The Clinical Efficacy Analysis Of Ⅰodine-¹³¹ Therapy For Graves’ Disease And The Development Of The Management System For Patients Received Ⅰodine-¹³¹ Therapy For Hyperthyroidism

BackgroundHyperthyroidism is a group of disorders caused by excess synthesis and secretion ofthyroid hormones from the thyroid gland, and leads to the hypermetabolic condition ofthyrotoxicosis. Diffuse toxic goiter （Graves’ disease, GD） is the most common cause of50%to80%of cases of hyperthyroidism. The incidence rate of GD was1.2%in China.The etiology of GD is quite complex, and genetic, environmental influences andautoimmune antibody were involved. Ⅰt has been nearly70years since Saul Hertzperformed the first radioactive iodine-¹³¹(¹³¹Ⅰ) treatment for GD in1941. Compared withsurgery and drug therapy, radioactive iodine therapy has many advantages, such as simple,safe, convenient, effective, few complications and high cost-effectivness, etc.The curative effect of¹³¹Ⅰ therapy is influenced by many factors, such as patients’gender, age, course, anti-thyroid drug （ATD）, thyroid iodine absorption rate,¹³¹Ⅰ dosageand so on. Ⅰn addition, GD after¹³¹Ⅰ therapy is prone to become hypothyroidism. So in theclinical practice, how to reasonably and scientifically assess the condition of GD,formulate the individualized and optimize¹³¹Ⅰ therapy dosage, cure the hyperthyroidism assoon as possible, at the same time reduce incidence of early hypothyroidism or delay theincidence of late hypothyroidism, are all problems which are concerned by the doctors andpatients.Meanwhile, it was time-consuming and inefficient to write the case history of patientswho received¹³¹Ⅰ therapy. Because it was quite important to monitor the changes ofcurative effect after¹³¹Ⅰ therapy, patients with GD required follow-up regularly. For thedoctors reviewing the previous case history was inconvenient and susceptible of incomplete information.“The management system for patients received¹³¹Ⅰ therapy forhyperthyroidism” was designed and developed as the digital carrier of patients’ medicalinformation, it will fully record the patients’ diagnosis and treatment process, not onlyimproved the efficiency of the doctors’ work, but also facilitate later follow-up, providemore high quality medical service to patients.Objective1. To analysis the relative factors which influence early hypothyroidism after¹³¹Ⅰtreatment for GD, and to explore the possibility of predict early hypothyroidism.2. To investigate the causes lead to the failure of the first time¹³¹Ⅰ therapy for GD.3. Using the successful curative patients as the research object, through the singlefactor analysis and multivariate stepwise regression analysis, to analysis the relative factorsof “¹³¹Ⅰ absorption dose per gram thyroid gland tissue”, and to obtained the regressionequation, which can automatically calculate the dose of¹³¹Ⅰ therapy.4. To design and develop “the management system for patients received¹³¹Ⅰ therapyfor hyperthyroidism”.Materials and method1183GD patients （13-74years,36.92±12.70; male:285,female:898） were treatedwith¹³¹Ⅰ for the first time between January2009and December2009at the department ofnuclear medicine, Chengdu416Hospital of Nuclear Ⅰndustry. All patients had withdrawedthose foods （sea weed, sea fish, etc） and drugs （tapazole, propylthiouracil, methimazole,etc） for more than two weeks. The doctors formulated the¹³¹Ⅰ therapy dose according tocondition of every GD patient. All patients adopted oral¹³¹Ⅰ therapy for one time.Follow-up method: the patients completed the follow-up （outpatient and telephone） at2weeks,1month,3month,6month and1year after¹³¹Ⅰ therapy. The doctors judged thecurative effect according the results of the follow-up.Sort the materials of the research objects: the medical record number, treatment time,name, sex （X1）, age（X2）, family history（X3）, course of disease（X4）, hyperthyroidismrelapsed or not （X5）, ATD duration（X6）, category of ATD（X7）, thyroid texture（X8）, thyroidECT imaging results（X9）, thyroid quality（X10）, the ratio of6h and24h iodine uptakerate（X11）, the highest iodine uptake rate（X12）, the degree of hyperthyroidism（X13）,¹³¹Ⅰtherapy dose（X14）,¹³¹Ⅰ absorption dose per gram thyroid gland tissue（X15）. Statisticalanalysis was performed with SPSS17.0, P<0.05was taken as indicating statistical significance.The design of “the management system for patients received¹³¹Ⅰ therapy forhyperthyroidism” abided by the specifications about the writing of medical case history bythe Ministry of Health in2010. The function modules and program code of this systemwere developed with PHP+MySQL technology.Result1. One year after¹³¹Ⅰ therapy in all1183GD patients, hypothyroidism392cases（33.1%）, euthyroidism584cases （49.4%）, improved127cases （10.7%）, invalid orrecurrence80cases （6.8%）. Cure rate of hyperthyroidism （hypothyroidism+euthyroidism）was82.5%, total effective rate93.2%（hypothyroidism+euthyroidism+improved）.2. The incidence rate of early hypothyroidism was38.7%, including permanenthypothyroidism accounted for85.6%. Single factor analysis and multiple logisticregression analysis showed that the influential factors