The Preventive Effect of Parotid Gland Massage on Salivary Gland Dysfunction During High-Dose Radioactive Iodine Therapy for Differentiated Thyroid Cancer: A Randomized Clinical Trial

Purpose To evaluate the preventive effect of parotid gland (PG) massage for PG damage during the ¹³¹I therapy, we prospectively investigated the serum amylase value and salivary gland scintigraphy (SGS) after ¹³¹I therapy. Materials and Methods One hundred patients with thyroidectomized differentiated thyroid cancer who underwent high-dose ¹³¹I therapy were enrolled in the clinical trial and randomized into 2 groups (PG massage group and nonmassage group). The serum amylase value was obtained before and 24 hours after ¹³¹I therapy, and the SGSs were also taken just before and at 8 months after the ¹³¹I therapy. Change in serum amylase value and SGS was compared between PG massage and nonmassage groups. Results The difference value of serum amylase was significantly lower in PG massage group than in nonmassage group (P = 0.0052). Worsening of PG function on SGS was observed in 43 (45.3%) of the 95 patients. The incidence rate of PG abnormality on F/U SGS was significantly lower in PG massage group than in nonmassage group (odds ratio, 0.3704; P = 0.0195). In the multiple regression analysis, PG massage significantly affected the abnormality on the 8-month F/U SGS (r_partial = -0.2741, P = 0.0090) after adjusting for clinical variables (age, sex, TNM stage, TSH preparation methods for the ¹³¹I therapy, and ¹³¹I dose). Conclusions PG gland massage significantly reduced the incidence rates of salivary gland dysfunction on the 8-month F/U SGS and the level of the serological marker of salivary gland destruction after ¹³¹I therapy. Therefore, PG gland massage could alleviate salivary gland damage related to ¹³¹I therapy.