Lung Nodule Treatment

A lung nodule is an area of increased density within the lung tissue, smaller than 3 cm, round or oval in shape, and most often detected incidentally. Nodules are generally benign, but because they may carry a risk of malignancy, careful evaluation is required. They are monitored with follow-up and biopsy if necessary.

Nodule types and evaluation criteria are based on radiological features such as the size, margin structure, density, and growth rate of the nodule. Solid, subsolid, and calcified nodules carry different clinical meanings. Risk factors such as smoking history and age are also taken into consideration in the analysis.

The diagnostic process and follow-up protocols begin with low-dose computed tomography (CT). In suspicious nodules, PET-CT, transthoracic needle biopsy, or bronchoscopy may be required. Nodules with low suspicion of malignancy are monitored at intervals determined according to the Fleischner criteria.

Treatment approaches and surgical options are shaped according to the malignancy risk of the nodule. Surgical resection is preferred for high-risk or growing nodules. In diagnosed cancer cases, additional oncological treatments may be planned. Early intervention positively affects the prognosis.

What Is a Nodule in the Lung?

A nodule in the lung is an abnormal formation within the lung tissue, usually smaller than 3 centimeters, limited and round in appearance. Most develop due to benign causes, especially infections or previous inflammatory processes. However, some nodules may be a sign of early-stage lung cancer. They are generally detected incidentally during imaging. The need for follow-up and further examination is determined according to the size and structure of the nodule and the patient’s risk factors.

What does a nodule in the lung mean?

The term “solitary pulmonary nodule,” which we frequently encounter in medical reports, is actually not a disease diagnosis but a radiological definition. Simply put, we call nodules those round or oval formations within the air-filled, spongy tissue of the lung that should not normally be there and are generally smaller than 3 centimeters in diameter. You can think of it like a mole or spot that appears later on your skin. Just as not every spot on our skin indicates a dangerous disease, not every nodule in our lung means cancer.

In fact, lung nodules are quite common. With the development of technology, we can now perform much thinner-section and higher-resolution tomography scans. This enables us to detect millimetric formations, as small as a grain of rice, that we would never have been able to see with old-style X-ray devices. When a nodule is detected, the most decisive factor for us is time. If you have a scan from two years ago and that same nodule is in the same place and of the same size, you can take a deep breath. Because while malignant formations grow uncontrollably, the likelihood that nodules whose size does not change are benign is almost certain.

What are the causes that pave the way for the formation of these nodules?

Our lungs are organs that are in constant contact with the outside world and filter the air we breathe. The infections we have had throughout our lives, the dusts or smoke we have inhaled, leave some marks in the lung tissue. Our body’s defense mechanism builds a wall around a microbe or substance it considers harmful and traps it in order to neutralize it. The nodule we see years later when a scan is taken may actually be the remnant of a battle our body won in the past.

The most common factors that may cause nodule formation are as follows:

• Previous tuberculosis infection
• Fungal infections
• Residual bacterial pneumonia
• Sarcoidosis
• Rheumatoid arthritis
• Wegener granulomatosis
• Histoplasmosis
• Hydatid cyst
• Hamartomas
• Intrapulmonary lymph nodes
• Lung abscesses
• Occupational dust exposure

What do the size and shape of the nodule tell us?

The first feature we look at when evaluating a nodule is its size in millimeters. Size is a mathematical compass we use when performing risk analysis. Nodules smaller than 4 millimeters in diameter are as common as stars in the sky, and the statistical probability of these being cancer is below one percent. These very small nodules are generally considered “clinically insignificant,” and in most cases only follow-up is sufficient. In some cases, even follow-up may not be required.

However, as the diameter of the nodule increases, so does our level of attention. Nodules between 8 millimeters and 2 centimeters are in the “intermediate-risk” group and deserve more detailed examination. If the nodule is larger than 2 centimeters, the risk of cancer increases significantly. In addition to size, the shape of the nodule also whispers a lot to us. Nodules with smooth, regular margins, as if drawn with a pencil, are generally benign in character. However, nodules with irregular margins and spiky extensions like a sea urchin (spiculation) carry a risk of malignancy because they show an aggressive attitude toward the surrounding tissue. In addition, whether there is calcification within the nodule is another vital clue. If there are popcorn-like or eggshell-like calcifications within the nodule, this usually points to a benign process.

Which factors are taken into account in risk assessment?

