The statistics from the World Health Organization indicate that among all cancer patients, 45% can achieve clinical remission. Among them, 22% are cured by surgery, 18% are cured by radiotherapy, and an additional 5% rely on chemotherapy for their cure. Thus, patients cured by radiotherapy account for 40% of all those who are cured. Meanwhile, 70% of all cancer patients require radiotherapy. For example, nasopharyngeal cancer is one of the most common cancers in Guangdong.