Washington, D.C. (December 14, 2010) — The manufacturing of semiconductor wafers used in all types of electronics involves etching small features onto a wafer with lasers, a process that is ultimately limited by the wavelength of the light itse…
Surgeons in Philadelphia say they are finding success by combining light-based cancer therapy with surgery to treat patients with advanced lung cancer that has spread within the chest. While the number of patients treated to date is small, many patients are living three to four times longer than did those patients who did not receive the therapy. In photodynamic therapy (PDT), a nontoxic photosensitizing agent, photofrin, is injected into the bloodstream and absorbed by cells all over the body. These compounds tend to concentrate more in cancer cells than in normal cells. When the compound is exposed to a certain wavelength of light, it absorbs the light energy and produces a form of oxygen that kills the cells. The damage occurs only where the light is shined. In the study, each patient is given chemotherapy until the cancer stops responding, meaning the disease begins to grow again. If the cancer has not spread beyond the chest, the patient then receives photofrin 24 hours prior to surgery to remove the tumor. During surgery, he or she receives an appropriate dose of light therapy. Of the 16 patients evaluated to date, at least one-half have lived more than 23 months, which is between three and four times the usual time.