Lymphoscintigraphy in the Time of COVID-19: Effect of Molybdenum-99 Shortage on Feasibility of Sentinel Node Mapping.

Background: In the current study, we reported our experience on sentinel node mapping of breast cancer patients during the extreme shortage of Mo99-Tc99m generators using Tc-99m phytate. Methods and Results: During the period from March 7, 2019, to April 18, 2020, due to disruption of molybdenum supply chain, we used low specific activity Tc-99m pertechnetate elute (0.5-2 mCi of 99mTcO4 in 5 mL) for each kit preparation. Two or three intradermal periareolar injections were done for each patient (0.02-0.1 mCi/0.2 mL for each injection). Immediately following injection, dynamic lymphoscintigraphy was done. Surgery was done the same day of injection and the axillary sentinel node was sought using a gamma probe. Overall, 35 patients were included in the study. The specific activity of the Tc-99m elute (in 5 mL) used for kit preparation was 2 mCi/10 mg in four, 1.5 mCi/10 mg in eight, 1.25 mCi/10 mg in eight, 1 mCi/10 mg in three, 0.75 mCi/10 mg in five, and 0.5 mCi/10 mg of 99mTc-Phytate in seven patients. For the first four groups of patients, we used two 0.2 mL injections, while in the latter two groups, three 0.2 mL injections were used. At least one sentinel node was detected in all patients but three in whom axilla was involved. Conclusion: Sentinel node biopsy can be achieved with low specific activity of Tc-99m elute at the time of Mo99-Tc-99m generator shortage. If special personal protection is used, sentinel node mapping can be done in nuclear medicine departments with excellent results despite the COVID-19 pandemic and disruption of generator shipment.

Potential Ways to Address Shortage Situations of 99Mo/99mTc.

99mTc, the most common radioisotope used in nuclear medicine, is produced in a nuclear reactor from the decay of 99Mo. There are only a few aging nuclear reactors around the world that produce 99Mo, and one of the major contributors, the National Research Universal (Canada), ceased production on October 31, 2016. The National Research Universal produced approximately 40% of the world's 99Mo supply, so with its shut down, shortages of 99Mo/99mTc are expected. Methods: Nuclear pharmacies and nuclear medicine departments throughout the United States were contacted and asked to provide their strategies for coping with a shortage of 99Mo/99mTc. Each of these strategies was evaluated on the basis of its effectiveness for conserving 99mTc while still meeting the needs of the patients. Results: From the responses, the following 6 categories of strategies, in order of importance, were compiled: contractual agreements with commercial nuclear pharmacies, alternative imaging protocols, changes in imaging schedules, software use, generator management, and reduction of ordered doses or elimination of backup doses. Conclusion: The supply chain of 99Mo/99mTc is quite fragile; therefore, being aware of the most appropriate coping strategies is crucial. It is essential to build a strong collaboration between the nuclear pharmacy and nuclear medicine department during a shortage situation. With both nuclear medicine departments and nuclear pharmacies implementing viable strategies, such as the ones proposed, the amount of 99mTc available during a shortage situation can be maximized.

Assessment of Using 99Mo and 99mTc Isotopes in Kuwait Medical Sector.

The Ministry of Health (MOH) in the state of Kuwait currently depends on importing the radioisotope molybdenum (Mo) in its isotopic form (Mo) to fulfill its demands. The present study was conducted on all nuclear medicine departments in the state of Kuwait. Daily, weekly, and monthly data were analyzed to statistically determine the current and future demands for the isotope Tc. This analysis was performed by collecting and analyzing data on MOH consumption of Tc for different diagnostic applications. The overall results indicate a partial decrease of 1.012% in the overall total demand for Tc up to the year 2018 for the state of Kuwait.

["Technetium crisis" -  causes, possible solutions and consequences for planar scintigraphy and SPECT diagnostics]. / "Techneciová krize" -  príciny, mozná resení a dopad na dia-gnostiku planární scintigrafií a SPECT.

