Transarterial Radioembolization: Medical Staff Dosimetry for 90Y-Resin, 90Y-Glass, and 166Ho-PLLA Microspheres.

Background Transarterial radioembolization (TARE) of liver tumors exposes medical staff to radiation. Comparative data between three microspheres, 90Y-resin, 90Y-glass, and 166Ho-poly-L-lactic acid (PLLA), is lacking. Purpose To evaluate radiation exposure among medical staff in a real-world setting and provide reliable data for involved occupations and microspheres. Materials and Methods This prospective consecutive single-tertiary care center study included individuals undergoing TARE between February 2024 and February 2025. Radiation exposure of five radiopharmacists, seven interventional radiologists, five medical physics experts, five nuclear medicine physicians, eight radiologic technologists, and six nurses was monitored using multimodal dosimetric surveillance. Skin surface doses on hands, body doses on the chest, maximum procedural dose rates, and exposure times were measured per step. Comparisons between microspheres were conducted using analysis of variance and post hoc Tukey honestly significant difference tests. Pearson correlation coefficients for body doses, exposure times, and therapeutic radioactivity were determined. Results A total of 53 participants (mean age, 64 years ± 11; 42 male) underwent 60 TARE procedures (20 per microsphere type). Radiation exposure was generally low, with body and hand doses under 5 and under 350 µSv, respectively, per procedure. 166Ho-PLLA generated the highest body doses (maximum, 17 µSv) due to direct gamma radiation and higher therapeutic radioactivity. 90Y-resin generated the highest hand doses due to procedural handling (maximum, 309 µSv). Interventional radiologists received the highest body (mean, 2.5-4.5 µSv) and hand (mean, 146-309 µSv) doses per procedure among all occupations because of additional angiography. Maximum dose rate (adjusted to 1 GBq therapeutic radioactivity) was 1157 µSv/h during portioning of 90Y-resin by radiopharmacists. Results show moderate overall correlation between exposure time and body dose (rp = 0.51, P < .001). Conclusion TARE radiation exposure to medical staff was generally low, but highest for interventional radiologists. Since 90Y-resin microspheres result in high hand doses due to procedural handling, their portioning, assembly, and application should be performed with optimal efficiency by trained staff using long tweezers. © The Authors 2026. Published by the Radiological Society of North America under a CC BY 4.0 license.