Abstract

Objectives: Demonstrate the accuracy of internal pair-production PET/CT in the depiction of the treatment distribution of Y-90 radioembolization, as well as quantify the specific activity of the treated areas with TN ratios. These will be correlated with other metrics such as admistered activity and ultimately to survival and recurrence data to ascertain possible prognostic value. Methods:The measures include: Degree of correlation with expected vs. achieved tumor coverage by the treatment; Degree of anatomic dose correlation between treatment distribution depicted by the two modalities; Determination of TN ratios of treated areas vs. non-treated background liver parenchyma, for later correlation with various patient outcomes; Detection of non-target embolization, where applicable, and qualitative comparison between the two modalities as to the conspicuity of the abnormality. Results: We have thus far demonstrated high quality and accurate PET/CT studies in all subjects, which correlate well with both the known distribution of tumor burden and with the angiographic findings. 3 patients received BS SPECT and Y-90 PET/CT post-radioembolization with a commonly used Phillips Gemini scanner. Acquisition time was in the range of 20-30 minutes. Conclusions: Assessment of Y-90 embolization can be achieved readily with commonly used PET or PET/CT scanners PET may provide superior resolution when compared to traditional Brehmsstrahlung SPECT Improved imaging resolution post-Y-90 embolization may aid in more accurately determining dose distribution and non-target embolization where SPECT/CT is not readily available. As PET technology continues to evolve and as our experience with this often overlooked technique improves, internal pair-production PET/CT may eventually become the standard of care in this setting. Future studies will further explore PET/CT–based dosimetric methadologies, and paired with Pre- and post- Y-90 FDG PET or CTA, may potentially prove to have prognostic value.