Neutron-activated biodegradable samarium-153 acetylacetonate-poly-L-lactic acid microspheres for intraarterial radioembolization of hepatic tumors

Table 1 Neutron activation protocols for activation of samarium acetylacetonate-poly-L-lactic acid microspheres

Protocol	Pneumatic transfer system	Rotary specimen rack
Thermal neutron flux, θth (n/cm2/s)	5.0 x 1012	2.0 x 1012
Maximum duration of neutron activation	Up to 5 min	Up to 6 h
Location of neutron activation	Near to the core	Peripheral to the core
Sample delivery	Automatic	Manual

Table 2 Physicochemical properties of the neutron-activated samarium-153 acetylacetonate-poly-L-lactic acid microspheres

Physicochemical properties	100% (w/w) 153SmAcAc-PLLA	150% (w/w) 153SmAcAc-PLLA	175% (w/w) 153SmAcAc-PLLA	200% (w/w) 153SmAcAc-PLLA
Mean diameter (µm)	34.35 ± 0.18	36.56 ± 0.16	37.29 ± 0.17	38.77 ± 0.21
Density (g/cm3)	1.25 ± 0.030	1.29 ± 0.006	1.31 ± 0.047	1.35 ± 0.068
Number of microspheres per g	37 million	30 million	28 million	24 million
Settling velocity (cm/s )	0.016 ± 0.0004	0.019 ± 0.0002	0.022 ± 0.0003	0.027 ± 0.0004
Specific activity (GBq/g)	1.74 ± 0.05	2.45 ± 0.05	2.69 ± 0.07	2.77 ± 0.09
Activity per particle (Bq)	46.31 ± 1.33	81.01 ± 1.65	95.40 ± 2.48	114.37 ± 3.72
Samarium content (%)	12.06 ± 0.69	14.56 ± 0.28	16.32 ± 0.34	17.28 ± 0.46

¹⁵³SmAcAc-PLLA: Samarium-153 acetylacetonate-poly-L-lactic acid.