237.What is radiation therapy?
A survey shows that about 70% of tumor patients need to receive radiation therapy during their whole treatment process. So what is radiation therapy? Radiation therapy is one of the three major means of malignant tumor treatment (surgery/radiotherapy/chemotherapy), which is referred to as “radiotherapy”, commonly known as “baking electricity”. Radiation therapy is a treatment method that applies radiation of different energies to irradiate tumors, and with the help of the penetrating ability of radiation, it destroys the internal components of tumor cells, so as to inhibit or kill them. Since the sufficient dose of radiotherapy only works on the irradiated area, radiotherapy is a “local treatment” like surgery, but different from chemotherapy, which is a “systemic treatment”. Therefore, radiotherapy is mainly used to treat solid malignant tumors, but sometimes it can also be used to treat some benign tumors, such as pituitary tumors and aneurysms.
The development of radiotherapy has a long history, and the first patient was cured by radiotherapy as early as 1899. The distant irradiation such as 3D conformal radiotherapy, intensity modulated conformal radiotherapy, stereotactic radiotherapy X-knife, r-knife, etc., and the brachytherapy such as intracavitary radiotherapy, intraoperative radiotherapy, etc.
238.When should radiotherapy be chosen? Which tumors are mainly applicable for treatment?
Radiotherapy can be used either alone or as a part of comprehensive treatment, together with surgery and chemotherapy, etc. The main modalities include
1. Radiotherapy alone or synchronous radiotherapy: There are many tumors that can be cured by radiotherapy alone or synchronous radiotherapy, for example, early stage Hodgkin’s lymphoma, early stage nasal NK/T-cell lymphoma, orbital lymphoma, mucosa-associated lymphoma, early stage mucosa-associated lymphoma, mucosa-associated lymphoma, mucosa-associated lymphoma. Mucosa-associated lymphoma, early testicular seminoma, early nasopharyngeal carcinoma and head and neck squamous carcinoma, early non-small cell lung cancer, prostate cancer, early cervical cancer, pituitary tumor, etc.; while tumors requiring simultaneous radiotherapy include anal canal cancer, locally advanced non-small cell lung cancer, limited stage small cell lung cancer, locally advanced nasopharyngeal carcinoma and head and neck squamous carcinoma, locally advanced cervical cancer, bladder cancer, etc.
2.Pre-operative radiotherapy or pre-operative synchronous radiotherapy: Many patients with malignant tumors are unable to undergo surgical resection temporarily because their symptoms appear late or they do not care about their physical discomfort until they are seen by a doctor. At this time, preoperative radiotherapy or preoperative simultaneous radiotherapy can shrink or even disappear the tumor of some patients, so that those patients who were inoperable can get the chance to operate again, thus achieving the purpose of tumor treatment and preserving organ function and improving patients’ quality of life. This method is mostly seen in the treatment of locally advanced rectal cancer, esophageal cancer (especially cervical esophageal cancer), gastroesophageal junction cancer (previously called cardia cancer), locally advanced non-small cell lung cancer (especially apical lung cancer), some soft tissue sarcomas, locally advanced squamous carcinoma of the head and neck, etc.
3.Postoperative radiotherapy or postoperative synchronous radiotherapy: The purpose of postoperative radiotherapy or synchronous radiotherapy is, firstly, to eliminate cancer cells that may be latent or planted around the tumor bed after surgery, which are invisible to the naked eye, so as to reduce the chance of their “rekindling”; secondly, for tumors that are not removed cleanly during surgery and remain, postoperative radiotherapy can further Secondly, for tumors that are not removed during surgery, postoperative radiotherapy can further control the growth of residual tumor cells. Postoperative radiotherapy is needed for breast cancer, locally advanced breast cancer, locally advanced esophageal cancer, gastric cancer, rectal cancer, locally advanced non-small cell lung cancer, thymic cancer, soft tissue sarcoma, central nervous system malignant tumor, etc.
4.Intraoperative radiotherapy: irradiate the tumor bed, residual tumor or unresectable tumor during surgery to improve tumor control rate and prolong survival, which is more often used in the treatment of breast cancer and pancreatic cancer.
