 An iodine-131 whole-body scan is a procedure that is performed to check for recurrence of thyroid cancer in the body following a complete thyroidectomy. On the day of the scan, please inform the staff in case you are pregnant or have missed your period. Fasting is not required before the scan. A small dose of radioisotope solution is given to you orally. In this, the iodine will get absorbed into any thyroid tissue you may have and the scan is done 24-48 hours later. You will be advised to drink lots of water for at least 48-72 hours after the isotope has been administered. Please avoid close contact with pregnant or lactating women and young kids for 48-72 hours after the test.