Impact of the COVID-19 Pandemic on Patient Flow in the Nuclear Medicine Department of a COVID-19 Reference Hospital in Greece.

BACKGROUND: The COVID-19 pandemic has influenced medical practices globally, including nuclear medicine (NM). This study aimed to assess the impact of the pandemic on patient flow in the Nuclear Medicine Department of the American Hellenic Educational Progressive Association (AHEPA) University Hospital, a COVID-19 reference center in Greece, by comparing the yearly number of examinations and collective doses (CDs) from 2019 to 2023. MATERIALS AND METHODS: Our Department keeps detailed records of all activities administered for diagnostic and therapeutic procedures. Administered activities for pediatric patients are calculated using the European Association of Nuclear Medicine (EANM) pediatric dosage card. According to the International Atomic Energy Agency (IAEA) recommendations, administered activities for adult patients are calculated based on the patient's weight. This practice results in similar effective doses for all patients. CDs can thus be estimated by multiplying the typical effective dose per examination by the corresponding number of patients. CDs for the pre-pandemic year (2019), the intra-pandemic period (2020-2021), and the post-pandemic years (2022-2023) were estimated. RESULTS: A total of 8945 exams were performed during this period (2019: 2486; 2020: 1649; 2021: 1098; 2022: 1484; 2023: 2228). About 6417 (71.7%) were myocardial perfusion (MP) scans, followed by 627 (7%) bone scans. Yearly CDs (in man-sieverts (manSv)) were: 2019: 8.62 manSv; 2020: 6.11 manSv; 2021: 4.93 manSv; 2022: 5.46 manSv; 2023: 8.08 manSv. MP scans were responsible for 64.5% of the CDs, followed by diagnostic iodine-131 (I-131) scans (8.2%), bone scans (7.2%), and iodine-123 (I-123) ioflupane brain single-photon emission computed tomography (SPECT) scans (6.5%). Exams mostly affected by the pandemic (comparing years 2021 and 2019) included dynamic renograms (-88.9%), technetium (Tc)-99m hexamethylpropyleneamine oxime (HMPAO) brain scans (-83.6%), and Tc-99m thyroid scans (-77.5%). On the other hand, the number of Tc-99m macroaggregated albumin (MAA) lung perfusion scans increased by 70.6%. Most exams only partially recovered in the last post-pandemic year. CONCLUSION: The COVID-19 pandemic significantly impacted the number of diagnostic exams in our Department. The most significant decline occurred in 2021, with a 55.8% reduction in the number of exams and a 42.9% decrease in CD compared to pre-pandemic levels. Two years later, the patient flow has not yet fully recovered to the pre-COVID-19 levels.