VOA标准英语2011--Study: Early CT Scans Increase Lung Canc

Study: Early CT Scans Increase Lung Cancer Survival Rates

A new study has found smokers¹ and former smokers who develop lung cancer are more likely to survive if their disease is detected with a computed² tomography, or CT scan instead of a standard chest x-ray, according to a recent study.
That's because a CT scan picks up lung cancer tumors at a much earlier and more treatable stage.
The five-year study, conducted by the US National Cancer Institute, compared conventional, single-image chest x-rays to CT scans in a group of more than 53,000 heavy smokers and former smokers at 33 centers around the United States.
Between 2002 and 2004, researchers enrolled³ participants - between the ages of 55 and 74 - who either received one chest x-ray per year for three years or got an annual computed tomography scan for three years.
CT scans give radiologists a three-dimensional view of the lung, detecting potentially cancerous nodules as small as a grain of rice.
In December 2009, when investigators⁴ followed up, they discovered a 20 percent higher survival rate among those who received CT scans compared to the x-ray group. The reason - the more sensitive computer tomography picked up cancerous lung lesions at a much earlier stage, when they were smaller and easier to treat.
Christine Berg, the study's lead author, is not ready to recommend lung CT screening for all heavy smokers and former smokers.
For one thing, she says, CT scans are known to produce both a high rate of positive results and so-called false positives, which identify lung nodules that might be cancerous but often turn out to be benign⁵.
"The rate of positive testing was 24.2 percent throughout the study on average," says Berg. "That's a high rate and then these individuals need to have a lot of follow-up examinations. And so I think that before one considers embarking⁶ on a program of screening, either for an individual or full a health care organization, one needs to look at the full picture."
Claudia Henschke, who heads the Lung and Cardiac Screening Program at Mount Sinai Medical Center in New York, has been conducting her own lung screening program using low-dose CT imaging.
She's found that heavy smokers and former smokers who undergo regular CT scans increase their chances of survival by 90 percent when the cancer is detected early.
"I feel delighted for the people at high risk of lung cancer that there's further confirmation⁷ of our results and that hopefully people will avail themselves of that," says Henschke.
Critics have said the benefits of yearly scans have to be weighed against the risk of false positives, unnecessary radiation exposure and potentially risky⁸ diagnostic work-ups.
Because of these concerns, Henschke believes it will be some time before there are any official recommendations for lung screening, as there are now for breast or colon⁹ cancer.
"I think, in the meantime, there are programs that provide screening and have protocols¹⁰ in place, and then individuals can make up their minds after talking to their physicians as to whether they want to have such a screening test."

1 smokers   

吸烟者( smoker的名词复数 )

参考例句：

• Many smokers who are chemically addicted to nicotine cannot cut down easily. 许多有尼古丁瘾的抽烟人不容易把烟戒掉。
• Chain smokers don't care about the dangers of smoking. 烟鬼似乎不在乎吸烟带来的种种危害。

2 computed   

adj.[医]计算的，使用计算机的v.计算，估算( compute的过去式和过去分词 )

参考例句：

• He computed that the project would take seven years to complete. 他估计这项计划要花七年才能完成。 来自《简明英汉词典》
• Resolving kernels and standard errors can also be computed for each block. 还可以计算每个块体的分辨核和标准误差。 来自辞典例句

3 enrolled   

adj.入学登记了的v.[亦作enrol]( enroll的过去式和过去分词 )；登记，招收，使入伍（或入会、入学等），参加，成为成员；记入名册；卷起，包起

参考例句：

• They have been studying hard from the moment they enrolled. 从入学时起，他们就一直努力学习。 来自《简明英汉词典》
• He enrolled with an employment agency for a teaching position. 他在职业介绍所登了记以谋求一个教师的职位。 来自《简明英汉词典》

4 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

5 benign   

adj.善良的，慈祥的；良性的，无危险的

参考例句：

• The benign weather brought North America a bumper crop.温和的气候给北美带来大丰收。
• Martha is a benign old lady.玛莎是个仁慈的老妇人。

6 embarking   

乘船( embark的现在分词 )； 装载； 从事

参考例句：

• He's embarking on a new career as a writer. 他即将开始新的职业生涯——当一名作家。
• The campaign on which were embarking was backed up by such intricate and detailed maintenance arrangemets. 我们实施的战争，须要如此复杂及详细的维护准备。

7 confirmation   

n.证实，确认，批准

参考例句：

• We are waiting for confirmation of the news.我们正在等待证实那个消息。
• We need confirmation in writing before we can send your order out.给你们发送订购的货物之前，我们需要书面确认。

8 risky   

adj.有风险的，冒险的

参考例句：

• It may be risky but we will chance it anyhow.这可能有危险，但我们无论如何要冒一冒险。
• He is well aware how risky this investment is.他心里对这项投资的风险十分清楚。

9 colon   

n.冒号，结肠，直肠

参考例句：

• Here,too,the colon must be followed by a dash.这里也是一样，应当在冒号后加破折号。
• The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。

10 protocols   

n.礼仪( protocol的名词复数 )；（外交条约的）草案；（数据传递的）协议；科学实验报告（或计划）

参考例句：

• There are also protocols on the testing of nuclear weapons. 也有关于核武器试验的协议。 来自辞典例句
• Hardware components and software design of network transport protocols are separately introduced. 介绍系统硬件组成及网络传输协议的软件设计。 来自互联网