ABSTRACT
Due to global COVID-19 pandemic, environmental control system design for building and mobility products would be increasingly demanded to ensure comfortable indoor environments, and to ensure the effective biological contamination control. In this paper, 3D simulation tool is introduced to address such brand-new needs by coupling CFD with epidemiological model. The characteristics of anti-activation function was mathematically modeled and incorporated into the coupled analysis. A trial analysis in an office with air-conditioning system showed that 92% infection risk reduction was realized before and after the anti-activation on the air-conditioning. With the developed tool, space design such as HVAC system layout can be proposed to satisfy contamination safety as well as thermal comfort by quantifying and visualizing the change of contamination propagation and infection risk distribution.
ABSTRACT
BACKGROUND: According to previous reports, in patients with preoperative coronavirus disease 2019 (COVID-19) infection, mortality is increased if they undergo surgery within 6 weeks of diagnosis. However, the optimal timing and preoperative examination for gastrectomy with a previous COVID-19 infection are still controversial. We experienced three cases in which patients successfully underwent open radical gastrectomy following preoperative chemotherapy even though they developed COVID-19 infection during the chemotherapy. CASE PRESENTATION: Case 1: A 58-year-old man with locally advanced gastric cancer caught COVID-19 during preoperative chemotherapy comprising 5-fluorouracil, calcium folate, oxaliplatin, and docetaxel. Although the patient had specific lung shadows indicating COVID-19 infection and deep venous thrombosis in the lower extremities, he underwent distal gastrectomy 10 weeks after the COVID-19 diagnosis. He had a good postoperative course. Case 2: A 56-year-old man with gastric cancer and lymph node and peritoneal metastasis caught COVID-19 during palliative chemotherapy comprising S-1, oxaliplatin, and trastuzumab. He underwent total gastrectomy as conversion surgery 8 weeks after COVID-19 infection. His postoperative course was uneventful. Case 3: A 55-year-old man with gastric cancer and paraaortic lymph node and liver metastases caught COVID-19 during S-1 and oxaliplatin treatment as neoadjuvant chemotherapy. He underwent distal gastrectomy, paraaortic lymph node sampling, and partial hepatectomy 8 weeks after COVID-19 infection although he had residual lung shadows and deep venous thrombosis in the lower extremities. He had an uneventful postoperative course. CONCLUSIONS: Computed tomography for preoperative evaluation was performed for all three patients and revealed that lung shadows remained post-COVID-19 infection. Despite this finding, the patients had good operative courses and were discharged as planned. Surgery after 7 weeks from the diagnosis of COVID-19 infection can be performed safely even when patients are post-chemotherapy and have residual lung findings and deep venous thrombosis. This report may contribute to the development of a consensus on performing safe gastrectomy for advanced gastric cancer in patients previously infected with COVID-19.
ABSTRACT
PURPOSE: Patients who receive trastuzumab (T-mab) plus chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer sometimes respond remarkably well and can undergo radical surgery. However, the clinical outcomes of preoperative T-mab combined chemotherapy with radical gastrectomy remain unclear. We conducted this study to investigate the clinical outcomes of this multimodal treatment. METHODS: From among a total of 199 patients who received T-mab-based chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer between 2011 and 2018, the subjects of this retrospective analysis were 20 patients who subsequently underwent radical gastrectomy. RESULTS: Seven patients had gastroesophageal junction cancer and 13 had gastric cancer. Eleven patients had unresectable stage IV cancer and 9 had resectable metastatic disease. Chemotherapy regimens included capecitabine, cisplatin + T-mab (11 patients), and S-1, oxaliplatin + T-mab (nine patients). The median number of chemotherapy cycles before surgery was three (range, 2-62). During preoperative chemotherapy, grade 3/4 adverse events developed in six patients. None suffered grade ≥ 3b postoperative complications. The 3-year relapse-free survival (RFS) and overall survival (OS) rates were 58.9% and 89.5%, respectively. CONCLUSION: Combined preoperative T-mab-based chemotherapy and surgery appears to be safe and effective for stage IV HER2-positive gastric or gastroesophageal junction cancer, with a clinically meaningful impact on RFS and OS.