Table 1. Comparison of Properties of Radioactive Beta Emitting Radioisotopes.

Radioisotope	Emits	Maximum beta Energy (MeV)	Range	Half-life (days)
131Iodine	Beta	0.6	1.6 mm. (avg.)	8
90Yttrium	Beta	2.3	5 mm. (avg.)	2.7
32P	Beta	1.7	Up to 5 mm.	14.3

Bexxar (¹³¹I-anti-CD20) and Zevalin (⁹⁰Y-anti-CD20) are FDA-approved for the treatment of non-Hodgkin's lymphoma.