Currently, the effective radical treatment for nasopharyngeal cancer is radiation therapy or radiotherapy-based comprehensive treatment. With the update of radiotherapy equipment and continuous improvement of radiotherapy techniques, especially the precise radiotherapy techniques such as intensity modulated conformal radiotherapy and image guided radiotherapy techniques have been applied in clinical practice, the survival rate of patients has been significantly improved. However, while radiation therapy cures tumors, it inevitably damages normal tissues and organs, which seriously affects patients’ quality of life. There are many complications due to large irradiation volume and long radiotherapy course during radiotherapy for nasopharyngeal cancer. In order to improve patients’ quality of life and reduce or mitigate the late damage of radiotherapy, timely and correct treatment of complications in radiotherapy and guidance of functional exercise after radiotherapy are more important. The following is a summary of radiotherapy complications and prevention measures for nasopharyngeal cancer.
1 Hearing loss and deafness
1.1 Clinical manifestations
While improving the symptoms of ear blockage, tinnitus and hearing loss caused by tumor compression, radiation therapy for nasopharyngeal cancer can also cause radioactive otitis media and middle ear effusion. The damage is more serious especially when re-irradiated. Early clinical manifestations are mainly ear pain, ear stuffiness and ear canal leakage, and in case of combined infection, pus flow, tinnitus, balance disorder and abnormal sensitivity to noise. After several months to several years of radiation, with the progressive degeneration and fibrosis of blood vessels and connective tissues, it may lead to perforation of the tympanic membrane, adhesion atresia of the ear canal, gradual necrosis of cochlear hair cells and sclerosis of the auditory tuberosity, so the late clinical manifestations are sensorineural, conductive or mixed deafness. According to the literature, the incidence of deafness can reach 55% 2 years after radical radiotherapy for nasopharyngeal cancer.
The incidence of deafness can reach 55% 2 years after radical radiotherapy for nasopharyngeal carcinoma.
1.2 Prevention and treatment measures
First, minimize the dose of irradiation to the ear. Second, when the eardrum is overflowed by radioactive otitis media penetration, keep the drainage open, avoid entering dirty water and dirty materials, and use antibacterial type ear drops early. Third, rinse the external ear canal with 3% hydrogen peroxide to keep it locally clean, remembering that the pressure should not be too high. Fourth, do not dig the ear canal by yourself to reduce exogenous infection of the middle ear. Fifth, use 1% ephedrine nasal drops and insist on daily rinsing of the nasopharyngeal cavity during or after radiotherapy to remove nasopharyngeal secretions and reduce obstruction of the eustachian tube. Sixth, timely treatment of acute and chronic inflammation of the nasopharynx to avoid papillary infection caused by bacteria through the open eustachian tube. Seventh, keep the outer ear clean, block the outer ear canal with sterile cotton balls when bathing or swimming, strengthen your own exercise, pay attention to keeping warm, prevent colds and reduce the chance of infection.
2 Radiation cremasteropathy
2.1 Clinical manifestations
It mostly appears within 1 to 3 years after radiotherapy. In mild cases, it manifests as a feeling of electric shock or numbness radiating from the neck to the extremities when lowering the head or lifting the legs, and in severe cases, it can develop from the bottom upward, from sensory disorder to motor disorder, leading to limb paralysis.
2.2 Preventive and treatment measures
First, try to use new radiotherapy techniques, such as intensity-modulated conformal radiotherapy, to reduce the amount of irradiation to the crestal pulp. Second, it usually lasts for 4-6 months and can disappear on its own. Third, the treatment of radioactive crestal pulp injury is routinely based on steroid therapy, supplemented with dehydration (mannitol) and vitamin therapy. Fourth, Chinese medicine is used to activate blood stasis, activate the meridians and nourish the liver and kidney.
