SUMMARY Whole brain radiotherapy (WBRT), stereotactic radiosurgery (SRS), and the combination of both treatment methods were used for the management of single brain metastasis from lung cancer. The purpose of this study is to compare these three different treatment options in terms of local response, survival, and quality of life. From June 1995 to July 1998, 70 lung cancer patients with new diagnosed single brain metastasis were treated with either WBRT alone (n = 29), or SRS alone (n = 23), or the combination of both methods (n = 18). Multiple endpoints, including survival, freedom from local progression (FFLP), freedom from new brain metastasis (FFNBM), local control, Karnofsky performance status (KPS), and causes of death, were measured from the date of treatment completion and compared using univariate and multivariate analyses. For patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, the median survivals were 5.7, 9.3, and 10.6 months, the median FFLP were 4.0, 6.9, and 8.6 months, the median FFNBM were 4.1, 6.7, and 8.6 months, and the local response rates were 55.6, 87.0, and 88.9%, respectively. Four of the 29 patients treated with WBRT-alone continued with progression of disease. The post treatment KPS showed improvement in 41.4, 82.6, and 88.9% of patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. The progression of new and/or recurred metastatic brain tumor as the cause of death accounted for 51.7%, 50.0%, and 28.3% of the patients treated with WBRT-alone, SRS-alone, and SRS+WBRT, respectively. Univariate analyses showed that the significant differences among the three treatment arms were observed based on all of the above mentioned endpoints. However, the comparison between SRS-alone and SRS+WBRT groups indicated that adding WBRT only improves FFNBM (P = 0.0392). Cox regression analyses revealed no significant difference in both of the KPS (P = 0.1082) and causes of death (P = 0.081) among the three arms. Both SRS alone and SRS+WBRT seem better in prolonging life and improving quality of life than WBRT alone for patients with single brain metastasis from lung cancer. But the combined therapy did not show significant advantage over SRS alone in improving survival, enhancing local control, and quality of life except for a more favorable FFNBM. Further investigation via a randomized trial is needed to access the value of adding WBRT to SRS in the management of this group of patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 37-45 (2000).
Phased arrays generate ultrasonic waves by using recisely-defined time delays for each element in an ultrasonic array group, this permits constructive and destructive interference of the wavefronts to form the pre-defined beam. So, ultrasonic phased arrays are well suited to weld inspections. First, beams can be multiplexed across the array, in what is called “electronic scanning”. This permits very rapid inspections of components, typically an order of magnitude faster than a single transducer raster scan. Second, the beam can be swept through a range of angles without moving the array; this is called “beam steering”, and the inspections are typically called “azimuthal” scans or “sectorial” scans. Before weld inspecting, the time delays between elements were computed using a specific model and compared to experimental delays obtained using through transmission tests. This paper describes the application of phased array on pipelines’ weld inspection. The detail hardware designs of linear phased arrays system and the summary of system performance are presented. This inspection system includes eight ultrasonic signal transmitting and receiving circuit units, which are used to control time sequence of ultrasonic beam and select channel used for waves construction, and amplify the received ultrasonic signal. Each unit is connected with 16 probe elements (total 128 elements in this system), and can receive 4-way ultrasonic signals (channel selection is done by RF switching). Additional performance is gained by intensively using FPGA (Field Programmable Gate Arrays) technology for memory and delay counters. Since the working frequency or FPGA is 100MHz, the delay time less than 10 ns is realized by analogue delay line. This system not only has the functions of conventional ultrasonic inspector, but also can display the defect shape and its size on the screen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.