[Panxiong Science] Small lung nodules enter individualized diagnosis and treatment. Should an 8 mm nodule be treated with surgery or observation? How to achieve a successful surgery?

As the public pays more attention to health, more and more people are undergoing lung CT scan screening, and many small lung nodules have been found. Patients are often very panicked after CT scans find small lung nodules. So what should we do if we find small lung nodules?

■

Jiang Yuequan

Director of the Thoracic Tumor Center of the Affiliated Cancer Hospital of Chongqing University, chief physician, doctor of medicine, master's supervisor, and chief expert on esophageal cancer of the hospital.

He has been engaged in clinical and scientific research work in thoracic surgery for more than 30 years. He is good at thoracic surgery for esophageal cancer, lung cancer and mediastinal tumors, especially thoracoscopic and laparoscopic combined esophageal cancer radical resection, single-port lobectomy and segmental resection.

Clinic hours: Monday morning

What are pulmonary nodules?

In clinical practice, CT scans show that the lungs have a diameter of less than 30 mm and are round or irregular shadows with increased density, which are called lung nodules. If the diameter is less than 20 mm, it is usually called a small lung nodule, and if the diameter is less than 5 mm, it is called a micronodule. CT scans show that some nodules have a very high density or calcification, some show pure ground-glass shadows, and some show mixed ground-glass nodules.

When a nodule is found on the lung, one naturally wants to know whether it is benign or malignant. The next step is how to treat it. Patients may go to many hospitals for treatment and search for relevant knowledge online, and the answers they get may be different. Some believe that the possibility of lung nodules being lung cancer is very small, and they recommend observation and follow-up. Some recommend surgery, and some recommend puncture examination. Which doctor's advice should the patient listen to? This is a very complicated issue. Since doctors give different suggestions and there is no definite plan, it means that there are many issues that need further research.

The most authoritative NCCN guidelines recommend: observation for diameters below 8mm, and surgery can be considered for diameters above 8mm. But is the diagnosis and treatment of lung nodules really as simple as the guidelines? The diagnosis and treatment of small lung nodules involve many factors, and surgery can completely cure lung cancer. If a small lung nodule is lung cancer, the sooner the surgery, the better. Therefore, the options for patients with small lung nodules are actually follow-up observation or surgery.

Some patients may ask, is it possible to have a puncture to confirm the diagnosis before surgery?

Recommendation: For patients who are scheduled to undergo surgery, do not attempt a needle biopsy before surgery.

There are two results of biopsy: finding cancer cells and not finding them. But if cancer cells are not found, the possibility of lung cancer cannot be ruled out, and surgery is still needed; if cancer cells are found, surgery is definitely needed, so biopsy is of no value to patients who need surgery. On the contrary, biopsy will definitely puncture the basement membrane of the tumor, which may cause cancer cells to implant, spread to the blood and lymph nodes, and turn early-stage lung cancer into late-stage lung cancer.

Although some articles have reported that the possibility of lung nodules being lung cancer is very small, 90% of patients with lung nodules who underwent surgery after consultation in our hospital were diagnosed with lung cancer. Therefore, if you find a lung nodule, you must not take it lightly. You must go to a regular tertiary hospital, especially the thoracic surgery department of a cancer hospital, and listen to the opinions of experts.

Whether to observe or undergo surgery, the following factors need to be considered comprehensively.

Lesion size

CT shows that the nodule is large, with a diameter of more than 8mm. Even if the nodule is highly suspected of lung cancer, it should be observed for at least 2 weeks to see whether the nodule will shrink or disappear, and then consider whether surgery is needed.

If the nodule is very small, with a diameter of less than 5mm, most of them can be followed up for a long time, unless the nodule morphology is highly suspicious of lung cancer, and the nodule persists or even has slight changes after follow-up, surgical resection can be considered.

Nodular characteristics

If CT scans reveal proliferative lesions or calcifications, follow-up is generally recommended, as the possibility of benign lesions is high. In this case, annual CT scans are recommended.

Pure ground glass nodules with small diameters can be followed up with chest CT every six months or one year. Larger ones are considered adenocarcinoma in situ, which will not metastasize, so there is no need to worry too much even if the follow-up time is long.

Mixed ground glass nodules, especially those with a majority of solid components, significantly increase the possibility of lung cancer and may be infiltrated by cancer cells. They are not suitable for long-term follow-up and should be operated on as soon as possible, even if the nodule diameter is less than 8 mm.

Nodule location

The location of the nodule is also important in planning your diagnosis and treatment. Each lung is divided into the upper, middle (lingual) and lower lobes. Each lobe is made up of many segments.

Long-term observation and follow-up of lung nodules is recommended. We will recommend the length of the observation and follow-up interval based on the location, size and shape of the lesions. If the nodule is close to the hilum of the lung, lung cancer may be considered, and close observation and CT scans are recommended every 3 months. Because nodules close to the hilum of the lung are more difficult to remove surgically once they grow larger, and hilar lymph node metastasis is more likely to occur. If the follow-up interval is long, the tumor will grow faster. Due to its proximity to the hilum of the lung, the edge of the mass may not be close to the resection margin of normal tissue, and the tumor is prone to recurrence or even cannot be completely removed.

