Endobronchial Ultrasound (EBUS)

Lung cancer, one of the most common cancers both in our country and worldwide, is a disease for which rapid diagnosis in the early stages is crucial for long survival rates. Despite the importance of early diagnosis, many smoking patients often attribute symptoms such as sputum and cough to smoking, leading them to consult a doctor late. Screenings are very important, especially since individuals over the age of 55 who have smoked a pack of cigarettes daily for 20 years are advised to undergo at least one low-dose lung tomography, even if they exhibit no symptoms. This is essential for detecting lung cancer at an early stage and starting treatments without delay. One of the prominent methods used in the diagnosis of lung cancer is endobronchial ultrasound (EBUS)...

Endobronchial Ultrasound in the Diagnosis of Lung Cancer

There are many methods currently used for the diagnosis of lung cancer. The most commonly used method is "flexible bronchoscopy," where a flexible, thin, lighted tube is used to visualize and examine the airways in the lungs, and biopsies are performed. In some patients, biopsies can be done externally, with a needle guided by tomography, while in others, biopsies may be performed under ultrasound guidance. However, the focus of this article is on endobronchial ultrasound (EBUS), which allows for faster diagnosis and is used in some centers in Turkey, although it is not yet widely common.

Why is the Method Used for Diagnosis Important? What are the Differences and Advantages of EBUS?

Deciding which diagnostic method to use among the various techniques available is crucial for the patient. When determining which diagnostic method to choose, the success rate of the method in making a diagnosis and its low complication risk are two important factors. Selecting the most accurate diagnostic method based on the stage of the disease and the general characteristics of the tumor is vital for obtaining a diagnosis in the shortest possible time. Additionally, the experience of the specialist making and performing the decision is another critical point. Minimizing side effects and risks during this process is important to ensure that valuable time is not lost for the patient.

After the diagnosis through bronchoscopy or biopsy with tomography, staging—determining the extent of the cancer—is necessary before starting treatment for lung cancer. Therefore, if endobronchial ultrasound is not available, mediastinoscopy under general anesthesia is performed to sample affected mediastinal lymph nodes related to cancer. Mediastinoscopy is a procedure performed by entering through the neck area to obtain samples from the lymph nodes; however, it is not the first recommended approach due to its complication risks. Furthermore, the complication risks of mediastinoscopy are much higher than those of endobronchial ultrasound, and it can only be performed on a patient once. Repeating the mediastinoscopy procedure is very difficult; however, EBUS can be easily applied to a patient again. From a cost perspective, EBUS is also a more cost-effective method compared to mediastinoscopy. If conditions permit, the first recommended diagnostic and staging method is endobronchial ultrasound. Its important advantages include lower complication risks and the ability to provide diagnosis and staging simultaneously in a single session. For example, if a patient has a tumor on the outer part of the lung, and its size is smaller than 3 cm with no distant metastasis (spread to other organs), the recommended treatment for that patient will be surgical without further diagnostic procedures. However, if the tumor is larger or centrally located, EBUS is recommended. Additionally, for patients with pathological mediastinal lymph nodes detected by lung computed tomography or positron emission tomography/computed tomography (PET/CT), sampling with EBUS is necessary.

How is EBUS Performed?

Endobronchial ultrasound (EBUS) is a imaging method that combines bronchoscopy and ultrasonography, typically performed under general anesthesia for patient comfort. In this method, a small needle extends from the tip of a camera inserted through the mouth to obtain tissue samples. Instead of visualizing the bronchi, EBUS focuses on the mediastinal lymph nodes or sometimes mass lesions to take samples for examination. This method also features Doppler ultrasonography, which allows for imaging not only the lymph nodes but also the nearby blood vessels, preventing damage to vascular structures. While diagnosis and subsequent staging processes using bronchoscopy may take over 30 days, EBUS allows for diagnosis and staging of the disease in just 2 days. In fact, with the rapid on-site examination (ROSE) method, the biopsy results can be known immediately after the procedure is completed.

Who Can Undergo EBUS?

In addition to diagnosing and staging lung cancer, EBUS is also used for diseases affecting the lymph nodes, such as lymphoma and tuberculosis (TB). It is also utilized for biopsies of lung lesions aside from lymph nodes. Furthermore, EBUS is beneficial in investigating metastases related to cancers other than lung cancer and in cases where there is a need for re-biopsy for further genetic examination in patients with advanced lung cancer who have not responded to chemotherapy, as well as in determining recurrences of lung cancer. Of course, it is not appropriate for every patient; its use is not recommended in patients who have had a heart attack in the last four weeks, those with bleeding disorders, patients experiencing respiratory failure, or those on long-term oxygen support.

The pulmonary diseases specialty responsible for diagnosing lung cancer hands over the treatment process to medical oncology, radiation oncology, and surgical specialties. At Anadolu Health Center, patients are assessed in multidisciplinary tumor boards in accordance with international standards, taking a collaborative approach from all relevant specialties. Surgical treatments are generally applied to lung cancer patients up to stage 3, while radiation oncology treatments may be administered if there are accompanying conditions. After chemotherapy is administered to stage 3 patients, they are then evaluated for surgical candidacy. For stage 4 cancer patients, all these options can be combined with treatment (chemotherapy and/or radiotherapy).

How Long Does EBUS Take?

The duration of EBUS varies depending on whether the procedure is performed under general or local anesthesia. However, it typically lasts about 20-30 minutes, and patients can go home on the same day after the procedure is completed.

One in every ten smokers develops lung cancer. However, even more striking is the fact that one in every two smokers dies from smoking-related diseases. Unfortunately, cancers such as laryngeal, esophageal, stomach, and bladder cancer, as well as cardiovascular diseases, are on the rise due to smoking. Therefore, we recommend that all smokers quit smoking.

According to a recent study, while the incidence of lung cancer has decreased somewhat among men in recent years, it has increased among women due to rising smoking rates.

Lung cancer is the most commonly diagnosed cancer type among men and the second most common type after breast cancer among women.