Current status and prospects of reactor produced medical radioisotopes in China

Abstract

Medical radioisotopes as the cornerstone of modern nuclear medicine play an irreplaceable role in diagnostic imaging and therapy of various diseases, like malignant tumors, cardiovascular and brain disorders, according to achieve molecular level imaging tracking and precise targeted clearance of small lesions. The most commonly used reactor produced medical radioisotopes include molybdenum-99/technetium-99m (99Mo/99mTc) generator, iodine-131/125 (125/131I), strontium-89 (89Sr), and lutetium-177 (177Lu) and so on. Amongst them, 99mTc is by far the most widely used and best known diagnostic isotope. 131I and 177Lu are already being applied routinely in nuclear medicine nowadays and will increase further as new precise targeted therapies developed, especially 177Lu combined with various targeted molecules to achieve a variety of systemic metastasis of malignant tumors is recognized as a revolutionary prospect in the medical community. In the future, many more patients will suffer from different kinds of diseases, which are need medical radioisotopes to diagnostic imaging and therapy. Therefore, safeguarding a reliable supply to make medical radioisotopes available for all patients who require radiotherapy or imaging is highly important. In this review, a brief account of various aspects of the recent research progress of reactor produced medical radioisotopes in China is introduced. For each medical radioisotope under consideration, like 99Mo, 131I, 125I, 177Lu, 89Sr and 90Y and so on, the status of technology for clinical scale production as well as clinical application is discussed. There are many challenges that face reactor produced radioisotopes production and application for medical diagnostics and therapy in China. The serious relying on importation of reactor produced medical radioisotopes from overseas is pointed out. 99Mo,125I, 89Sr and 90Y are imported completely and the vast majority of 131I and 177Lu are also imported. The import dependent of medical radioisotopes has become a bottleneck for the advances in nuclear medicine and has seriously restrained the healthy development of national public health in China. Some real experience in the development of the production of medical radioisotopes in China indicates that progress in this field is possible if the following conditions are fulfilled. Firstly, establish long-term national plan and improve support management for the independent supply of medical radioisotopes. Secondly, increase the production capacity and alleviate supply-demand contradiction by optimizing the production organization process in the existing reactor resource. Thirdly, increase the annual appropriated budget for research and development to realize the independent production of medical radioisotopes and radiopharmaceuticals. Finally, establish a technology innovation platform of production, teaching and research integration for medical radioisotopes and radiopharmaceuticals. We also discuss the potential and future uses of reactor produced medical radioisotopes. In the future, the production and application of medical radioisotopes will be one of the hot spots in the field of nuclear technology application. From the standpoint of radioisotope therapy, particular hopes for the future are related to “targeted” therapy, in which a radioisotope is delivered directly into the affected cell by biological “transporters” to kill malignant tumors with radiation. “Personalized” medicine (radiotheranostics) refers to the use of medical radioisotopes-labeled agents to perform simultaneous imaging and therapy of a target lesion is the key development direction of new radiopharmaceuticals. These new directions require development of a broad dedicated production of radioisotopes specially intended for these purposes. In addition, 223Ra, 225Ac and other α-nuclide labeled radiopharmaceuticals will also be focused on.