Reply from Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University: You need to re-evaluate after treatment to know whether you need a second iodine 131 treatment, usually one time is fine for those without remote metastasis. Question from patient: Hi Prof. Cheng, this is the result of my follow-up report 3 months after taking iodine, now my dosage is 4 tablets, i.e. 200ug in total. Do I need to take another dose of Iodine 131 again? Thank you. Reply from Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University: tsh is still greater than 0.1, how long should I take 200ug? How should I take it? Reply from Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University: It is recommended to stop eugenol for iodine 131 scan. Question from patient: Hello Professor Cheng, I started taking 200ug of eugenol on December 2, and the method of taking it is a single dose in the morning on an empty stomach. Do I have to abstain from iodine? Thank you. Reply from Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University: How much did you take before? Generally, if there is any suspicion more than 3 months after treatment, an iodine 131 scan should be performed for evaluation. It is necessary to stop taking medication and abstain from iodine 3 weeks before the scan. Question from patient: Hi Prof. Cheng, I have been taking iodine since August 28th and gradually increased the dosage to two and a half tablets (125ug) and in October I increased to three tablets (150ug) and in November three and a half tablets (175ug) and in December I started taking 200ug. Reply from Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University: Since the scan needs to be stopped for more than 3 weeks, you need to make an appointment before stopping the medication, otherwise the scan cannot be guaranteed to be done on schedule after stopping the medication. Do I need to adjust the dose of Eugenol (I’m taking 200ug), and I had an iodine scan before, and no abnormalities were found. Thank you, Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University Reply: How long should I take Eugenol after the current scan? The role of eugenol is one is to replace the physiological needs, and the other is to inhibit the growth of thyroid tumor, which requires to keep the TSH below 0.1, and can be relaxed appropriately after stabilization. At present, your TSH still cannot reach the standard (0.34>0.1), so you need to continue to adjust the dosage of Eugenol. Patient Question: Hi Professor Cheng, is it good or bad to have a stimulated TG > 1ng/mL? I am currently taking Eugenol for one month after the scan. What if TSH is controlled at about 0.1 and free T3T4 is too high? Thank you Cheng Muhua, Department of Nuclear Medicine, The Third Affiliated Hospital of Sun Yat-sen University Reply: It is okay to have a slightly high free T3T4.