Does an individual estimation of halflife improve the results of radioiodine therapy of Graves’ disease?

2002 ◽  
Vol 41 (06) ◽  
pp. 240-244 ◽  
Author(s):  
C. Körber ◽  
N. Körber-Hafner ◽  
H. Hänscheid ◽  
Chr. Reiners ◽  
P. Schneider
Keyword(s):  
Radioiodine Therapy ◽  
Dose Calculation ◽  
Multiple Regression Model ◽  
Therapeutic Outcome ◽  
Graves Disease ◽  
Therapeutic Success ◽  
Logit Transformation ◽  
Therapy Success ◽  
The Impact ◽  
Delivered Dose

SummaryAim: The impact of our dosimetry concept on radioiodine therapy success in Graves’ disease (GD) was analysed. Three questions arised: Did individual estimation of pretherapeutic halflife improve therapeutic success?. Did individual dosimetry result in accurate dose calculation?. Did antithyroid medication have a measurable influence on therapeutic success under the prevailing conditions?. Methods: 126 consecutive patients were treated with 200 Gy I-131 in our therapy ward for GD and followed-up six to nine months after therapy. Success quote was assessed using a standardized protocol and treatment was classified as successful when the patient was eu- or hypothyroid, or unsuccessful when he or she presented with a suppressed TSH-level or in hyperthyroid condition after antithyroid medication withdrawel. Antithyroid medication, activity I-131, dose, concentration of fT3 and fT4, specific delivered dose and halflife were put into a multiple regression model to assess their influence on therapeutic success. In order to assess possible factors disturbing the therapeutic outcome, relevant parameters were analyzed using Logit transformation. Results: Out of 126 patients 84 were classified as successfully treated and 42 (33,3%) as failures. A significant influence on the outcome only was found for thyroid mass. However, therapeutic success appeared to be more distinctly determined by the specific delivered dose using an estimated halflife of 5.5 days (Odds: 10.0, p <0.001). Accurate intratherapeutic dosimetry did not play a significant role to enhance therapeutic success. Neither did antihyroid medication during radioiodine therapy exert any significant impact. Conclusions: Measurement of individual intratherapeutic halflife as opposed to an estimate using a standard halflife did not provide improved results concerning the target dose. Retrospectively, the therapeutic outcome on the basis of a measured halflife as compared to a standard halflife did not significantly improve. In addition, no influence of antithyroid medication on therapy success was found.

scholarly journals Optimized radioiodine therapy of Graves' disease: analysis of the delivered dose and of other possible factors affecting outcome

1999 ◽  
Vol 141 (2) ◽  
pp. 117-121 ◽  
Author(s):  
B Catargi ◽  
F Leprat ◽  
M Guyot ◽  
N Valli ◽  
D Ducassou ◽  
...  
Keyword(s):  
Radioiodine Therapy ◽  
Urinary Iodine ◽  
Organ Dose ◽  
First Episode ◽  
Urinary Iodine Excretion ◽  
Graves Disease ◽  
Therapeutic Success ◽  
Number Of Patients ◽  
The Relationship ◽  
Delivered Dose

