Wrist dosimeter in nuclear medicine – An alternative for the ring dosimeter?

Highlights • The paper focuses on the dosimetry in nuclear medicine. • The personal dose equivalent H p (0.07) in workers handling ^99mTc isotopes was analysed. • Correction coefficients for fingertips when using a wrist dosimeter was developed. • A wrist dosimeter can be used to measure the values of H p (0.07) for fingertips. Abstract Purpose Individual dosimetry is undoubtedly one of the best methods of assessing the exposure of personnel to ionizing radiation, however in case of nuclear medicine, the method applied to measure the dose does not always present a picture of the worker's actual exposure. The highly non-homogeneous dose distribution on the hand means that the ring dosimeter, routinely used to measure the H p (0.07), provides only approximate dose values received by fingertips, the body part most exposed to ionizing radiation. This paper is an attempt to answer the question whether the wrist dosimeter used as a replacement for the ring dosimeter is able to provide information on doses for the most exposed fragments of the hand of an employee during handling procedures with the use of radiopharmaceuticals. Materials Throughout measurements performed in five nuclear medicine facilities, high-sensitivity thermoluminescent detectors were used. Results Correction coefficients have been determined, which constitute an amendment to be made to move from the dose recorded by the wrist dosimeter to the doses received by the most exposed hand fragments. The fingertips received on average 25 times higher doses, compared to the values recorded by the wrist dosimeter. Conclusions A wrist dosimeter can be used to measure the H p (0.07) in nuclear medicine, including as a gauge of the most exposed parts of the hand – the fingertips. However, the applicability of correction coefficients makes it necessary to ensure a stable position of the wrist dosimeter during routine procedures. [ABSTRACT FROM AUTHOR]