Sialoadenitis secondary to ¹³¹I therapy for well‐differentiated thyroid cancer

Abstract

Radioiodine (131 I) is an important therapy for patients who have well-differentiated thyroid cancer. However, 131I may also result in side effects in multiple organs and glands. The glands that are frequently affected are the salivary glands with the major untoward effects including sialoadenitis and increased risk of second primary malignancy. This report will review sialoadenitis secondary to 131 I therapy including (1) proposed mechanisms, (2) incidence and clinical presentations, (3) possible approaches to improve prevention, (4) management, and (5) sequelae of sialoadenitis (e.g. xerostomia and salivary duct obstruction). A discussion of second primary malignancies is beyond the scope of this review. With a better understanding of the above, dentists, oral surgeons, otolaryngologists, endocrinologists, nuclear medicine physicians, and nuclear radiologists will be more likely to implement more effective preventive measures to reduce the incidence and severity of 131 I-induced sialoadenitis, and if it does occur, to identify and treat sialoadenitis sooner, thereby potentially reducing not only the severity of the initial symptoms, but also the severity of subsequent sequelae.Oral Diseases (2011) 17, 154-161

Sialendoscopy for Patients with Radioiodine-Induced Sialadenitis and Xerostomia

“…The iodine uptake may be mediated by the sodium-iodide symporter, which is expressed in various extrathyroidal tissues, including the ductal cells of the salivary glands (9,10). Serous acini have shown increased uptake of RAI compared to mucinous acini, resulting in injury of the parotid glands more commonly than the submandibular and sublingual glands (2,11).…”

Effects of Radioiodine Treatment on Salivary Gland Function in Patients with Differentiated Thyroid Carcinoma: A Prospective Study

“…Because radioiodine is mainly concentrated in the ductal system, the b-radiation may generate luminal debris, which may cause ducts to narrow (4). These processes can lead to obstruction of the ductal system, causing an inflammatory response in the secretory tissue (sialoadenitis), and glandular degeneration (5). Moreover, salivary gland stem cells, which have been proposed to mainly reside in the excretory ducts (6), may be affected because of the exposure to b-radiation resulting in a reduced regenerative potential (2).…”

Salivary gland duct obstruction after radioiodine therapy: a case report

“…As radioiodine is mainly concentrated in the ductal system, beta radiation may generate luminal debris which may cause ducts narrowing. These processes can lead to obstruction of the ductal system, causing an inflammatory response in the secretory tissue (sialoadenitis), as well as glandular degeneration [4]. Reduced flow and increased transit of thickened saliva may lead to increased radiation dose delivery to ducts.…”