Hyposalivation: the roles of radioactive iodine and stapes surgery.

PURPOSE: The aim of this study is to call attention to the role that radioactive iodine ((131)I) and stapes surgery may play in causing hyposalivation. MATERIALS AND METHODS: The manner in which (131)I and stapes surgery can cause salivary damage was reviewed. A case report is presented to illustrate the involved pathophysiology. RESULTS: The case report clearly shows the significant injury to the parotid glands caused by the (131)I. However, subjective symptoms of oral dryness only developed after injury to the chorda tympani nerve (CTN) during stapes surgery. CONCLUSIONS: The loss of function of both parotid glands after (131)I therapy for thyroid cancer was initially compensated by the secretions of the more radiation-resistant submandibular and sublingual salivary glands (SMSG/SLSG). Damage to the CTN's secretory fibers in one SMSG/SLSG complex led to subjective oral dryness by accentuating an existing objective hyposalivation.

Salivary gland injury resulting from exposure to radioactive iodine: case reports.

BACKGROUND: Radioactive iodine 131 ((131)I) is an effective treatment for differentiated thyroid carcinomas. (131)I targets thyroid tissue and is picked up by the salivary glands. Collateral damage results in the development of radiation sialadenitis. CASE DESCRIPTION: The authors describe salivary gland injuries that developed in two patients who received therapeutic doses of (131)I used to treat thyroid carcinoma. Accurate assessment of the glandular damage was achieved via a radioisotope study using technetium Tc 99m pertechnetate. CONCLUSION AND CLINICAL IMPLICATIONS: In the majority of cases, when a patient receives therapeutic doses of (131)I, the patient develops an asymmetric radiation sialadenitis. Obstructive symptomatology is to be expected. Oral dryness occurs less often and is related directly to high dosages and the passage of time. Clinicians should be aware of the condition to avoid unnecessary diagnostic and therapeutic measures.

Radioactive iodine and the salivary glands.

Radioactive iodine ((131)I) targets the thyroid gland and has been proven to play an effective role in the treatment of differentiated papillary and follicular cancers. Simultaneously, this radioisotope hones in on the salivary glands where it is concentrated and secreted into the saliva. Dose related damage to the salivary parenchyma results from the (131)I irradiation. Salivary gland swelling and pain, usually involving the parotid, can be seen. The symptoms may develop immediately after a therapeutic dose of (131)I and/or months later and progress in intensity with time. In conjunction with the radiation sialadenitis, secondary complications reported include xerostomia, taste alterations, infection, increases in caries, facial nerve involvement, stomatitis, candidiasis, and neoplasia. Prevention of the (131)I sialadenitis may involve the use of sialogogic agents to hasten the transit time of the radioactive iodine through the salivary glands. However, studies are not available to delineate the efficacy of this approach. Recently, amifostine has been advocated to prevent the effects of irradiation. Treatment of the varied complications that may develop encompass numerous approaches and include gland massage, sialogogic agents, duct probing, antibiotics, mouthwashes, good oral hygiene, and adequate hydration.