With the popularity of CT scans, more and more lung nodules are being detected during medical check-ups. Because lung cancer is the most deadly of all cancers, some people worry about getting cancer after a lung nodule is detected.
Can a lung nodule be cancer?
Lung nodules are very common nowadays. All lung cancers evolve from lung nodules, and some studies suggest that about 1 in 20 lung nodules will become lung cancer. So some people think that if they have lung nodules, they are close to having lung cancer.
In fact, the majority of lung nodules are benign (non-cancerous) and regular follow-up is all that is needed. According to statistics, 96% of small lung nodules found during physical exams in the United States are benign. In particular, small solid nodules are not a cause for concern. Even if you are unlucky and the nodule may become cancerous later, you can get a good result with regular follow-up and timely intervention.
Is it safer to have multiple lung nodules?
Some people are relieved to find out they have multiple lung nodules instead, thinking that they are safer or even benign.
Research has proven that this is partly true, but not entirely.
Lung nodules are divided into three categories based on their density: solid nodules, part-solid nodules, and ground-glass nodules. Of these, part-solid nodules have the highest risk of being cancerous, followed by ground-glass nodules and solid nodules in that order. Solid nodules, if multiple, usually have a high probability of being benign. However, in the case of part-solid and ground glass nodules, “multiple” does not necessarily mean that they are more likely to be benign.
What is the best interval for follow-up scans?
When nodules are found in the lungs, follow-up is often recommended, most often by regular CT scans. The interval between follow-ups is based on the risk level of the lung nodule.
Benign lung nodules are usually slow-growing, and if they are not large, then follow-up is preferable. The initial CT review takes place in 3-6 months. And then it’s extended to 6-12 months if there is no change. This usually continues for 2-3 years, with yearly checkups thereafter. If a nodule tends to get progressively larger in the process, it is important to consult a specialist.
X-ray, MRI, PET-CT, CT, which is better?
Some patients, having detected a small nodule, want to check the nature of the nodule at once. Therefore, they want to go for PET-CT or MRI. So, which test is better for small lung nodules?
There are advantages and disadvantages to each test. MRI has no radiation, but it is less sensitive to lung nodules, and the test is slower, taking 20-30 minutes for a single test, and some patients are more averse to the confined space of MRI. Although PET-CT is a sensitive method for detecting tumors, it is not effective for small nodules and is more expensive. And chest X-rays often do not accurately detect smaller lung nodules. So the best screening tool available is a low-dose spiral CT scan, which in most cases can determine whether a nodule is benign or malignant. In high-risk groups, annual low-dose CT exams are even more necessary.
Is it harmful to expose to radiation with repeated CT scans?
Patients may worry that if they do not have CT follow-up, their lung nodules will get worse. But if they undergo CT scan regularly, they are afraid of radiation exposure. They have heard that exposure to radiation can cause a variety of tumors, including leukemia, thyroid cancer, breast cancer, and lung cancer, so repeated CT scans may not cause lung nodules to develop, but may instead cause other cancers.
In fact, there is no need to worry much about “radiation consumption”. The dose of radiation received from a standard CT scan of the chest is 7 mSv, which is within the safe range for several CT exams a year. Low-dose CT scans are even lower, at 1.5 mSv each. Therefore, the effect on the body is minimal and there is no need to be too anxious about it.