Clinical Outcome of Parotid Gland Massage for Preventing Parotid Gland Dysfunction in Patients Treated with Radioiodine Therapy for Differentiated Thyroid Cancer: a Prospective Longitudinal Follow-Up Study

ABSTRACT

Background and Objectives@#The aim of this study was to determine the clinical effectiveness of parotid gland (PG) massage for the prevention of PG dysfunction after administration of radioiodine (I-131) therapy for treatment of differentiated thyroid cancer (DTC). @*Materials and Methods@#One hundred patients with DTC with planned high-dose I-131 therapy were enrolled in the clinical trial and randomized into two groups (massage and non-massage group). Serum amylase values were obtained before and 24 h after I-131 therapy, and salivary gland scintigraphy (SGS) were taken before and at eight months after the I-131 therapy. Additional SGS (addSGS) were taken when the patients complained symptoms related to salivary gland dysfunction. Questionnaire surveys were performed before and until two years after I-131 therapy. @*Results@#Ninety-five of 100 patients finished the study protocol. Changes in survey scores tended to be higher in the non-massage group. The non-massage group had more severe symptoms related to salivary gland dysfunction. Among 32 patients who underwent addSGS, 27 had normal 8-month SGS. Of these 27 patients, 18 (66.7%) had salivary gland dysfunction on the addSGS. Amylase values were significantly increased in patients with normal 8-month SGS but abnormal addSGS, as compared to patients who were normal on both 8-month SGS and addSGS (p=0.046). Amylase difference values were a significant predictor of abnormal addSGS (p=0.002). Conclusion: PG massage reduced symptoms related to salivary gland dysfunction. The PG massage may be helpful in preventing damage to salivary glands caused by I-131 therapy.