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

Abstract

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 99m TcO 4 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 99m Tc-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.

Breast Cancer Management in the Era of Covid-19; Key Issues, Contemporary Strategies, and Future Implications

“… 33 In Iran, Sadri et al reported on the successful application of low specific activity of Tc-99m elutes to help with diagnosis and treatment approaches, including surgery with generator shortages. 88 There was also a 35.5% reduction in breast cancer surgeries in Pakistan during the early stages of the pandemic. 89 Breast cancer patients were typically divided in Pakistan into those that require urgent surgery, those where surgery can be altered or delayed for 4–8 weeks, and those where surgery can be postponed until the end of the pandemic combined with other management approaches.…”

“… Surgeries of early breast cancer were significantly altered due to COVID-19, especially in Hubei. Sadri et al, Iran 88 Observational study 7 Mar 2019–18 Apr 2020 35 (48 years) Application of Tc-99m elute during Mo99-Tc-99m generator shortage SLNB can be done with excellent results using Tc-99m pertechnetate elute during Mo99-Tc-99m generator shortage. Using special personal protection, nuclear medicine Departments can perform lymphatic mapping and biopsy.…”

Hybridised production of technetium-99m and technetium-101 with fluorine-18 on a low-energy biomedical cyclotron

“…Tc-99m can be produced through various nuclear transmutation methods, but commercially speaking, it is generally derived from molybdenum-99 ( 99 Mo, t h) via 235 U targets [ 1 ]. However, the current commercial production and distribution of 99m Tc rely on a complex supply chain that has proven itself prone to disruptions in years past, which was most recently observed during the SARS-CoV-2 pandemic [ 2 ]. Ultimately, this leads to delays in the diagnoses of patients due to postponed imaging procedures as well as the loss of material and capital.…”

Fusion-Based Neutron Generator Production of Tc-99m and Tc-101: A Prospective Avenue to Technetium Theranostics

“…The supply chain has been interrupted several times in recent years leading to shortages of the drug(s) [6][7][8][9]. Over the last decade, efforts to integrate redundancy within the production side of the supply chain (coordinated scheduling, back-up producers, varying production loads, etc.)…”