MED
In the literature: open
Quantitative imaging of low-yield therapeutic emitters
In plain words
To compute the dose, the drug must be seen and counted inside the body, but alpha-emitting drugs give off very few detectable photons.
Precise statement
Achieve activity quantification to better than 10 percent for therapeutic nuclides with sparse or complex photon emission, notably Ac-225 at administered activities of order 2.7 microCi per kg (about 0.2 mCi per patient), imaged through the daughter gamma lines at 218 keV (Fr-221) and 440 keV (Bi-213), and Pb-212 at 239 keV, including scatter, collimator septal penetration and partial-volume correction. An answer is a calibrated imaging and reconstruction protocol with measured accuracy.
What would settle it
Phantom and patient measurements with independent activity ground truth demonstrating the stated accuracy.