5.Used sequentially with chemotherapy, there are various combination modes: such as radiotherapy-chemotherapy; chemotherapy-radiotherapy; chemotherapy-radiotherapy-chemotherapy; mainly used for the treatment of malignant lymphoma, small cell lung cancer, etc.
6.Palliative radiotherapy: its purpose is to alleviate the symptoms caused by tumor invasion or compression of surrounding normal tissues and organs, to improve patients’ survival quality and prolong survival period, such as radiotherapy for brain metastasis, bone metastasis, liver metastasis, inoperable pancreatic cancer, etc.
239.What is meant by synchronous radiotherapy?
Combined radiotherapy and chemotherapy is the most common combination mode in clinical treatment of tumor. As the name implies, “synchronous radiotherapy” is to give patients oral or intravenous chemotherapy drugs at the same time of radiotherapy, including synchronous radiotherapy alone, preoperative radiotherapy and postoperative radiotherapy. The purpose is, firstly, to increase the sensitivity of tumor to radiation by applying the radiosensitizing effect of chemotherapeutic drugs, which helps tumor cells to be destroyed more completely. Secondly, chemotherapeutic drugs themselves have the effect of killing potential metastatic cells in remote areas.
Clinical research data from home and abroad confirm that in the treatment of many tumors such as esophageal and gastrointestinal tract tumors, lung cancer, head and neck squamous cancer, cervical cancer, bladder cancer, etc., simultaneous radiotherapy is more effective than radiotherapy alone.
240.Under what circumstances can patients with gastric cancer undergo simultaneous radiotherapy?
Synchronous radiotherapy can be performed if the patient is in good general condition; age is less than 70 years old; blood routine and liver and kidney function are basically normal; no history of allergy to synchronous chemotherapy drugs; no serious underlying diseases, such as uncontrollable diabetes mellitus, recent myocardial infarction, severe arrhythmia, psychiatric disease, etc.; and sufficient daily dietary intake can be guaranteed.
241.What are the commonly used chemotherapeutic drugs in synchronous radiotherapy for gastric cancer? How to administer the drugs?
The commonly used chemotherapeutic drugs in synchronous radiotherapy for gastric cancer are 5-fluorouracil (5Fu) or 5Fu drugs such as capecitabine and tegeo; adriamycin; platinum drugs such as cisplatin and carboplatin; paclitaxel and doxorubicin. The above drugs can be used either alone or in combination. Among them, all of them are administered intravenously, except for capecitabine and tegeo, which are administered orally. Usually, oral drugs are given daily during radiotherapy, and intravenous drugs are given once a week or once every two weeks.
With the rapid development of medical technology, new chemotherapeutic drugs are emerging and different chemotherapy regimens may have different effects when combined with radiation therapy. Radiologists and medical oncologists are constantly working to find the best combination of radiotherapy and chemotherapy. Currently, the 5FU drugs capecitabine and tegeo, with their lower toxic side effects and more convenient oral administration, are gradually replacing 5FU as the main drug for chemotherapy of gastrointestinal tract tumors.
242.What are the side effects of radiotherapy or simultaneous radiotherapy for gastric cancer?
Each patient may experience different degrees of side effects during radiotherapy. Due to individual differences, the severity of side effects varies among patients. There is no need to worry too much, radiotherapists will deal with various side effects before and during the treatment to help and support patients to complete the treatment successfully.
Radiotherapy alone for gastric cancer: Since the target area of radiotherapy only targets the local gastric tumor and its surrounding lymph nodes, the side effects are mainly local upper gastrointestinal reactions or local skin reactions, such as nausea, vomiting, acid reflux, loss of appetite, stomach discomfort, indigestion, difficulty in swallowing, painful swallowing, skin pigmentation and pore expansion in the radiation field area, etc.; while radiotherapy alone has less impact on blood picture and usually does not cause severe The effect of radiotherapy alone on blood picture is less, and usually does not cause serious bone marrow suppression, such as the decrease of white blood cells, platelets and hematocrit.
