Dealing with dry waste disposal issues associated with 177mLu impurities: a long-term challenge for nuclear medicine departments

EJNMMI Physics

Table 4 Data for N biohazard containers measured in July 2021 to determine (ER/2BKG) ratios

Period of treatments	November 2017–June 2018	Second half 2018	First half 2019
Number of biohazard containers stored (N)	18	17	26
Storage time (median [range] in months)	40.1 [37.5–44.8]	34.7 [31.9–37.1]	26.7 [23.1–30.9]
(ER/2BKG) Ratio*—July 2021(median [range])	0.7 [0.5–1.2]	0.7 [0.6–3.0]	1.1 [0.7–2.3]
Additional storage time required (months)	0	12	6
Calculated date of disposal	July 2021	July 2022	December 2021
Compliance with predicted storage times (3 years)	Yes	Yes (94.1%)**	Yes

*ER Exposure rate measured in contact with the container; 2BKG = 0.1 μSv.h⁻¹ regulatory clearance level of twice-the-background
**Only 1 of 17 containers with an ER of 0.3 μSv.h⁻¹ requires 12 additional months for decay. Others were disposed of in July 2021