3 Nasal adhesions, atrophic rhinitis
3.1 Clinical manifestations
Mucous membrane congestion, swelling, decay and bleeding and white film formation after nasal cavity and sinus irradiation cause the nasal turbinates and nasal septum to tightly adhere, plus the nasal passages are filled with mucous-purulent or pus-blood secretions, resulting in sinus mouth obstruction, which leads to post-radiation complications such as nasal adhesions, nostril atresia, sinusitis and atrophic rhinitis. The cumulative incidence of nasal adhesions and sinusitis after radiotherapy for nasopharyngeal cancer for one and a half years is about 30% and 90%. The clinical manifestations are persistent nasal congestion with runny nose and reduced or lost sense of smell after radiotherapy. Although nasal adhesions after radiotherapy do not directly affect their prognosis, they significantly reduce their survival quality, and symptoms such as open mouth whistling, dizziness, mental depression, insomnia and fatigue occur.
3.2 Preventive and curative measures
First, insist on rinsing the nasopharyngeal cavity with 0.3% hydrogen peroxide and saline alternately twice a day during and after radiotherapy. Secondly, use vasoconstrictor drops to improve nasal drainage.
4 Radiation oral dryness
4.1 Clinical manifestations
After radical radiotherapy of nasopharyngeal cancer, salivary glands (including parotid gland, submandibular gland, sublingual gland, oral cavity and small salivary glands of oropharynx) are damaged to different degrees, salivary secretion is significantly reduced and becomes sticky, patients complain of persistent dry mouth, sometimes producing burning sensation and loss of taste sensation.
4.2 Preventive and curative measures
First, use new radiotherapy techniques to reduce the volume and dose of salivary gland irradiation.
The parotid gland secretion index can be restored to 95.2% of the original level 2 years after the study of Wu Liuqing and Wang Bojun. Secondly, when salivary secretion is reduced, the oral cavity is easily infected, so it is especially important to pay attention to oral hygiene, insist on rinsing the mouth 6-8 times a day, and use fluoride toothpaste to brush the teeth. Third, smoking and drinking will aggravate the symptoms of dry mouth, so patients should quit smoking and drinking. Fourth, you can usually chew gum, contain American ginseng, hawthorn, etc. to stimulate saliva secretion. Fifth, use Chinese herbal medicines such as honeysuckle, chrysanthemum and maitong to drink water to alleviate the symptoms of dry mouth and throat and use herbal medicines to invigorate blood circulation, nourish yin and promote fluid production. Sixth, try to avoid drinks that are too sweet or contain caffeine, such as cola. Seventh, you can take small sips of soup or water instead of saliva during meals to help swallowing. You can choose some soft, fine and easy to swallow snacks, such as pudding, jelly, steamed eggs, etc. Eighth, the combined use of protective agent amphotericin treatment during radiotherapy can obviously reduce the damage of salivary gland parenchyma caused by radiotherapy and improve the quality of life of patients.
5 Radiation caries
5.1 Clinical manifestations
The decrease of salivary secretion after radiotherapy reduces the self-cleaning function of the oral cavity and increases the number of bacteria, which leads to the occurrence of dental caries. It is reported that the incidence of radioactive caries after radiotherapy for nasopharyngeal cancer is 49.2%, and the longer the time after radiotherapy, the greater the chance of radioactive caries.
5.2 Prevention and treatment measures
Firstly, before radiotherapy, teeth must be cleaned, carious teeth must be repaired, diseased teeth must be extracted, including residual teeth, dead pulp teeth, partially blocked or incomplete teeth, and various oral diseases, such as periodontitis and gingivitis, should be treated as much as possible. Tooth extraction before radiotherapy should allow a certain period of healing of the tooth bed, generally about 1 week after tooth extraction is appropriate for radiotherapy. The literature reports that the incidence of radioactive caries in patients who had oral treatment before radiotherapy was 17.2%-48.7%, which was significantly lower than those who did not have oral treatment (88%). Secondly, it is necessary to maintain good oral hygiene habits during and after radiotherapy, and insist on rinsing the mouth at least 6-8 times a day to remove food residues. Gargling agent can be Dobelle solution, chlorhexidine solution, 5% sodium bicarbonate solution or saline gargle. Third, brush your teeth with fluoride toothpaste in the morning and evening. Fluorine can promote the remineralization of teeth, improve the hardness of dental tissues and resist acid erosion, increase the anti-disease function of teeth, and has significant effect on the prevention of radioactive caries. Zhang Yanqun and Yuan Ping reported that because the salivary gland destruction caused by radiotherapy is mostly irreversible, dry mouth often persists, therefore, patients with head and neck tumors receiving radiotherapy need to adopt caries prevention measures for life. Fourthly, pay attention to the reasonable nutrition structure, eat less sugar sweet food, avoid spicy food, quit smoking and alcohol.
