A NEW SIMPLE, PERSONALIZED, AND QUANTITATIVE EMPIRICAL METHOD FOR DETERMINING I ACTIVITY IN TREATING GRAVES' DISEASE.

CONTEXT

The I activity for treating Graves' disease (GD) is usually determined based on physician's experience.

OBJECTIVE

This study aimed to design an empirical method that was not only personalized and quantitative, but also simple, convenient, and easy to grasp.

SUBJECTS AND METHODS

The study population comprised patients with GD, selected between May 2013 and May 2016, who received I therapy in the Outpatient Department of Shanghai Ninth People's Hospital. The first-visit patients of physician 1 were placed in the traditional group: the activity of I (mCi) was calculated using the routine formula: [empirical activity (0.07-0.12 mCi/g) × thyroid mass]/[24-h thyroid I uptake]. The first-visit patients of physician 2 were placed in the personalized group. The activity of I (mCi) was calculated in two steps. First, the initial activity was calculated: 0.1 mCi/g × thyroid mass (g), and then a personalized and quantitative calibration table of I activity was used to obtain a final I activity. The cure rate with a single activity of I was recorded 1 year later.

RESULTS

The traditional and personalized groups included 241 and 282 patients, respectively. Interestingly, the personalized group achieved a higher cure rate [86.5% (244/282) 73.4% (177/241), P = 0.000] with a relatively higher I activity for the first treatment [8.7 (7, 3.5-30) mCi 6.7(6, 2.5-30) mCi, P = 0.000] compared with the traditional group, while the incidence rate of permanent hypothyroidism was not significantly different between the two groups (P = 0.175).

CONCLUSION

The empirical method designed in this study was reliable.