177mLu impurity: Practical aspects of 177mLu hospital waste management
1248 Objectives In our facility we performing weekly up to two treatments with a standard dose of 7,5 GBq [Lu-177][DOTA0, Tyr3]octreotate. Due to the similar half-lives I-131 ( t1/2=8 d), Lu-177 ( t1/2= 6,7 d) and Y-90 (t1/2=2,6 d) were released in one tank. Depending on the production route there could be impurities of durable 177mLu (t1/2= 160 d) which prevents the timely release of the waste. The aim of our study was the development of a conversion method of the liquid wastes into gel the resulting possibility of disposal at the national collection point. Methods 10 GBq 177Lu-DOTA-tate (n=3)were prepared with an automatic synthesis unit. After the nephroprotectic infusion of 1,5 l Aminosteril N-Hepa 8% 7,5 GBq [177Lu][DOTA0,Tyr3]octreotate were administered. The excreta of the patient were collected within the first 24 h and the volume and activity was measured. The absorption behavior of super-absorbers for water, NaCl and urine was estimated. Storage for a period of 3 months was tested. Results The labeling results in radio-chemical yields ≥ 98 % and a total volume of 20 mL. We found that the precipitated volume was 2,42 ± 0,18 L containing 74 ±2,2 % (5602 ± 166 MBq) of the administered activity. Based on this data’s, an accumulation of approximately 10GBq 177Lu and 12 MBq 177mLu at the end of 40 days were calculated. The superabsorber showed a absorber-volume ratio for water of 0,013 and for sodium chloride which is similar to urine of 0,02 . No changes in the properties or release of activity could be observed Conclusions Because of the high activities of 7,5 GBq per patient and the resulting amount of ~ 3 MBq 177mLu the waste has to be collected separately. The conversion from liquid to solid form using superabsorbers guaranteed an easier and saver handling, storing at smaller space as well as uncomplicated collecting, shipping and deposition for decay. But the most important argument is the huge financial savings per year.