Photodynamic therapy offers new hope for cancer patients
Dr. Ron Allison holds the diode laser used in photodynamic therapy.
(Apr. 3, 2001)
For many years, cancer patients were faced with limited treatment options: surgery, chemotherapy and radiation therapy being the main three. Today, one of the newest cancer treatment options is photodynamic therapy, now available at the Leo W. Jenkins Cancer Center.
The Photodynamic Therapy Center at the cancer center, jointly supported by Pitt County Memorial Hospital and the Brody School of Medicine at East Carolina University, began treating patients Feb. 23. The Greenville center is one of only a handful in the state using the technology.
Photodynamic therapy or PDT, uses a combination of photosensitizing agents and a specific frequency laser light to kill cancerous tumors. The agents are absorbed by cells all over the body but for unknown reasons stay longer in the cancer cells. When the treated cancer cells are exposed to the laser light a few days after the initial injection, the photosensitizing agent, Photofrin, absorbs the light and produces a form of energy that destroys the treated cancer cells.
Physicians at the Brody School of Medicine say they are excited about offering this new cancer treatment to their patients because it minimizes damage to the surrounding healthy tissue and does not interfere with any other treatments the patient may receive.
â€œPhotodynamic 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,â€쳌 said Dr. Gordon Downie, a pulmonologist at the Brody School of Medicine and medical director for the Photodynamic Therapy Center.
One of the first patients receiving photodynamic therapy at the Leo W. Jenkins Cancer Center described the sensation of the laser light on her chest as â€œtingling and itchy, but no pain.â€쳌 Dr. Flora â€œRonnyâ€쳌 VanSant, director of the N.C. Teaching Fellows program at ECU, was treated for a recurrence of chest wall tumors.
VanSant isnâ€™t a new PDT patient. She traveled three times to Roswell Park Cancer Institute in Buffalo, N.Y., to receive the therapy from Dr. Ron Allison, now clinical director of the Department of Radiation Oncology at the Brody School of Medicine. â€œPDT is just a miracle that it causes so little discomfort,â€쳌 she said. VanSant is also pleased that instead of a plane flight she only had to drive across town for her treatment.
Photodynamic therapy employs a diode laser, which emits the specific frequency of red 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 three lasers used in the Photodynamic Therapy Center cost $150,000 total.
The photodynamic therapy program will first focus on patients with airway and esophageal tumors, chest wall tumors, breast cancer tumors, skin cancers such as melanoma and tumors needing surgery to access the treatment site. In the near future, patients with cancer in the ear-nose-throat region or gastrointestinal tract also will be able to have photodynamic therapy.
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.
After her PDT sessions, VanSant was told the treatment area would turn a little red; the tumors would turn black showing the therapy had worked to kill the tumors.
Downie added that photodynamic therapy isnâ€™t a cure for cancer but a way to kill tumors. â€œIf 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. Itâ€™s a palliative treatment, which means it h