A multicentre and multi-national evaluation of the accuracy of quantitative Lu-177 SPECT/CT imaging performed within the MRTDosimetry project

EJNMMI Physics

Table 2 SPECT/CT acquisition parameters

Collimator	Medium energy
Photopeak energy (keV)	208.4 ± 20.8 (20% width)^a
Lower scatter energy (keV)	181.3 ± 6.3 (6% width)^b
High scatter energy (keV)	235.5 ± 6.3 (6 % width)^b
Flood uniformity	As per clinical imaging protocol for ¹⁷⁷Lu
Energy calibration peak and source activity	208.4 keV (activity as per manufacturer recommendation)
Matrix size	128
SPECT movement	Body contour
Number of projections	120 (60 per detector)
Time/projection	60 s
Detector movement	Step-and-shoot
CT	Standard low-dose protocol

^aAccording to [11], reasonable quantitative accuracy can be achieved using only the 208 keV peak or including the 113 keV peak for a medium energy collimator. ^b Scatter windows may be adjusted as required by a specific SPECT system or scatter correction method (as used for clinical measurements)