Which radioactive source can be used for a dose calibrator accuracy test?

The choice of a radioactive source for a dose calibrator accuracy test is crucial in ensuring that the device measures radioactivity levels correctly. The ideal source should emit gamma radiation, facilitating calibration checks at appropriate energy levels that correspond to the isotopes commonly used in nuclear medicine.

Cesium-137 (137Cs) is particularly suitable for this purpose because it emits gamma radiation with a well-defined energy peak at 662 keV. This energy is optimal for verifying the accuracy of dose calibrators, as it is relevant to a range of radiopharmaceuticals used in practice. By using a standard source like 137Cs, facilities can ensure that their dose calibrators provide precise measurements, which is vital for patient safety and treatment efficacy.

The other choices present isotopes with characteristics that make them less ideal for this specific task. Technetium-99m (99mTc), although widely used in nuclear medicine, emits gamma photons at 140 keV, which may not cover the high energy spectrum that 137Cs provides. Moreover, the activity levels of the other options either do not meet the regulatory standards for accuracy testing or do not provide the necessary stability for reliable readings.