Radioiodine Scanning for Pre-surgical Evaluation of Follicular Thyroid Nodules


About this study

The objective of this study is to determine intensity of I-123 uptake in follicular thyroid lesions before surgery and correlate with final pathology findings.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Age ≥ 18 years.
  • Any gender.
  • Negative urine pregnancy test within 48 hours before the administration of radiopharmaceutical in women under 55.
  • Bethesda IV cytopathology on biopsy of thyroid nodule.
  • Any outside FNA reports have to be reviewed by Mayo pathologist.
  • Nodules 1-4 cm with solid appearance on ultrasound.
  • Ultrasound images and report documented in medical record, including the size of the nodule and location (upper, mid or lower portion of the thyroid lobe).
  • At least 2/3 of either thyroid lobe without nodules should be present to allow for the measurement of uptake in unaffected thyroid tissue.
  • TSH 0.3-2.0 mIU/L.
  • Patient scheduled for surgical resection of the nodule.
  • I-123 planar and SPECT/CT can be scheduled at least 2-3 days after biopsy and before surgery.

Exclusion Criteria:

  • Recent iodinated contrast, including IV and oral CT contrast or interventional vascular or cardiac study (within 6 weeks).
  • Current thyroid hormone supplementation.
  • Current use of anti-thyroid medications (methimazole or propylthiouracyl).
  • Less than 2-3 days after thyroid nodule FNA/biopsy.
  • Presence of another nodule of similar size in the same area of thyroid lobe, which could impair localization of the nodule on PET/CT images.
  • Less than 2/3 of normal thyroid tissue present in either thyroid lobe without nodules.
  • Positive pregnancy test.
  • Women who are breast feeding.


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Jolanta Durski, M.D.

Open for enrollment

Contact information:

Amber Stephan C.Ph.T.

More information


Publications are currently not available

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