Piyarat Parklug
Faculty of MedicineVajira Hospital , Navamindradhiraj University, Bangkok 10300, Thailand
Title: Outcome of using Penpat Pinyowattanasilp equation for prediction of 24-hour uptake, first and second therapeutic doses calculation in Graves’ disease patient
Biography
Biography: Piyarat Parklug
Abstract
The radioactive iodine thyroid uptake (RAIU) has been widely used in differentiate cause of thyrotoxicosis and treatment. Twenty-four hours RAIU is routinely used to calculate dose of radioactive iodine (RAI) therapy; however 2 days is required. Several previous authors presented early-to-late RAIU conversion equations replace Twenty-four hours RAIU. However, all of these equations were applied to patients who recieved any RAI doses. Pinyowattanasilp et al. proposed alternative equation, her equation is predicted 24 hours RAIU (P24U) = 32.5+0.702 (3 hours RAIU). This study aims to evaluate Penpat Pinyowattanasilp equation for prediction of 24-hour uptake, including calculate therapeutic dose separation first and second therapeutic dose in Graves’ disease patient. A retropsective study was done in 135 patients with first RAI dose and 36 patients with second RAI dose. The P24U are highly correlate with actual 24-hour RAIU in first and second therapeutic doses ( r = 0.913 , 95% CI = 0.876 to 0.939 and r = 0.806 , 95% CI = 0.649 to 0.897). The predictive therapeutic dose are highly correlated with the actual dose in first and second therapeutic doses ( r = 0.907, 95% CI = 0.868 to 0.935, r = 0.953, 95% CI = 0.909 to 0.976). The results from Bland-Altman plot shows that, mean difference between predictive and actual 24 hours upatake in the first dose and second dose are less than 1 mCi (-0.94 and -0.5 mCi). This equation is simply used in clinical practice especially in patient with 3 hours RAIU between 20-80%.