Personnel dose reduction in 90 Y microspheres liver-directed radioembolization: from interventional radiology suite to patient ward.

OBJECTIVE: To describe a method to reduce the external radiation exposure emitted from the patient after liver-directed radioembolization using 90 Y glass microspheres, to quantitatively estimate the occupational dose of medical personnel providing patient care to the patient radioembolized with the use of the method and to discuss radiation exposure to patients who are adjacent if the patient radioembolized needs hospitalization.

METHODS: A lead-lined blanket of lead equivalence of 0.5 mm was used to cover the patient abdomen immediately after the 90 Y radioembolization procedure, in order to reduce the radiation emitted from the patient. The interventional radiologist used a rod-type puncture site compressor for haemostasis to avoid direct contact with possible residual radioactivity at the puncture site. Dose rates were measured at the interventional radiologist chest and hand positions during puncture site pressing for haemostasis with and without the use of the blanket. The measurement results were applied to estimate the occupational dose of colleagues performing patient care to the patient radioembolized. The exposure to patients adjacent in the ward was estimated if the patient radioembolized was hospitalized.

RESULTS: The radiation exposures measured at the radiologist chest and hand positions have been significantly reduced with the lead-lined blanket in place. The radiologist, performing puncture site pressing at the end of radioembolization procedure, would receive an average hand dose of 1.95 μSv and body dose under his own lead apron of 0.30 μSv for an average 90 Y microsphere radioactivity of 2.54 GBq. Other medical personnel, nurses and porters, would receive occupational doses corresponding to an hour of background radiation. If the patient radioembolized using 90 Y needs hospitalization in a common ward, using the lead-lined blanket to cover the abdomen of the patient and keeping a distance of 2 m from the patient who is adjacent would reduce the exposure by 0.42% of dose limit for the general public.

CONCLUSION: By placing a lead-lined blanket on the patient abdominal region after 90 Y radioembolization, hospital staff receive minimal radiation exposure in order to comply with the radiation protection "as low as reasonably achievable" principle. There will be no increase in radiation level in ward if the patient radioembolized using 90 Y needs to be hospitalized. Therefore, the patient radioembolized can be accommodated alternatively at a corner bed of a common ward if an isolation room with private toilet facility is not available. Advances in knowledge: To reduce exposure to personnel providing patient care to patients radioembolized using 90 Y.