Extremity radiation dose reduction in radiosynoviorthesis procedures by development of 3D printed finger protection ring.

Radiation exposure to the fingers of clinicians carrying out radiosynoviorthesis with yttrium citrate (90Y) can be an area of concern if equipment or practice is sub-optimal, with contact dose rates in the mSv·s-1range around the syringe and needle neck. Syringe shields reduce potential exposure around the syringe but offer no protection around the needle neck. There are no commercially available protection products in the United Kingdom to address this deficiency. Clinical safety requires that the clinician is able to feel the position of the needle and limit the amount of needle movement at critical times. Although direct handling of the needle neck presents the easiest solution, radiation protection concerns make this unacceptable, and leave forceps the only established alternative to minimise finger doses. We present a further method to address these issues-a locally designed infection control compliant finger protection ring which has been 3D printed and used at the authors' hospital. Potential extremity doses have been measured for three methods. 1, direct finger contact with the needle neck, 2, forceps, and 3, use of a 3D printed ring. Finger dose coefficients with the first method (direct contact) have been demonstrated experimentally to be as high as 33µSv·MBq-1, with even higher results recorded in clinical practice at 79.5µSv·MBq-1. The second method (forceps) reduces the potential skin dose coefficient to less than 1µSv·MBq-1. The third method (finger protection ring) achieves a similar dose coefficient to forceps. Forceps are more technically demanding for the clinician. This new finger protection ring ensures that patient safety is maintained, the procedure is technically easier for the clinician, finger doses are as low as Reasonably Practicable, and contamination risk is reduced.