Nuclear medicine is an important field of nuclear medicine, especially thanks to its role in in vivo imaging of important processes in human organism. An overwhelming majority of nuclear medicine examinations comprises of planar scintigraphy and single photon emission computed tomography, for decades relying on the labeling by metastable technetium nuclide (99mTc), used with a great diversity of ligands for various applications. Nuclear medicine departments utilize commercially available molybdenum technetium generators, being able to elute the nuclide at any time and prepare the radiopharmaceutical. The mother nuclide, molybdenum-99 (99Mo), is produced in just a handful of places around the world. The production places are without exception research nuclear reactors working far past their life expectancy. A concurrent temporary shutdown of two of them in the year 2009 caused a critical worldwide shortage of 99mTc. An unavoidable permanent shutdown of part of these capacities in the second decade of the 21st century will cause the second, and this time rather permanent "technetium crisis". The article focuses on history, present, potential future and possible solutions in regard to SPECT diagnostics.

Diversification in the Supply Chain of (99)Mo Ensures a Future for (99m)Tc.

The uncertain availability of (99m)Tc has become a concern for nuclear medicine departments across the globe. An issue for the United States is that currently it is dependent on a supply of (99m)Tc (from (99)Mo) that is derived solely by production outside the United States. Since the United States uses half the world's (99)Mo production, the U.S. (99)Mo supply chain would be greatly enhanced if a producer were located within the United States. The fragility of the old (99)Mo supply chain is being addressed as new facilities are constructed and new processes are developed to produce (99)Mo without highly enriched uranium. The conversion to low-enriched uranium is necessary to minimize the potential misuse of highly enriched uranium in the world for nonpeaceful means. New production facilities, new methods for the production of (99)Mo, and a new generator elution system for the supply of (99m)Tc are currently being pursued. The progress made in all these areas will be discussed, as they all highlight the need to embrace diversity to ensure that we have a robust and reliable supply of (99m)Tc in the future.

Technetium-99m -- new production and processing strategies to provide adequate levels for SPECT imaging.

The most important radioisotope for use in Nuclear Medicine is (99m)Tc, supplied in the form of a (99)Mo/(99m)Tc generator. After the supply crisis of (99)Mo starting in 2008 the availability of (99)Mo became a worldwide concern. The purpose of this work is to do a brief story of the availability of (99)Mo in the world followed by an overview of the production routes of (99)Mo and the generators technology.

Future of low specific activity molybdenum-99/technetium-99m generator.

In last few years, the shortage of molybdenum-99 (99Mo) was felt in the developed and developing countries hospitals, where diagnostic nuclear medicine is practiced. To overcome the shortage of 99Mo various routes of its production by accelerators and reactors generating low and high specific activity products have been planned. High specific activity 99Mo obtained by fission of uranium-235 (235U) has completely dominated in the manufacturing of technetium-99m (99mTc) generators in last 3-4 decades, but due to proliferation and dirty bomb, issues non fission routes of 99Mo production are emphasized. Future of low specific activity 99Mo is discussed.

Ergonomic study of an operator's work of a molybdenum plant.

This study was part of an ergonomic program which is being carried out through an agreement between the University of Concepción and a Chilean private mining company. The purpose of this case study was to identify working conditions in which the physical and mental workload could be over the capabilities of the operator. He was responsible for loading trucks with sacks of molybdenum and for downloading reagents and handles them. The methods employed in this study included electronic records, interviews, surveys, review of the company standards, a time study and physical and mental workload analysis. Results showed that 84% of the time the operator was carrying out principal and secondary activities and no break periods were detected. It was found that the pace of work and the shift system generated unfavorable conditions by imbalance in the workload on the different days of the week. In the light of the results recommendations were made for a number of ergonomic changes. Most of them were accepted by the company. The most important achievement was a change in the shift system. The overload of the operator was due to the fact that he was in a shift working 5 days and resting on weekends. The imbalance was mainly because the work of the week end was accumulated for Monday. As a result of the study, the company contracted a second worker for this job and adopted a 7x7 shift system, meaning that they work seven days and rest seven days. An evaluation carried out two month after adopting the new shift revealed that changes were well accepted by the worker.

