Treatment for Papillary and Follicular Thyroid Cancer
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for Western Australians
                            Written by Monique Atkinson and endorsed by Dr Hieu Nguyen

Surgery -Thyroidectomy or Lobectomy

Most patients with thyroid cancer have a total thyroidectomy (removal of the thyroid gland),
but a small percentage of patients may only have a lobectomy (removal of one lobe).
Sometimes cancerous lymph nodes in the neck are removed as well. If only one lobe is
removed, then the residual thyroid gland may or may not produce enough thyroid hormone.
When the whole thyroid gland is removed, the patient will be on full thyroid hormone
replacement therapy for life.

Any surgery on the thyroid gland should be done by an experienced surgeon who performs
high volume surgery on the thyroid to minimize adverse outcomes. This is usually done by an
endocrine surgeon. However patients are sometimes referred to a general surgeon, who may
not have as much experience with surgery on the thyroid gland. Behind the thyroid gland are
four small parathyroid glands and it is preferable to preserve their function. If the parathyroid
glands are damaged, calcium levels will drop. Approximately 20 % of patients experience a
transient drop of calcium. However, only 1 % of patients develop permanent
hypoparathyroidism (underactive parathyroid glands). The thyroid gland is also located close
to the nerves that control the voice box (called recurrent laryngeal nerves). The risk to
impaired nerve function (voice impairment) is also about 1%.


Radioactive Iodine Treatment – Thyroid Remnant Ablation

Radioactive iodine treatment may be used after a thyroidectomy or near total thyroidectomy,
which will destroy any remaining thyroid cells (including normal and cancerous cells). The size
of the remnant is quite small when surgery is performed by high volume surgeons. This
treatment is also referred to as thyroid remnant ablation. Thyroid cells that have spread to
other parts of the body will be destroyed as well. The dose of radiation (the radioactive iodine)
is given either in a capsule or a liquid. Not all patients will need this treatment.

For the radioactive iodine to effectively destroy any remaining thyroid cells (either normal or
cancerous), the TSH (thyroid stimulating hormone) has to be high. This encourages the cells
to take up the maximum amount of radioactive iodine.

There are two ways in which you can achieve a high TSH;

    1.  After the thyroidectomy you have to wait for about 4 to 6 weeks until your TSH has
    reached a high level. So the weeks following surgery you will become severely
    hypothyroid and you may suffer physically, mentally & emotionally. Some doctors
    prescribe Tertroxin (T3) for the first few weeks, then stop the Tertroxin for 3 weeks by
    which time the TSH has increased enough. T3 is given, because it has a shorter half
    life in the body (disappears faster from the body). It is also recommended that you eat
    foods that are low in iodine in the weeks leading up to the treatment and for about one
    week after treatment. This way any remaining thyroid cells are more likely to take up the
    iodine during the treatment, because the cells have been deprived of iodine.

    2. There is also a drug available that can increase the TSH to a high level within two
    days, called Thyrogen. When Thyrogen is used, the patients can continue thyroid
    hormone replacement therapy, without suffering from the mental and physical effects of
    hypothyroidism. A low iodine diet is still recommended for about two weeks.

    Thyrogen is a synthetic TSH (recombinant TSH). Thyrogen (thyrotropin alfa powder for
    injection) is an authority script that can be used under the following condition;

    “3193 – Ablation of thyroid remnant tissue, in combination with radioactive iodine, in a
    post thyroidectomy patient without known metastatic disease” (Pharmaceutical Benefits
    Scheme 2011)

In Western Australia, radioactive iodine treatment for thyroid cancer patients is only
administered in approved hospitals. You receive the treatment in a hospital room which has
lead lined walls and a bathroom, where you need to stay in isolation. You cannot leave the
room until the radiation level in your body is safe for other people. A urine test is used to
check your radiation level. Drinking plenty of water will help shorten your stay. When you are
allowed to go home, you still need to avoid close contact with other people for one more week
(you need to keep a safe distance of two metres from other people and pets). After the
radioactive iodine treatment, thyroglobulin levels and its antibodies will be measured. These
levels are useful markers for ongoing monitoring. Unfortunately thyroid cancers can return, so
it may be necessary to receive subsequent radioactive iodine treatments.


Thyroid Hormone Replacement Therapy

After the treatment you will need to take thyroid hormone replacement therapy for life to
replace the hormones normally produced by the thyroid. We cannot live without thyroid
hormone. Initially the endocrinologist will aim for a TSH which is suppressed to prevent the
growth of any cancer cells which may still reside in the body. Suppression therapy is
recommended for both papillary and follicular cancer, but not for medullary cancer and
anaplastic cancer. It is recommended that you see an endocrinologist who has experience in
the management of thyroid cancer.

Thyroid WA Support Group Inc.  -  ABN  84 263 220 330
T4 = thyroxine. TSH = thyroid stimulating hormone. * Achieved by discontinuing thyroid replacement
therapy for 1 month. Recombinant TSH has a potential role. † To detect non-iodine-avid disease

“MacKenzie EJ and Mortimer RH. 6: Thyroid Nodules and Thyroid Cancer. MJA 2004; 180: 242-247. ©
Copyright 2004. The Medical Journal of Australia – reproduced with permission”
Algorithm for follow-up after treatment of differentiated thyroid cancer