Radiation dose of caregivers could be reduced in thyroid carcinoma patients requiring high dose of radioactive iodine: A case report

Document Type : Case Report


1 Department of Nuclear Medicine, Cerrahpaşa Faculty of Medicine, Istanbul University, Istanbul, Turkey

2 Nuclear Physics Department, Faculty of Science, Istanbul University, Istanbul, Turkey


Undesired radiation exposure to caregivers is an important problem in radioiodine therapy in thyroid carcinoma patients, especially when patient is non-ambulatory. Special precautions are needed to keep the exposure to caregivers low when higher dose of radioiodine is necessary. Here we present a case-report of a 74-year old male patient with papillary thyroid carcinoma with local invasion and distant metastases, who received 9250 MBq I-131. The patient was confined to bed and needed special assistance for nasogastric tube and urinary catheter. Two family members helped the patient for daily care under the supervision of nursing staff. Caregivers were instructed for radiation protection and lead aprons, lead collars, two pair of gloves and lead screen were used during close contact with the patient. The patient was given daily amount of 4 liter water to increase the urinary excretion of radioiodine. The patient stayed at the hospital for 2 days and discharged when dose rate fell below 30 mSv/h at 1 m. Caregivers at home used lead aprons and lead collars for 3 more days. Cumulative radiation dose measured at the 5th day for two caregivers was 1320 μSv (264 μSv/day), which is under the safety limit of 5 mSv given by ICRP.


Main Subjects

  1. The 2007 Recommendations of the International Commission on Radiological Protection. ICRP publication 103. Ann ICRP. 2007;37(2-4):1-332.
  2. Barrington SF, Kettle AG, O'Doherty MJ, Wells CP, Somer EJ, Coakley AJ. Radiation dose rates from patients receiving iodine-131 therapy for carcinoma of the thyroid. Eur J Nucl Med. 1996 Feb;23(2):123-30.
  3. Ramírez-Garzón YT, Ávila O, Medina LA, Gamboa-deBuen I, Rodríguez-Laguna A, Buenfil AE, Ruíz-Trejo C, Estrada E, Brandan ME. Measurement of radiation exposure in relatives of thyroid cancer patients treated with (131)I. Health Phys. 2014 Nov;107(5):410-6.
  4. Jeong KH, Jung JW, Kim CB, Ahn BC, Lee HK, Yoo SJ, Day O, Lee JK. Estimation of external radiation dose to caregivers of patients treated with radioiodine after thyroidectomy. Health Phys. 2014 Apr;106(4):466-74.
  5. Kusakabe K, Yokoyama K, Ito K, Shibuya H, Kinuya S, Ito M, Higashi T, Togawa T, Koizumi K, Yoshimura M, Uchiyama M, Okamoto T, Kanaya S, Kanaya K, Yoneyama T, Ikebuchi H, Yanagida S, Shibata K, Segawa K, Yamamoto A. Thyroid remnant ablation using 1,110 MBq of I-131 after total thyroidectomy: regulatory considerations on release of patients after unsealed radioiodine therapy. Ann Nucl Med. 2012 May;26(4):370-8.
  6. Greaves C, Tindale W. Radioiodine therapy: care of the helpless patient and handling of the radioactive corpse. J Radiol Prot. 2001 Dec;21(4):381-92.