Endobronchial therapies for non–small cell lung cancer
Advanced non–small cell lung cancer may grow and block the large airways of the lungs (the bronchi), causing coughing, problems breathing, bleeding and pain.
Endobronchial therapies are done inside the bronchi to remove a blockage and help with symptoms. They may also be offered if a person with non–small cell lung cancer cannot have surgery or radiation therapy.
Endobronchial therapies are done during a bronchoscopy. A bronchoscopy uses long thin tube with a light on the end, called a bronchoscope. For endobronchial therapies to be effective, the bronchoscope must reach the tumour.
The following are different types of endobronchial therapies used for non–small cell lung cancer.
Bronchial debridement is done to remove as much of a tumour as possible to open up the airway and quickly relieve symptoms. Cutting tools passed through the bronchoscope remove tissue from the bronchi. Sometimes a small tube (stent) needs to be placed in the bronchus to keep the airway open. Bronchial debridement can be repeated if the tumour grows back.
A stent is a small metal or plastic tube that is placed into the bronchus to keep the airway open and allow air into the lungs.
A stent may be left in place permanently or it may be removed if the tumour shrinks with chemotherapy or radiation. If necessary, a larger stent can be placed if the tumour continues to grow and block the airway.
Stents are used when immediate treatment is needed to open an airway.
Laser surgery uses an intense, narrow beam of light (called a laser beam) to destroy cancer cells. The most common type of laser used for non–small cell lung cancer is the Nd:YAG laser. The laser is passed through the bronchoscope to reach the tumour.
Laser surgery is used to quickly remove a blockage that is causing symptoms. It can be repeated if the tumour continues to grow and blocks the airway again.
Electrocautery uses a high-frequency electric current to destroy cells or tissues. It may be used to seal off blood vessels to stop bleeding from a tumour, or to shrink and remove parts of a tumour that is blocking the airways.
Electrocautery does not reach deep tissues. It may be used instead of laser surgery if there are large blood vessels near the tumour.
Photodynamic therapy (PDT)
Photodynamic therapy (PDT) destroys cancer cells with a drug called a photosensitizer, which makes cells very sensitive to light. It may be offered as a treatment for non–small cell lung cancer in some cancer centres in Canada.
PDT is done in 2 stages. First, the photosensitizer drug is injected into the body and is absorbed by all cells. Over time, the photosensitizer leaves most normal cells, but stays in the cancer cells. After about 48 hours, cancer cells containing the photosensitizer are exposed to a low-intensity laser light. The photosensitizer in the cancer cells absorbs the light and a chemical reaction occurs that kills the cancer cells. Most normal cells are not affected.
Special precautions need to be taken because the photosensitizer makes the skin and eyes sensitive to light (known as photosensitivity) for 4–6 weeks or more after the treatment.
PDT is not used to treat blockages causing symptoms that need treatment right away. It is used to treat a tumour that could block an airway as it grows. PDT can be repeated if needed.
Cryosurgery (also called cryotherapy) is a procedure that destroys cancer cells by freezing them. Cryosurgery delivers an extremely cold liquid or gas to the tumour in the lung through a metal tube called a cryoprobe. The area is allowed to thaw and is frozen again. The freeze-thaw cycle may need to be repeated a few times.
Cryosurgery is not used as often as other endobronchial therapies for non–small cell lung cancer because another bronchoscopy is needed to remove the dead tissue.