Interventional sialendoscopy for radioiodine-induced sialadenitis: quo vadis?

Salivary gland toxicity is a common adverse effect of radioactive iodine (I) for the treatment of thyroid cancers with a prevalence ranging from 2% to 67% of the I exposed population. Recently, sialendoscopy has been introduced as an attractive diagnostic and therapeutic tool for management of patients with radioiodine-induced sialadenitis that is unresponsive to standard medical treatments. The objective of the current review was to assess the impact of this procedure on outcomes in patients suffering from radioiodine sialadenitis. Overall, eight studies were included and 122 patients underwent 264 sialendoscopic procedures. Duct stenosis and mucous plugs were observed in 85.7% of endoscopic findings, supporting the role of ductal obstruction in the pathophysiology of radioiodine sialadenitis. In total, 89.3% of patients experienced complete or partial resolution of sialadenitis recurrences without any major adverse events, and parotidectomy was advocated in only 1 case. However, outcomes mainly concerned subjective reports and only two clinical experiences evaluated objective measurement with dissimilar results. Limited to few studies, xerostomia and obstructive symptoms responded differently after sialendoscopy. The optimal timing of salivary gland videoendoscopy needs to be further analysed in order to define the best management of radioiodine-induced obstructive sialadenitis.