Radiation protection issues of treating hyperthyroidism with 131I in patients on haemodialysis

Abstract

We report on the cases of two patients referred for 131I treatment of hyperthyroidism who were dependent on haemodialysis. Following 131I administration, all disposable lines and filters from dialysis were collected and measured for 131I radioactivity. The amount of 131I retained by the filters at the end of each successive dialysis session was found to decay with effective half-lives of 6.6+/-0.2 and 6.3+/-0.2 days. Dose rate measurements at 1m from the patients were recorded to find the effective half-life of the radioiodine clearance, which were found to be 6.9 and 7.1 days. From measured dose rates taken at 30 cm, the radiation hazard to ward staff involved in patient management was shown to be negligible.

Iodine 131 treatment for differentiated thyroid carcinoma in patients with end stage renal failure: dosimetric, radiation safety, and practical considerations

“…Although the information available in some of the cases was minimal, the absence of short-term side effects, the short-term success of the treatment with respect to thyroid remnant ablation, and the information concerning radiation safety, 30 as well as the co-operation challenges presented by this kind of case might still be useful to others; so might also be our experience relating to retention and clearance of 131 I, which were measured when this was feasible. Although no dosimetric calculations were used for the 131 I activities given to our patients, we did measure the Irrespective of the method used to determine the amount of therapeutic 131 I to be administered, there are several other important choices to be made and questions to be answered when treating patients with ESRD on haemodialysis.…”

Radioyodo como tratamiento de hipertiroidismo en un paciente en hemodiálisis: Caso clínico

“…Estudios han mostrado que la actividad máxima del 131-I se produce al segundo día post administración 3,[6][7][8] . La tasa de eliminación después de cada sesión de HD es menor en hipertiroidismo que en CDT (2,7-5,5% versus 50-70%, respectivamente) 3,11,12 , determinando tiempos de vida media efectiva en pacientes hipertiroideos de 6,5-7,1 días 3,11,12 . En este caso se utilizó una dosis estándar de 131-I para hipertiroidismo, teniendo en consideración que, a diferencia de lo que ocurre en pacientes tiroidectomizados por CDT, la dosis requerida para tratamiento del hipertiroidismo es significativamente menor, además de que esta dosis sería captada en su gran mayoría por el tejido tiroideo sin exponer a exceso de radiación a otros órganos; por otra parte, se estimó una dosis suficiente para tratar en forma definitiva el hipertiroidismo y evitar la necesidad de una segunda dosis de 131-I.…”

“…La tasa de exposición a distancia evidenció una curva descendente con una pendiente poco pronunciada (Figura 1), lo que refleja una tasa de eliminación menor, con registros de exposición a radiación de 0,013 mSv/Hr a 1 metro y 69% de disminución de radioactividad al décimo día de la administración, comparable con las series de Homer et al y Simpson et al 11,12 . La baja actividad de 131-I medida en sangre y líquido de dializado antes, durante y después de las sesiones de HD refleja la baja tasa de exposición de los tejidos extratiroideos y la baja tasa de eliminación en líquido de dializado, respectivamente, esto también se explica por la mayor captación del 131-I por el tejido tiroideo, lo que determina menor blindado cuando no estaba en contacto directo con la paciente.…”

Can radioiodine be administered effectively and safely to a patient with severe chronic kidney disease?

“…Dialysis staff spend, on average, from 3 to 5 h in close proximity to the patient during a single HD procedure. Most opinions expressed on the matter support the position that the risk of exposure to radiation is minimal . However, some consider that there are risks associated with the high ablative doses of I‐131 used in advanced thyroid cancer cases and that specific safety measures are required in such cases .…”