Studies in the area of life sciences reported from Nagoya University
2009 JUL 23 - (NewsRx.com) -- "Intraoperative electron beam radiotherapy (IOERT) is a technique in which a single-fraction high dose is intraoperatively delivered to subclinical tumour cells using an electron beam after breast-conserving surgery. In IOERT, an attenuation plate consisting of a pair of metal disks is commonly used to protect the normal tissues posterior to the breast," scientists in Japan report. "However, the dose in front of the plate is affected by backscatter, resulting in an unpredictable delivered dose to the tumour cells. In this study, an experimental attenuation plate, termed a shielding plate, was designed using Monte Carlo simulation, which significantly diminished the electron beam without introducing any backscatter radiation. The plate's performance was verified by measurements. It was made of two layers, a first layer (source side) of polymethyl methacrylate (PMMA) and a second layer of copper, which was selected from among other metals (aluminium, copper and lead) after testing for shielding capability and the range and magnitude of backscatter. The optimal thicknesses of the PMMA (0.71 cm) and copper (0.3 cm) layers were determined by changing their thicknesses during simulations. On the basis of these results, a shielding plate was prototyped and depth doses with and without the plate were measured by radiophotoluminescence glass dosimeters using a conventional stationary linear accelerator and amobile linear accelerator dedicated for IOERT," wrote T. Oshima and colleagues, Nagoya University. The researchers concluded: "The trial shielding plate functioned as intended, indicating its applicability in clinical practice.." Oshima and colleagues published their study in Physics in Medicine and Biology (An experimental attenuation plate to improve the dose distribution in intraoperative electron beam radiotherapy for breast cancer. Physics in Medicine and Biology, 2009;54(11):3491-3500). For additional information, contact T. Oshima, Nagoya University, Graduate School Medical, Higashi Ku, 1-1-20 Daikou Minami, Aichi 4618673, Japan. The publisher's contact information for the journal Physics in Medicine and Biology is: IOP Publishing Ltd., Dirac House, Temple Back, Bristol BS1 6BE, England. Keywords: Japan, Life Sciences, Breast Cancer, Breast Carcinoma, Oncology, Women's Health, Surgery, Nagoya University. This article was prepared by World Disease Weekly editors from staff and other reports. Copyright 2009, World Disease Weekly via NewsRx.com.
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