Outcome of using Penpat Pinyowattanasilp equation for prediction of 24-hour thyroid uptake, first and second therapeutic doses calculation in Graves’ disease patients
Article Sidebar
Main Article Content
Abstract
Introduction : The Radioactive Iodine Thyroid Uptake (RAIU) is used in calculation the I-131 treatment dose for Graves’ disease. The duration time for the standard RAIU is 24-hours, then the patient is required to visit hospital in 2 consecutive days. The Penpat Pinyowattanasilp equation has been applies 3-hours RAIU to predict 24-hours RAIU. Thus, we can reduce duration of the study time.
Objective : The study aims to evaluate the correlation between the I-131 treatment doses that calculated by Predictive 24-hours RAIU (P24U) from Penpat Pinyowattanasilp equation and I-131 treatment dose that calculated by actual 24-hour RAIU. The study was performed in both the first and the second Therapeutic Doses (TD) in Graves’ disease.
Materials and Methods : A retrospective study was performed in Graves’ disease patients who underwent thyroid uptake and radioactive iodine treatment. Two groups were identified as the first and the second therapeutic doses. For each group, predictive value of 24-hours RAIU was calculated by Penpat Pinyowattanasilp equation. The equation in 24-hour RAIU = 32.5 + (0.702 × 3-hour RAIU). The TD and PTD were calculated and compared.
Results : The patients with the first therapeutic dose is 92 and the second therapeutic dose is 36. The first therapeutic dose, the correlation (r) between 24U and P24U is 0.902 and the second therapeutic doses, the correlation (r) between 24U and P24U is 0.806. The first therapeutic dose, mean TD and PTD are 7.38 and 7.06 millicuries. The second therapeutic dose, mean TD and PTD are 6.15 and 6.01 millicuries. The correlations between TD and PTD in the first and second therapeutic doses are 0.954 and 0.953 respectively. The mean difference between TD and PTD of the first and second therapeutic doses are less than 1 millicuries (-0.3 to -0.5), there is no statistically significant difference in both groups.
Conclusion : The Penpat Pinyowatanasilp equation is an alternative tool to calculate I-131 dose for Graves’ disease patients in the first and second therapeutic doses. The mean difference of the TD and PTD are less than 1 millicuries in both groups. However, the equation should be tested before use in other populations.
Article Details
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
References
Ross DS, Burch HB, Cooper DS, Greenlee MC, Laurberg P, Maia AL, et al. 2016 American thyroid association guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis. Thyroid 2016;26:1343-421.
Vanderpump MP. The epidermology of thyroid disease. Br Med Bull actions 2011;99:39-51.
มาคุ้มครอง โปษยะจินดา. การตรวจและรักษาโรคของต่อมไทรอยด์ด้วยสารกัมมันตภาพรังสี. กรุงเทพฯ: จรัลสนิทวงศ์การพิมพ์จำกัด; 2551.
Meier DA, Brill DR, Becker DY, Clarke SEM, Silberstein EB, Royal HD, et al. Procedure guideline for therapy of thyroid disease with131Iodine. J Nucl Med 2002;43:856-61.
Hayes AA, Akre CM, Gorman CA. Iodine-131 treatment of Graves’ disease using modified early iodine-131 uptake measurements in therapy dose calculations. J Nucl Med 1990;31:519-22.
Clerc J, Izembart M, Dagousset F, Heshmati JH, Chevalier A, Le´gar AF, et al. Influence of dose selection on absorb dose profiles in radioiodine treatment of diffuse toxic goiters in patients receiving or not receiving carbimazole. J Nucl Med 1993;34:387-93.
Hennessey JV, Berg LA, Ibrahim MA, Markert RJ. Evaluation of early (5 to 6 hours) iodine 123 uptake for diagnosis and treatment planning in Graves' disease. Arch Intern Med 1995;155:621-4.
Vemulakonda US, Atkins FB, Ziessman HA. Therapy dose calculation in Graves’ disease using early I-123 uptake measurements. Clin Nucl Med 1995;21:102-5.
Morris LF, Waxman AD, Braunstein GD. Accuracy considerations when using early (four- or six hour) radioactive iodine uptake to predict twenty-four hour values for radioactive iodine dosage in the treatment of Graves’ disease. Thyroid 2000;10:779-87.
Osaki Y, Sakurai K, Arihara Z, Hata M, Fukazawa H. Prediction of late (24-hour) radioactive iodine uptake using early (3-hour) uptake values in Japanese patients with Graves' disease. Endocr J 2012;59:173-7.
Pinyowatanasilp P, Uaratanawong S. Therapy dose calculation in hyperthyroidism using 3-hour early I-131 uptake Measurement. Vajira Medical Journal 2005;49:147-52.
