Q: What is radiation therapy? A: Radiation therapy, referred to as “radiotherapy”, commonly known as “baking electricity” in the north, the people often confuse radiation therapy with chemotherapy and radiography. Radiotherapy is a discipline that treats malignant tumors (and occasionally benign diseases) with the help of ionizing radiation. The clinical application of radiation therapy has a history of more than 100 years. After the discovery of X-rays by Roentgen in 1895 and the discovery of the natural radioactive element radium by Mr. and Mrs. Curie in 1898, the history of human beings’ use of radiation for the treatment of diseases has begun. After more than 100 years of development, external irradiation technology, which uses medical electronic linear gas pedals to generate radiation for long-distance treatment, and internal irradiation technology, which uses radioactive particles to permanently or temporarily enter the patient’s body to emit radiation for near-distance treatment, have been formed. Q: What is the difference between radiotherapy and chemotherapy? A: When it comes to tumor treatment, doctors will say that radiotherapy and chemotherapy are needed, and common people tend to confuse radiotherapy and chemotherapy, in fact, radiotherapy and chemotherapy are two completely different treatments: radiotherapy is a kind of local treatment, which is to use radiation to kill tumor cells, and it can be used alone or together with surgery to treat local tumors and prevent the recurrence of local tumors. Chemotherapy, on the other hand, is a kind of systemic treatment, which uses chemical drugs to kill tumor cells and prevent the spread of tumor through the blood system after injection and oral administration. Therefore, the relationship between radiotherapy and chemotherapy is the relationship between point and surface, between local and whole. Only by arranging radiotherapy and surgery in a planned and systematic way can the best efficacy of tumor treatment be achieved. Q: Do those tumors need radiotherapy? A: According to the clinical data of western countries, about 60% of tumor patients need radiotherapy. The clinical data in China show that only 28% of tumor patients have received radiotherapy, which is still a big gap with advanced countries. According to the clinical treatment specification, many tumor patients need to receive radiation therapy at certain stages of treatment to cure the tumor, reduce the local recurrence rate of the tumor or relieve the symptoms caused by tumor compression and metastasis. For example, nasopharyngeal cancer must be cured by radiotherapy; early laryngeal cancer and cervical cancer can achieve the same curative effect of surgery by radiotherapy alone; locally advanced rectal cancer can improve the surgical resection rate by preoperative radiotherapy. However, many hospitals do not have radiotherapy departments, and many clinicians do not have knowledge about tumor radiotherapy. Therefore, many tumor patients do not receive radiotherapy advice from relevant doctors. At present, there are treatment specifications for the treatment of malignant tumors, and it is recommended that patients with tumors can consult with the radiotherapy department on their own to see if there are indications for radiotherapy. Q: What are the new radiotherapy techniques in clinic at present? A: In the past 20 years, with the development of computer technology and nuclear industry technology, radiotherapy equipment has developed rapidly. Simulation and localization with CT has become routine, and three-dimensional conformal radiotherapy has also become the basic treatment technology of radiotherapy at present. On this basis, two types of technology have been developed: the first type is intensity-modulated radiation therapy technology: the so-called intensity-modulated technology is to ensure that normal tissues are within the normal tolerance amount under the circumstance of maximizing the radiation dose to the tumor target area. The disadvantage of this technique is the long duration of each treatment. Recently, a kind of rotational intensity-modulation technique has been developed, which can shorten the treatment time under the condition that the efficacy of intensity-modulation technique remains unchanged. The second category is stereotactic radiosurgery, which is often referred to as X (γ)-knife, characterized by a large dose of radiotherapy each time, and a shorter number of days of treatment only 1-5 days. On the basis of the previous treatment technology, image-guided radiation therapy has also been developed, which is a flat-panel CT added to the gas pedal, and a CT image verification is done before each treatment to ensure the accuracy of each radiotherapy (like a radar scanning before the launch of a missile to ensure the hit rate of the missile). In addition, some equipment can be added to control and minimize the impact of breathing movements on the treatment, the so-called respiratory gating technology. This year, the Radiotherapy Department of Shanghai Third People’s Hospital has introduced a whole set of internationally advanced and mainstream radiotherapy systems, which are capable of accomplishing these new radiotherapy techniques. Q: Is the efficacy of the so-called “γ-knife”, proton and heavy ion therapy better than conventional radiotherapy? A: The so-called “γ-knife” and “X-knife” are commonly known in the society nowadays. Compared with the conventional radiotherapy, it is a form of radiotherapy with a high single treatment dose and a small number of treatments (1-5 times). It is suitable for relatively small tumors that can be cured radically. For example, at present, the United States is using this technology to treat early lung cancer, the efficacy of 1-3 years of follow-up is no less than the efficacy of surgical treatment, and now it is still in clinical trials. Foreign countries call this technology as “surgical radiotherapy technology”, which is only a special form and supplement of radiotherapy, and cannot replace conventional radiotherapy. At present, many radiotherapy departments have the ability of this “surgical radiotherapy technology” because there is no mature program of radiotherapy for many tumors. At present, many radiotherapy departments have the ability of this “surgical radiotherapy technique”, because there is no mature program for radiotherapy of many tumors, so the clinical application is relatively small. It is recommended that patients or their family members should consult the radiotherapy department of regular hospitals to choose the type of radiotherapy that is beneficial to them. Another radiotherapy technique developed nowadays does not use photon rays, but protons and other heavy ions as the rays for treatment. Its advantage is that it has good curative effect on some tumors that are not sensitive to photon rays. The disadvantage is that the equipment is very expensive, they are all in the stage of individual trials, the products are not mass-produced, and there is no clinical conclusion on whether the efficacy is better than conventional radiotherapy for most tumors. Q: Are there many side effects of radiotherapy on human body? Will I lose hair after radiotherapy? A: Radiotherapy is a kind of local treatment like surgery, therefore, the side effects of radiotherapy mainly occur in the treated area, and seldom have systemic reaction, but nowadays, the commonly used synchronization of radiotherapy and chemotherapy may lead to more serious systemic reaction. If radiation therapy is used to treat a tumor in the head, alopecia can occur in the irradiated scalp area. However, when irradiating other parts of the body (e.g., the chest), hair loss will never occur. The most common reaction to radiation therapy is radioactive skin damage. If skin peeling with oozing occurs, radiation therapy needs to be suspended. The most dangerous radiation reaction is radiation myelitis. Radiotherapy for head and neck tumors can cause dry mouth and ulceration of the oral mucosa. Radiotherapy for chest tumors can cause radiation pneumonitis, radiation esophagitis, and myocardial injury. The most dangerous complication of radiation therapy for abdominal tumors is radiation small bowel inflammation, which in severe cases can lead to perforation. Common reactions to radiation therapy for pelvic tumors are radiation cystitis and radiation proctitis. Generally speaking: during radiotherapy, there will be radiotherapy reactions in the irradiated area, but the radiotherapist will make a precise treatment plan before the treatment and close observation during the treatment to avoid serious radiotherapy complications.