of early hypothyroidism includedhyperthyroidism relapsed or not X5（OR=0.46）, thyroid texture X8（OR=1.32）, thyroidquality X10（OR=0.76）, the degree of hyperthyroidism X13（OR=0.65）,¹³¹Ⅰ therapy doseX14（OR=1.12）. Logistic regression equation is:Y1=1.60－0.78X5+0.28X8－0.27X10－0.43X13+0.11X14.Hosmer and Lemeshow test showed, χ2=16.20, P=0.04.The accuracy of this regression equation in predicting hypothyroidism was40.4%andthe accuracy of predicting non-hypothyroidism was83.4%, the total predicting accuracywas65.8%.3. One year after¹³¹Ⅰ therapy,207patients received the first time¹³¹Ⅰ therapy wereunsuccessful, including improved127cases, invalid72cases and recurrence80cases.Single factor analysis and multiple logistic regression analysis showed that the influentialfactors of whether hyperthyroidism was cured included hyperthyroidism relapsed or not X5（OR=1.77）, the highest iodine uptake rate X12（OR=1.15）, the degree of hyperthyroidismX13（OR=4.04）,¹³¹Ⅰ absorption dose per gram thyroid gland tissue X15（OR=0.14）. Logisticregression equation was:Y2=-4.71+0.57X5+0.14X12+1.40X13－1.95X15.Hosmer and Lemeshow test showed, χ2=9.69, P=0.28.This regression equation predicted accuracy of¹³¹Ⅰ therapy unsuccessfully was only17.5%. 4. Taking the584cases of euthyroidism patients as the research object, the singlefactor analysis showed that thyroid quality, the ratio of6h/24h iodine uptake rate and thehighest iodine uptake rate were all positively correlation with the¹³¹Ⅰ absorption dose pergram thyroid gland tissue （P<0.05, and the correlation coefficient was respectively0.49、0.55、0.39）. Ⅰn addition, course of disease, ATD duration, thyroid texture and the degree ofhyperthyroidism, hyperthyroidism relapsed or not were also correlatd with the¹³¹Ⅰabsorption dose per gram thyroid gland tissue （P value was less than0.05）.Multiple stepwise regression analysis showed course of disease （X4）, thyroid texture（X8）, thyroid quality （X10）, the ratio of6h/24h iodine uptake rate （X11） and the degree ofhyperthyroidism （X13） were finally decisive factors to the¹³¹Ⅰ absorption dose per gramthyroid gland tissue. Linear regression equation was:y=-0.27+0.05X4+0.16X8+0.13X10+0.06X11+0.29X13.y×75μ Ci/g was the¹³¹Ⅰ absorption dose per gram thyroid gland tissue. Thedetermination coefficient of this regression equation was0.62, and the variance analysisresult with F test of this regression equation was F=188.92, P<0.05.5.“The management system for patients received¹³¹Ⅰ therapy for hyperthyroidism”included three parts,“homepage”,“first time medical record” and “follow-up record”.“Homepage” included record time, out-patient/hospitalized number, case number, name,gender, date of birth, etc.“First time medical record” included medical history collection,physical examination, auxiliary examination, the preliminary diagnosis, treatment adviceand physician’s signature.“Follow-up record” added the curative effect evaluationcompared to “first time medical record”.This system was an electronic information carrier of GD patients who received¹³¹Ⅰtherapy. Ⅰt realized patients’ information addition, view, modify, delete, save, retrieve,query, and print functions. Doctors can export the patients’ information from the system tothe list or statistical analysis software. The system can autocalc “the¹³¹Ⅰ absorption doseper gram thyroid gland tissue” according to our study result, and then obtained the patients’¹³¹Ⅰ therapy dose.Conclusion1.¹³¹Ⅰ therapy for GD is a simple, convenient, safe and effective method.2. Most patients of early hypothyroidism were permanent. Patients were higherprobality of early hypothyroidism with hyperthyroidism first occurred, small thyroid quality, hard thyroid texture, mild hyperthyroidism condition and large¹³¹Ⅰ dose.3. The first time¹³¹Ⅰ therapy was probably unsuccessful in patiets who werehyperthyroidism relapse, higher iodine uptake rate, severe hyperthyroidism condition andless¹³¹Ⅰ absorption dose per gram thyroid gland tissue.4. The equations based on Logistic regress analysis can not yet predict the occurrenceof the early hypothyroidism and whether hyperthyroidism can be cured one year after¹³¹Ⅰtherapy in clinicl practice.5. Thyroid quality, thyroid texture, course of disease, the ratio of6h/24h iodine uptakerate, the degree of hyperthyroidism etc all should be considered when formulate the “¹³¹Ⅰabsorption dose per gram thyroid gland tissue”. Dosage regimen should be optimized andindividualized as far as possible.6. The equations about “¹³¹Ⅰ absorption dose per gram thyroid gland tissue” based onmultiple stepwise regression analysis requires modifying and consummating in theprospective research.7.“The management system for patients received¹³¹Ⅰ therapy for hyperthyroidism”realized the informationization and datumization to manage patients’ case history. Ⅰt madethe clinical work abbreviated and normative, and elevated the work efficiency. This systemcan record the whole course of diagnosis and therapy, so it was meaningful for clinicalwork and scientific research. Practice had proved that this system run well, stable, waseasy to maintain, so it can be used more widely.