Molybdenum-99/technetium-99m management: race against time.

Molybdenum-99 is a parent of diagnostic nuclear medicine. It decays to technetium-99m, which used in over 30 million investigations per year around the world. Supplies of Tc-99m remained fragile in the last few years, which may occur again in the short and long term. Few suggestions have been registered in this letter to cope inadequate supply of the most wanted radionuclide for patient care.

Alternative production methods to face global molybdenum-99 supply shortage.

The sleeping giant of molybdenum-99 ((99)Mo) production is grinding to a halt and the world is wondering how this happened. Fewer than 10 reactors in the world are capable of producing radio nuclides for medicine; approximately 50% of the world's supply of raw material comes from National Research Universal (NRU) reactor in Canada. Many of these reactors, like the NRU, are old and aging. No one of these reactors, and probably not even all of them in combination, can replace the production of NRU. As the healthcare industry faces an aging population and the demand for diagnostic services using (99m)Tc continues to rise, the need for a consistent, reliable supply of (99)Mo has become increasingly important, so alternative methods to produce (99)Mo or even directly (99m)Tc had to be considered to avoid a supply shortage in the coming years. This need guides to the production of (99)Mo by replacing the Highly Enriched Uranium (HEU) target in a nuclear reactor with Low Enriched Uranium (LEU) and furthermore to the use of accelerators for manufacturing (99)Mo or for directly producing (99m)Tc.

Short- and long-term responses to molybdenum-99 shortages in nuclear medicine.

Most nuclear medicine studies use (99)Tc(m), which is the decay product of (99)Mo. The world supply of (99)Mo comes from only five nuclear research reactors and availability has been much reduced in recent times owing to problems at the largest reactors. In the short-term there are limited actions that can be taken owing to capacity issues on alternative imaging modalities. In the long-term, stability of (99)Mo supply will rely on a combination of replacing conventional reactors and developing new technologies.

Questionnaire survey of hospitals in Saitama Prefecture regarding the shortage of 99mTc-labeled radiopharmaceuticals and 99Mo/99mTc generators.

OBJECTIVE AND METHODS: A questionnaire survey was conducted at all 32 hospitals in Saitama Prefecture to investigate the current difficult situation in terms of nuclear medicine management in the face of the (99m)Tc shortage due to insufficient supply, and 29 hospitals (90.6%) replied. RESULTS: Of the 29, 15 (51.7%) reported a reduction in the number of nuclear medicine studies performed due to the shortage of supply, although the reduction was small. The decrease per month was less than 20 studies in 73% of the institutions. Of the nuclear medicine studies that involve the use of (99m)Tc, the studies whose reduction in number most seriously affected patient management were, in decreasing order: (99m)Tc-MAA lung perfusion scans, (99m)Tc-MAG(3), (99m)Tc-DTPA, or (99m)Tc-DMSA renoscans, (99m)Tc-MDP bone scans, (99m)Tc-HMPAO or ECD brain SPECT studies, (99m)Tc-MIBI or tetrofosmin myocardial SPECT studies, (99m)Tc-radiocolloid sentinel lymphoscintigraphy, (99m)Tc-HSA-D or pyrophosphate bleeding scans, (99m)Tc-GSA hepatic function reserve scans, and (99m)Tc-MIBI parathyroid scans. The reduction is probably ascribable to factors such as cancellations of emergency studies, absence of substitute studies, sequential studies using the same radiopharmaceutical, and higher cost of the syringe-type products than the vial-type products. Substitutes for (99m)Tc studies were performed at 52% (15/29) of the institutions. Myocardial perfusion imaging with (201)Tl chloride was the most common substitute study. CONCLUSIONS: The results of this survey suggested the several procedures to resolve the issues related to the shortage. The staffs at all institutions except one gave the impression that their nuclear medicine ordering systems had been greatly affected by the shortage of supply. This adverse circumstance, however, may provide a good opportunity to educate the public about nuclear medicine studies that use (99m)Tc and SPECT, with which citizen are now unfamiliar.