Exposición a la radiación de los operadores en la preparación y administración de microesferas de itrio-90 en el tratamiento de lesiones hepáticas malignas: ¿cuál es el riesgo?

Abstract

Liver radioembolization (RE) is an emerging treatment against liver primary and secondary tumours. The whole procedure of RE involves different health care specialists with different expertise. During the fractionation and infusion phases, the personnel manipulates high activities of 90Y. In our centre, the number of RE treatments per year is increasing; the aim of this study is to monitor the dose to the operators and to estimate the radiological risk for the operators involved in the RE. At present, two medical devices are approved: Sir-Sphere® and Therasphere™, both loaded with 90Y. The dosimeters used were TLD placed over the fingertips, for a total of four dosimeters for each phase; the selected dose descriptor was Hp0.07. The study concerned 17 patients affected by malignant hepatic lesions, treated from September 2017 to March 2018. We performed 27 procedures: 10 fractionations (with Sir-Sphere®) and 17 infusions to the patients (10 with Sir-Spheres®, seven with Theraspheres™). For fractionation phase, the average activity of each preparation was 3.34 GBq, the average value of Hp0.07 was 0.50 mSv. For infusion phase, the average activity was 1.51 GBq for Sir-Sphere® and 2.10 GBq for Theraspheres™, the average value of Hp0.07 was 0.10 mSv. No significant differences were found between senior (Hp0.07 = 0.08 mSv) and young operators (Hp0.07 = 0.09 mSv), respectively. Similarly, no significant differences were found between the right and left hand, with the same average value of Hp0.07 (0.01 mSv). In conclusion, the results are encouraging, since fingertips reported doses very low. The handling of 90Y microspheres and the RE procedure can be carried out under safe conditions.