Revolutionary laser procedure treats early vocal cord cancer without harming healthy tissue
March 14, 2018
Laryngeal surgeon Semirra Bayan, MD, assistant professor of surgery at the University of Chicago Medicine, is an expert in using an innovative potassium titanyl phosphate (KTP) laser procedure to treat early vocal cord cancers. Here, Dr. Bayan expounds upon what the KTP laser procedure entails, why it can be superior to traditional treatments, and which patients are eligible for care.
Question: Why is traditional radiation treatment of vocal cord cancer problematic?
Dr. Semirra Bayan: The vocal cords are made up of several layers: epithelium (cover of the vocal cord), superficial lamina propria (“jelly” of the vocal cord made up of collagen and elastin), and muscle. The superficial lamina propria (SLP) is an important part of your vocal cords, helping them vibrate to make sound.
Early vocal cord cancers (cancers confined to the superficial aspects of the true and false vocal cords) have traditionally been treated with radiation therapy. Radiation therapy, while incredibly effective, treats both the diseased and non-diseased parts of the vocal cords and surrounding structures (including the esophagus). That means it can impact tissue that is healthy and can destroy or scar the SLP in parts of the vocal cords not involved with cancer. Patients can also develop swallowing issues years after their radiation therapy as a result. Radiation treatment is also something that can only be used once in a part of the body, meaning it often cannot be repeated if additional cancers arise in that area.
Q: At UChicago Medicine, physicians are using a KTP laser to treat vocal cord cancer. How is this treatment different from traditional radiation?
SB: Cancer growth is highly dependent on new blood vessels to help it grow and survive, a process called angiogenesis. KTP laser is also known as a “photoangiolytic” laser, meaning it targets the blood vessels of the cancer while preserving the underlying healthy tissue underneath the cancer. Under a microscope, ultranarrow margins are obtained as the laser gradually removes the cancer layer by layer until healthy tissue is reached. This allows for maximum preservation of normal healthy vocal cord tissue.
As early as 2005, Dr. Steven Zeitels at Massachusetts General Hospital started using the KTP laser to treat these early vocal cord cancers. Not every cancer surgeon or laryngologist uses this method of treatment. However, specialists at UChicago Medicine have used the KTP laser to treat early vocal cord cancers since 2016.
Q: How effective is the treatment? Are there any side effects for patients?
SB: KTP laser treatment is as effective as radiation therapy in treating early vocal cord cancers. There are no additional side effects following the surgery. The benefit is that you preserve all of the soft, healthy tissue not involved with cancer and do not have the same issues with swallowing that you can see in patients who have had radiation.
If additional concerning spots on the vocal cord arise, the laser procedure can always be repeated, unlike radiation therapy which can only be used once. Some patients can develop precancerous lesions on their vocal cords in addition to cancer. These precancerous lesions can be addressed with the laser as well and, if small enough, can be done under local anesthetic without the need for general anesthesia.
Q: What does the procedure entail?
SB: The procedure involves putting the patient to sleep under general anesthesia. A metal laryngoscope is placed in the throat to help visualize the vocal cords. The entire procedure is done under a microscope and through the mouth. It does not require any incisions on the neck to be completed.
The surgery is outpatient and patients can eat right after the procedure. They will be put on a soft diet for up to two weeks and will need to avoid “reflux” foods (no greasy, spicy, citrus, or caffeine). Sometimes, a period of voice rest is required after surgery. Depending on how extensive the cancer is, a patient may require additional surgery six to eight weeks after the first one to completely remove all of the cancer.
After the procedure, patients will be followed closely for one year to make sure the vocal cords are healing appropriately and no new cancers arise. After the first year, patients will still need to come in for surveillance but the follow-up period will gradually increase from every three months to yearly after five years of observation.
Q: What types of patients would you recommend for this treatment?
SB: This treatment is for patients who are healthy enough to tolerate a general anesthesia procedure and have an early vocal cord cancer (T1 or T2) or precancers/dysplasia confined to the superficial parts of the vocal cord or false vocal cords.