Feasibility assessment of yttrium-90 liver radioembolization imaging using amplitude-based gated PET/CT

Abstract

PurposeThe usage of PET/computed tomography (CT) to monitor hepatocellular carcinoma patients following yttrium-90 (90Y) radioembolization has increased. Respiratory motion causes liver movement, which can be corrected using gating techniques at the expense of added noise. This work examines the use of amplitude-based gating on 90Y-PET/CT and its potential impact on diagnostic integrity.Patients and methodsPatients were imaged using PET/CT following 90Y radioembolization. A respiratory band was used to collect respiratory cycle data. Patient data were processed as both standard and motion-corrected images. Regions of interest were drawn and compared using three methods. Activity concentrations were calculated and converted into dose estimates using previously determined and published scaling factors. Diagnostic assessments were performed using a binary scale created from published 90Y-PET/CT image interpretation guidelines.ResultsEstimates of radiation dose were increased (P<0.05) when using amplitude-gating methods with 90Y PET/CT imaging. Motion-corrected images show increased noise, but the diagnostic determination of success, using the Kao criteria, did not change between static and motion-corrected data.ConclusionAmplitude-gated PET/CT following 90Y radioembolization is feasible and may improve 90Y dose estimates while maintaining diagnostic assessment integrity.

EANM dosimetry committee series on standard operational procedures: a unified methodology for 99mTc-MAA pre- and 90Y peri-therapy dosimetry in liver radioembolization with 90Y microspheres

“…For 99m Tc SPECT, studies of the respiratory motion under fluoroscopy are under development, but are not currently commercially available [73,74]. For 90 Y PET, gating is challenging, given the low abundance of annihilation photons, although a case study has reported that this might be feasible [75]. A possible improvement could be obtained using a gated CT, if the performance of the CT scanner is adequate [76].…”

Technical note: Respiratory impacts on static and respiratory gated 99mTc‐MAA SPECT/CT for liver radioembolization: A simulation study

“…Respiratory gated (RG) has been developed and proven to be an efficient method to minimize RM for myocardial PET 9 and SPECT, 10,11 as well as thoracic PET 12 and SPECT 13 in clinical practice. Its usage was also preliminarily demonstrated in reducing the motion‐related image and quantitation degradations in 99m Tc‐MAA SPECT/CT 7,14 and 90 Y microsphere PET/CT 15 …”

“…Its usage was also preliminarily demonstrated in reducing the motion-related image and quantitation degradations in 99m Tc-MAA SPECT/CT 7,14 and 90 Y microsphere PET/CT. 15 Previously, we evaluated different CTs as AC and segmentation maps for static 99m Tc-MAA SPECT in LSF and TNR estimation, where a mismatched CT could cause substantial estimation errors especially for large motion amplitudes. 16 This may also influence the LSF and TNR estimation in RG 99m Tc-MAA SPECT/CT.…”

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

“…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 ].…”