Sialoendoscopic treatment for radioiodine induced sialadenitis

The use of radioiodine (RI) for the ablation of residual thyroid tissue and metastatic thyroid cancer lesions after thyroidectomy has become established as standard treatment in the management of differentiated thyroid cancer and subsequent sialadenitis is the most common complication of RI therapy. The purpose of this study was to establish a new treatment modality for RI-induced sialadenitis.

The study group consisted of 115 patients with a mean age of 47.7 (range, 24-78) years. All patients received RI therapy after total thyroidectomy. The incidence of RI-induced sialadenitis, salivary gland involvement, administered RI dose, treatment modality, and result of treatment by interventional sialoendoscopy were evaluated.

The incidence of RI-induced sialadenitis was 18% (21/115), with involvement of the parotid more frequent than the submandibular gland. The average development period of RI-induced sialadenitis was 4.8 months. The average RI dosage for the sialadenitis group was higher than for the nonsialadenitis group, suggesting that RI-induced sialadenitis may be dose related, although the data were not statistically significant because of the small numbers in the high-dose group. Conservative management was effective in 71% (15/21) of the cases, and interventional sialoendoscopy was successful in 50% of those cases that did not respond to conservative treatment. The causes of treatment failure in the remaining cases were a totally obstructed parotid duct and stenosis at the bifurcation site.

Sialadenitis is the most common complication after RI therapy. Sialadenitis was successfully managed by conservative treatment in most cases, and interventional sialoendoscopy is an alternative method of treatment in selected cases such as in partial ductal stenosis.