RNA相关的低剂量辐射响应标志物

电离辐射会对人体造成损伤,根据受照剂量、时间等因素的不同可诱发多种生物效应。目前对于低剂量辐射产生的健康效应仍有争议,筛选对低剂量敏感的辐射响应生物标志物,对于完善低剂量辐射生物效应机制、拓宽低剂量辐射在临床中的应用均具有重要理论意义。综述探讨各核糖核酸(RNA)在低剂量辐射反应中的变化及其对辐射敏感性的调节作用,同时评估各RNA作为低剂量辐射响应标志物的潜力。     

European consensus on patient contact shielding

Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff.     

Dose Rate Simulation of the Urine Collection Bag of Patients Undergoing Bone Scintigraphy

ObjectiveThe objective of the study was to estimate the determined dose rate in the urine collection bag of patients undergoing bone scintigraphy.MethodThe ^99m Tc-methylene diphosphonate accumulated activity eliminatedin urine was estimated and calculated by the Committee on Medical Internal Radiation Dose 14 method. This allowed the calculation of the dose rate emitted at distances of 10, 50, and 100 cm and the creation of a simulation collection bag to validate the calculations by means of measurements carried out with a Geiger Müller counter in the same situations. A linear regression test was performed to verify the significant difference between the measurements and validate the dose rate estimate.ResultsThe calculated and measured dose rates showed the highest values at a distance of 10 cm up to 3 hours after administering the radiopharmaceutical to the patient. After this period, as the collection bag was emptied for image acquisition, the dose rate was close to the background radiation.ConclusionThe maximum accumulated activity in the urine collection bag, and consequently, the maximum dose rate, occurs at the time of emptying the bag for image acquisition. Therefore, in addition to exposure to radiation, there is a considerable risk of contamination by ionizing radiation for the professional who performs the procedure. To minimize this risk and the exposure, the recommendation is to use personal protective equipment and to consider radiological protection factors, which are shorter exposure time, longer distance, and greater barrier between the professional and the radioactive source.     

Magnetron Sputtered CsPbCl3 Perovskite Detectors as Real-Time Dosimeters for Clinical Radiotherapy

The aim of this study is to investigate the feasibility of manufacturing thin real-time relative dosimeters for clinical radiotherapy (RT) with potential applications for transmission monitoring in vivo dosimetry and pre-treatment dose verifications. Thin (≈1 μm) layers of a high sensitivity, wide bandgap semiconductor, the inorganic perovskite CsPbCl₃, have been grown for the first time by magnetron sputtering on plastic substrates equipped with electrode arrays. Prototype devices have been tested in real-time configuration to evaluate the dose delivered by a 6 MV photon beam from a linear accelerator. Linearity of the charge with the dose has been verified over three order of magnitudes, linearity of the current signal with the dose rate has been also successfully tested in the range 0.5-4.3 Gy/min. The combination of high sensitivity per unit volume and wide bandgap provides high signal-to-noise ratios, up to 70, even at moderate applied voltages. The Schottky diode configuration allows the detector to operate without bias voltage (null bias).The blocking-barrier structure allows to confine the active volume within sub-millimetric sizes, a quite attractive feature in view to increase granularity and achieve the high spatial resolutions required in modern RT techniques. All the above-mentioned features indeed pave the way to a novel generation of flexible, transmission, real time dosimeters for clinical radiotherapy.     

Endostar,an Antiangiogenesis Inhibitor,Combined With Chemoradiotherapy for Locally Advanced Cervical Cancer