Nodules near the periphery of the lungs, especially those near the pleura, can be actively surgically removed after a period of follow-up if the nodules resemble lung cancer. The reasons are:

1. Nodules close to the pleura are prone to metastasis and pleural implantation;

2. Relatively little lung tissue is removed from peripheral lung nodules, which has little impact on the patient's lung function.

Figure 1 Pulmonary nodules are located deep in the lung parenchyma

If the pulmonary nodule is located deep in the lung parenchyma (Figure 1), but in the middle of a lung segment, a segmental resection can be performed, and this situation can also be relatively aggressive surgery. However, if the nodule is located deep and at the junction of several segments, and is not suitable for subsegmental resection, it can be observed and considered for lobectomy if the nodule continues to grow or some solid components appear.

Patient's physical condition

Lung function is also a factor that needs to be considered when formulating a surgical plan. Some patients have poor lung function and can only undergo segmental or wedge resection, or even cannot undergo surgery. In this case, we can consider radiofrequency ablation and postoperative adjuvant therapy after diagnosis. For multiple lung nodules, more lung tissue needs to be removed, but lung function does not allow it. Some superficial lung nodules can be removed, and deep nodules can be ablated by radiofrequency. These patients need chemotherapy and targeted therapy after surgery.

Doctor's surgical skills

Thoracoscopic surgery is already widely used, with less trauma and faster recovery. The single-port laparoscopic surgery we carry out (Figure 2) is less invasive, and a 3cm small hole can be used to complete various lung surgeries. If you do not master the single-port laparoscopic technique, especially if some doctors even have to open the chest to open the ribs, which is a more traumatic surgical method, surgery on lung nodules can be more conservative, with a longer follow-up time, and surgery can be performed after the diagnosis is confirmed.

Figure 2 Single-port laparoscopic surgery

Hospital conditions and precise nodule location methods

In the treatment of lung nodules, hospital equipment conditions are also very important. In addition to surgical equipment, lung nodule positioning equipment is more important. Because we perform single-port laparoscopic surgery, it is difficult and inaccurate to touch ground glass nodules with fingers. Some parts cannot be reached by fingers, so some equipment methods are needed to accurately locate lung nodules before and during surgery.

Figure 3 Three-dimensional imaging technology

Three-dimensional imaging technology (Figure 3) is the most widely used in clinical practice because it does not require high equipment. All you need is a computer and download the mimics software to locate lung nodules and plan surgery. This is actually integrating thin-layer CT images into three-dimensional graphics, which facilitates more intuitive observation of the anatomical position and the relationship with the bronchi and blood vessels. However, this technology has great limitations in locating lung nodules. CT is a graphic acquired when the lungs are inflated, so the three-dimensional image produced is an image of the lungs when they are inflated. During surgery, our lungs are collapsed and the lungs are much smaller, which is very different from when they are inflated. If the lung nodule is just in the middle of the segment, it is very helpful to perform segmental resection with the help of three-dimensional imaging. However, if the nodule is at the junction of several segments or close to the edge of the segment, the surgery may miss the nodule or cut the nodule into pieces, resulting in recurrence of lung cancer.

Currently, more advanced equipment includes pulmonary nodule navigation systems, including magnetic navigation and more advanced LUNG-pro navigation technology (Figure 4), which can locate nodules deep in the lungs, inject dyes, or place markers for positioning.

Figure 4 Pulmonary nodule navigation system

Mobile CT in the operating room (Figure 5) can make surgery easier. The hybrid operating room of the Affiliated Cancer Hospital of Chongqing University is equipped with mobile CT. After the patient is anesthetized, the surgical position is set and then the positioning needle is used for positioning. The patient is in an anesthetized state, the positioning is more accurate, the patient does not feel fear, and there is no risk.

Figure 5 Mobile CT in the hybrid operating room of Chongqing University Cancer Hospital

When surgically removing lung segments, it is necessary to determine the interface between lung segments. Most hospitals use the expansion-deflation method. However, since some patients have emphysema and cannot collapse the lungs well during surgery, this method is not applicable. The fluorescent laparoscope (Figure 7) of the Affiliated Cancer Hospital of Chongqing University can accurately locate the lung segment interface. When the corresponding pulmonary segment artery is cut off and indocyanine green is injected intravenously, the lung segment to be removed will not show staining. This method is accurate, shortens the operation time, and can perform the most precise surgery.

In summary

Whether to observe or operate on a small lung nodule is not just about the size and whether there is a solid component. It is also necessary to consider various factors based on the individual situation of each patient and strive for an individualized treatment plan. In order to achieve accurate treatment of small lung nodules, all doctors in the Thoracic Tumor Center of the Affiliated Tumor Hospital of Chongqing University use single-port lung nodule surgery. The center is equipped with the most advanced equipment in the world and has the world's leading comprehensive strength. Always escort the health of patients.

Text/Fat Bear Photos/Internet (Please contact us to delete) Review/Chest Tumor Center

Member of China Medical We-Media Alliance

Science Popularization China Co-construction Base

Chongqing Science Popularization Base/Chongqing Health Promotion Hospital

Chongqing Science and Technology Communication and Popularization Project

National Health Commission National Basic Public Health Service Health Literacy Project