1.Conventional two-dimensional radiation therapy for nasopharyngeal cancer: The scope of radiation includes the primary nasopharyngeal foci, the adjacent areas of possible expansion and infiltration, and the nasopharyngeal lymphatic drainage area. The radiation field design and placement should be precise, and isocentric irradiation should be given to the irregular face-neck joint field and the irregular face-neck subfield after reduction of the field through the low melting point lead block, which can better protect the brain, brain stem, spinal cord, crystal and other important tissues and organs, reduce the reaction to radiotherapy and improve the quality of survival. Irradiation dose: nasopharyngeal irradiation dose 66-70Gy/(33-35 times, 6.5-7 weeks); cervical lymph node positive patients are given radical dose 60-70Gy/(30-35 times, 6-7 weeks); cervical lymph node negative patients are given prophylactic dose 50-56Gy/(25-28 times, 5-5.5 weeks).
2.Three-dimensional conformal radiation therapy: It is a radiation technique which can make the spatial dose distribution in the high-dose area consistent with the three-dimensional shape of the target volume, while the surrounding normal tissues and organs are irradiated by the minimum dose.
It can make the shape of the irradiated area fit the shape of the irradiated tumor in three-dimensional direction, and also give different irradiation doses according to the needs of the tumor and the surrounding normal tissues, which can further reduce the dose of irradiation to the normal tissues or organs adjacent to the tumor, which is more conducive to the protection of the normal tissues and organs. This is more conducive to the protection of normal tissues and organs.
4.Proton radiotherapy: Unlike conventional two-dimensional radiotherapy, three-dimensional radiotherapy and intensity-modulated radiotherapy which use X-ray irradiation, proton radiotherapy uses proton beam irradiation, and the energy of proton beam is 70-250MV, which can protect the normal tissues and organs before and after the tumor and reduce the reaction of radiotherapy by using its Bragg peak.
Complications of radiation therapy for nasopharyngeal cancer Complications of radiation therapy for nasopharyngeal cancer include radiation reaction and radiation damage. Radiation reaction is a temporary and recoverable systemic or local reaction under the effect of radiation. Systemic reactions include insomnia, dizziness, weakness, nausea, vomiting, loss of appetite, abnormal taste, etc. Local reactions are mainly acute reactions of skin, oral and nasal mucosa and parotid gland. Radiation damage is irreversible permanent damage to tissues and organs caused by the action of radiation, such as radioactive parotid injury, radioactive otitis media, radioactive mandibular arthritis, radioactive mandibular osteomyelitis, radioactive dental caries, radioactive hypopituitarism, radioactive optic nerve injury, radioactive cerebrospinal cord injury, radioactive neck skin atrophy and muscle fibrosis.