Heavy ion therapy can deliver high doses with high precision. However, image guidance is needed to reduce range uncertainty. Radioactive ions are potentially ideal projectiles for radiotherapy because their decay can be used to visualize the beam. Positron-emitting ions that can be visualized with PET imaging were already studied for therapy application during the pilot therapy project at the Lawrence Berkeley Laboratory, and later within the EULIMA EU project, the GSI therapy trial in Germany, MEDICIS at CERN, and at HIMAC in Japan. The results show that radioactive ion beams provide a large improvement in image quality and signal-to-noise ratio compared to stable ions. The main hindrance toward a clinical use of radioactive ions is their challenging production and the low intensities of the beams. New research projects are ongoing in Europe and Japan to assess the advantages of radioactive ion beams for therapy, to develop new detectors, and to build sources of radioactive ions for medical synchrotrons.

重离子疗法可以高精度地提供高剂量。然而，需要图像制导来减少距离的不确定性。放射性离子可能是放射治疗的理想射弹，因为它们的衰变可用于使光束可视化。在劳伦斯伯克利实验室的试点治疗项目期间，以及后来在 EULIMA 欧盟项目、德国的 GSI 治疗试验、欧洲核子研究中心的 MEDICIS 和 HIMAC 中，已经研究了可以用 PET 成像可视化的正电子发射离子的治疗应用在日本。结果表明，与稳定离子相比，放射性离子束在图像质量和信噪比方面提供了很大的改进。放射性离子临床应用的主要障碍是它们具有挑战性的生产和低强度的光束。