Abstract:

Objective To understand the dose distribution of the radiation field in Yttrium-90（Y-90） treatment room under the guidance of digital subtraction angiography（DSA） and the exposure dose of the operators near the machine，in order to provide scientific basis and technical guidance for the design of radiation protection of treatment room and the formulation of personal protection decisions. Methods The research focused on the DSA apparatus typed INNOVA 4100-IQ（with a current of ≥800 mA） used for guiding Y-90 microsphere therapy and its operating treatment room were used as the objects researched. Within the planned 45-day monitoring period，under the condition of all 48 cases of DSA-guided Y-90 treatment-related surgeries were finished，the dose levels at different positions within the DSA operating treatment room were measured using thermoluminescent dosimeter（TLD） point placement and cumulative measurement. The dose received by the operators near the couch was measured using an active personal dosimeter（APD） in combination with TLD，and a dedicated database was established for statistical analysis. Results The maximum dose rates on the south and north sides of the treatment room，parallel to the longitudinal axis of the treatment couch and close to the inner walls，were 0.42 and 0.34 mSv/h，respectively，with average values of 0.14 and 0.16 mSv/h，respectively. The dose levels on the south and north sides of the room were basically symmetrical. At a distance of 50 cm from the center of the irradiation field corresponding to the patient's abdomen on the side of the couch，the maximum dose rate was 8.03 mSv/h，which was much higher than the dose rates on the side of the couch at the head and lower limbs of the corresponding patients. This was in line with the dose distribution characteristic that the dose gradually decreased towards both ends at the central position. In the single-pass DSA-guided Y-90 infusion surgery，the external doses on the lead suits of the first and second surgeons were 20 and 110 μSv，respectively，which were basically consistent with the theoretical calculated values. Conclusion The measured data on the dose distribution of radiation field in treatment room and the exposure dose of personnel during the Y-90 treatment under the guidance of DSA have practical value in the design of workplace radiation protection and the formulation and implementation of personal protection decisions. It is necessary to conduct in-depth research on the project by combining intelligent monitoring technology.

Key words: Interventional radiology, Y-90 microsphere, Treatment room, Radiation field, Dose distribution, Radiation protection