Study On The Effect Of Hyperthermia On Thyroid Function Recovery In Patients With Nasopharyngeal Cancer Treated With Radiotherapy

Objective:In recent years,the morbidity and mortality of head and neck cancer in China are gradually increasing,among which the incidence of nasopharyngeal carcinoma is higher.Head and neck cancer is a kind of malignant cancer,the incidence of which belongs to the top ten incidence of malignant tumor.Because the head and neck contains many important organs,is the most complex part of the human body.The surgical injury is huge,therefore radiotherapy take an important position during the treatment of head and neck cancer.Nasopharyngeal carcinoma is sensitive to radiation.Radiotherapy is recognized and effective radical therapy at present.Radiotherapy alone is generally used in the early stage and radiotherapy combined with chemotherapy is used in the late stage.When radiotherapy,the neck is often preventive irradiation.The thyroid gland is an important endocrine organ of the human body located in the neck,it is partially or completely irradiated during radiotherapy.Many studies have shown that some tumor patients have hypothyroidism after radiotherapy,which has a certain impact on the quality of life of patients.Deep hyperthermia can be accurately targeted in the treatment of thyroid diseases,during hyperthermia,cells are subjected to biological magnetic and electrical induction,increased vitality,increased permeability of biofilm,and then improve blood circulation and metabolism,thus playing a role in repairing thyroid function.The purpose of this study was to study the effect of radiotherapy combined with cervical hyperthermia on thyroid function in nasopharyngeal carcinoma(NPC).Methods:The study selected 90 patients with nasopharyngeal carcinoma who met the criteria in the first affiliated Hospital of Zhengzhou University from May 2015 to May 2017.According to the different treatment methods,they were naturally divided into observation group(58 cases)and control group(32 cases).The observation group was treated with intensity modulated radiation therapy(intensity modulated radiation therapy,IMRT),DT: 1.8~2.12 Gy/ time / field / day,5 day / week,pGTVnx 70 Gy,PTV1 60 Gy,PTV2 50-60 Gy,the course of treatment was 6 ~ 7 weeks.Synchronous hyperthermia was performed 0.5 to 1 hour after radiotherapy.The temperature range was 41 ~ 43 ℃,45 min each time,3 times a week,20 times as a course of treatment.Control group: radiotherapy regimen was the same as that in the observation group.All patients received radiotherapy in the cervical region and some or all of the thyroid region was irradiated.The levels of serum FT3,FT4 and TSH were measured in different stages of radiotherapy,the time of blood collection was before radiotherapy,1 month after radiotherapy,3 months after radiotherapy,6 months after radiotherapy,9 months after radiotherapy and 12 months after radiotherapy.At the same time,the clinical symptoms and thyroid ultrasound of the patients were observed.Observe and compare the changes of thyroid hormone levels in the two groups.Results:Observation group: the first hypothyroidism occurred 3 months after radiotherapy,a total of 2 cases(3.45%)of hypothyroidism were detected.By 1 year follow-up,13 cases(22.4%)had hypothyroidism,of which 3 cases were clinical hypothyroidism,it accounted for 21.4% of all hypothyroidism patients,11 cases of subclinical hypothyroidism and 78.6% of hypothyroidism patients.The average time of hypothyroidism occurred was 9 months after radiotherapy.In the control group,there were 3 cases of hypothyroidism for the first time 3 months after radiotherapy,and 9 cases(28.13%)of hypothyroidism at 12 months after radiotherapy,including 3 clinical hypothyroidism(33.3%)and 6 subclinical hypothyroidism(66.7%).There was no significant difference in the incidence of hypothyroidism between the control group and the observation group(P = 0.360> 0.05).The results of anova analysis of repeated measurements showed that there was no significant difference in FT3 level and FT4 level,but TSH level showed an upward trend in both groups.The increase of TSH level in the observation group was relatively slow,P =0.046 <0.05,which indicated that there was significant difference in the level of TSH between the observation group and the control group.Conclusion:The effect of cervical radiotherapy on thyroid function in nasopharyngeal carcinoma patients exists,with time prolonging after radiotherapy,the incidence of cervical radiotherapy may increase,and hyperthermia can promote the repair of thyroid function injury after radiotherapy.It can delay the occurrence of hypothyroidism to a certain extent,and then reduce the occurrence of hypothyroidism after radiotherapy.