;43(4):5-113. doi: 10.1177/0146645314559144.
The goal of external-beam radiotherapy is to provide precise dose localisation in the treatment volume of the target with minimal damage to the surrounding normal tissue. Ion beams, such as protons and carbon ions, provide excellent dose distributions due primarily to their finite range, allowing a significant reduction of undesired exposure of normal tissue. Careful treatment planning is required for the given type and localisation of the tumour to be treated in order to maximise treatment efficiency and minimise the dose to normal tissue. Radiation exposure in out-of-field volumes arises from secondary neutrons and photons, particle fragments, and photons from activated materials. These unavoidable doses should be considered from the standpoint of radiological protection of the patient. Radiological protection of medical staff at ion beam radiotherapy facilities requires special attention. Appropriate management and control are required for the therapeutic equipment and the air in the treatment room that can be activated by the particle beam and its secondaries. Radiological protection and safety management should always conform with regulatory requirements. The current regulations for occupational exposures in photon radiotherapy are applicable to ion beam radiotherapy with protons or carbon ions. However, ion beam radiotherapy requires a more complex treatment system than conventional radiotherapy, and appropriate training of staff and suitable quality assurance programmes are recommended to avoid possible accidental exposure of patients, to minimise unnecessary doses to normal tissue, and to minimise radiation exposure of staff.
外照射放疗的目标是在靶区治疗体积内实现精确的剂量定位，同时使对周围正常组织的损伤最小化。离子束，如质子和碳离子，主要因其有限射程而能提供出色的剂量分布，从而显著减少正常组织的不必要照射。对于给定类型和位置的待治疗肿瘤，需要进行仔细的治疗计划，以最大限度提高治疗效率并使正常组织所受剂量最小化。野外体积中的辐射暴露源于次级中子和光子、粒子碎片以及活化材料产生的光子。应从患者放射防护的角度考虑这些不可避免的剂量。离子束放疗设施中医护人员的放射防护需要特别关注。对于可被粒子束及其次级产物活化的治疗设备和治疗室内空气，需要进行适当的管理和控制。放射防护和安全管理应始终符合监管要求。目前光子放疗中职业照射的规定适用于质子或碳离子的离子束放疗。然而，离子束放疗需要比传统放疗更复杂的治疗系统，建议对工作人员进行适当培训并实施合适的质量保证计划，以避免患者可能受到的意外照射，使正常组织所受不必要剂量最小化，并使工作人员的辐射暴露最小化。
