Photodynamic Therapy
Photodynamic therapy is a relatively new method of treatment for pre-cancerous and cancerous disease in humans. It has been used in experimental studies over the last decade and recently has been approved by the FDA for treatment of early and advanced lung cancer and also for advanced esophageal cancer. In our center we are also using PDT to treat patients with Barrett’s esophagus and pre-cancerous dysplasia as well as patients with early cancer.
What is PDT and how does it work?
PDT involves the intravenous injection of a light-sensitive drug (Photofrin® or Levulan®.) The drug is distributed to all tissues including lungs, brain, skin, esophagus, etc. In PDT with Photofrin, 48 to 72 hours after the drug has been injected, the physician performs an endoscopy and treats the diseased area of the esophagus using a high intensity, powerful red laser light. In contrast, Levulan (Levulan-PDT, aka ALA-PDT) is given orally and endoscopic laser treatment is carried out within four to six hours. The laser light is delivered through the endoscope using special equipment including sausage-shaped balloons and linear diffuser probes so that the physician can target the exact area of the diseased esophagus for treatment.
The light stimulates the drug, which has been absorbed into the lining of the esophagus, to produce a chemical that destroys the cells. We perform endoscopy again 48 hours after the first light exposure to observe the effect of the initial treatment. If there are any areas that do not fully respond to the treatment, we re-treat the area as needed.
The effect of the treatment is profound. Commonly, there will be destruction of the lining of the treated area of the esophagus. Associated with this will be symptoms, including chest pain which most patients describe as moderate. Some patients become nauseated and experience loss of appetite. Indeed, patients do not eat well because of the marked inflammation in their esophagus. We provide medication for the pain and for nausea.
The treatment is all performed on an outpatient basis. The home health care team will visit the patient at the Fellowship Center and provide intravenous fluids if needed for a day after the treatment in order to help maintain hydration. Typically, patients begin to resume liquids and soft foods such as puddings and mashed potatoes in two to three days, but occasionally a longer time is necessary. After patients are able to drink adequately and achieve enough oral intake to maintain nutrition, they are ready to return home. Usually this is three to five days after treatment with Photofrin®-PDT and two days after Levulan-PDT®. The time will vary from patient to patient.
Photosensitivity
Photosensitivity is an issue that all patients must address. Photofrin® remains in the skin for about one month. The drug is light-sensitive and is in all tissues, including the skin. The patient must be covered up when exposed to direct sunlight during the first month after injection of Photofrin®. Covering should be complete and involve a hat, ski mask, long sleeves, gloves, long pants, dark glasses to protect eyes, and so on. We recommend that our patients begin very brief exposures to direct sunlight immediately after receiving Photofrin® as this will "bleach" the drug from the skin. Indirect sunlight or room light is fine and should not cause any problems. Lights can be on and windows can be open and not shaded. Just do not expose skin to direct sunlight except as mentioned below. Also, avoid sitting in reflected sunlight (such as a mirror or car window) or close to a fire.
Days1-2 (day of Photofrin® injection)
For brief exposure to sunlight, we typically recommend the patient wear shorts and a tee shirt and walk quickly through an area of direct sunlight, for example that beaming in through a window or even a quick 2-3 seconds in direct sunlight, 3-4 times a day.
Days 3-4
If there is no sunburn in two days, we recommend that walking through the sunlight be slowed down to a slower pace. The patient should again do this three to four times a day.
Days 5-7
If there is no sunburn, we suggest increasing the exposures into direct sunlight outside lasting no more than 10-15 seconds, three to four times per day.
Day 6-7
Exposures can be increased to 30 seconds several times a day, gradually increasing the time interval but not to exceed one minute during the first week.
The time intervals can be gradually increased during the second week at home, providing sunburn does not occur. At one month we recommend the patient expose one hand to direct sunlight for 10-15 minutes and if there is no sunburn, the next day the other hand for a longer period up to 20-25 minutes. If the patient has followed these instructions and there is no sunburn, the patient can enter the sunlight without being covered up for periods beginning with 15 minutes and then increasing. It is important to understand that areas unexposed to sunlight (for example, legs) may become hypersensitive to sunburn even two to three months after the drug injection. All areas of skin must be gradually re-exposed to sunlight. To ignore this advice and go directly into sunlight is to invite severe sunburn, even to a point of blistering. We have had several patients ignore this advice, get into a car and drive home into the western sun. They all call the next morning saying they have extreme swelling of the exposed skin, such as hands and face.
For Levulan®-PDT, light sensitivity is much less an issue, since the drug remains in the body for only approximately 48 hours. It is best to remain in a room with reduced lighting during the first 48 hours. For those who must go outside into sunlight, covering the entire skin as described before is essential. The light sensitivity should be gone in 48 hours.
Possible complications
In more than 350 patients treated with Photofrin®-PDT, we have had to hospitalize fewer than a dozen. The treatment for the others has been totally outpatient. We have had no death, stroke or heart attack in our first 350 patients. The major complication seen following Photofrin®-PDT is esophageal stricture, which occurs in 15-20 percent of patients.
The intense inflammation in the esophagus created by PDT heals in some patients as a scar which can narrow and restrict the esophagus, producing difficulty in swallowing. If this occurs, your gastroenterologist will dilate your esophagus using rubber tubes or balloons to stretch the scar. Typically, two to four dilations are required, but occasionally patients with severe stricture require a large number of repeated procedures. In that case, we may ask the patient to return to Knoxville so we can perform the dilations. All patients who have had dilation are swallowing essentially normally.
Esophageal strictures are not a problem with Levulan®-PDT, as the treatment does not produce tissue injury as deep as Photofrin® . Many patients, however, will experience rather intense nausea for six to 12 hours after administration of the drug. Also, hypotension (low blood pressure) occurs after ingestion of Levulan®, sometimes requiring treatment with intravenous medications to correct the hypotension.
If you come to Knoxville for photodynamic therapy, we will try to assist you in arranging living quarters at the Fellowship Center. This center is the result of an outstanding effort by local benefactors to provide pleasant efficiency apartments for patients coming to Knoxville for treatment. The apartments are large enough for the patient and a caregiver or two. The staff is wonderful. More information on the Fellowship Center is available on request. Please call 865-521-6729 to make reservations, subject to space availability.
As you will find out, during your stay here you will become part of our team of excellence. We take pride in you and hope you take pride in us.
If you have any questions about PDT, we will be glad to try to answer them. Contact us at 865-588-5121 (Clinical Coordinator: Karen Abbott, L.P.N.; email: kabbottlpn@aol.com; www.gihealthcare.com).