Photodynamic Therapy

What is Photodynamic Therapy?

Photodynamic therapy (PDT) is a therapy that is used to treat advanced esophageal cancer, Barrett’s esophagus with high-grade dysplasia and some forms of lung cancer. For the purpose of this article, we will focus on use of PDT in gastroenterology. This therapy involves an intravenous injection of a photosensitizing agent, called Photofrin (porfirmer sodium). Photofrin selectively accumulates in cancer or dysplastic cells in higher concentration than in normal tissue. The next part of the therapy includes the use of a low-power laser light to activate the drug. This photochemical reaction results in tumor necrosis of the cancerous or dysplastic tissue.

PDT Schedule

Patients usually require three appointments over the course of one week in order to complete this therapy. At Johns Hopkins Hospital (JHH), we schedule our patients on Monday, Wednesday and Friday. Other hospitals may use different schedules. At JHH the Photofrin is given on a Monday morning. Light activation is performed when the drug is at its peak effect (between 40-50 hours after injection), therefore we schedule our patients on Wednesday for an upper endoscopy (EGD) with light activation. Friday, the patient returns for a follow-up exam to assess the effectiveness of Wednesday’s treatment. Patients being treated for advanced esophageal cancer will have an EGD with clean up or debridement of the tumor, and then a second light-dose application can be administered. On Friday, the drug level has begun to decrease but is still high enough.

Education

Education of the patient and family is a critical part of this therapy and an important role of the nurse. The education process begins long before the patient arrives to receive the drug and continues during and after the treatment. Once the patient has been seen and evaluated for PDT by his/her gastroenterologist, they are given written educational materials as well as a video tape. After the patient has reviewed these educational materials a telephone appointment with a nurse is scheduled. This is a very important part of the PDT process. This phone counseling session is done with the patient and usually with a family member or significant other on the phone at the same time. This counseling session can take from 30-60 minutes or more depending on how much that patient knows about the treatment. Some patients have already looked on the Internet and have a basic understanding of what’s involved, and others have no idea what this therapy is about. The nurse begins by teaching the patient how the drug destroys cancerous or pre-cancerous cells. Then in detail the nurse reviews and instructs patients on photosensitivity, diet, pain management and the ongoing follow-up care that will be necessary.

Photosensitivity

The first issue we discuss with the patient is this: Not only does the drug accumulate in dysplastic or cancerous cells, it is in normal tissues as well and there is a systemic affect. This means that if the patient is exposed to sunlight they can develop a photosensitivity reaction or in other words “sunburn.” It can range from a very mild to serious reaction. The goal during this therapy is that the patient does not experience any photosensivity reactions. This can be achieved if they adhere to all of the instructions we give them, including those on photobleaching. Reactions can happen with sunlight as well as some indoor lighting. It is also important for patients to avoid any dental lights, exam lights (such as in an operating room) as well as the bouffant-style hairdryers, because of the intense heat and light they give off.

The nurse reviews in detail the proper attire the patient will need. This includes a wide-brim hat, face mask or scarf, sunglasses, gloves, long sleeves and long pants. When the patient arrives for the injection of the drug on Monday, the patient must have the proper attire with them. If the patient arrives for injection and does not have proper attire and the nurse cannot locate proper attire, the injection should not occur. The patient’s eyes and all of their skin must be covered and protected when the patient goes outside. It is important to inform patients that the use of sunscreen will not prevent sunburn. During the first two to three weeks the drug levels are at their highest and we recommend that the patient not go outside except to go to treatment appointments for the first couple of weeks after injection of the drug. It is, however, safe to go outdoors after the sun has completely set. This time could vary greatly depending on the time of year.

Photosensitivity reactions that happen during this time period are almost always from inadvertent, accidental exposure. This is also the time when reactions are the most severe.

Indoor precautions should also be reviewed, making sure that the patient does not hibernate in complete darkness. Patients should be exposed to ambient background lighting in the home. They should have the shades and blinds drawn and not be in direct sunlight during the first two-and-a-half weeks after the injection. Patients should also be careful not to sit next to a reading lamp for an extended period unless they are protected with clothing. Walking by an uncovered window quickly and occasionally is not a problem.

