Percutaneous transtracheal ventilation in a canine shock model with an open thorax

This study evaluates the effectiveness of percutaneous transtracheal ventilation (PTV) in a canine shock model. Five mongrel dogs (25 to 35 kg), splenectomized two weeks prior to study, were anesthetized (pentobarbital, 22 mg/kg) and bled to and sustained at a mean arterial pressure (MAP) of 20 mm Hg for 60 minutes. Ringer's lactate was infused and the descending thoracic aorta was cross-clamped. Simultaneously, PTV was begun with 60% O2 through the cricothyroid membrane. Hemodynamic measurements and arterial blood gases were obtained at 0, 5, 15, and 30 minutes following the initiation of PTV. Orotracheal ventilation was then instituted in place of PTV and continued for 30 minutes, and measurements were repeated. Auto-transfusion was also begun at this time. During PTV, PO2 and PCO2 were adequate in all dogs at each interval. We conclude that PTV provides effective oxygenation and ventilation in dogs subjected to profound shock, thoractomy, and thoracic aortic cross-clamp.     

利用Elekta-iViewGTTM进行三维适形放疗摆位误差分析

目的 针对头颈部、胸部和盆腔部病变,利用Elekta-iViewGTTM验证射野位置分析摆位误差.方法 选择85例接受三维适形放疗患者,其中头颈部24例、胸部39例和盆腔部22例.利用iViewGTTM进行正侧位射野位置验证,拍摄340张射野验证片,并通过iViewTM对比分析软件计算射野验证图像与计划系统所生成的数字重建射野图像DRR中射野位置的误差.结果 通过射野验证图像与参考图像的对比可以发现,在水平(RL)方向、上下(SI)方向和前后(AP)方向,对于头颈部摆位误差为: (-0.7±1.4)mm,( 0.4±1.3)mm,( 0.4±1.5)mm; 胸部:(-2.1±3.8)mm,(-2.8±4.7)mm,( 3.6±5.1)mm; 盆腔部: (-1.5±1.7)mm,(-2.0±2.2)mm,( 2.1±2.6)mm.结论 头颈部和盆腔部患者射野位置误差较小,但胸部较大,特别是靠近下肺和膈肌的病变,由于受到呼吸作用的影响,射野位置误差最大接近10mm.针对不同位置的病变,在勾画PTV时,可根据得出的结果在CTV基础上选择合适的外放范围.     

用带有弯曲进样管的程序升温汽化进样器进样CGC法测定注射液中丙二醇含量

本文采用带有弯曲增样管程序升温进化进样器进样，毛细管气相色谱（CGC）法测定注射液中丙二醇含量，实验结果表明：这种方法不仅比常规CGC中采用的分流方法能得到更为准确和精密的结果（回收率约99％，RSD＜2％），分别周期短（＜7分钟），测定时不需预处理直接进释释样即可，不存在损伤毛细柱的可能；而且比迄今发表的程序升温汽化进样（PTV）方法也有优越之处。     

用带有弯曲进样管的程序升温汽化进样器进样CGC法测定注射液中丙二醇含量(英)

本文采用带有弯曲进样管程序升温汽化进样器进样，毛细管气相色谱（CGC）法测定注射液中丙二醇含量，实验结果表明：这种方法不仅比常规CGC中采用的分流方法能得到更为准确和精密的结果（回收率约99％，RSD＜2％），分析周期短（＜7分钟），测定时不需预处理直接进稀释样即可，不存在损伤毛细柱的可能；而且比迄今发表的程序升温汽化进样（PTV）方法也有优越之处。     

Prostate planning treatment volume margin calculation based on the ExacTrac X-Ray 6D image-guided system: margins for various clinical implementations

PURPOSE: To assess the prostate motion from day-to-day setup, as well as during irradiation time, to calculate planning target volume (PTV) margins. PTV margins differ depending on the clinical implementation of an image-guided system. Three cases were considered in this study: daily bony anatomy match, center of gravity of the implanted marker seeds calculated with a limited number of imaged days, and daily online correction based on implanted marker seeds. METHODS AND MATERIALS: A cohort of 30 nonrandomized patients and 1,330 pairs of stereoscopic kV images have been used to determine the prostate movement. The commercial image guided positioning tool employed was ExacTrac X-Ray 6D (BrainLAB AG, Feldkirchen, Germany). RESULTS: Planning target volume margins such that a minimum of 95% of the prescribed dose covers the clinical target volume for 90% of the population are presented. PTV margins based on daily bony anatomy match, including intrafraction correction, would be 11.5, 13.5, and 4.5 mm in the anterior-posterior, superior-inferior, and right-left directions, respectively. This margin can be further reduced to 8.1, 8.6, and 4.8 mm (including intrafraction motion) if implanted marker seeds are used. Finally, daily on line correction based on marker seeds would result in the smallest of the studied margins: 4.7, 6.2, and 1.9 mm. CONCLUSION: Planning target volume margins are dependent on the local clinical use of the image-guided RT system available in any radiotherapy department.     

Re-Irradiation for Locally Recurrent Lung Cancer: A Single Center Retrospective Analysis

The treatment of locally recurrent lung cancer is a major challenge for radiation-oncologists, especially with data on high-dose reirradiation being limited to small retrospective studies. The aim of the present study is to assess overall survival (OS) for patients with locally recurrent lung cancer after high-dose thoracic reirradiation. Thirty-nine patients who were re-irradiated for lung cancer relapse between October 2013 and February 2019 were eligible for the current retrospective analysis. All patients were re-irradiated with curative intent for in-field tumor recurrence. The diagnostic work-up included a mandatory ¹⁸F-FDG-PET-CT scan and—if possible—histological verification. The ECOG was ≤2, and the interval between initial and second radiation was at least nine months. Thirty patients (77%) had non-small cell lung cancer (NSCLC), eight (20%) had small cell lung cancer (SCLC), and in one patient (3%) histological confirmation could not be obtained. More than half of the patients (20/39, 51%) received re-treatment with dose differentiated accelerated re-irradiation (DART) at a median interval of 20.5 months (range: 6–145.3 months) after the initial radiation course. A cumulative EQD₂ of 131 Gy (range: 77–211 Gy) in a median PTV of 46 mL (range: 4–541 mL) was delivered. Patients with SCLC had a 3 mL larger median re-irradiation volume (48 mL, range: 9–541) compared to NSCLC patients (45 mL, range: 4–239). The median cumulative EQD2 delivered in SCLC patients was 84 Gy (range: 77–193 Gy), while NSCLC patients received a median cumulative EQD2 of 135 Gy (range: 98–211 Gy). The median OS was 18.4 months (range: 0.6–64 months), with tumor volume being the only predictor (p < 0.000; HR 1.007; 95%-CI: 1.003–1.012). In terms of toxicity, 17.9% acute and 2.6% late side effects were observed, with a toxicity grade >3 occurring in only one patient. Thoracic high dose reirradiation plays a significant role in prolonging survival, especially in patients with small tumor volume at recurrence.     

肺癌精确放疗中PTV外扩边界的研究进展

介绍了PTV外扩边界的相关定义和计算方法。重点论述了呼吸运动和摆位误差对PTV外扩边界的重要影响,以及通过探索肺癌肿块在呼吸运动过程中的位移规律,建立预测数学模型计算PTV外扩边界的研究进展。指示了采取呼吸控制、精确摆位等技术对减小靶区外扩边界的作用。