Dosimetry of 137Cs sources with the Fletcher-Suit gynecological applicator

Measurements were made in water about the tandem and ovoid structures of the Fletcher-Suit applicator loaded with a 137Cs source. The dose rate was found to vary as much as 25% as a result of differential absorption in the ovoid. Empirically based trigonometric expressions are suggested which provide the absorption correction as a function of the two angles of a spherical coordinate system. Computer calculated dose rates, with and without the absorption corrections, are compared.