The best approach to radioiodine dose selection in the treatment of Graves' hyperthyroidism remains highly controversial. The formula to calculate the individual dose of (131)I to be delivered has been used for half a century and takes into account the thyroid mass, the effective half-life and the maximum uptake of (131)I. The objective of the present study was to evaluate the accuracy of this formula by determining the relationship between the administered dose of (131)I calculated to deliver a target dose of 50Gy to the thyroid and the actual exact organ dose. We further analyzed if therapeutic success, defined by euthyroidism following the individually calculated dose, can be predicted by different pretreatment parameters and particularly by organ dose. One hundred patients with a first episode of Graves' disease and who had received optimal thyroid irradiation after precise dosimetry were retrospectively reviewed. The patients were categorized according to their thyroid function (plasma free thyroxine (T(4)) serum concentration) as eu-, hyper- or hypothyroid during and 1 year after treatment. The relationship between the administered dose and organ dose was assessed by simple regression. We compared free T(4), free tri-iodothyronine, thyroid weight, the number of patients with antithyroperoxidase antibodies and TSH receptor autoantibodies, 24h urinary iodine excretion, (131)I uptake, and the exact dose of (131)I delivered to the thyroid as pretreatment variables. Although we found a correlation between administered dose (mCi) and organ dose (Gy) (r=0.3, P=0.003), the mean coefficient of variation for organ dose was 45%. Individualized radioiodine therapy enabled euthyroidism in 26% of patients and failed in 74% of patients (33% had persistent or recurrent hyperthyroidism and 41% permanent hypothyroidism). (131)I uptake was significantly higher in the hyperthyroidism group in comparison with the euthyroid group. However, organ dose and other pretreatment variables did not differ among the three groups. In conclusion, these results confirm the low performance of individual dosimetry using what are established ratios, since the delivered dose to the gland, although correlated to the intended dose, is highly variable. The finding that other usual pretreatment variables are not different between groups, gives little hope for improving the way of calculating the ideal dose of radioiodine. We suggest to those not yet ready to give a standard or an ablative dose for Graves' hyperthyroidism that they abandon this way to calculate the (131)I dose.

Graves' disease and radioiodine therapy

2008 ◽  
Vol 47 (04) ◽  
pp. 153-166 ◽  
Author(s):  
I. Weber ◽  
W. Eschner ◽  
F. Sudbrock ◽  
M. Schmidt ◽  
M. Dietlein ◽  
...  
Keyword(s):  
Success Rate ◽  
Thyroid Function ◽  
Therapeutic Dose ◽  
Radioiodine Therapy ◽  
Antithyroid Drugs ◽  
Graves Disease ◽  
Inclusion Criteria ◽  
End Point ◽  
Point Measure ◽  
The Impact

SummaryAim: This study was performed to analyse the impact of the choice of antithyroid drugs (ATD) on the outcome of ablative radioiodine therapy (RIT) in patients with Graves' disease. Patients, material, methods: A total of 571 consecutive patients were observed for 12 months after RIT between July 2001 and June 2004. Inclusion criteria were the confirmed diagnosis of Graves' disease, compensation of hyperthyroidism and withdrawal of ATD two days before preliminary radioiodine-testing and RIT. The intended dose of 250 Gy was calculated from the results of the radioiodine test and the therapeutically achieved dose was measured by serial uptake measurements. The end-point measure was thyroid function 12 months after RIT; success was defined as elimination of hyperthyroidism. The pretreatment ATD was retrospectively correlated with the results achieved. Results: Relief from hyperthyroidism was achieved in 96 % of patients. 472 patients were treated with carbimazole or methimazole (CMI) and 61 with propylthiouracil (PTU). 38 patients had no thyrostatic drugs (ND) prior to RIT. The success rate was equal in all groups (CMI 451/472; PTU 61/61; ND 37/38; p=0.22). Conclusion: Thyrostatic treatment with PTU achieves excellent results in ablative RIT, using an accurate dosimetric approach with an achieved post-therapeutic dose of more than 200 Gy.

What is the best pre-therapeutic dosimetry for successful radioiodine therapy of multifocal autonomy?

2006 ◽  
Vol 45 (05) ◽  
pp. 206-212 ◽  
Author(s):  
C. Rubner ◽  
A. Bauhofer ◽  
F. Berce ◽  
W. J. G. Oyen ◽  
J. Goecke ◽  
...  
Keyword(s):  
Half Life ◽  
Radioiodine Therapy ◽  
Thyroid Volume ◽  
Dose Calculation ◽  
Target Dose ◽  
Therapeutic Success ◽  
Organ Doses ◽  
Therapeutic Activities ◽  
Higher Doses