This phase II randomized clinical trial aimed to assess the efficacy and toxicity of Endostar, an antiangiogenesis inhibitor, combined with concurrent chemoradiotherapy (CCRT) for locally advanced cervical cancer (LACC). Patients with LACC were randomly assigned to either CCRT plus Endostar (CCRT+E arm) or CCRT alone (CCRT arm). All patients received pelvic intensity-modulated radiation therapy (IMRT) and brachytherapy. Weekly cisplatin was administered concurrently with IMRT. Patients in the CCRT+E arm also received concurrent Endostar every 3 weeks for two cycles. The primary endpoint was progression-free survival (PFS) and acute toxicities. The exploratory endpoint was the impact of vascular endothelial growth factor receptor-2 (VEGFR2) expression on long-term survival. A total of 116 patients were enrolled. Patients in the CCRT+E arm and in the CCRT arm had similar acute and late toxicity profile. The 1- and 2-year PFS were 91.4% versus 82.1% and 80.8% versus 63.5% (p=0.091), respectively. The 1- and 2-year distance metastasis-free survival (DMFS) were 92.7% versus 81.1% and 86.0% versus 65.1% (p=0.031), respectively. Patients with positive VEGFR2 expression had significant longer PFS and overall survival (OS) compared with those with negative VEGFR2 expression. Patients in the CCRT+E arm had significantly longer PFS, OS, and DMFS than those in the CCRT arm when VEGFR2 expression was positive. In conclusion, CCRT plus Endostar significantly improved DMFS but not PFS over CCRT alone. The addition of Endostar could significantly improve survival for patients with positive VEGFR2 expression.     

基于TGF-β1/p38MAPK/FN信号通路的放射性食管炎发病机制的研究

Objective To investigate the pathogenesis mechanism of radiation esophagitis from the perspective of mucosal regeneration and to determine whether it is associated with TGF-β1/p38MAPKs/FN signaling pathway. Methods The pathological analysis of esophageal specimens was performed by HE staining method. The expression of FN and TGF-β1 genes were observed by real time-PCR method, and the expression of tissue proteins TGF-β1, p38 and FN were detected by Western blot. Results The weights, food intakes and water intakes at the first week after the occurrence of radiation esophagitis were significantly decreased (P<0.05) and recovered at the fourth week. The esophageal mucosa was destructed at the first and second weeks, and the regeneration occurred in the fourth weeks; TGF-β1 and p38MAPK protein expression increased first and then decreased, while FN protein expression decreased first and then increased. Conclusion The TGF-β1/p38MAPK/FN signaling pathway may be involved in the process of mucosal repair. © 2020, CHINA RESEARCH ON PREVENTION AND TREATMENT. All rights reserved.     

Survival benefit of adjuvant chemoradiotherapy for positive or close resection margin after curative resection of pancreatic adenocarcinoma

BackgroundThis study was conducted to identify patients who may benefit from adjuvant chemoradiotherapy (CRT) for positive or close resection margin (RM) after curative resection of pancreatic adenocarcinoma.MethodsFrom 2004 to 2015, total of 472 patients with pancreatic adenocarcinoma underwent curative resection. After excluding patients with RM > 2 mm or unknown, remaining 217 patients were retrospectively analyzed. Forty-six (21.2%) patients were treated with adjuvant chemotherapy alone (CTx; mainly gemcitabine-based), 142 (65.4%) with adjuvant CRT (mainly upfront), and 29 (13.4%) patients didn’t receive any adjuvant therapy (noTx group).ResultsLocoregional recurrence rate was significantly lower in the CRT group (43.7%) than in the CTx group (71.7%) or noTx group (65.5%) (p = 0.001). Significant survival benefits of CRT over CTx (HR 0.602, p = 0.020 for overall survival (OS); HR 0.599, p = 0.016 for time to any recurrence (TTR)) were demonstrated in multivariate analysis. CRT group had more 5-year survivors than other groups. In the subgroup analysis, such benefits of adjuvant CRT over CTx was observed only in patients with head tumor & vascular RM > 0.5 mm, but not in patients with body/tail tumor or vascular RM ≤ 0.5 mm. In the CRT group, radiation dose≥54 Gy was significantly associated with better TTR and OS.ConclusionsAdjuvant CRT could improve TTR and OS compared to adjuvant CTx alone in patients with close RM under 2 mm. Radiation dose escalation may be beneficial when feasible. Modern CRT regimen–based randomized evidence is needed for these high-risk patients.