Assessment of Radiation Dosage to the Hippocampi during Treatment of Multiple Brain Metastases Using Gamma Knife Therapy.

Background and Objectives: Brain metastases (BMs) pose significant clinical challenges in systemic cancer patients. They often cause symptoms related to brain compression and are typically managed with multimodal therapies, such as surgery, chemotherapy, whole brain radiotherapy (WBRT), and stereotactic radiosurgery (SRS). With modern oncology treatments prolonging survival, concerns about the neurocognitive side effects of BM treatments are growing. WBRT, though widely used for multiple BMs, has recognized neurocognitive toxicity. SRS, particularly Gamma Knife (GK) therapy, offers a minimally invasive alternative with fewer side effects, suitable for patients with a quantifiable number of metastases and better prognoses. Materials and Methods: A retrospective analysis was conducted on 94 patients with multiple BMs treated exclusively with GK at an academic medical center. Patients with prior WBRT were excluded. This study focused on the mean radiation dose received by the hippocampal area, estimated according to the 'Hippocampal Contouring: A Contouring Atlas for RTOG 0933' guidelines. Results: The precision of GK equipment results in mean doses of radiation that are lower than those suggested by RTOG 0933 and observed in other studies. This precision may help mitigate cognitive dysfunction and other side effects of hippocampal irradiation. Conclusions: GK therapy facilitates the administration of smaller, safer radiation doses to the hippocampi, which is advantageous even for lesions in the temporal lobe. It is feasible to treat multiple metastases, including cases with more than 10, but it is typically reserved for patients with fewer metastases, with an average of 3 in this study. This underlines GK's potential for reducing adverse effects while managing BMs effectively.

Intravenous Thrombolysis for Acute Ischemic Stroke during the COVID-19 Pandemic-Polish Single-Center Retrospective Cohort Study.

COVID-19 has affected the entire world and has had a great impact on healthcare, influencing the treatment of patients with acute ischemic stroke (AIS). The aim of this study was to determine the impact of the COVID-19 pandemic on the care of patients with AIS. We performed a retrospective analysis of 1599 patients diagnosed with AIS and hospitalized in the authors' institution from January 2018 to December 2021. The final sample consisted of 265 patients treated with thrombolysis without a diagnosis of COVID-19. The initiation of thrombolytic treatment during the pandemic was delayed (2:42 ± 0:51 vs. 2:25 ± 0:53; p = 0.0006). The delay was mainly related to the pre-hospital phase (1:41 ± 0:48 vs. 1:26 ± 0:49; p = 0.0014), and the door-to-needle time was not affected. There were no differences in stroke severity and patients' outcomes. Patients with AIS were less likely to have previously been diagnosed with atrial fibrillation (16.9% vs. 26.7%; p = 0.0383), ischemic heart disease (25.3% vs. 46.5%; p = 0.0003) and hyperlipidemia (31.2% vs. 46.5%; p = 0.0264). Patients treated during the pandemic had higher glycemia (149.45 ± 54. vs. 143.25 ± 60.71 mg/dL; p= 0.0012), while no significant differences in their lipid profiles were found. Conclusions: The COVID-19 pandemic affected the treatment of AIS patients locally at our stroke center. It caused treatment delay and hindered the recognition of risk factors prior to the occurrence of AIS.