RESUMO
BACKGROUND: Patients with non-small cell lung cancer (NSCLC) driven by activating epidermal growth factor receptor (EGFR) mutations are best treated with therapies targeting EGFR, i.e., tyrosine kinase inhibitors (TKI). Radiolabeled EGFR-TKI and PET have been investigated to study EGFR-TKI kinetics and its potential role as biomarker of response in NSCLC patients with EGFR mutations (EGFRm). In this study we aimed to compare the biodistribution and kinetics of three different EGFR-TKI, i.e., 11C-erlotinib, 18F-afatinib and 11C-osimertinib. METHODS: Data of three prospective studies and 1 ongoing study were re-analysed; data from thirteen patients (EGFRm) were included for 11C-erlotinib, seven patients for 18F-afatinib (EGFRm and EGFR wild type) and four patients for 11C-osimertinib (EGFRm). From dynamic and static scans, SUV and tumor-to-blood (TBR) values were derived for tumor, lung, spleen, liver, vertebra and, if possible, brain tissue. AUC values were calculated using dynamic time-activity-curves. Parent fraction, plasma-to-blood ratio and SUV values were derived from arterial blood data. Tumor-to-lung contrast was calculated, as well as (background) noise to assess image quality. RESULTS: 11C-osimertinib showed the highest SUV and TBR (AUC) values in nearly all tissues. Spleen uptake was notably high for 11C-osimertinib and to a lesser extent for 18F-afatinib. For EGFRm, 11C-erlotinib and 18F-afatinib demonstrated the highest tumor-to-lung contrast, compared to an inverse contrast observed for 11C-osimertinib. Tumor-to-lung contrast and spleen uptake of the three TKI ranked accordingly to the expected lysosomal sequestration. CONCLUSION: Comparison of biodistribution and tracer kinetics showed that 11C-erlotinib and 18F-afatinib demonstrated the highest tumor-to-background contrast in EGFRm positive tumors. Image quality, based on contrast and noise analysis, was superior for 11C-erlotinib and 18F-afatinib (EGFRm) scans compared to 11C-osimertinib and 18F-afatinib (EGFR wild type) scans.
RESUMO
PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic resulted in accelerated market access to remdesivir worldwide. Therefore, data about complications experienced during use of the drug are limited. This is the first published case series (1 case report exists) to describe remdesivir infiltration in 3 patients with COVID-19. SUMMARY: In the first case, a 91-year-old woman experienced remdesivir infiltration resulting in edema, hematoma at the area of infiltration; on palpation, the affected area felt cooler than the surrounding areas. Swelling was still present after 6 weeks. In the second case, remdesivir infiltration occurred in a 72-year-old male, resulting in edema, hematoma, and pain at the area of infiltration. The hematoma lasted for 7 days. The third case concerned a 67-year-old woman, in whom remdesivir infiltration led to edema and a small hematoma. The hematoma regressed to a negligible size within 3 days. However, a week after infiltration, redness had reappeared. In 2 cases, the patient was immediately treated with hyaluronidase injections, but no specific treatments were provided in the other case. CONCLUSION: Based on the product information provided by remdesivir's manufacturer, we believe symptoms and signs observed in the 3 cases may have resulted from the low pH (~4) of the nonbuffered remdesivir solution, although the patients were not formally assessed for caustic injury. Previous experience with other noncytotoxic medications suggests that infusion-specific factors (eg, volume of leaked fluid) and patient-specific factors (eg, advanced age) may have a role in the outcome of remdesivir infiltration. The possibility of symptoms caused by cyclodextrins in the formulation or by intrinsic toxicity of remdesivir warrants exploration.
