Characterization of salivary gland side effects secondary to ¹³¹I therapy: Report of the Thyroid Cancer Survivors’ Association, Inc. (ThyCa) national survey for intermediate and long term results

Objectives Sialoadenitis (SA) is an important side effect of ¹³¹I therapy (tx) for differentiated thyroid cancer (DTC); however, its reported frequency, severity, and time of onset are quite variable in the literature. In this study, a nationwide survey was implemented to better characterize the above parameters for SA in patients (pts) with DTC who were treated with ¹³¹I. The current report details the intermediate (I) (7 d-3 mo) and long term (LT) (3-12 mo) results of the survey.

Methods A survey regarding the side effects of ¹³¹I tx was e-mailed to ~15,000 associates of ThyCa and made available on its website. Responses of pts who had their last ¹³¹I tx in the USA were tabulated. The frequency, severity, and time of onset of SA in regards to salivary gland pain, swelling, and xerostomia are reported for I and LT periods.

Results Of 2811 total respondents, 2573 pts met the above criteria. Pain (P) was reported in 653/2024 (32%) 7 d to 3 mo after tx. Of 637 pts responding, P was categorized as Grade (Gr) 1-2: 46 (7%), Gr 3-4: 165 (26%), Gr 5-6: 221 (35%), Gr 7-8: 152 (249%), Gr 9-10: 53 (8%). Of 521 pts responding, the frequency of pts for the time of onset of pain during each of the following periods were: 214 (41%) 1-<2 wks, 48 (9%) 2-<3 wks, 31 (6%) 3-<4 wks, 20 (4%) 4-<5 wks, 10 (2%) 5-<6 wks, 9 (2%) 6-<7 wks 20 (4%) 7-<8 wks, 16 (3%) 8-<9 wks, 7 (1%) 9-<10 wks, 10 (2%) 10-<11 wks, 29 (65%) 11-<12 wks, and 107 (21%) in the 12th wk. The same above data for the LT (3-12 mo) of salivary pain as well as for both I and LT for salivary swelling and xerostomia are also reported.

Conclusions This is the largest report in the literature further characterizing the signs and symptoms of sialoadenitis occurring up to one year after ¹³¹I tx