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Radioiodine secretion in tears

S M Bakheet1, M M Hammami, A Hemidan

  • 1Department of Radiology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.

Journal of Nuclear Medicine : Official Publication, Society of Nuclear Medicine
|August 26, 1998
PubMed

Insights

Radioiodine is secreted in tears, confirmed by measuring radioactivity in tear samples from a patient treated with thyroxine. This finding suggests potential risks to the lacrimal gland from radioiodine treatments.

Area of Science:

  • Nuclear Medicine
  • Ophthalmology
  • Endocrinology

Background:

  • Radioiodine secretion into tears has been suggested by scintigraphic data.
  • This study quantifies radioiodine levels in tears from a patient undergoing thyroxine therapy post-thyroid ablation.

Observation:

  • Tear samples were collected over 24 hours after oral administration of iodine-123 (123I).
  • Radioactivity was measured in tear samples using a well counter, with corrections for decay and counting efficiency.

Findings:

  • Radioiodine was detected in tears from 15 minutes up to 24 hours post-ingestion, peaking around 60 minutes.
  • An estimated 56 kBq of radioactivity was secreted in tears within the first 4 hours, representing approximately 0.01% of the administered dose.

Implications:

  • Ingested radioiodine is appreciably secreted into tears.
  • Further research is needed to assess potential lacrimal gland damage from high-dose radioactive iodine (131I) treatments.
Abstract

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