6 Radiation osteomyelitis (radiation osteonecrosis of the jaw)
6.1 Clinical manifestations
After a certain amount of irradiation of the jaw bone, it can cause inflammatory reaction of the internal artery of the jaw bone, swelling of the endothelium, vascular embolism, and fibrous change of the periosteum, resulting in local blood supply and nutrition disorders, reduced bone vitality, and easy to occur aseptic radiation osteonecrosis. More than 90% of radiation osteonecrosis occurs in the mandible because it has higher bone density and less vascular supply. It usually occurs 2 to 3 years after radiotherapy. Initially, there is persistent stabbing pain or severe pain, swollen gums, overflowing pus in the tooth socket, loosening and loss of teeth. In severe cases, there is jawbone defect and jaw deformity. In the later stage, chronic osteomyelitis is manifested, with exposure of the bone surface and the formation of fistulas in the oral mucosa and facial skin, with long-term pus flowing and untreated. It can also be accompanied by difficulty in opening the mouth or even closing the teeth. Pathological fracture and oral maxillary sinus fistula may occur in some patients.
6.2 Prevention and treatment measures
Firstly, make a reasonable radiotherapy plan, avoid overlapping doses between irradiation fields, and minimize the radiation dose to the normal tissues around the target area. Second, clean the teeth and repair the caries before radiotherapy, and extract the caries or residual roots that cannot be repaired, and the interval between tooth extraction and radiotherapy should be not less than 1 week. Thirdly, perform hyperbaric oxygen and systemic support treatment, and use antibiotics appropriately. Hyperbaric oxygen therapy is now recommended as the most effective conventional adjuvant treatment for radiation osteonecrosis.
7 Difficulty in opening the mouth
7.1 Clinical presentation
Mostly caused by temporomandibular joint disorder and occlusal muscle fibrosis. The main clinical manifestations are tightness and pain at the temporomandibular joint when opening the mouth, gradual reduction of the incisal spacing, or even dental closure, difficulty in speech and eating, and inability to perform oral and pharyngeal examinations. The key is prevention.
7.2 Prevention and treatment measures
First, the use of intensity-modulated conformal radiotherapy can reduce the damage to the temporomandibular joint, and the external radiation dose of nasopharyngeal cancer should be controlled at about 70
Gy is appropriate. Secondly, timely and effective prevention and treatment of various inflammatory lesions in the relevant areas before, during and after radiotherapy can reduce the occurrence of radiological temporomandibular joint disorders. Thirdly, patients should be instructed to insist on opening and closing their mouths during and after radiotherapy at least 3 times a day.
20 times a day, and perform bilateral temporomandibular joint area massage, etc. Fourth, use a wooden opener to practice mouth opening.
8 Radiographic soft tissue fibrosis of the head and neck
8.1 Clinical presentation
The soft tissues in the radiation field can undergo degenerative changes after a certain amount of irradiation, resulting in muscle atrophy and fibrosis and hardening, thus causing a series of symptoms. Clinical manifestations are 1 to 2 years after radiation treatment, patients may develop sclerosis of the neck, isthmus, soft palate, epiglottis, etc., impaired neck movement, swelling of the head and face, choking, choking into the trachea by mistake, involuntary paroxysmal cervical muscle, tongue muscle, bite muscle spasmodic convulsions, and therefore recurrent episodes of transient oblique neck and shrunken tongue and teeth. Once radioactive head and neck soft tissue fibrosis occurs, it is difficult to treat and the effect is poor, therefore, prevention is important.
