A Multiradionuclide Automatic Dispensing System for Syringes of Radiopharmaceuticals: The Effect on Operator Hand Dose.

The radiation exposure of the hands of nuclear medicine laboratory technicians is largely due to the dispensing of radiopharmaceuticals into syringes. To reduce this exposure, a multiradionuclide automatic dispensing system (ADS) for syringes of radiopharmaceuticals was introduced. The aim of this study was to determine the effect of this ADS on hand dose compared with manual dispensing. Methods: The total hand dose per month for all personnel (12 technicians) was measured with ring dosimeters at the base of the index finger for 13 mo: 7 mo with manual syringe dispensing (radiopharmaceuticals containing 99mTc,18F, 177Lu, 68Ga, 90Y, and 223Ra) and 6 mo with ADS (automatic: radiopharmaceuticals containing 18F and 177Lu; manual: radiopharmaceuticals containing 99mTc, 68Ga, 90Y, and 223Ra). Results: The mean total hand dose per month was reduced from 52.8 ± 10.2 mSv with manual dispensing to 21.9 ± 2.7 mSv with ADS (P < 0.001), which is an absolute decrease of 59%. Meanwhile, the total handled activity increased from 369 to 505 GBq (P < 0.001). 18F-containing radiopharmaceuticals were the most commonly dispensed, at 182 GBq per month. The increase in total handled activity was largely due to an increase in 177Lu (from 25 to 123 GBq), partially because of the introduction of [177Lu]Lu-PSMA-I&T. When correcting for this increase in handled activity, the hand dose was reduced by 69%. Conclusion: The introduction of a multiradionuclide syringe ADS decreased the hand dose to personnel by 69% when corrected for the increase in handled activity. Expanding the number of radiopharmaceuticals being dispensed by the system could potentially further decrease personnel hand dose.

Occupational Radiation Exposure of Radiopharmacy, Nuclear Medicine, and Surgical Personnel During Use of [99mTc]Tc-PSMA-I&S for Prostate Cancer Surgery.

The aim of this study was to estimate and subsequently measure the occupational radiation exposure for all personnel involved in producing, administering, or performing imaging or surgery with [99mTc]Tc-PSMA-I&S, which has been introduced for identification of tumor-positive lymph nodes during salvage prostate cancer surgery. Methods: The effective dose was estimated and subsequently measured with electronic personal dosimeters for the following procedures and personnel: labeling and quality control by the radiopharmacy technologist, syringe preparation by the nuclear medicine laboratory technologist, patient administration by the nuclear medicine physician, patient imaging by the nuclear medicine imaging technologist, and robot-assisted laparoscopic salvage lymph node dissection attended by an anesthesiology technologist, scrub nurse, surgical nurse, and surgeon. The dose rate of the patient was measured immediately after administration of [99mTc]Tc-PSMA-I&S, after imaging, and after surgery. Results: The estimated dose per procedure ranged from 1.59 × 10-10 µSv (imaging technologist) to 9.74 µSv (scrub nurse). The measured effective dose ranged from 0 to 5 µSv for all personnel during a single procedure with [99mTc]Tc-PSMA-I&S. The highest effective dose was received by the scrub nurse (3.2 ± 1.3 µSv), whereas the lowest dose was measured for the surgical nurse (0.2 ± 0.5 µSv). If a single scrub nurse were to perform as many as 100 procedures with [99mTc]Tc-PSMA-I&S in a year, the total effective dose would be 320 µSv/y. Immediately after administration, the dose rate at 50 cm from the patient was 18.5 ± 1.6 µSv/h, which dropped to 1.8 ± 0.3 µSv/h after imaging the following day, reducing even further to 0.56 ± 0.33 µSv/h after surgery. Conclusion: The effective dose for personnel involved in handling [99mTc]Tc-PSMA-I&S is comparable to that of other 99mTc-radiopharmaceuticals and therefore safe for imaging and radioguided surgery.