New guidelines for the management of patients with thyroid nodules and well-differentiated thyroid cancer: Part 2
Thomas Repas, DO, FACP, FACE, CDE
December 4, 2009 09:18 AM
update to the American Thyroid Association guidelines for the
management of patients with thyroid nodules and well-differentiated thyroid
cancer was recently released.
In patients with confirmed or suspected thyroid cancer, preoperative
ultrasound is advised to assist with staging and in determining which patients
may benefit from more extensive lymph node dissection at the time of initial
thyroidectomy. However, one problem with ultrasound is that it is operator
dependent. Other preoperative imaging studies such as MRI, CT and/or PET are
not routinely recommended.
Near total or total thyroidectomy is recommended if the thyroid cancer
is >1 cm or there are additional high-risk factors. Central lymph node neck
dissection should be performed at time of initial thyroidectomy in patients
with central and/or lateral lymph node involvement. Therapeutic lateral neck
lymph node dissection should be performed in those with biopsy proven
In low-risk patients with papillary cancer <1 cm, unilateral thyroid
lobectomy may be an option. However, thyroid lobectomy prevents the use of
radioactive iodine ablative therapy, also known as I-131, and serum thyroglobulin monitoring to
detect recurrence. That should not be an issue in a low-risk disease but must
be discussed with the patient in detail.
Over the years, there has been a trend towards less use and lower doses
of postoperative I-131 ablative therapy. This is reflected in the
guidelines which discuss the merits and risks associated with I-131 ablation and provide an algorithm to assist clinicians. The task force
advises the use of staging systems to assist in predicting prognosis and
determining long term monitoring. Recombinant human thyroid-stimulating hormone
may be used to prepare for I-131 ablation instead of thyroid
hormone withdrawal, especially in those patients intolerant of hypothyroidism
and/or who are unable to achieve a sufficiently elevated TSH >30 mU/L.
The recommendations also provide an algorithm for management of
differentiated thyroid cancer 6 to 12 months after I-131 remnant
ablation. The guidelines for thyroid hormone suppressive therapy are similar to
those advised previously. In addition to stimulated and non-stimulated
thyroglobulin, an increased role is suggested for cervical ultrasound in the
surveillance of patients with history of thyroid cancer. 18FDG-PET imaging may
be considered in those patients who are thyroglobulin positive and negative on
I-131 imaging, and/or those with more aggressive or invasive
poorly differentiated cancers.
The updated recommendations cover many issues beyond those I can cover
here in detail. I strongly encourage colleagues involved in the management of
patients with thyroid nodules and cancer to read these guidelines for
There is one final point I would like to make. Every guideline should
serve as only a "guide" to assist clinicians in their decision making process.
There will be times when it may be appropriate for a clinician to not follow
recommendations exactly. However, whenever I deviate from expert guidelines, I
always explain why to the patient and make my rationale for doing so clear in
my notes. Guidelines should never be considered a substitute for good clinical
judgment and individualized care.