Photobleaching

After the first two to three weeks we instruct the patient to begin what is called the “photo bleaching process.” This involves beginning to expose the skin and eyes to indirect sources of light. We instruct the patient to open the blinds and curtains and to walk around the house in shorts and a short-sleeve shirt. They should sit in a room with light coming in but not directly in front of the window. The key to this process is a gradual exposure to the light. It is crucial that patients and families understand the importance of photobleaching. This gradual re-exposure to light is critical in order to decrease the chance of having a photosensitivity reaction. On day 31 after the Photofrin injection, patients are instructed to cut a hole in a paper bag, about the size of a quarter, place a hand in the bag, and expose the hand to direct sunlight for five minutes. The next day they should observe the hand and if there is no redness they should repeat the test on the opposite hand for 15 minutes. Again, check the next day for signs of reaction and if there is no reaction then the process of photobleaching continues outside. At this point they are encouraged to gradually expose themselves to the light outside. We instruct them to begin to go outside without protective clothing or sunglasses for 15 minutes early in the morning and then repeat this for 15 minutes in late afternoon. If they don’t have a photosensitivity reaction, then each day they should double the time until they are eventually out during the peak sun hours. They should be instructed and reminded that they should not go out uncovered during peak sun hours uncovered until they have built up the time they are outside. The key to photobleaching is gradual re-exposure of the skin to light. This process can take up to three months, however for most patients it takes four to six weeks.

Diet Instructions

An inflammatory process occurs as a result of the photochemical reaction; most patients gradually begin to experience degrees of dysphagia and chest pain. The lumen of the esophagus becomes narrowed from the inflammatory process which is what gives them the symptoms of dysphagia. Part of the education for these patients is providing them with a “shopping list” of the kinds of foods to have on hand during this time. We encourage them to eat soft foods and to chew their foods thoroughly and carefully. The dysphagia improves as the inflammation goes down and we instruct them to gradually resume a normal diet as their swallowing allows. Fluids should be encouraged to prevent dehydration during the initial phase of treatment.

Pain Management

The pain that these patients experience is extremely variable. Some patients have relatively no pain at all, others report mild to severe discomfort. Therefore some patients require no analgesics and others require a large amount of narcotics in order to control their discomfort. This is highly individualized, and all patients should receive the medications necessary to relieve their particular pain. At JHH, patients leave after the Wednesday treatment with three prescriptions for pain medications. Some patients do not have prescription coverage and have to pay out-of-pocket for drugs and some may not end up needing them. Thus, we encourage them to fill the prescriptions as needed. The first medicine we encourage them to use is Larry’s solution. This is a mixture of Maalox, Benadryl and lidocaine in an elixir form. We instruct patients who are experiencing pain to take a dose about 30 minutes before they try to eat food. This solution numbs and soothes the esophagus and it also decreases the pain or discomfort while patients are eating and drinking. This drug is prescribed to be used every four hours as needed but not more often, due to the Lidocaine. For some patients this is the only medication they use. If they have pain that happens between meals we next suggest that they use Lortab elixir which can be taken every three to four hours. We suggest they alternate this with Larry’s solution to give them something to use every two hours if needed. If they have severe pain they are given a prescription for Oxycontin to use every 12 hours as needed.

Other Possible Complications

Approximately three percent of patients who undergo PDT develop atrial fibrillation. This is usually self limiting and resolves when the inflammation goes away. A stricture after PDT can also occur. This is usually most problematic to the patient. As the esophageal tissue heals some scar tissue develops, and if this is bad enough an esophageal stricture can develop. Most patients who develop this respond well to esophageal dilation and some require injection of steroids into the stricture.

Follow-up Care

Patients generally need close follow up and open lines of communication with a nurse and/or physician during their recovery period. They frequently have questions that arise and they must be able to reach someone so that they can get the answers to their questions.

Patients see the gastroenterologist in a clinic or office one month post treatment. This may vary depending on what the indication is for the treatment and other co-morbidities the patient may have. At JHH, if we are treating for Barrett’s esophagus then patients will return every three months for at least a year for surveillance biopsies. If they are being treated for cancer this will depend on how they are doing and when the gastroenterologist would like to see them again.

In summary, PDT is an effective palliative treatment for those with advanced esophageal cancer. It is also FDA-approved for use in patients who have Barrett’s esophagus with high-grade dysplasia. It is important for patients to know that this is not just a simple procedure that you have and then go back to work in a week. There is a level of commitment on the patient’s part to be compliant with all aspects of this treatment. This requires very detailed education for the patient and the family, and requires the nurse to be available to support the patient before, during and after treatment. On a personal note, I found this specialty to be the most rewarding nursing job I have ever had. If provided the opportunity to care for this group of patients again, I would do so.

Christine L. Smith, RN, MSN, CGRN, is nurse manager of endoscopy at Johns Hopkins Hospital, inpatient and outpatient units. She has been a nurse for 26 years, worked in endoscopy for 15 years and has been a nurse manager for two years.

Lori Wroblewski, RN, CGRN, is a nurse clinician III in the endoscopy division of gastroenterology at Johns Hopkins Hospital.