頭皮皮膚血管肉腫に対する根治的な寡分割高線量放射線治療の実行可能性と有効性の検討

Cutaneous angiosarcoma is a rare but highly aggressive vascular tumor resistant to all treatment modalities available. The aim of this study was to analyze the treatment outcomes of patients who received definitive hypofractionated high-dose radiotherapy (RT) for angiosarcoma of the scalp. Between April 2008 and December 2014, 11 patients with histologically proven cutaneous angiosarcoma of the scalp visited our Department of Radiation Oncology, because dermatologists suggested that there was no indication for surgery in those cases. One patient rejected all radical treatments and the other 10 patients were treated by RT with curative intent along with chemotherapy or immunotherapy. Eight patients were treated with 6 - 12 MeV electron beams and the other 2 patients were treated with 4 MV X-ray Intensity Modulated Radiation Therapy (IMRT) and electron beams. The total irradiated dose was 63 - 75 Gy (median: 72.5 Gy) in 26 - 30 fractions, and the fraction size was 2.5 Gy in principle. The median age of the patients treated with RT was 80 years old (range: 73 - 91) and the median follow-up time was 16.5 months (range: 5.6 - 86.3). Four patients are still alive. A complete response (CR) was achieved in 10 patients (100%) and only one patient suffered local relapse 20 months after RT. Medians of overall survival (OS), progression-free survival (PFS), and local relapse-free survival (LRFS) were 38.7, 13.4, and 19.8 months, respectively. Local control rates were 100 and 75% at 1 and 2 years, respectively. Skin ulceration was CTCAE grade 2 in 5 patients (50%) and grade 3 in 5 (50%), alopecia was grade 2 in all patients (100%), but no patient developed grade 4 or more severe adverse events after RT. Hypofractionated high-dose RT was feasible and achieved excellent local control of cutaneous angiosarcoma in the elderly patients.博士（医学）・甲第646号・平成28年3月15日Copyright: © 2015 Shimoda E. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The definitive version is available at " http://clinmedjournals.org/articles/ijccr/international-journal-of-cancer-and-clinical-research-ijccr-2-032.php?jid=ijccr

COVID-19 vaccine effectiveness against severe COVID-19 requiring oxygen therapy, invasive mechanical ventilation, and death in Japan: A multicenter case-control study (MOTIVATE study).

INTRODUCTION: Since the SARS-CoV-2 Omicron variant became dominant, assessing COVID-19 vaccine effectiveness (VE) against severe disease using hospitalization as an outcome became more challenging due to incidental infections via admission screening and variable admission criteria, resulting in a wide range of estimates. To address this, the World Health Organization (WHO) guidance recommends the use of outcomes that are more specific to severe pneumonia such as oxygen use and mechanical ventilation. METHODS: A case-control study was conducted in 24 hospitals in Japan for the Delta-dominant period (August-November 2021; "Delta") and early Omicron (BA.1/BA.2)-dominant period (January-June 2022; "Omicron"). Detailed chart review/interviews were conducted in January-May 2023. VE was measured using various outcomes including disease requiring oxygen therapy, disease requiring invasive mechanical ventilation (IMV), death, outcome restricting to "true" severe COVID-19 (where oxygen requirement is due to COVID-19 rather than another condition(s)), and progression from oxygen use to IMV or death among COVID-19 patients. RESULTS: The analysis included 2125 individuals with respiratory failure (1608 cases [75.7%]; 99.2% of vaccinees received mRNA vaccines). During Delta, 2 doses provided high protection for up to 6 months (oxygen requirement: 95.2% [95% CI:88.7-98.0%] [restricted to "true" severe COVID-19: 95.5% {89.3-98.1%}]; IMV: 99.6% [97.3-99.9%]; fatal: 98.6% [92.3-99.7%]). During Omicron, 3 doses provided high protection for up to 6 months (oxygen requirement: 85.5% [68.8-93.3%] ["true" severe COVID-19: 88.1% {73.6-94.7%}]; IMV: 97.9% [85.9-99.7%]; fatal: 99.6% [95.2-99.97]). There was a trend towards higher VE for more severe and specific outcomes. CONCLUSION: Multiple outcomes pointed towards high protection of 2 doses during Delta and 3 doses during Omicron. These results demonstrate the importance of using severe and specific outcomes to accurately measure VE against severe COVID-19, as recommended in WHO guidance in settings of intense transmission as seen during Omicron

線形二次曲線モデルの寡分割照射への適用性

Background: The linear-quadratic (LQ) model is used for evaluating fractionation schedules in radiation oncology. It has been suggested that the biologically effective dose based on the LQ model cannot be applied to hypofractionated radiotherapy. Methods: Glioblastoma cells were transplanted into nude mice. Four equivalent dose fractionation schedules (12 Gy/1 fraction (fr). 15.06 Gy/2 fr, 18.16 Gy/4 fr, and 20.96 Gy/8 fr) were calculated based on the LQ model. The tumor size was measured to evaluate the number of days required for the relative tumor volume to double and become five t imes the initial value (TGD₂ and TGD₅, respectively). A histopathological study was performed after the evaluation of growth delay. Result: The mean TGD₂ of the unirradiated control group and 12 Gy/1 fr, 15.06 Gy/2 fr. 18.16/4 fr, and 20.96 Gy/8 fr groups was 5.69, 22.64, 37.26. 36.81, and 28.96 days, respectively. The mean TGD₅ was 17.83, 48.03. 60.30, 60.40, and 64.94 days, respectively. All TGDs of the irradiated groups were longer than those of the control group. However, no significant differences were observed among the four irradiated groups. Histologically, irregular giant cells were found, but there were no significant differences among the four groups. There was no significant difference in the Ki-67 labeling index and the CD133 and CD44 expression among the groups. Conclusion: The four dose fractionation schedules equivalent to 12 Gy/1 fr yielded comparable responses, suggesting that the LQ model may be applicable to hypofractionated radiotherapy, with a high dose per fraction of up to 12 Gy.博士（医学）・甲第756号・令和2年9月30