Facile access to 154Eu, a new reference source for calibration in gamma ray spectrometry

Development of granular radioactive reference source from 152,154Eu adsorbed on tin tungstate matrix

A reference source with the granular active portion was made using 152,154Eu(III) loaded tin tungstate material. Batch equilibration method was used to investigate the interaction of 152,154Eu(III) radiotracer (10−4 M) in acid solutions on tin(IV) tungstate gel matrix. The sorption behavior of 152,154Eu(III) showed high affinity towards tin(IV) tungstate gel matrix at low pH values. Tin tungstate gel matrix was loaded with 152,154Eu from batch at pH 3. Standardization of the source was done spectroscopically with reference to primary certified set of radioactive sources and with the aid of HPGe detector. Random and true coincidence summing was carried out by following-up coincidence in 152Eu and possible interference between γ lines of 152Eu and 154Eu. The relation between the grain size and the activity of samples was studied. Correction factor for capsule attenuation was applied.

Samarium lexidronam (153Sm-EDTMP): skeletal radiation for osteoblastic bone metastases and osteosarcoma

Radiation therapy can be an effective means to treat bone metastases, which occur in more than 50% of cancer patients. (153)Samarium lexidronam ((153)Sm-EDTMP; Quadramet, Cytogen) is a radiopharmaceutical designed for deposition into bone metastases. Bone scans can identify patients that may benefit from targeted radiation therapy with (153)Sm-EDTMP. As an unsealed source of radiation therapy, (153)Sm-EDTMP is simple to administer: 1 mCi/kg is given in a similar fashion to a bone scan injection ((99m)Tc-MDP bone scan injection is given at 0.2-0.35 mCi/kg. Therefore, both are administered intravenously. However, the radiation-absorbed dose and radiopharmaceutical energy are different). Nevertheless, despite simplicity of administration, (153)Sm-EDTMP is underutilized for improving cancer pain in the skeleton. Repeated cycles and combined treatment with other modalities such as bisphosphonates, chemotherapy and/or external beam radiation are possible. (153)Sm-EDTMP combined with bisphosphonates, chemotherapy and/or radiation may provide better palliation of bone metastases and also in bone-forming tumors (osteosarcoma). Encouraging experience using high-dose (153)Sm-EDTMP for total marrow irradiation in hematologic malignancies involving the bones (e.g., myeloma or acute leukemia) is also reviewed.