The investigation of acute adverse effects induced by radioiodine therapy in patients with differentiated thyroid cancer

Objectives After radioiodine ablation, the patients with differentiated thyroid cancer(DTC) have early complaints of uncomfortable clinical manifestations, such as the pain and swelling of neck, dry mouth, gastrointestinal symptoms, and so on. The purpose of the study was to analyze and summarize these acute adverse effects in DTC patients induced by radioiodine therapy during the early stage.

Methods 117 cases with DTC for radioactive iodine therapy were enrolled in this study. The oral doses of 3.7-9.2GBq of 131-iodine(131I) were administrated for ablating the thyroid remnant and(or) metastases. After taking 131I, the patients were followed-up through the telecommunication under the standardized questionnaire at different time points, containing the pain and swelling of neck, dry mouth, gastrointestinal symptoms, vocal cord paralysis and so on. The acute adverse effects and related clinical factors were analyzed.

Results Among 117 patients, 55 cases(47.0%) complained of neck’s pain and swelling, including 5 at 2h, 31 at 24h, 15 at 48h, 2 at 72h and 2 at 96h.79 patients(67.5%) reported gastrointestinal symptoms, containing 9 at 2h, 51 at 24h, 9 at 48h, 8 at 72h and 2 at 96h. The pain and swelling of salivary and dry mouth occurred in 15 patients(12.8%), headache and vertigo in 10(8.5%), insomnia in 9(7.7%), vocal cord paralysis in 6(5.1%), fatigue or general malaise in 6(5.1%), and foreign body sensation in 5(4.3%). Sporadical manifestations such as body numbness and urinary disorder were observed in only 1 case, respectively. Moreover, 3 female patients were in their menstrual period when they were ready for radioiodine treatment, and after that, they all developed menstrual irregularities. Most of the acute adverse effects were associated with clinical factors, such as TSH level, numbers of therapy, metastases and so on.

Conclusions The acute adverse effects induced by radioiodine therapy in DTC patients mostly start from 24h to 48h, and alleviate after 72h, relating with sex, TSH level, numbers of therapy and metastases and so on