Butterfly Thyroid Cancer Trust : The Treatment Journey : Challenge scan

At about seven months after treatment you will be due to have your first ‘Challenge scan’.

This is to check that the RAI treatment has been fully effective in destroying any remaining thyroid tissue and whether you will require any further treatment or not.

This will be done either by stopping your thyroxine treatment (often referred to as ‘thyroxine withdrawal’) or by using Thyrogen (Recombinant Human TSH).

In order to prepare for the Challenge scan you will be asked to:

Commence on low iodine diet for three weeks
Switch from T4 to T3 for two weeks
Stop T3 for two weeks
Attend the Nuclear Medicine Department as an outpatient for:

Day 1: Low dose RAI capsule (10 minutes) usually done on a Wednesday

Day 2: Neck scan (approx eight minutes) on Thursday

Day 3: Body scan (approx 40 minutes) on Friday

You will also have blood taken to test thyroglobulin levels.
Or you may be given Thyrogen (Recombinant Human TSH). If so, you will not need to stop thyroxine but will need to come to the hospital each day for a week as follows:

Day 1 Thyrogen injection (10 minutes)

Day 2 Thyrogen injection (10 minutes)

Day 5 Blood test for thyroglobulin (in some cases a scan will also be done on Day 4 after a small dose of RAI on Day 3)

The Treatment Journey

Challenge scan

Scanning the neck