Simultaneous radiotherapy and chemotherapy for gastric cancer: Adding chemotherapy during radiotherapy will increase the side effects of patients while increasing the efficacy of tumor treatment because of the synergistic effect of the two. In addition to the above mentioned upper gastrointestinal reactions, bone marrow suppression will also be aggravated, and lower gastrointestinal reactions, such as diarrhea and constipation, or abnormal liver and kidney functions, hair loss, etc. may also occur. Capecitabine is commonly used in synchronous radiotherapy for gastric cancer. The incidence of hand-foot syndrome is high, mainly manifested as numbness, dullness, abnormal sensation, pins and needles, skin swelling or erythema, desquamation, blistering or severe pain in the palms or/and soles of the feet.
243.What is gastroesophageal junction cancer? What is the significance of this definition for radiotherapy?
Previously, “gastric cancer” was divided into cardia (fundus) cancer (upper 1/3 of the stomach), gastric body cancer (middle 1/3 of the stomach), and gastric sinus cancer (lower 1/3 of the stomach) according to the location of the tumor. Cardia (fundic) cancer, now known as gastroesophageal junction cancer, is currently defined as a malignant tumor located between 5 cm above the gastroesophageal junction line (lower esophageal portion) and 5 cm below the line (upper 1/3 portion of the stomach). Tumors located in this area have become a separate classification from gastric body and sinus cancer because of their own biological behavior and prognosis. Moreover, the previous term “cardia cancer” has been abandoned and is now collectively referred to as “gastroesophageal junction cancer”.
Therefore, just as different surgical procedures are needed for different tumor sites, the timing and indications for radiotherapy for gastroesophageal junction cancer are different from those for gastric body and sinus cancer. Generally speaking, preoperative radiotherapy/preoperative simultaneous radiotherapy is more effective for gastroesophageal junction cancer, while patients with gastric body and sinus cancer mostly choose postoperative radiotherapy/preoperative simultaneous radiotherapy.
244.For patients with gastroesophageal junction cancer (formerly called “cardia cancer”), under what circumstances should preoperative radiotherapy/preoperative simultaneous radiotherapy be given?
For gastroesophageal junction cancer (formerly called “cardia cancer”), because the tumor grows in the upper third of the stomach or the lowermost part of the esophagus, radiotherapy does not need to irradiate the whole stomach, so the response to radiotherapy is relatively small and well tolerated by patients.
Except for very early lesions limited to the mucosal layer or submucosal layer (i.e. carcinoma in situ or T1), without lymph nodes or distant metastases, endoscopic resection or radiofrequency is recommended, other patients with gastroesophageal junction cancer without distant metastases and without complete obstruction and in fair general condition can be treated with preoperative radiotherapy or preoperative simultaneous radiotherapy first. After radiotherapy, surgeons and diagnostic imaging doctors will consult together and decide whether surgery can be performed next according to the tumor regression. Data from the Department of Radiotherapy of Cancer Hospital of Chinese Academy of Medical Sciences show that preoperative radiotherapy can significantly improve the survival rate of patients. 5-year survival rate can be increased from 20% to 30% and 10-year survival rate from 13% to 20%. In May 2012, data from a study published in a leading foreign medical journal showed that for esophageal or gastroesophageal junction carcinoma, preoperative radiotherapy with carboplatin and vincristine was used to improve survival. In patients with adenocarcinoma, preoperative concurrent radiotherapy increased the predicted 5-year survival rate from 33% to 45%, with a low incidence of serious adverse events.
245.For patients with gastroesophageal junction cancer (formerly called “cardia cancer”), as well as gastric body and sinus cancer, under what circumstances should simultaneous postoperative radiotherapy be performed?
1.In the first case, patients whose tumors are found to be unresectable or cleanly resected during surgery, or who have tumor residues (including visual and microscopic residues) after resection, should routinely undergo postoperative synchronous radiotherapy to control tumor growth or reduce local recurrence rate, so as to relieve symptoms and prolong survival time.
2. Another situation is that, although the tumor is cleanly resected during surgery, the number of lymph nodes cleared (less than 15) or the scope of clearance (no lymph nodes cleared or only the lymph nodes around the stomach cleared) is not enough, and postoperative simultaneous radiotherapy is recommended for these patients.
In the last case, if the surgery is complete, with complete resection of the tumor and complete lymph node dissection, then the decision to receive postoperative concurrent radiotherapy should be based on the postoperative pathology results. Current research evidence shows that patients with postoperative pathology suggesting lymph node metastasis can benefit from postoperative synchronous radiotherapy, especially patients with a high number of metastatic lymph nodes and lymph node envelope invasion.
