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【medical-news】精心调制的“射线鸡尾酒”能够减
A carefully determined mixture of electron and x-ray beams precisely treated breast tumors while significantly reducing collateral skin damage in 78 patients, researchers will report on August 1 at the annual meeting of the American Association of Physicists in Medicine in Orlando. The key to choosing the right mixture of beams, as well as their individual properties, was a sophisticated computer approach developed by medical physicists Jinsheng Li, Ph.D. (Jinsheng.Li@fccc.edu) and Chang-Ming Ma, Ph.D. of Fox Chase Cancer Center in Philadelphia.
In treating shallow tumors such as those that occur in the breast, physicians have been turning to mixed-beam radiation therapy (MBRT), which employs separate beams of electrons and photons (x-rays). The two types of radiation complement one another, as electrons generally travel to shallow depths while the x-rays can penetrate to deeper parts of the tumor as needed.
However, each beam interacts in complex ways with its environment, making their exact path to the tumor region hard to predict. Nonetheless, physicists can calculate the probability for a given beam to follow a desired trajectory.
Therefore, Li and Ma use computers to simulate billions of trips of each beam to the unique landscape of each tumor. Gathering the statistics from these billions of trials, they determine the best beam properties and mixtures.
The computer simulations helped oncologists send accurately targeted doses for 78 breast cancer patients receiving "hypofractionated" treatments, in which the patients received fewer, but more potent, doses of radiation. The beams delivered all the radiation within a small margin of the tumor's edge, dramatically reducing radiation damage to surrounding healthy tissue. The researchers expect their approach to provide benefits for reducing collateral damage in the treatment of shallow tumors in the breast, chest wall, and head-and-neck region.
Associated Meeting Papers:
TU-D-224A-6, "Advanced Mixed Beam Therapy Using MERT and IMRT," Tuesday, August 1, 2006, 2:30 PM, Room 224 A. Click Here for Technical Abstract
WE-E-224C-3, "Advanced Mixed Beam Radiotherapy for Breast and Head and Neck," Wednesday, August 2, 4:24, Room 224A. Click Here for Technical Abstract
Presented at: 48th Annual Meeting of the American Association of Physicists in Medicine, July 30-August 3, 2006, Orange County Convention Center, Orlando, FL. Click Here for Meeting Homepage
ABOUT AAPM
AAPM (www.aapm.org) is a scientific, educational, and professional organization of more than 6,000 medical physicists. Headquarters are located at the American Center for Physics in College Park, MD. Publications include a scientific journal ("Medical Physics"), technical reports, and symposium proceedings
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Targeting of a breast tumor (depicted in blue). Courtesy Jinsheng Li.
screen.width-333)this.width=screen.width-333" width=308 height=356 title="Click to view full breasttumor.jpg (308 X 356)" border=0 align=absmiddle> 这篇我来翻译 精心调制的“射线鸡尾酒”能够减轻乳腺癌放疗的副损伤.
研究人员将于8月1日在奥兰多市的美国医学物理学家协会年会上做报告,指出用精心设计的电子和X线束混合射线照射治疗78名乳腺肿瘤患者,既可以准确的治疗肿瘤又可明显减轻皮肤副损伤.
关键是选择合适的射线束混合体并考虑射线束各自的性能,为此费城福克斯詹士癌症中心医学物理学家 Li Jinsheng博士 (Jinsheng.Li@fccc.edu)和 Ma Chang-Ming博士开发了一整套精密的计算机选择方法.
在治疗浅表肿瘤,像发生在乳腺的,内科医师则求助于混合射线照射疗法,这种疗法使用的是分离的电子和光子(X线)束.两种不同性质的射线互补,即电子束通常照射到浅表部位而X线则能根据需要穿透肿瘤深处.
然而,每束射线在各自的环境下其作用方式很复杂,致使很难预测它到达肿瘤区域的精确途径.但物理学家可以计算某一特定射线束沿着期望的轨道行进的可能性.
因此, Li 和 Ma 用计算机模拟
每一射线束到每个肿瘤的特定位置的无数条轨迹.
计算机模拟有助于肿瘤学家对78名接受低分割放射治疗的乳腺癌患者发射准确的目标剂量,此法使患者受到放射线的剂量更小,但更有效.
射线束所有的辐射都限制在肿瘤边缘很小的范围内,明显减轻了对周围组织的放射损伤.
研究人员期望他们的方法能减轻放射线治疗乳房,胸壁和头颈部的浅表肿瘤引起的副损伤.
Associated Meeting Papers: 相关学术论文:
TU-D-224A-6, "Advanced Mixed Beam Therapy Using MERT and IMRT," Tuesday, August 1, 2006, 2:30 PM, Room 224 A. Click Here for Technical Abstract
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作者:admin@医学,生命科学 2011-02-17 18:02
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