Unlike other needle biopsies, lung needle biopsy is performed only in a small number of centers. This is because of the possibility of complications such as pneumothorax (air leakage between the lung membranes) and bleeding. For this reason, lung biopsy is still not performed in many centers or it is applied as a fine needle biopsy which has a low diagnostic value. In many patients, biopsy is performed by surgical operation.
However, the surgical biopsy is actually a lung surgery and is performed with a large incision under general anesthesia. After surgical biopsy, patients may develop marked pain and operation-related complications. Patients return to their normal life quite late and standart treatments such as chemotherapy and radiotherapy may be delayed. Therefore, trucut needle biopsy should be preferre for lung lesions and surgery for lung biopsy should be performed as a last resort.
In some centers where lung biopsy is performed, fine needle aspiration biopsy (FNAB) is applied instead of a trucut biopsy to reduce the risk of pneumothorax. However, since only clusters of cells instead of tissue fragments are taken in FNAB, the diagnostic value is decreased and histochemical, genetic and receptor analyzes that direct can cancer treatment cannot be performed. Therefore, lung biopsy should not be performed as FNAB unless it is mandatory.
The ideal biopsy method in the lung is trucut needle biopsy. In this method, first an external (coaxial) needle is inserted into the lung under local anesthesia and placed into the mass under CT guidance. Then a thinner trucut needle is advanced through this needle and a large number of pieces are removed from the mass. After a sufficient amount of samples are obtained, both needles are taken out and the procedure is terminated. In experienced hands, the diagnostic value of such a lung biopsy is over 95%.
The most common complications of lung biopsy are bleeding and pneumothorax. During the procedure, a small amount of blood may come out of the mouth and stops spontaneously. Pneumothorax is common in patients with emphysema and may cause severe respiratory distress. The risk of pneumothorax may be increased with the number of passes through the lung membrane and the thickness of the needle. The experience of the operator is one of the most important factors reducing the risk of pneumothorax. If the pneumothorax is mild, does not increase and there is no respiratory distress in the patient, only follow-up is sufficient, otherwise treatment is required. In the treatment, the suction of the air with the needle is first tried, if not enough, a thin catheter is placed and intermittent air aspiration is applied. In cases of persistent pneumothorax, a surgical chest tube may be required.
Although lung biopsy is usually performed under CT guidance, cone beam CT devices, which have become widespread in recent years, are also suitable for lung biopsy. While classical tomography provides only 2-dimensional images, in cone beam CT devices, the needle, lung, and target mass can be displayed simultaneously in three planes perpendicular to each other. In our center, nearly 1800 lung biopsies were performed in the last 6 years with cone beam CT. In only 10% of these biopsies pneumothorax developed, most of which did not require treatment, and in those that required treatment, either a needle or a tiny catheter solved the problem. In only 1% of our patients who underwent biopsy, a chest tube was placed surgically.
Video information: "CT-guided lung and mediastinum biopsies"
As a result, lung needle biopsy is a method with low complication rate and high diagnostic value when applied in high volume and experienced centers. Lung biopsy should be performed with a trucut needle instead of FNAB and surgical biopsy should be considered as a last resort if needle biopsy cannot be performed or proved unsuccessful.
Interventional oncology in cancer management
Prof Saim Yilmaz, MD