When a patient comes to us, we do not make a decision only by looking at the scan. The patient’s story is just as important as the scan itself. By using scientific risk calculation tools such as the “Mayo Clinic Model,” we create a personal risk map for each patient. This map helps us determine what the next step will be (watch and wait, perform a biopsy, or operate).

The factors that increase cancer risk are as follows:

• Advanced age
• Active smoking
• History of smoking
• Family history of lung cancer
• Chronic Obstructive Pulmonary Disease
• Idiopathic pulmonary fibrosis
• Asbestos exposure
• Radon gas exposure
• Previous history of cancer
• Arsenic exposure
• Silica dust exposure
• Previous radiotherapy to the chest region

Is it necessary to perform a PET/CT scan?

PET/CT, popularly known as a “color scan” or “contrast whole-body scan,” is not a method we use for every patient with a nodule. It generally comes into play in nodules larger than 8-10 millimeters and in cases where the suspicion of cancer is intermediate or high. The working principle of this technology is quite clever; it is based on the fact that cancer cells, because they proliferate uncontrollably, need much more energy, that is, sugar, than normal cells. A labeled sugar molecule is given to the patient intravenously, and it is monitored which tissue in the body consumes this sugar the most.

If the nodule in the lung takes up this sugar intensively by “lighting up,” this shows that the cells there are very active and strengthens the suspicion of cancer. However, PET/CT does not give us a one hundred percent definitive result; it only shows probabilities. Because active infections (for example tuberculosis) or inflammatory conditions may also consume a lot of sugar just like cancer and may light up on the scan. We call this “false positivity.” On the other hand, some slow-growing cancer types or very small foci may not light up on the scan because they do not consume enough sugar. Therefore, the PET/CT result is an important piece of the puzzle that the surgeon uses when making a decision, but it does not make the judgment on its own.

In which cases is a biopsy required?

For masses in other parts of the body, a standard approach is usually to first perform a biopsy, name it, and then move on to treatment. However, things work a little differently in the lung. Because the lung is an organ that is constantly moving and filled with air, a biopsy procedure is not always risk-free or easy. When deciding on a biopsy, the location and size of the nodule and the patient’s general condition are decisive. Sometimes the risk of performing a biopsy may be higher than the risk of operating directly, or the biopsy result may not give us a clear answer.

The methods used for biopsy are as follows:

• Transthoracic Needle Aspiration
• Fiberoptic bronchoscopy
• Endobronchial Ultrasonography
• Navigational bronchoscopy
• Electromagnetic navigation
• Virtual bronchoscopy

Why is the breathing test important before surgery?

When we decide to surgically remove a nodule, another issue that is at least as important as the nodule itself is whether the patient can tolerate this surgery. During surgery, we may need to remove a certain amount of healthy lung tissue together with the nodule. Therefore, we need to calculate millimetrically whether the patient’s remaining lung capacity will be sufficient. With pulmonary function tests (PFT), we measure the patient’s breathing capacity and the openness of the airways.

However, sometimes the blowing test alone is not enough. Especially in patients who have smoked, have a history of COPD, or experience shortness of breath when climbing stairs, we resort to more advanced examinations such as the “Cardiopulmonary Exercise Test” (CPET). These tests measure the body’s oxygen consumption capacity (VO2 max). If the patient’s reserves are borderline, we change the type of surgery we will perform. For example, instead of removing an entire lobe, we try to preserve lung tissue by removing only the small segment containing the nodule (segmentectomy). Our aim is not only to clear the cancer but also to ensure that the patient can continue life comfortably after surgery without experiencing shortness of breath.

How is the closed surgery (VATS) method applied?

In the past, when thoracic surgery was mentioned, what came to mind were open surgeries in which the space between the ribs was widely opened, large muscles were cut, and the recovery process was quite painful. However, with the development of technology and surgical techniques today, the closed methods that we call “VATS” (Video-Assisted Thoracoscopic Surgery) have become the gold standard. We can now perform these surgeries without opening the chest cavity and without separating the ribs.

In this method, usually 1, 2, or 3 small holes (ports), each 1-2 centimeters, are made in the patient’s chest wall. Through one of these holes, a high-resolution camera is sent inside and the image of the lung is reflected on giant screens. The surgeon performs the operation by looking at the screen with special and thin surgical instruments inserted through the other holes. The comfort this method provides to the patient is invaluable. Because the incisions are very small, postoperative pain is much less, patients spend less time in intensive care, the risk of infection decreases, and the time to return to daily life is incredibly shortened. Cosmetically, only tiny scars remain.

What is the Frozen procedure performed during surgery?

