Photodynamic therapy
Photodynamic therapy (PDT) often is used to treat inoperable lung cancer. Photodynamic therapy involves the injection of a light-activated drug (e.g., photofrin/polyhaematoporphyrin, lumin). Then, during bronchoscopy (examination of the airways using a flexible scope), the lung tumor is illuminated by a laser fiber that transmits light of a specific wavelength. At that time, the laser light is used to destroy the sensitized tumor tissue. Skin photosensitivity (light sensitivity) is a side effect of PDT.
The curative potential of PDT is the most exciting aspect of this therapy in lung cancer patients whose tumors are occult (hidden, unseen) on chest x-ray. The tissue-sparing effects of PDT may be particularly important for patients who have limited lung function.
Electrosurgery is surgery performed using a needle, bulb, or disk electrode. Nd-YAG laser therapy (neodymium-yttrium/argon laser that concentrates high-energy electromagnetic radiation to destroy tissue), cryotherapy (destruction of tissue using extreme cold), and brachytherapy (treatment with ionizing radiation) are additional tumor debulking, or size-reducing, techniques that may be performed during bronchoscopy. These methods are especially useful for obstructive, inner cavity (intraluminal) lung tumors.
Radiotherapy, also known as radiation therapy, is a treatment method that uses high-energy, ionizing radiation (e.g., gamma rays) to kill cancer cells. Ionizing radiation is produced by a number of radioactive substances, such as cobalt (60Co), radium (228Ra), iodine (131I), radon (221Rn), cesium (137Cs), phosphorus (32P), gold (198Au), iridium (192Ir), and yttrium (90Y). Radiotherapy may be applied to shrink a tumor that is later removed by surgery, to relieve symptoms, or to destroy malignant cells in a tumor that cannot be removed surgically.
Because cancer cells usually multiply faster than most normal body tissues, they are especially affected by radiation, which prevents cell division and the formation of DNA (deoxyribonucleic acid; human genetic material). Other bodily tissues that divide rapidly, such as hair and skin, are also particularly vulnerable to radiotherapy.
Side effects of radiotherapy include hair loss and skin disorders, such as erythema (skin redness due to blood vessel congestion), itching (puritis), desquamation (sloughing-off of outer skin layers), pain, shrinking (atrophy), increased pigmentation, and swelling (edema).
Radiation also can cause the following:
- Anorexia (loss of appetite)
- Changes in taste perception
- Damage to the fetus (in women who are pregnant)
- Increased heart rate (tachycardia)
- Increased risk for infection
- Malaise
- Nausea
- Vomiting
Radiosurgery, also called stereotactic radiosurgery or radiation surgery, is a type of external radiation therapy that may be used to treat inoperable lung cancer. In this treatment, a single large dose of radiation is administered precisely to the tumor, causing little damage to healthy tissue. In spite of its name, stereotactic radiosurgery is not a surgical procedure. The CyberKnife® System is a type of radiosurgery that may be used in patients who have lung cancer.
Physician-developed and -monitored.
Original Date of Publication: 15 Aug 1999
Reviewed by: Stanley J. Swierzewski, III, M.D.
Last Reviewed: 04 Dec 2007
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