A novel tool for motion-related dose inaccuracies reduction in 99mTc-MAA SPECT/CT images for SIRT planning

Dosimetric impact of 3D motion-compensated SPECT reconstruction for SIRT planning

“…On patient cohort, Santoro et al [ 25 ] compared mean absorbed doses of lungs and tumors and showed a variability of ± 4 Gy and ± 50 Gy, respectively, which is consistent with our results (± 2 Gy and ± 38 Gy). The impact of respiratory movement on the activity to be prescribed does not appear to have been studied previously.…”

“…In [ 23 , 24 ], the authors evaluated dosimetric impacts of motion by performing simulations from digital XCAT phantoms with different sets of parameters (body type, lung shunt fraction (LSF), tumor volume and localization). Likewise, Santoro et al [ 25 ] tested a novel method to compensate for motion on a modified CIRS dynamic phantom and applied it on the data of twelve selected patients (HCC, single lesion). However, the realism of simulations and phantoms is limited (perfect respiratory cycle and simplifications in the movement, characteristics of each patient, assumption of a perfectly compensated scatter [ 24 ]).…”

“…However, the realism of simulations and phantoms is limited (perfect respiratory cycle and simplifications in the movement, characteristics of each patient, assumption of a perfectly compensated scatter [ 24 ]). In contrast to our method based on list-mode data, Santoro et al [ 25 ] corrected for respiratory motion by realigning the barycenters of the lesions in the projections with each other before realigning them on the CT to improve attenuation correction and VOI definitions [ 36 ]. The latter registration consisted to have the same distance between the hepatic dome defined on the CT and the top of the lesion on two imaging modalities (SPECT and CT).…”

“…However, to our knowledge, it is not used during SIRT although the liver movement due to breathing is well known [ 22 ]. Bastiaannet et al [ 23 ] and Lu et al [ 24 ] studied the dosimetric impact of breathing motion on numerical phantoms (physical phantoms in [ 25 ]) and showed that it is the main undesirable effect for the quantification in radioembolization. To our knowledge, this impact has only been evaluated by Santoro et al [ 25 ] on 12 SPECT patients images with a single liver lesion, which is not representative of all patients treated by SIRT.…”

“…Bastiaannet et al [ 23 ] and Lu et al [ 24 ] studied the dosimetric impact of breathing motion on numerical phantoms (physical phantoms in [ 25 ]) and showed that it is the main undesirable effect for the quantification in radioembolization. To our knowledge, this impact has only been evaluated by Santoro et al [ 25 ] on 12 SPECT patients images with a single liver lesion, which is not representative of all patients treated by SIRT. Such an evaluation was performed on post-treatment PET imaging [ 26 ] and has shown dose differences in the lesions and in the liver [ 27 ].…”