8.2 Preventive and curative measures
First, protect the skin in the irradiated field during or after radiotherapy, wear cotton clothes, avoid chemical (local application or dressing of irritating chemicals, cleaning agents, cosmetics) and physical (hot and cold compresses, collar friction, scratching) stimulation, etc. Secondly, during or after radiotherapy, insist on doing head and neck functional health exercises, mouth opening and closing exercises, neck muscle rotation, temporomandibular joint massage, etc.
9 Radiation injury of the nervous system
9.1 Clinical manifestations
Some temporal lobes of the brain, brainstem and cranial nerves of nasopharyngeal carcinoma are affected by radiation or radiation during radiation therapy, and there are different degrees of damage, and the common clinical manifestations are as follows.
9.1.1 Neuropsychiatric symptoms
Memory loss, slowness, insomnia, transient thinking pauses or loss of consciousness, some patients show abnormal excitement, talk a lot, near agitated emotions.
9.1.2 Endocrine disorder symptoms
Menstrual disorders, amenorrhea, loss of libido, impotence, weakness, and chilliness.
9.1.3 Symptoms of peripheral nerve injury
Paralysis of a certain cranial nerve, such as atrophy of the tongue muscle, difficulty in swallowing, and paralysis of the abducent nerve of the eye.
9.2 Prevention and treatment measures
First, use intensity-modulated conformal radiation therapy techniques to reduce the amount of normal tissue exposure around the irradiated field. Second, use nerve cell-assisted drugs, commonly used are brain activator, brain rejuvenator, cytidylcholine, vitamin B1, B6, B12 and vitamin E, etc. Third, where available, hyperbaric oxygen therapy is feasible, 2 to 3 times a week, 1 to 2 h each time, which is helpful for the recovery of brain cells.
10 Radiation skin injury
Late skin reactions are delayed until months or years before manifestation, mainly delayed reactions occur in the dermis, manifested as dry, brittle and thinning skin, minor injuries can cause ulcers that are difficult to heal, and thickening or even occlusion of the walls of blood vessels and lymphatic vessels.
10.2 Preventive and curative measures
After the end of radiotherapy, continue to keep the skin in the radiotherapy area clean, wear cotton clothes, and avoid chemical (local application or application of irritating chemicals, cleaning agents, cosmetics) and physical (hot and cold sun, hot and cold compresses, collar friction, scratching) stimulation.
11 Radiation face and neck subcutaneous edema
Due to poor lymphatic flow in the face and neck after irradiation, deep capillary edema is occluded and obstructed, causing edema in the face, lower jaw and neck, with no local redness, pain or heat, no dysfunction, and the edema changes with body position, heavier in the morning and decreases after activity. If the edema is heavy and induces infection, causing acute cellulitis, it should be actively treated, preferably with high-dose antibiotics given intravenously.
Summary
Intensity-modulated conformal radiotherapy can irradiate the tumor target area with high dose precision, while the irradiation of normal tissues around the tumor is significantly reduced, which well protects normal tissues and organs, thus improving the local control rate, reducing complications caused by radiotherapy, and improving the survival rate and quality of life of patients. Due to the anatomical location of nasopharyngeal carcinoma and the distribution of surrounding lymph nodes, as well as the presence of many important tissues and organs (such as cremaster, pituitary gland, parotid gland, temporomandibular joint, eye, etc.), the field design is the most complicated and difficult among head and neck tumors. Intensity-modulated conformal radiotherapy, correct management of complications in radiotherapy, and adherence to functional exercise can reduce or minimize the late damage of radiotherapy for nasopharyngeal cancer patients, alleviate the sequelae of radiotherapy for nasopharyngeal cancer, and improve patients’ quality of life.