FIGURE 6. Plot of theoretic curve for air dose rate calculated according to general formula described in text and considering 99mTc point source according to Radionuclide and Radiation Protection Data Handbook 1998 (148) (2.5–5 mGy/h/MBq at 100 cm). For normalization purposes, all dose evaluations reported in plot have been derived from published data by conversion to air dose rate calculated at injection time and at different distances from source. Theoretic curve (2.3e-5 mGy/h/MBq at 100 cm, totally independent from data points plotted in graph) well describes pattern of distribution of datasets reported by other groups, either estimated according to other formulas or measured in vivo (patients) or in vitro (phantoms). By slightly overestimating reported dose rates, general formula actually approximates values in excess—a definite plus for radiation safety purposes. – = data from Cremonesi et al. (145) (measured from patients at time of tracer injection); 
= data from Pijpers et al. (146) (measured from patients); 
= data from Pijpers et al. (146) (measured with phantom); 
= data from Stratmann et al. (149) (measured from patients); 
= data from Motta et al. (150) (estimated); • = data from Motta et al. (150) (measured from patients); x = data from Waddington et al. (151) (estimated).