Summary:Purpose: Dose calculation for radioiodine therapy (RIT) of multifocal autonomies (MFA) is a problem as therapeutic outcome may be worse than in other kinds of autonomies. We compared different dosimetric concepts in our patients. Patients, methods: Data from 187 patients who had undergone RIT for MFA (Marinelli algorithm, volumetric compromise) were included in the study. For calculation, either a standard or a measured half-life had been used and the dosimetric compromise (150 Gy, total thyroid volume). Therapeutic activities were calculated by 2 alternative concepts and compared to therapeutic success achieved (concept of TcTUs-based calculation of autonomous volume with 300 Gy and TcTUs-based adaptation of target dose on total thyroid volume). Results: If a standard half-life is used, therapeutic success was achieved in 90.2%(hypothyroidism 23,1%, n=143). If a measured half-life was used the success rate was 93.1% (13,6% hypothyroidism, n=44). These differences were statistically not significant, neither for all patients together nor for subgroups eu-, hypo-, or hyperthyroid after therapy (ANOVA, all p>0.05). The alternative dosimetric concepts would have resulted either in significantly lower organ doses (TcTUs-based calculation of autonomous volume; 80.76±80.6 Gy versus 125.6±46.3 Gy; p<0.0001) or in systematic over-treatment with significantly higher doses (TcTUs-adapted concept; 164.2±101.7 Gy versus 125.6±46.3 Gy; p=0.0097). Conclusions: TcTUsbased determination of the autonomous volume should not be performed, the TcTUs-based adaptation of the target dose will only increase the rate of hypothyroidism. A standard half-life may be used in pre-therapeutic dosimetry for RIT of MFA. If so, individual therapeutic activities may be calculated based on thyroid size corrected to the 24h ITUs without using Marinelli’s algorithm.

Results of a risk adapted and functional radioiodine therapy in Graves’ disease

2005 ◽  
Vol 44 (06) ◽  
pp. 238-242 ◽  
Author(s):  
V. Neumann ◽  
U. Staub ◽  
P. Groth ◽  
H. Künstner ◽  
C. Schümichen ◽  
...  
Keyword(s):  
Radioiodine Therapy ◽  
Thyroid Volume ◽  
Therapeutic Failure ◽  
Graves Disease ◽  
Clinical Parameters ◽  
Target Dose ◽  
Therapeutic Success ◽  
Thyroid Metabolism ◽  
First Time

SummaryAim of this study was to find out, if results of a functional orientated radioiodine therapy in Graves’ disease could be optimized using a risk adopted dose concept. Patients, method: 351 patients with Graves’ disease were treated for the first time between 11/97 and 8/01. The basic dose was 125 Gy, which was increased up to 250 Gy in a cumulative manner depending on clinical parameters (initial thyroid metabolism, thyroid volume, immunoreactivity). Two different methods of dosimetry were used. Occasional thyreostasis was withdrawn two days before the radioiodine test was started. Follow up was done on average 8 ± 2,4 (4-17,2) months. TSH ≥0,27 μIU/mL confirmed as a measure of the success. Results: With improved pretherapeutic dosimetry and a mean target dose of 178 ± 31 Gy (n=72) therapeutic success occurred in 66,7%, in 51,4% euthyreosis was restalled and in 15,3% of patients hypothyroidism was seen (TSH >4,20 μIU/mL). With simplified pretherapeutic dosimetry and a mean target dose of 172 ± 29 Gy (n=279) results were moderately impaired (63,8%, 40,1% and 23,7%). With increasing target dose therapeutic failure increased, as unsufficiently adopted risk factors for therapeutic failure turned out the initial thyroid metabolism, the TcTU(s) as the (h)TRAb titer. Conclusion: Functional orientated RIT can be optimized by including illness specific characteristics, principal limitations are a high initial thyroid metabolism, a large thyroid volume and a high (h)TRAb-titer.

scholarly journals Cigarette Smoking Has no Impact on the Effect of Radioiodine Therapy in Patients with Graves Disease / Pušenje cigareta nema uticaj na ishod radiojodne terapije kod bolesnika sa Grejvsovom bolešću

2015 ◽  
Vol 32 (1) ◽  
pp. 67-75
Author(s):  
Vladan Sekulić ◽  
Milena P. Rajić ◽  
Marina Vlajković ◽  
Slobodan Ilić ◽  
Miloš Stević ◽  
...  
Keyword(s):  
Cigarette Smoking ◽  
Radioiodine Therapy ◽  
Response To Therapy ◽  
Stressful Events ◽  
Antithyroid Drugs ◽  
Graves Disease ◽  
Significant Difference ◽  
Iodine 131 ◽  
The Impact

