Table 1.

Characteristics of hypothetical “ideal radionuclide”

Characteristic	Ideal requirement
Availability	Relative ease of manufacture making it economically viable across a range of healthcare systems
Mechanism of uptake	Innate affinity for areas of bone metastases or easily chelated with other species conferring such affinity
Efficacy	Response rates, with regard to pain, similar to or better than those seen with external beam radiotherapy
Safety—patient	Acceptable toxicity profile
Safety—public	Minimal radiation protection issues—avoiding isolation/inpatient treatment if possible
Safety—environment	Physical half-life allowing practical time from manufacture for delivery and administration but ensuring safe and timely decay within subject or shortly after excretion