Preparation for radioactive iodine therapy is not a risk factor for the development of hyponatremia in thyroid cancer patients.
The aim of this study was to evaluate whether the preparation for radioactive iodine (RAI) therapy by thyroid hormone withdrawal (THW) or a low-iodine diet (LID) can be risk factors for the development of hyponatremia in patients with differentiated thyroid cancer after thyroidectomy.We retrospectively reviewed the medical records and laboratory findings of 326 patients who underwent preparation for RAI therapy after thyroidectomy from 2012 to 2014. Demographic and clinical variables including the method of thyrotropin stimulation and duration of LID were assessed. Serum sodium was measured twice, before operation and before RAI therapy.Hyponatremia was detected in only 3 patients (0.9%) before operation, but in 15 patients (4.6%) before RAI therapy. None of the patients had severe hyponatremia after preparation for RAI therapy. Pre-RAI therapy serum sodium was correlated with the method of thyrotropin stimulation (TWH vs recombinant human thyroid stimulating hormone, P = 0.014) and duration of LID (r = -0.131, P = 0.018); however, the preparation of RAI therapy, THW and LID, did not affect the development of hyponatremia in logistic regression analysis. Preoperative serum sodium was a significant risk factor for hyponatremia during preparation for RAI therapy.Preparation for RAI therapy by THW or LID is not a risk factor for the development of hyponatremia in patients with thyroid cancer. The development of hyponatremia was neither frequent nor severe during preparation for RAI therapy. Physicians should not be greatly concerned about rare life-threatening hyponatremia during preparation for RAI therapy.
Department of Nuclear Medicine, Chonnam National University Hospital Department of Nuclear Medicine, Chonnam National University Hwasun Hospital Division of Endocrinology and Metabolism, Department of Internal Medicine, Chonnam National University Hospital Department of Surgery, Chonnam National University Hospital, Gwangju, Republic of Korea.
Jahae
J
Kim
Sang-Geon
SG
Cho
Sae-Ryung
SR
Kang
Seong Young
SY
Kwon
Dong-Hyeok
DH
Cho
Jin-Seong
JS
Cho
Ho-Chun
HC
Song
D000368:Aged; D013956:Antithyroid Agents / Q000009:adverse effects*; D004035:Diet Therapy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000209:etiology*; D007455:Iodine / Q000008:administration & dosage*; D007457:Iodine Radioisotopes / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012964:Sodium / Q000097:blood; D013964:Thyroid Neoplasms / Q000097:blood / Q000532:radiotherapy*; D013965:Thyroidectomy; D014131:Trace Elements / Q000008:administration & dosage*; D028761:Withholding Treatment
D013956:Antithyroid Agents; D007457:Iodine Radioisotopes; D014131:Trace Elements; D007455:Iodine; D012964:Sodium