Sialadenitis following I-131 therapy for thyroid carcinoma: concise communication

Area of Science:

• Oncology
• Nuclear Medicine
• Otolaryngology

Background:

• Radioactive iodine (I-131) is a standard treatment for thyroid carcinoma.
• Salivary gland dysfunction is a known potential side effect of I-131 therapy.
• The incidence and characteristics of I-131-induced sialadenitis require further elucidation.

Purpose of the Study:

• To determine the incidence of acute and/or chronic sialadenitis in patients treated with therapeutic doses of I-131 for thyroid carcinoma.
• To characterize the affected salivary glands (parotid, submandibular, or both).
• To analyze factors such as prior I-131 therapy and dosage influencing sialadenitis development.

Main Methods:

• Retrospective analysis of 87 patients treated for thyroid carcinoma over a 4-year period.
• Documentation of sialadenitis diagnosis, affected glands, prior I-131 exposure, and I-131 dosage.
• Assessment of symptom onset and duration.

Main Results:

• Ten out of 87 patients (11.5%) developed sialadenitis.
• Parotid glands were involved in five patients, submandibular in four, and both in one.
• Nine patients had prior I-131 therapy; doses ranged from 10 to 164 mCi.
• Symptom onset varied from 1 day to 6 months, with durations from 3 weeks to 2.5 years.

Conclusions:

• Sialadenitis is a significant complication of therapeutic I-131 for thyroid carcinoma, occurring more frequently than previously recognized.
• Both parotid and submandibular glands can be affected, with varying onset and chronicity.
• Understanding these risks is crucial for patient counseling and management strategies.