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In the detection and characterization of neuroendocrine tumors (NETs), the NETSPOT 68 Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) utilizes a somatostatin analog to capture whole body imaging of somatostatin receptors. Here, we report a rare case of incidental coronavirus disease 2019 (COVID-19) detection using 68 Ga-DOTATATE PET/CT for a 48-year-old patient with COVID-19 who presented to our nuclear medicine department for oncologic and neuroendocrine indications. Current maximal intensity project image from 68Ga-DOTATATE PET/CT demonstrated numerous hypermetabolic foci in the upper abdominal lymph nodes, consistent with somatostatin-avid pancreatic islet cell neoplasm. Radiotracer uptake corresponding to the anatomic infiltrates was also seen in the bilateral pneumonia. With the rise of worldwide COVID-19 cases, and the continued use of NETSPOT for somatostatin avid neoplasms, it is imperative that diagnostic measures of this disease are clearly understood. This case highlights the importance of including COVID-19 on the differential diagnosis when radiotracer uptake appears in 68 Ga-DOTATATE PET/CT. [ABSTRACT FROM AUTHOR]

As COVID-19 vaccination rates continue to rise, it is becoming increasingly important to understand diagnostic imaging associations' resultant from the vaccines. Here, we report a case of a 59-year-old female who was in remission for gastrointestinal neuroendocrine carcinoma and presented for standard follow-up imaging evaluation. Positron-emission tomography (PET) images from a 68Ga-DOTATATE PET (NETSPOT) demonstrated moderate focal radiotracer uptake in the right axilla. Interestingly, this uptake localized to several normal-sized lymph nodes on the corresponding computed tomography (CT). A medical history revealed the patient received both doses of an ipsilateral COVID-19 messenger ribonucleic acid vaccine injection at 17 and 38 days before the PET/CT study. Subsequent scans 2 months later revealed no radiotracer uptake. [ABSTRACT FROM AUTHOR]

Acceptable and reproducible radiochemical purity (RP) for 68 Ga-DOTATATE was difficult to obtain with the NETSPOT kit because the manufacturer instructions lacked details on the heater or needles used. Methods: The drug was prepared in an International Organization for Standardization (ISO) 5 environment. Multiple dry baths and needle types were used to investigate the effects of reaction temperature and metal contamination, respectively. Temperature curves were obtained with a calibrated thermocouple. The influence of the accuracy of the NETSPOT reagent volume and its effect on outcome were investigated. Results: The AccuBlock dry bath required recalibration for the ISO 5 environment; after calibration, the temperature was stable (only ±0.1°C from the set point). When we followed package insert recommendations (dry bath temperature set to 98°C, reaction time of 8 min), the reaction temperature was 90.6°C. When Becton Dickinson needles were used for reconstitution, 15 of 18 runs (83%) did not meet the RP specification. However, B. Braun Medical needles achieved satisfactory and stable RP. When the 68 Ga generator was eluted with 5.0 mL of 0.1 M hydrochloric acid (HCl), only 3.8-3.9 mL of eluate reached the reaction vial; this volume did not impact labeling (final pH was 3.8). The labeling success rate increased markedly if the 68 Ga eluate was passed through a conditioned silica gel cartridge or if no cartridge was used; then, RP was more than 99%. HCl contact with the septum of the labeling vial reduced RP. Conclusion: The needle type and the temperature setting of the dry bath have critical roles in 68 Ga-DOTATATE preparation. The AccuBlock dry bath has excellent stability and accuracy and can be used for reliable preparation. By using a conditioned silica gel cartridge or by eliminating the cartridge altogether, the RP is reliably high and stable., (© 2020 by the Society of Nuclear Medicine and Molecular Imaging.)

The objective of this study was to develop instant thin-layer chromatography (ITLC) conditions for the determination of radiochemical purity of 68 Ga-DOTATATE in a shorter time period than those stated in the NETSPOT (Advanced Accelerator Applications, Saint-Genis-Pouilly, France; AAA) kit package insert (PI). A faster ITLC system is needed to reduce the 48- to 50-min development time so that more radioactivity is available for single patient use and wait times are shorter in the event of kit failure. Methods: Variations of the PI mobile system were evaluated with microfiber chromatography paper impregnated with silica gel (ITLC-SG). After a more suitable mobile system was identified, evaluation began by attempting to shorten the 10-cm development distance to 7, 8, and 9 cm. Results: Experiments using variations of PI mobile phase showed that increasing the proportion of methanol in the mobile phase decreased development time. Additionally, if the ratio of 1 M ammonium acetate was reduced to 10% or less, retention factor values fall outside specification. Reducing the development distance shortened development time as expected; however, it also affected the resolution aspect of the radiochromatogram. Conclusion: The fastest developing ITLC system, which maintained resolution and peak shape, was methanol:1 M ammonium acetate (80:20 V/V) with ITLC-SG using a development distance of 8 cm., (© 2018 by the Society of Nuclear Medicine and Molecular Imaging.)