The impact of body mass index on the external dose rate from patients treated with radioiodine-131: A preliminary study

Document Type: Original Article


Department of Protection and Safety, Atomic Energy Commission of Syria, Damascus, Syria


Introduction: The relation between patient Body Mass Index (BMI) and the external dose rate of thyroid cancer patients treated with 131I has been investigated.
Methods: A total of 183 patients treated with 131I were selected randomly and divided according to their administrated activity into three groups: 3.7GBq, 5.5GBq and 7.4GBq. They were also stratified into three groups according to their BMI values namely normal, overweight and obesity. A telescopic radiation survey meter was used to measure the dose rate at 1 meter from patient neck level. The measurement was effectuated after 1, 24 and 48 hours post dose administration.
Results: Our findings showed that regardless the patient sex, age, and administrated dose, the external dose rate values in normal BMI range patient group were higher by 11% (as an average) as compared to overweight and obesity groups when the  dose administrated was 150 and 200 mCi while it was higher by 49% for patient received 100 mCi.

Conclusion: The BMI patient value may be taken into account in the radiation protection optimization process by the physicist during isolation period and general public after patient discharge.


Main Subjects

de Klerk JMH. 131I Therapy: Inpatient or Outpatient? J. Nucl. Med. 2000;41(11):1876-78.

Parthasarathy KL, Crawford ES. Treatment of thyroid carcinoma: emphasis on high-dose 131I outpatient therapy. J Nucl Med Technol. 2002 Dec;30(4):165-71.

Amaral H, Michaud P. I-131 therapy for thyroid diseases: Doses, new regulations and patient advice. In: IAEA-TECDOC-1228. Proceedings of international seminar on therapeutic applications of radiopharmaceuticals; 2001 January 18-22; Hyderabad, India.

National Council on Radiation Protection and Measurements. Management of radionuclide therapy patients. Report 155, NCRP. 2006.

International Commission on Radiological Protection. Release of patients after therapy with unsealed radionuclides. Ann. ICRP. 2004;34(2): ICRP Publication 94.

International Atomic Energy Agency. Release of patients after radionuclide therapy. IAEA Safety Reports Series No. 63, 2009.

Ahmadi Jeshvaghane N, Paydar R, Fasaei B, Pakneyat A, Karamloo A, Deevband MR, Khosravi HR. Criteria for patient release according to external dose rate and residual activity in patients treated with 131I-sodium iodide in Iran. Radiat Prot Dosimetry. 2011 Sep;147(1-2):264-6.

Tabei F, Neshandar Asli I, Azizmohammadi Z, Javadi H, Assadi M. Assessment of radioiodine clearance in patients with differentiated thyroid cancer. Radiat Prot Dosimetry. 2012 Dec;152(4):323-7.

Demir M, Parlak Y, Cavdar I, Yeyin N, Tanyildizi H, Gümüser G, Sayit E, Erees S, Sayman H. The evaluation of urine activity and external dose rate from patients receiving radioiodine therapy for thyroid cancer. Radiat Prot Dosimetry. 2013;156(1):25-9.

Venencia CD, Germanier AG, Bustos SR, Giovannini AA, Wyse EP. Hospital discharge of patients with thyroid carcinoma treated with 131I. J Nucl Med. 2002 Jan;43(1):61-5.

World Health Organization. Physical status: the use and interpretation of anthropometry. WHO, Technical Report Series No. 854, 1995.

Schubauer-Berigan MK, Frey GD, Baron L, Hoel DG. Mammography dose in relation to body mass index, race, and menopausal status. Radiat Prot Dosimetry. 2002;98(4):425-32.

Chan VO, McDermott S, Buckley O, Allen S, Casey M, O'Laoide R, Torreggiani WC. The relationship of body mass index and abdominal fat on the radiation dose received during routine computed tomographic imaging of the abdomen and pelvis. Can Assoc Radiol J. 2012 Nov;63(4):260-6.

Shah A, Das P, Subkovas E, Buch AN, Rees M, Bellamy C. Radiation dose during coronary angiogram: relation to body mass index. Heart Lung Circ. 2015 Jan;24(1):21-5.

Yavas G, Yavas C, Kerimoglu OS, Celik C. The impact of body mass index on radiotherapy technique in patients with early-stage endometrial cancer: a single-center dosimetric study. Int J Gynecol Cancer. 2014 Nov;24(9):1607-15.

Syrian Prime Minister. Radiation protection and safety and security of radiation sources. Decree No. 134, 2007.