Radiation exposure and radiation protection of the physician in iodine-131 Lipiodol therapy of liver tumours

Abstract

Intra-arterial iodine-131 labelled Lipiodol therapy for liver cancer has been investigated for safety and efficacy over a number of years, but data on radiation exposure of personnel have remained unavailable to date. The aim of this study was to assess the radiation exposure of the physician during intra-arterial 131I-Lipiodol therapy for liver malignancies and to develop appropriate radiation protection measures and equipment. During 20 intra-arterial administrations of 131I-Lipiodol (1110-1924 MBq), radiation dose equivalents (RDE) to the whole body, fingers and eyes of the physician were determined for (a) conventional manual administration through a shielded syringe, (b) administration with an automatic injector and (c) administration with a lead container developed in-house. Administration by syringe resulted in a finger RDE of 19.5 mSv, an eye RDE of 130-140 microSv, and a whole-body RDE of 108-119 microSv. The injector reduced the finger RDE to 5 mSv. With both technique (a) and technique (b), contamination of angiography materials was observed. The container allowed safe transport and administration of the radiopharmaceutical from 4 m distance and reduced the finger RDE to <3 microSv and the eye RDE to <1 microSv during injection. During femoral artery compression, radiation exposure to the fingers reached 170 microSv, but the whole-body dose could be reduced from a mean RDE of 114 microSv to 14 microSv. No more contamination occurred. In conclusion, radiation exposure was high when 131I-Lipiodol was administered by syringe or injector, but was significantly reduced with the lead container.

Exposure of medical personnel to radiation during radionuclide therapy practices

“…In our study, the WBD values for the radiopharmacist (syringe filling) and radiologist (injection and catheter retrieval) were lower. This can be partly explained because syringe filling was performed behind a large bench-mounted lead shield (thickness, 60 mm) using a 10 mm syringe shield sealed with a tungsten cap and because we used a mechanical device for femoral haemostasis instead of manual compression as seen in the studies by Risse et al [5] and Garin et al [4].…”

“…We also report a safer way for syringe filling using tubes allowing a five-fold decrease of hand exposure and a decrease of annual finger dose from 20.6 mSv to 8.5 mSv. Risse et al [5] tested different methods for the preparation and administration of 131 Ilabelled Lipiodol by the nuclear medicine specialists and reported alarming results since the calculated dose at the level of the fingers varied between 5 mSv and 19.5 mSv per injection (1813( -1924. In this work, Risse et al, demonstrated the efficiency of their self-developed shielded container allowing finger dose reduction down to 3 mSv per injection.…”

“…The radiation energy of these b -emitting radioisotopes ranges from 300 to 2300 keV and injected activities are up to 5550 MBq. Several published studies have estimated the equivalent body dose received by patients undergoing such treatments [1][2][3] and other by clinical and laboratory staff exposure [4][5][6][7][8][9]. One of the palliative treatments developed for hepatocellular carcinoma is radionuclide therapy using injection of 131 I-labelled Lipiodol (Lipiocis; 131 I, half-life 8 days; maximum beta energy of 0.61 MeV; gamma energy of 0.36 MeV) into the hepatic artery.…”

“…One of the palliative treatments developed for hepatocellular carcinoma is radionuclide therapy using injection of 131 I-labelled Lipiodol (Lipiocis; 131 I, half-life 8 days; maximum beta energy of 0.61 MeV; gamma energy of 0.36 MeV) into the hepatic artery. Patient [1] and medical staff [4,5] dosimetry for Lipiocis therapy has been performed. The study by Risse et al [5] reported alarming results since the finger exposure can reach 19.5 mSv per injection whereas the regulatory annual threshold for exposure at the extremities is 500 mSv.…”

“…Patient [1] and medical staff [4,5] dosimetry for Lipiocis therapy has been performed. The study by Risse et al [5] reported alarming results since the finger exposure can reach 19.5 mSv per injection whereas the regulatory annual threshold for exposure at the extremities is 500 mSv.…”