Assessment of the radiation exposure of relatives and caregivers of patients treated with Ra-223 – Results of a German multicenter study

Abstract A multicenter study was conducted to assess the radiation exposure of relatives and caregivers of patients suffering from castration resistant prostate cancer with bone metastases and treated with Ra-223 dichloride in an outpatient setting. As Ra-223 and most of its progeny emit alpha particles , especially the internal exposure of persons in the patient's vicinity had to be evaluated. Methods The external radiation was measured in distances of 1 m and 2 m. Wipe-tests were taken in the patients’ homes to identify significant contaminations and evaluated by liquid scintillation counting. Samples of saliva and sweat were taken and measured using gamma spectrometry . Results The external exposure from the patients measured 10-20 min post injection (p. i.) was  Conclusions The potential exposure of relatives by external irradiation and incorporation of Ra-223 excreted by the patient with saliva or sweat is estimated to be well below 1 mSv. No objections are seen regarding outpatient treatment.