Searching for just a few words should be enough to get started. If you need to make more complex queries, use the tips below to guide you.
Article type: Research Article
Authors: Liu, Su-Wen | Li, Jia-Min | Chang, Joe-Yujiao | Yu, Jin-Ming | Chen, Qing | Jiang, Qian-An | Mu, Xiang-Kui | Zhao, Mei-Hong | Tian, Ying | Wei, Qing-Long
Affiliations: Department of Proton Therapy Center, Zibo Wanjie Cancer Hospital, Zibo, Shandong, China | Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA | Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong, China
Note: [] Corresponding author: Jia-Min Li, M.D., Department of Proton Therapy Center, Zibo Wanjie Cancer Hospital, No.1 Jiankang Road, Wanjie, Zibo, Shandong 255213, China. Tel.: +86 533 4650083; Fax: +86 533 4650830; E-mail: wjlijiamin@yahoo.com.cn
Abstract: Background and purpose: A comparative treatment planning study was undertaken between proton beam therapy (PBT) and intensity-modulated x-ray therapy (IMXT) for patients with recurrent nasopharyngeal carcinoma (NPC), to assess the potential benefits and limitations of the two treatment modalities. Materials and methods: We retrospectively analyzed seven patients with recurrent NPC treated at our proton center with PBT from 2004 to 2007. Eclipse proton treatment planning system and Eclipse inverse treatment planning system for IMXT were employed. For each patient, the IMXT plan was optimized with nine evenly spaced coplanar fields. Three coplanar beams and passive scattering mode were used for PBT. The dose prescription in cobalt Gray equivalent (CGE) for gross tumor volume (GTV) was 66CGE and for planning target volume (PTV), 62.7CGE. Dose-volume histograms (DVH) were used to evaluate the difference in dosimetric distributions for the target volume and the organs at risk (OARs). Results: Optimal target volume coverage and similar target conformation were achieved in both PBT and IMXT. Median conformity index was 0.72 and 0.75 (p=0.15) and median inhomogeneity coefficient was 0.14 and 0.10 (p=0.08) for PBT and IMXT, respectively. Dose to OARs was significantly lower in PBT plans than IMXT. Median maximal dose to the brainstem was 27.89CGE(cobalt Gray equivalent) and 42.45Gy (p< 0.01), and the dose to 5% of the brainstem(D5) was 12.83CGE and 19.47Gy (p< 0.001 ), for PBT and IMXT, respectively. Median maximal dose to the spinal cord was 8.38CGE and 22.91Gy (p< 0.004), and the dose to 5% of the spinal cord was 2.18CGE and 13.62Gy (p< 0.001), for PBT and IMXT, respectively. Conclusions: The use of PBT, when compared with IMXT, resulted in similar levels of tumor conformation. PBT, however, exposed the OARs to a significantly lower dose, effectively sparing the brainstem, spinal cord, optic nerve and chiasm, temporal lobes and parotid glands. The superior dose distributions possible with PBT should translate into reduced morbidity and improved quality of life.
Keywords: Recurrent nasopharyngeal carcinoma, proton beam therapy, intensity-modulated x-ray therapy, comparative treatment planning, conformity index, inhomogeneous coefficient
DOI: 10.3233/XST-2010-0265
Journal: Journal of X-Ray Science and Technology, vol. 18, no. 4, pp. 443-450, 2010
IOS Press, Inc.
6751 Tepper Drive
Clifton, VA 20124
USA
Tel: +1 703 830 6300
Fax: +1 703 830 2300
sales@iospress.com
For editorial issues, like the status of your submitted paper or proposals, write to editorial@iospress.nl
IOS Press
Nieuwe Hemweg 6B
1013 BG Amsterdam
The Netherlands
Tel: +31 20 688 3355
Fax: +31 20 687 0091
info@iospress.nl
For editorial issues, permissions, book requests, submissions and proceedings, contact the Amsterdam office info@iospress.nl
Inspirees International (China Office)
Ciyunsi Beili 207(CapitaLand), Bld 1, 7-901
100025, Beijing
China
Free service line: 400 661 8717
Fax: +86 10 8446 7947
china@iospress.cn
For editorial issues, like the status of your submitted paper or proposals, write to editorial@iospress.nl
如果您在出版方面需要帮助或有任何建, 件至: editorial@iospress.nl