Verification of I-125 brachytherapy source strength for use in radioactive seed localization procedures.

A general-purpose nuclear medicine dose calibrator was assessed as a potential replacement for a dedicated air-communicating well-type ionization chamber (brachytherapy source strength verification instrument) for (125)I seed source strength verification for radioactive seed localization, where less stringent accuracy tolerances may be acceptable. The accuracy, precision and reproducibility of the dose calibrator were measured and compared to regulatory requirements. The results of this work indicate that a dose calibrator can be used for (125)I seed source strength verification for radioactive seed localization.

90Sr content in 90Y-labeled SIR-spheres and Zevalin.

Three different 90Y internally administered radionuclide therapies are currently used in both standard-of-care and clinical trial procedures atMD Anderson Cancer Center. TheraSphere and SIR-Spheres therapies utilize 90Y-labeled microspheres, while Zevalin is an 90Y-labeled radioimmunotherapeutic agent. Several publications have indicated radionuclidic impurities resulting from 90Y production methods.

Long-lived impurities of 90Y-labeled microspheres, TheraSphere and SIR-spheres, and the impact on patient dose and waste management.

Yittrium-90 microsphere brachytherapy procedures have increased in number due to their efficacy in treating some unresectable metastatic liver tumors. The discovery of long-lived impurities in two microsphere products, first reported between 2006 and 2007, has resulted in some radiation safety concerns. Since then, microsphere production processes have been refined, which reportedly lead to a reduction in detectable by-products.