Photodynamic therapy team adds another first
(May 6, 2005)
In late April, the photodynamic therapy team at the Leo W. Jenkins Cancer Center added to its list of accomplishments by treating a patient with esophageal cancer. A 76-year-old woman became the first patient at the center with that type of cancer to be treated with the therapy that uses a combination of photosensitizing agents and laser light to kill cancerous tumors.
Dr. Gordon Downie, medical director of the PDT program, performed the esophageal cancer treatment with Dr. Stefan Marcuard, a gastroenterologist with Carolina Physicians of Greenville. ECU medical physicists Helvecio Mota and Claudio Sibata also participated.
For patients with esophageal cancer, tumors can make swallowing difficult. In such a case, PDT is a palliative treatment that kills the tumor to ease swallowing.
The Photodynamic Therapy Center at the Leo W. Jenkins Cancer Center, jointly supported by Pitt County Memorial Hospital and the Brody School of Medicine at East Carolina University, began treating patients in 2001. It is one of only a handful of cancer centers in the state using the technology.
"We are the only multi-disciplinary photodynamic therapy program treating multiple organs," said Downie, a pulmonologist and assistant professor of internal medicine at ECU. The center treats patients with tumors in eight sites in the body with lung tumors, breast and chest wall tumors, and skin cancers such as melanoma being the three most frequently receiving photodynamic therapy.
Since April 2001, the program has treated 83 patients and evaluated more than 300 patients. "We end up treating only about one out of every three or four patients," Downie said. "We are very careful and conservative, and we treat patients only when we have proper indications for the therapy."
He explained that PDT can be used either for palliative care or for a cure, but the clinical definition for an attempt for a cure is strict, such as early-stage lung cancer or esophageal cancer patients who cannot have surgery because of other medical reasons.
"If your problematic symptoms are associated with the tumor itself, such as a tumor in the esophagus which is keeping you from swallowing, then PDT will help you. It's a palliative treatment, which means it helps the patient feel better. The goal of our program is to gather enough clinical data that the standard of care for cancer will include PDT as an option for patients," he said.
PDT works this way: Photosensitizing agents are given to the patient and absorbed by cells all over the body, but for unknown reasons they stay longer in the cancer cells. When the treated cancer cells are exposed to laser light of a specific frequency a few days after the injection, the photosensitizing agent, Photofrin, absorbs the light and produces a form of energy that destroys the treated cancer cells.
PDT causes minimal damage to the surrounding healthy tissue and does not interfere with any other treatments the patient may receive.
Photodynamic therapy uses a diode laser, which emits the specific frequency of light needed to kill the tumor but produces no heat to damage the healthy tissue. For patients with lung tumors, a bronchoscope is used to deliver the laser light to the treatment area.
The major side effect that patients encounter is sensitivity to sunlight for weeks after treatment. Because the photosensitizing agents can take up to three months to leave the body, patients must wear long sleeves, broad-brimmed hats and gloves to protect against second-degree burns from the sun.
"Photodynamic therapy is an excellent weapon to use in conjunction with chemotherapy, surgery and radiation. Photodynamic therapy can control local cancerous disease with little or no side effects, which profoundly improves patient pain, ability to perform activities of daily life and overall comfort," said Downie. "Another positive is that with PDT you