TABLE 2.

Background ²²⁴Ra Data

Study	Study design and statistical method	n	Sex (n)	Comparison group	Estimated activity (MBq)	Exclusion criteria	Last follow-up	Follow-up time (y)	Alive at analysis	Excess cancers	Excess per 100 subjects	Expected no. of cancers
Nekolla (10)	Site-specific incidence/SIR	682	M: 510 (75%); F: 172 (25%)	None	∼45	Age ≤ 20 y (full cohort, n = 899); lag time^†	2007	∼55	6%	92^*	13^*	56^*
Wick (11)	Site-specific incidence/SIR and RR	1,471	M: 1332 (91%); F: 139 (9%)	1,324	∼10 (0.17/kg)			Mean, 26	32%	23^*	0.3	159

↵* Lung cases not included.
↵^† Nekolla (10) used 5- and 2-y lag times for solid tumors and hematologic malignancies, respectively.
SMR = standardized mortality ratio; SIR = standardized incidence ratio; RR = relative risk.
Mean age was not possible to calculate; reported as <20 y or >20 y.