Many people with a lifetime of smoking will be concerned about their increased risk of cancer, and so the question of screening with either a CT or x-ray
often comes up in discussions with a physician. Because your specific health is a very personal matter, you should discuss your risks and any possible symptoms with your long term physician, who will also ask about a family history of any types of cancer, including cancers--such as lung cancer--that are more likely for people with a long smoking history.
Even more important than being screened as an asymptomatic person, however, is to quit smoking. No matter how old you are, your odds of living a long and healthy life immediately improve the second that you quit smoking, and numbers are very drastic as far as how much of a health benefit you can have regardless of your age at the time you quit. Your doctor
can discuss smoking cessation with you at the time you talk about any possible screening or imaging tests to see if they are necessary. In general, a CT test in the absence of any symptoms, family history, or other concerning findings would not be indicated, but, again, speak to your doctor to see if this applies to you.