The most exciting and critical stage of lung nodule surgeries is the “Frozen Section” collaboration we carry out with the pathologist inside the operating room. This procedure is applied in suspicious nodules whose diagnosis has not yet been finalized. While the patient is asleep under general anesthesia, the nodule in the lung and a small piece of healthy tissue around it (wedge resection) are removed using the closed method. This piece is sent without delay to the pathology laboratory inside or immediately next to the operating room.

The pathologist freezes the tissue in a special device, takes thin sections, and examines them under the microscope. Within about 15-20 minutes, a result is reported to the surgical team. If the result comes back as “benign,” the operation is terminated there. The patient is relieved of only that small nodule, there is no need to remove more tissue, and most of the lung is preserved. However, if the result comes back as “malignant,” that is, cancer, the extent of the surgery is expanded under the same anesthesia. In accordance with the principles of cancer surgery, the relevant lobe or anatomical segment is removed together with the lymph nodes. Thus, the patient completes both diagnosis and treatment in a single session; there is no need for a second surgery.

How is it decided how much tissue will be removed from the lung?

In lung surgery, our basic principle is to remove “as much as necessary, as little as possible” tissue. In other words, while completely clearing the cancerous tissue, we also try to preserve the patient’s healthy lung tissue to the maximum extent. The amount of tissue to be removed varies according to the size, location, and type of the nodule, and most importantly, the patient’s breathing capacity.

The surgical resection types applied are as follows:

• Wedge resection
• Anatomical segmentectomy
• Lobectomy
• Sleeve lobectomy
• Bilobectomy
• Pneumonectomy

In nodules caught at an early stage, small in size (generally under 2 cm), and not spread to the lymph nodes, the method we call “segmentectomy” is now coming to the forefront. In this method, instead of removing an entire lobe, only the anatomical unit containing the tumor is removed. In this way, the patient’s lung capacity is preserved without compromising oncological clearance. However, if the tumor is large or centrally located, the standard treatment, “lobectomy” (removal of one of the five lobes of the lung), is applied.

How is technology used in locating small nodules?

Some nodules are so small or so deep in the lung that especially during closed surgery it may not be possible for the surgeon to feel them with a finger or see them with the eye. When the lung is deflated, the nodule may also disappear within the tissue. This situation is like “looking for a needle in a haystack.” This is where modern technology comes into play.

We use various methods to “mark” the location of the nodule before or during surgery. Sometimes a special wire is placed next to the nodule under tomography guidance, and sometimes a special dye is injected into the location of the nodule by progressing through the airways inside the lung with a GPS-like system using the method called “navigational bronchoscopy.” In recent years, with the “Hybrid Operating Room” concept, C-arm CT devices capable of taking tomography scans of the patient on the operating table have been used. In this way, the location of the nodule is visualized millimetrically during surgery and it is removed with exact precision. These technologies eliminate the surgeon’s concern of “am I removing the right place?” and prevent unnecessary tissue loss.

What happens if it turns out to be benign or malignant?

If, as a result of the procedures performed, the nodule turns out to be benign (hamartoma, granuloma, etc.), this is the most pleasing scenario. In benign nodules removed by surgery, the treatment is considered complete. No additional drug treatment, radiation, or chemotherapy is needed. Since the nodule is completely removed from the body, there is no risk of recurrence. After a short recovery period, the patient continues normal life where they left off.

Even if the nodule turns out to be malignant, that is, lung cancer, the fact that it has been caught at the “nodule” stage is actually a great chance. Because this means that the disease is still in its initial stage (Stage 1). In early-stage lung cancer, surgical treatment has the potential to completely eliminate the disease (cure). Long-term survival rates are quite high in patients who are caught and operated on at this stage. Although some patients may require additional protective treatments according to the details of the pathology report, in most cases successful surgery alone is sufficient.

How does the follow-up process work?

Whether operated on or not, every patient in whom a nodule is detected should be followed within a certain discipline. In patients treated surgically, tomography control is generally recommended every 3 to 6 months during the first two years, and once a year in the following years. The purpose of these follow-ups is not only to see whether the disease has recurred. In people who have smoked or have risk factors, there is also a risk that a completely new and different nodule may develop years later in another part of the lung. For this reason, it is vitally important not to neglect controls by saying “I am already cured.”

The points paid attention to during follow-up are as follows:

• Development of a new nodule
• Increase in size of existing nodules
• Changes in the surgical area
• Enlargement of lymph nodes
• Fluid accumulation
• Complaint of shortness of breath

Frequently Asked Questions