246.Is radiotherapy feasible for patients with gastric cancer who cannot be operated or have local recurrence after surgery due to contraindications?
Some patients with gastric cancer are unable to undergo surgery due to their advanced age, poor nutritional status, poor cardiopulmonary function, serious underlying diseases or refusal to undergo surgery; and some patients with local recurrence of gastric cancer after surgery may have lost the opportunity for secondary surgery. At this time, radiotherapy can be administered to control tumor growth and relieve local symptoms caused by stomach tumor invasion or compression, such as gastric inlet obstruction, outflow tract obstruction, local pain and bleeding; jaundice caused by bile duct compression by metastatic lymph nodes, ascites or lower limb edema caused by compression of inferior vena cava, etc., so as to improve patients’ quality of life and prolong survival. If the patient’s general condition is good, simultaneous radiotherapy is recommended.
247.How long after the completion of preoperative radiotherapy or preoperative concurrent radiotherapy can surgery be performed?
In general, during the treatment of preoperative radiotherapy/preoperative concurrent radiotherapy, edema will appear at the primary tumor site, therefore, it may appear that the tumor is “enlarged” if the radiograph is taken during or just after the treatment. In addition, patients’ radiotherapy reactions usually do not resolve immediately after the treatment, and some patients’ radiotherapy reactions will worsen within 1-2 weeks after the treatment. Therefore, the patient should rest for 4-6 weeks after the end of radiotherapy, and then have the radiographs reviewed after the tumor edema has subsided, the patient’s radiotherapy reaction has disappeared, and the physical and nutritional status has recovered. Then, the surgeon and diagnostic imaging physician will jointly decide whether the next step can be surgery.
248.What kind of preparations are needed before radiotherapy for gastric cancer patients?
For gastric cancer patients, you need to prepare your mind before radiotherapy, understand the condition, treatment plan, prognosis, possible acute phase reactions and late phase reactions during and after treatment, and how to deal with these adverse reactions, and sign the informed consent form for radiotherapy/chemotherapy.
Given the special dietary requirements of gastric cancer patients, it is recommended that at least one close family member accompany and actively prepare variety and nutritious food to support the patient’s successful completion of treatment. For patients who are prepared for outpatient treatment, it is recommended to stay near the hospital during the treatment period to reduce the physical exertion caused by daily travel; and to minimize the time that patients stay in public places with many people to reduce the chance of infection.
249.Is it true that the radiologist needs a few days of preparation before the actual start of radiotherapy?
Yes. In fact, both the patient and the radiotherapist need to make appropriate preparations before the radiotherapy starts. The doctor first needs to clarify the purpose of treatment, whether it is radical or palliative, depending on each patient’s condition. Then consider how to better combine with surgery and chemotherapy to develop an individualized radiotherapy plan.
For patients undergoing 3D conformal or intensity modulated radiotherapy, the doctor will first explain to you the preparation work before positioning, such as fasting for several hours, when to drink water before positioning and how much water to drink, etc. When you are ready, you will be led to the CT simulator for positioning, making a fixation device (lying down with a thermoplastic body film fastened to the chest and abdomen) and performing CT scan. After the positioning is completed, you can take a few days off to refresh and prepare for the challenge. During these days, the radiotherapy clinician will outline, modify and refine your target area at the localization CT level layer by layer; then the radiotherapy physiotherapist will do the treatment planning, and depending on the difficulty of your plan, the time required by the physiotherapist will vary from one or two days to one week. After the physiotherapist has made the plan, the clinician will need to check and confirm it, and if it does not meet the requirements, the physiotherapist will need to revise or even redo the plan. Once the plan is confirmed, the physician will take you to the CT simulator again for alignment (to verify the center point of the irradiation). Once the alignment is complete, you are ready to begin your first radiation treatment.
The radiotherapy clinicians and physiatrists want to create the best possible radiation treatment plan for each patient in order to obtain the best possible oncologic outcome and minimal side effects, so patience is required before radiation therapy can begin. Every radiotherapist will do his or her best to get the patient started in the shortest possible time.
