Conversion factors in patient activity external rate Hp (10) in the patient environment in metabolic therapy with 1-131

The purpose of this study is to determine the conversion factors (h) of R-131 to H measured in the patients environment, as the provision of activity in the same body or tumor, and analyzing the magnitude of the variables most significant influence on the measure of H. Applying the same procedure developed by the working group SEFN based on external exposure measurements made CHin taking the patient during their hospital stay, will optimize the procedure.