An advanced cancer treatment known as photodynamic therapy (PDT) has been found to be efficient in extending the lives of terminal lung cancer patients, said a surgeon at the Taipei-based Shin Kong Wu Ho-Su Memorial Hospital Wednesday. The hospital, which purchased the PDT technology from a U.S. group in 2006, said that since then, 11 terminal lung cancer patients have received the treatment, said Hsieh Yei-san, chief of the Thoracic Surgery Department. Five of the patients are still alive, one of whom has survived since undergoing the therapy in November 2006, Hsieh said. 'Compared with chemotherapy and targeted therapy, PDT can extend patients' life by two times on average,' he said. Hsieh explained that lung cancer cells grow quickly. Many lung cancer patients are already in the terminal stage upon initial diagnosis and can only be prescribed the traditional treatments of chemotherapy or radiation therapy, he said. Those treatments, however, have only limited efficiency in extending the lives of patients, Hsieh said, citing statistics showing the five-year survival rate of such patients is only 20 percent to 30 percent. 'Even with targeted therapy, life can only be extended for an additional three months on average,' he added. Noting that 30 percent of terminal lung cancer patients will develop the complication of fluid in the pleura, Hsieh stated that in such cases, patients can suffer from breathing difficulties and some will also develop rejection against chemo and targeted therapies. Once the cancer spreads, the average survival rate will be reduced to between six and nine months, he said. PDT is a treatment that uses light-sensitive medication (sometimes called a photosensitizing agent) together with a particular type of light to destroy cancer cells. The therapy enables surgeons to kill cancer cells that other kinds of surgical operations cannot achieve, Hsieh said. In Taiwan, a PDT procedure costs about NT$500,000 (US$15,600) , according to Hsieh. 