250.What is the difference between conventional radiotherapy and 3D conformal/intensity modulated conformal radiotherapy?
Conventional radiotherapy is ordinary radiation therapy based on two-dimensional planes, which has a large irradiation field area, uneven dose distribution within the target area, resulting in large damage to normal tissues and greater patient side effects.
With the rapid development of modern application technology, “precision radiotherapy” based on three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated conformal radiotherapy (IMRT) has become the mainstream of tumor radiotherapy at present. “Precision radiotherapy” can be planned in three-dimensional direction according to the specific shape and location of the lesion, and can adopt multi-angle irradiation to obtain the same uniform dose distribution as the shape of the lesion, so as to increase the irradiation dose to the tumor area while minimizing the irradiation dose to the surrounding normal tissues or organs. Therefore, “precision radiotherapy” can largely improve the control rate of tumor radiotherapy and reduce the side effects of radiotherapy, and effectively improve the quality of life of patients while prolonging their survival. Three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated conformal radiotherapy (IMRT) are a revolution in the history of tumor radiotherapy and are the mainstream and direction of current radiotherapy technology.
251.Should patients with gastric cancer choose conventional radiotherapy or 3D conformal radiotherapy or intensity-modulated conformal radiotherapy?
There are several important tissues and organs around the stomach, such as small intestine, kidney, liver, spinal cord, etc. According to the above introduction, it is easy to see that the use of 3D conformal radiotherapy or intensity-modulated conformal radiotherapy can further reduce the adverse effects while improving the tumor control rate. If the patient has to choose between the two, it is recommended to choose intensity-modulated radiotherapy. Of course, the choice of conventional radiotherapy or 3-D conformal radiotherapy or intensity-modulated conformal radiotherapy depends on the patient’s financial situation. Generally speaking, intensity-modulated conformal radiotherapy is the most expensive, conventional radiotherapy is the cheapest, and 3-D conformal radiotherapy costs between the two.
252.How long does radiotherapy for gastric cancer usually take? How much is the dose of radiotherapy?
Unlike chemotherapy, which usually requires multiple courses of treatment, radiotherapy usually requires only one course of treatment. The length of radiotherapy varies according to the patient’s condition and the purpose of treatment. Meanwhile, it should be noted that as long as the patient’s physical condition permits, simultaneous radiotherapy and chemotherapy are recommended.
1.Pre-operative radiotherapy for gastric cancer: total dose 40~45Gy, fractionated dose 1.8~2Gy, five times a week, 4~5 weeks in total.
2.Post-operative radiotherapy for gastric cancer: total dose 45~50Gy, fractionated dose 1.8~2Gy, five times a week, completed in 5~6 weeks. If the tumor remains under the naked eye or microscope after surgery, it is necessary to perform field reduction and replenishment to the total dose of 55-60Gy after 45Gy, which takes 1~2 weeks.
3.Local recurrence radiotherapy after gastric cancer surgery: radiotherapy for postoperative recurrence belongs to palliative radiotherapy, the irradiated field area is relatively small, and the radiotherapy dose can be appropriately increased to a total dose of 50~60Gy, 1.8~2Gy/time, five times a week.
253.What is the effect of weight change during treatment on gastric cancer patients receiving radiotherapy?
For gastric cancer patients receiving radiotherapy, the most direct and common consequence due to adverse effects is the reduction of food intake and weight loss. The loss of weight will have many adverse effects on the treatment, and even lead to the interruption of radiotherapy and ultimately affect the efficacy of cancer treatment. Firstly, the body film used to fix the body position before radiotherapy is thermoformed according to the body shape of each patient before treatment. If the patient “slims down” during the treatment period, and the body membrane can only maintain the initial shape, the effect of fixation of the body membrane will be greatly reduced, and then the target area in the body may be displaced in different directions during each radiotherapy treatment. Secondly, insufficient nutritional intake of the patient will lead to increased bone marrow suppression, in which reduced white blood cells may lead to more serious infections or fever; reduced hematocrit makes the patient fatigued and also reduces the sensitivity of the tumor cells to radiation; decreased platelets may lead to more than one bleeding. Once one or more of the hematologic indicators falls below the threshold approved by the doctor, the radiotherapist will suspend or even terminate the patient’s radiotherapy treatment.