Summary Presently, there is very little data on the impact of nicotine and other components of tobacco smoking on the outcome of radioiodine therapy (RIT) in Graves’ disease (GD). Thus, this study was aimed to analyze a possible impact of cigarette smoking on the effect of radioiodine therapy in the patients with Graves’ disease. The study included 31 patients (16 smokers and 15 non-smokers) with GD, aged from 22 to 73 years, who were treated with a single dose of iodine-131 sodium iodide (131I-NaI) and subjected to a 12-month follow-up, thereafter. Patients were treated with antithyroid drugs (ATDs) before RIT and described very intense stressful events occurring prior to diagnosing Graves’ hyperthyroidism. A successful response to RIT was defined as euthyroidism and subclinical or clinical hypothyroidism, while an unsuccessful response was defined as persistent hyperthyroidism. Comparison of age (47.4±9.41 vs. 49.5±13.8 years, p=0.628) at the time of RIT, applied activity of 131I-NaI (372±78.4 vs. 363±43.7 MBq, p=0.675), and duration of ATDs therapy (3.47±3.33 vs. 4.94±5.62 years, p=0.387) between smokers and non-smokers showed no significant difference. The cumulative incidence of successful response to therapy in smokers and non-smokers was 31.2 vs. 46.7% (p<0.05), 50.0 vs. 60.0% (p>0.05), 56.2 vs. 60.0% (p>0.05), and 56.2 vs. 66.7% (p>0.05) after 3, 6, 9 and 12 months, respectively. The results showed that cigarette smoking has no impact on the effect of radioiodine therapy after twelve-month period in patients who had experienced stressful events before the occurrence of Graves’ disease. However, patients with smoking habits achieved successful response later than non-smokers.

Characterization of radioiodine therapy failures in Graves’ disease

2001 ◽  
Vol 40 (01) ◽  
pp. 1-6 ◽  
Author(s):  
M. Zimny ◽  
M. Schreckenberger ◽  
P. Reinartz ◽  
B. Nowak ◽  
E. Ostwald ◽  
...  
Keyword(s):  
Radioiodine Therapy ◽  
Thyroid Volume ◽  
Absorbed Dose ◽  
Stepwise Logistic Regression ◽  
Graves Disease ◽  
Significant Variable ◽  
Absorbed Energy ◽  
Volume Function ◽  
Energy Dose

Summary Aim of this study was a characterization of radioiodine therapy (RIT) failures in Graves’ disease without simultaneous Carbimazole. Method: 226 patients with a confirmed diagnosis of Graves’ disease received 686.8 ± 376.4 MBq of iodine-131 orally for thyroid ablation. Target dose was 250 Gy. All patients were followed up for 6 months. Therapy failures were compared with successes regarding possible influencing variables initial thyroid volume, thyroid function, immune activity (TRAb), 1-131 uptake, effective half-life, absorbed energy dose, age and gender. Results: 212 of 226 patients (93.8%) were treated successfully, 14 (6.2%) showed a hyperthyroidism relapse within 6 months which required a second radioiodine therapy. A success rate of 92.5% (62/67) could also be achieved with 67 patients who were hyperthyroid at the time of RIT. Compared to the therapy successes, the 14 failures achieved significantly lower absorbed doses (223.8 ±76.6 Gyvs. 285.2 ±82.1 Gy, ρ <0.005), but with no significant differences regarding age, thyroid volume, function or TRAb (all ρ >0.2). Of the 14 failures, η = 8 reached an absorbed dose <200 Gy and η = 1 a dose <250 Gy, although 5 of the failures reached an absorbed dose of >250 Gy. Stepwise logistic regression revealed only absorbed energy dose as a variable significantly influencing therapy success (p <0.005), but no influence of initial thyroid volume, function, TRAb value, age (all ρ >0.2) or gender (p = 0.13). Two-tailed Fisher’s exact test showed no significant influence of gender on success rates (failures/successes: male 1 /36, female 13/176, ρ = 0.48). Conclusions: Except for the absorbed energy dose, no other significant variable influencing the outcome of radioiodine therapy in Graves’ disease without simultaneous Carbimazole could be found. It should be noted, though, that 5 therapy failures (2.2%) reached an absorbed energy dose of >250 Gy.

