Alpha Omega Alpha Honor Medical Society

2012 Reseach Abstract

Internal Pair-Production Y-90 PET-CT after Radioembolization of Primary or Metastatic Liver Tumors Compared with Bremsstrahlung SPECT: Our Institutional Experience and Review of the Literature

Investigator: Michael O’Neill, MD (AΩA, Temple University, 2009)

Mentor: Stephanie A. Call, MD, MSPH

Institution: Jackson Memorial Hospital/University of Miami, Department of Diagnostic Radiology

Introduction: Y-90 radioembolization is a frequently utilized method of treating locally advanced liver tumors. Reliable post-therapy imaging is often required to confirm the expected treatment distribution and exclude non-target embolization. SPECT/CT is most commonly employed for this purpose, although it has limitations on spatial resolution. PET/CT can also be used for this purpose and has been increasingly studied in recent years. We present a case series of 7 such patients who underwent PET/CT after Y-90 radioembolization.

Methods: After IRB approval, 7 patients underwent a total of 9 Y-90 PET/CT scans after radioembolization with activities ranging from 0.5-1.7Gbq between January 2012 and January 2014. Enrollment was open to all patients undergoing radioembolization deemed medically stable enough to undergo both the PET/CT and the SPECT scans. Funding allowed for the enrollment of 7 subjects. Baseline clinical characteristics were documented and patients received clinical and imaging follow up per institutional protocol. All patients also underwent post-treatment planar SPECT scanning. PET/CT and SPECT images were examined on a dedicated PACS workstation and correlated with the corresponding angiographic images.

Results: All 7 patients were successfully imaged with both PET/CT and SPECT scans. The higher resolution PET/CT images correlated better with expected treatment distribution than the corresponding SPECT scans by visual assessment. No non-target embolization was noted. Resolution and image quality improved with increases in acquisition time and bed positions, but appeared unrelated to administered activity. Shielding devices and specialized quantitative dosimetric software was not employed.

Conclusions: Post-radioembolization Y-90 PET/CT is a recently emerged imaging technique that can achieve equivalent or higher resolution images of Y-90 distribution than can SPECT or SPECT/CT, and has advantages in dosimetry applications. As the collective clinical and published experience increases, it will likely replace SPECT/CT as the standard of care.

Last Updated: 6/19/14

Updated on June 19, 2014.

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