254.Do gastric cancer patients need infusion during radiotherapy?
During radiotherapy for gastric cancer patients, the following conditions require infusion: 1. The synchronous chemotherapy regimen contains drugs that need to be administered intravenously; 2. Patients with severe nausea, vomiting, acid reflux and other symptoms, which are not effective after oral or intramuscular injection of antiemetic and acid-suppressing drugs, need intravenous administration to alleviate the reaction; 3. If necessary, antibiotics should be applied intravenously to relieve the symptoms; 4. Poor feeding and insufficient oral nutrition intake, intravenous nutrition support is needed.
255.How to take care of the diet of gastric cancer patients during radiotherapy?
During radiotherapy, on the one hand, radiotherapy reaction causes patients to eat less, and on the other hand, the human body needs more energy than usual to recover during radiotherapy, so patients should ensure at least 1500 calories of energy intake daily; if the diet is insufficient, intravenous nutritional support is needed by doctors to help patients complete treatment. However, in principle, radiotherapists encourage patients to eat on their own, and will only order an infusion if it is really necessary to supplement nutrition.
The following are some of the experiences and suggestions on diet that radiotherapists have summarized from the clinical treatment period.
1. Encourage small and frequent meals and prohibit smoking and alcohol. It is recommended to have at least 4-5 meals per day, and if possible, additional meals before bedtime.
2, regardless of whether you have an appetite, it is recommended to eat regularly and quantitatively. Do not eat whenever you want to eat, but do not eat if you do not want to eat. Although there is no appetite, or even nausea and vomiting at the sight of food, you should force yourself to eat a small amount.
3, eat more easily digestible food, such as porridge, noodles, highly nutritious soup, etc.. Patients who like pasta should eat hairy noodle food and avoid sticky foods such as dumplings, zongzi and eight-piece rice.
4, encourage more meat, especially beef, oxtail, pork and other “red meat”. After drinking soup, it is recommended to eat the ingredients of the soup together instead of just drinking the soup. Because patients generally have symptoms of oil aversion, broth can be cold after boiling, remove the floating oil and then reheat to eat.
5, avoid eating stimulating, spicy, cold, hard food. The fruits and vegetables, milk or yogurt removed from the refrigerator should be placed at room temperature for a period of time before eating.
6, the diet spectrum is relatively fixed, eat the food they often eat; try to avoid eating in the stalls, street stalls or to taste the food they have never eaten.
7, try to drink more water, can brew chrysanthemum, honeysuckle, American ginseng, wolfberry, maitake, dates, etc. drink. More urination helps to discharge the waste produced by metabolism in the body and reduce the reaction to radiotherapy.
8, can be supplemented with daily multivitamin.
9.Enteral nutrition supplementation. Enteral nutrition contains all the nutrients required by human beings daily, such as protein, fat, sugar, vitamins and minerals, which can be used as the only daily nutrition supply or partial nutrition supplement for patients. It is available in both emulsions and powders. The emulsion can be consumed directly, while the powder is a white powder that can be added to liquid foods such as milk and porridge, or can be taken alone. There are also special enteral nutrition supplements for diabetic patients.
In general, there is no so-called “taboo”, and it is recommended to have a diversified diet.
In short, only to ensure that the patient’s daily energy intake is sufficient to ensure the successful completion of treatment. In this process, the close cooperation and full support of patients and their family members are indispensable.
256.Can gastric cancer patients take Chinese medicine during radiotherapy?
Chinese medicine has many functions such as nourishing qi, raising blood, nourishing yin, increasing appetite and helping digestion, etc., which can relieve patients’ discomfort to a certain extent when taken during radiotherapy. However, the current development of the TCM market is chaotic, and some manufacturers are over-exaggerating the effects of their TCM products in order to chase profits. Therefore, it is recommended that patients who want to take Chinese medicine go to a regular and larger Chinese medicine hospital instead of blindly listening to strangers or small advertisements. It is also important to note that if a patient takes Chinese medicine prescribed in an outside hospital during radiotherapy, he or she must inform the doctor in charge of the radiotherapy department so that he or she will know whether the prescription contains any drug ingredients that may affect radiotherapy, so as not to affect the treatment.