Europium-152 as a potential substitute for cobalt-60 in radiation therapy

Construction has begun of prototype europium-152 sources, with the principal goal of providing cost-effective teletherapy for emergent nations where prices for cobalt-60 are excessive, owing to replacement needs, and the use of linacs is economically prohibitive and technologically unfeasible. Eu-152 sources (T-1/2=13.4y vs T-1/2=5.26y for Co-60) are designed for absorbed dose rates >1.5 Gy/min at 1 m, with specific activities >5 TBq/gm, allowing substitution into existing irradiators. Costs of Eu-152 compare favorably with Co-60, taking account of extended useful lifetime. (C) 1996 American Association of Physicists in Medicine.