常见问题:肺癌筛查计划
What is the goal of a lung cancer screening using computed tomography (CT)?
任何筛检的目标都是延长寿命. This is accomplished by detecting disease early, when it is potentially more treatable. 例如, some lung cancers found using CT screening are small and have not yet spread within the chest or to other areas of the body. 治疗通常在这个阶段更有效. 如果没有进行筛选, it is possible that a lung cancer would only be discovered after it has spread to other places in the body, 这就更难治疗了.
哪些人应该使用CT进行肺癌筛查?
不像其他筛查项目, lung cancer screening CT is targeted to a specific group of patients. It is most useful for people who are at high risk for developing lung cancer, 即现在或以前的吸烟者. The length of time and number of cigarettes smoked affects whether a patient is a good candidate for CT screening. Most of the CT screening studies have been performed on patients who smoke 20 to 30 packs of cigarettes per year. 一项大型研究, 叫做全国肺部筛查试验, 评估每年吸烟超过30包的患者. Pack-years are calculated by multiplying the aver年龄 number of packs of cigarettes smoked each day times the total number of years smoked. If this number is equal to or greater than 30, you may benefit from a lung cancer screening CT. 病人 with a family member who has been diagnosed with lung cancer may also benefit from CT screening.
做CT筛查有什么缺点?
There are two potential negative consequences of getting a screening CT: The first is radiation. 这将在下一节中讨论. The second potential downside is that the CT may prompt additional testing, and in some cases that testing is done to diagnose benign (not cancerous) growths. 例如, a suspicious pulmonary nodule may be surgically removed only to find out that it wasn’t a cancer. There are some similarities in the appearances of cancer and benign growths; thus a CT scan cannot give 100 percent assurance that an abnormal finding represents cancer. 当发现可疑的异常时, 然而, 进一步的检查是必要的,比如PET扫描, 活检或手术, 这些药物有副作用吗.
我应该担心CT的辐射吗?
Medical radiation has been a popular topic in the news recently and has raised concerns about the possibility of radiation-induced cancers. UCSF is very aware of this concern and has adopted many different techniques for reducing radiation from CT scans, including the development of low-dose protocols and the purchase of special software specifically designed for radiation reduction.
Each person is exposed to radiation in his or her daily life from the environment. The yearly dose that each person receives is approximately 3 millisieverts (mSv). 相比, a standard chest CT imparts a dose of around 6 mSv (twice the yearly dose from the environment). It is estimated that the lifetime risk of developing a fatal cancer after receiving a dose of 10 mSv is 1 in 2000. Remember that, in general, one in four people will develop cancer in their lifetime. 在这种情况下考虑, the risk of developing a cancer from a CT scan only slightly increases a person’s overall risk from baseline.
Some people who get a screening CT will need one or more follow-up CTs for lung nodules. Small lung nodules have a low likelihood of representing cancer and are typically followed for a period of one to two years to ensure they are not growing. These additional CTs are performed using a low-dose technique that imparts a radiation dose of approximately 1/10th of a standard CT.
我有一个肺结节. 我应该担心吗??
Lung nodules are very common, and the vast majority of them are benign (not cancerous). More than 50 percent of our patients can be expected to have a lung nodule found on CT, 超过97%的结节是良性的. 任何结节都有可能代表癌症. CT扫描的作用不仅仅是检测结节, but also to determine the likelihood that any nodule is benign or malignant based upon that nodule's features. 良性结节的特征包括体积小, 随着时间的推移,平滑的边界和缺乏增长. Nodules that are likely benign are typically followed with serial CT scans to make sure they are not growing. 如果它们在一到两年内没有增长, they are considered to be benign and no further follow-up is required. If a nodule shows any suspicious features, some immediate action is generally warranted.
我有一个可疑的肺结节. 接下来我该做什么?
病人 with a lung nodule that demonstrates suspicious features on a CT scan should be referred to a specialist in either pulmonary medicine or thoracic surgery to man年龄 the work-up of that nodule. 病人 in the Lung Screening Program can discuss the results of their CT scan with one of the program’s pulmonary medicine specialists. 结节的可疑特征包括体积大, 不规则或具细刺的边缘和随时间生长. The next step in the work-up of that nodule depends upon multiple factors. Options include PET scanning, CT-guided lung biopsy, bronchoscopy and surgery. 所使用的测试将取决于您的CT扫描的外观, 吸烟史, 年龄, 其他疾病的症状和存在.
加州大学旧金山分校健康医学专家已经审查了这些信息. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encour年龄 you to discuss any questions or concerns you may have with your provider.