Guideline for radioiodine therapy for benign thyroid diseases (version 3)

2004 ◽  
Vol 43 (06) ◽  
pp. 217-220 ◽  
Author(s):  
J. Dressler ◽  
F. Grünwald ◽  
B. Leisner ◽  
E. Moser ◽  
Chr. Reiners ◽  
...  
Keyword(s):  
Radioiodine Therapy ◽  
Thyroid Volume ◽  
Thyroid Diseases ◽  
Antithyroid Drugs ◽  
Graves Disease ◽  
Co Morbidity ◽  
History Of ◽  
Individual Decisions ◽  
Prophylactic Use ◽  
Benign Thyroid

SummaryThe version 3 of the guideline for radioiodine therapy for benign thyroid diseases presents first of all a revision of the version 2. The chapter indication for radioiodine therapy, surgical treatment or antithyroid drugs bases on an interdisciplinary consensus. The manifold criteria for decision making consider the entity of thyroid disease (autonomy, Graves’ disease, goitre, goitre recurrence), the thyroid volume, suspicion of malignancy, cystic nodules, risk of surgery and co-morbidity, history of subtotal thyroidectomy, persistent or recurrent thyrotoxicosis caused by Graves’ disease including known risk factors for relapse, compression of the trachea caused by goitre, requirement of direct therapeutic effect as well as the patient’s preference. Because often some of these criteria are relevant, the guideline offers the necessary flexibility for individual decisions. Further topics are patients’ preparation, counseling, dosage concepts, procedural details, results, side effects and follow-up care. The prophylactic use of glucocorticoids during radioiodine therapy in patients without preexisting ophthalmopathy as well as dosage and duration of glucocorticoid medication in patients with preexisting ophthalmopathy need to be clarified in further studies. The pragmatic recommendations for the combined use of radioiodine and glucocorticoids remained unchanged in the 3rd version.

Low Dose Radioiodine Therapy for Graves' disease: comparison of outcomes following administration of different doses across two centres

2018 ◽  
Author(s):  
Natasha Sawhney ◽  
Carmen Diaz-Ortega ◽  
Sam Philip ◽  
Fraser Gibb ◽  
Prakash Abraham ◽  
...  
Keyword(s):  
Low Dose ◽  
Radioiodine Therapy ◽  
Graves Disease ◽  
Different Doses

scholarly journals The Impact of Work Characteristics on Social Distancing: Implications at the Time of COVID-19

2021 ◽  
Vol 18 (10) ◽  
pp. 5074
Author(s):  
Keisuke Kokubun ◽  
Yoshinori Yamakawa
Keyword(s):  
Information Processing ◽  
Multiple Regression ◽  
Explanatory Power ◽  
Work Conditions ◽  
Multiple Regression Model ◽  
Social Characteristics ◽  
Work Characteristics ◽  
Social Distancing ◽  
Using Data ◽  
The Impact

The coronavirus disease (COVID-19) continues to spread globally. While social distancing has attracted attention as a measure to prevent the spread of infection, some occupations find it difficult to implement. Therefore, this study aims to investigate the relationship between work characteristics and social distancing using data available on O*NET, an occupational information site. A total of eight factors were extracted by performing an exploratory factor analysis: work conditions, supervisory work, information processing, response to aggression, specialization, autonomy, interaction outside the organization, and interdependence. A multiple regression analysis showed that interdependence, response to aggression, and interaction outside the organization, which are categorized as ”social characteristics,” and information processing and specialization, which are categorized as “knowledge characteristics,” were associated with physical proximity. Furthermore, we added customer, which represents contact with the customer, and remote working, which represents a small amount of outdoor activity, to our multiple regression model, and confirmed that they increased the explanatory power of the model. This suggests that those who work under interdependence, face aggression, and engage in outside activities, and/or have frequent contact with customers, little interaction outside the organization, and little information processing will have the most difficulty in maintaining social distancing.

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