What are the indications and contraindications of radiotherapy for nasopharyngeal carcinoma?
Indications of radical radiotherapy: generally, the condition is moderate or above; There was no obvious bone destruction at the skull base; CT or MRI showed no or only mild or moderate infiltration near nasopharynx; The largest diameter of cervical lymph nodes is less than 8cm, which is active and has not yet reached the supraclavicular fossa; No distant organ metastasis.
Indications of palliative radiotherapy: tumor KSP grade above 60; Severe headache with moderate or more bleeding in the nasopharynx; There is a single distant metastasis or cervical lymph node metastasis greater than 10cm. After palliative radiotherapy, if the general condition improves and the symptoms disappear, distant metastasis can be controlled and radical radiotherapy can be changed.
Contraindications to radiotherapy: tumor KSP grade is below 60; Extensive distant metastasis; Patients with acute infection; Radiation-induced brain and spinal cord injuries.
The principle of re-radiotherapy for recurrence after radiotherapy does not apply to the following situations: the recurrence time of the same target area including nasopharyngeal and cervical target area after radiotherapy is less than 1 time; Radiation encephalopathy or radiation myelopathy occurs after radiotherapy; The total course of treatment of nasopharyngeal target area is no more than three courses, and that of cervical target area is no more than two courses.
Selection of radiation
Because the primary focus of nasopharyngeal carcinoma is deep and there are overlapping bones around it, we should choose high-energy radioactive sources such as 60 cobalt or high-energy X-ray of linear accelerator with strong penetration, small skin volume and little absorption. Of these two devices, the accelerator is the best, because it produces a small penumbra, a high and uniform deep dose, little damage to surrounding normal tissues and better curative effect. For the residual tumor after external irradiation, X-ray body cavity tube or afterloading cavity can be used as auxiliary treatment.
Radiation dose and time external irradiation
Although the long-term efficacy of the two methods is similar, the total time of the former is shorter and the reaction after radiotherapy is heavier. The latter takes a long time in radiotherapy, but the reaction after radiotherapy is light.
Radiation field design
The irradiation field of each case needs to include nasopharynx and its adjacent sinus cavity, space, skull base and neck. However, the doses between irradiation fields should not overlap or be ignored. In principle, all parts of the body should be irradiated at the same time. However, if the patient has a headache and a serious nosebleed, he can first use small liquid irradiation to relieve the symptoms, and then conduct comprehensive irradiation.
New technology of radiotherapy in recent years ① Radioactive sources commonly used in intracavitary brachytherapy are 192 iridium, 137 cesium, etc. The biggest advantage of brachytherapy is that it can not only increase the local radiation dose in the target area, but also reduce the radiation damage of the surrounding normal tissues. Brachytherapy is usually used as an auxiliary radiotherapy for external irradiation. In recent years, clinical studies have shown that the local control rate of localized superficial nasopharyngeal lesions is higher than that of conventional external irradiation alone. ② Gamma Knife Therapy Gamma Knife is a three-dimensional stereotactic high-energy focused multi-beam gamma-ray therapy device. After the tumor is accurately located, the tumor can be destroyed at one time by high-dose radiation. Little damage to surrounding normal tissues. Three-dimensional conformal radiotherapy Three-dimensional conformal radiotherapy is one of the most important advances in tumor radiotherapy in recent years, which can distribute radiation dose evenly in the target area according to different tumor shapes. ④ Conformal emphasis on radiotherapy Conformal emphasis on radiotherapy is a brand-new radiotherapy technology developed in recent years. This technology can grant different irradiation doses to different target areas according to the size, morphology and biological behavior characteristics of different tumors, which has unique protection advantages for important organs around tumors.
Complications of radiotherapy
Systemic reactions include fatigue, dizziness, anorexia, nausea, vomiting, tasteless or bad taste in the mouth, insomnia or drowsiness.
chemotherapy
Mainly used in advanced cases. Those who fail to control and relapse after radiotherapy are therefore an adjuvant or palliative treatment. There are three common management modes:
Systemic chemotherapy can be taken orally, intramuscularly or intravenously. Commonly used drugs include nitrogen mustard, cyclophosphamide, 5- fluorouracil, bleomycin and tiapine. A drug can be used alone or in combination.
Half-body chemotherapy is a therapy that compresses the abdominal aorta, temporarily blocks the blood circulation of the lower body, and rapidly injects nitrogen mustard from the upper limb vein. Nitrogen mustard will have an effect after 2 ~ 3 minutes, and the effect can be halved after 15 minutes, which can not only improve the drug concentration in the upper body, but also protect the hematopoietic function of the bone marrow in the lower body.
Contraindications of half-course chemotherapy: patients with hypertension and heart disease; Old, weak and obese; Superior vena cava compression; Cirrhosis and hepatomegaly; Liver and kidney function is seriously damaged; The white blood cell count is less than 3×109/l/l.
Arterial intubation chemotherapy can increase the concentration of drugs in nasopharynx and reduce systemic side effects. Retrograde intubation of superficial temporal artery or facial artery was used to inject anticancer drugs. It has a certain short-term effect on early stage (stage ⅰ and ⅱ) including a single small case of lymph node metastasis in deep upper cervical group, cases involving cranial nerves in late stage, or cases of nasopharyngeal local residue or recurrence after radiotherapy. Commonly used anticancer drugs are 5- fluorouracil, Pingyangmycin, cisplatin and so on.
Combination of radiotherapy and chemotherapy
For advanced nasopharyngeal carcinoma, radiotherapy and chemotherapy can be combined. Literature reports that the effect of combined therapy is obviously better than that of single therapy.
Surgical therapy
Indications are not the main treatment.
Only in a few cases. Indications are as follows: localized nasopharyngeal lesions do not subside or recur after radiotherapy. Cervical lymph node dissection is feasible when the metastatic lymph nodes in the neck do not subside after radiotherapy, and the primary nasopharyngeal lesions are controlled.
Taboo symptom
Skull base bone destruction or parapharyngeal infiltration, brain nerve damage or distant metastasis. General condition is poor or liver and renal insufficiency. There are other contraindications to surgery.
immunotherapy
There are interferon inducers, phytohemagglutinin-tumor vaccines, etc. It is still in the exploration stage.
What are the drug treatments for nasopharyngeal carcinoma?
Radiotherapy is the first choice for nasopharyngeal carcinoma, supplemented by surgery, chemotherapy and conservative treatment with traditional Chinese medicine. The treatment plan of nasopharyngeal carcinoma is mature, and most of them are effective. Ginsenoside RH2 can be supplemented to improve the success rate of treatment and reduce tumor recurrence and metastasis. Chinese medicine and western medicine have their own advantages in treating tumors. In the treatment of nasopharyngeal carcinoma, we should give full play to their respective advantages, adhere to long-term treatment, relax patients' psychological state, do psychological treatment well, increase diet nutrition and improve their autoimmune function.