Successful Migration from Radioactive Irradiators to X-ray Irradiators in One of the Largest Medical Centers in the US.

This paper summarizes about 9 years of effort by Mount Sinai to successfully migrate completely from radioactive irradiators to x-ray irradiators without compromising patient care or research studies. All the effort by Mount Sinai to permanently remove the risk of malicious use of radioactive materials as Radiological Dispersal Device or dirty bomb is reviewed. Due to the unique characteristics of the cesium chloride (CsCl) used in irradiators, it is especially susceptible to be used as a dirty bombs. Mount Sinai originally had four of such irradiators. To reduce and eventually remove the risk of malicious use of radioactive materials, Mount Sinai in New York City has taken several steps. One of such measures was to harden the radioactive irradiators to make the radioactive materials harder to be stolen for malicious purposes. By increasing the delay time, the local law enforcement agency (LLEA) will have more time to stop the intruder. Another measure taken was to implement enhanced security in facilities having radioactive materials. We collaborated with the National Nuclear Security Administration and used state-of-the-art security equipment such as Biometric Access Control and 24/7 video monitoring. In addition, a remote monitoring system with alarms was installed and connected to LLEA for constant monitoring and possible intervention, if necessary, in a timely manner. The other measure taken was to limit the number of people who have access to such radioactive materials. We adopted a single person operator method and reduced the number of people having access from 145 people to only a few people. The adoption of such measures has reduced the risk significantly; however, the best way to remove the permanent risk of these radioactive materials that may be used for a dirty bomb is to use alternative technology to replace these high-activity radioactive sources. In 2013, Mount Sinai purchased its first x-ray irradiator to investigate the feasibility of using x-ray irradiators instead of cesium irradiators for research purposes for cells and small mice. The results from comparison studies were promising, which led to the decision of permanent migration of all cesium irradiators to x-ray irradiators. As of January 2018, Mount Sinai successfully disposed all its Cs irradiators. At this time, Mount Sinai, as one of the largest health care institutions in NY with about 50,000 employees, has migrated completely to alternative technology and removed the risk of malicious use of radioactive materials permanently.

The renaissance of the 68Ge/68Ga radionuclide generator initiates new developments in 68Ga radiopharmaceutical chemistry.

68Ge/68Ga radionuclide generators have been investigated for almost fifty years now, since the cyclotron-independent availability of positron emitting 68Ga via the 68Ge/68Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally approach a reliable level of 68Ge/68Ga generator designs, adequate to the modern requirements of radiometal labeling chemistry. 68Ga radiopharmacy now is awaking from a sort of hibernation. The exciting perspective for the 68Ge/68Ga generator, now - more than ever, asks for systematic chemical, radiochemical, technological and radiopharmaceutical efforts, to guarantee reliable, highly-efficient and medically approved 68Ge/68Ga generator systems. The expected future broad clinical impact of 68Ga-labelled radiopharmaceuticals - beyond the 68Ga-DOTA-octreotide derivatives - for imaging tumors and many organs, on the other hand, identifies the development of sophisticated Ga(III) chelating structures to be a key factor. Today, open chain complexing agents have almost completely been displaced by macrocyclic DOTA and NOTA-derived conjugates. Structures of chelating moieties are being optimized in terms of thermodynamic stability and kinetic inertness, in terms of labeling efficacies at different, even acidic pH, and in terms of synthetic options towards bifunctionality, directed to sophisticated covalent coupling strategies to a variety of biologically relevant targeting vectors. Today, one may expect that the 68Ge/68Ga radionuclide generator systems could contribute to and facilitate the clinical impact of nuclear medicine diagnoses for PET in a dimension comparable to the established 99Mo/99(m)Tc generator system for SPECT.