Quantitative analysis of post transarterial radioembolization Yttrium-90 microsphere PET/CT images in advanced liver malignancy: Comparison with pretreatment 99mTc-macroaggregated albumin SPECT

초록

Objectives The purpose of this study is evaluating the feasibility and characteristics of 90Y-PET/CT images by quantitative comparison with 99mTc-macroaggregated albumin SPECT. Methods From 2010 January to 2012 December, thirty-three patients with advanced liver malignancy were retrospectively enrolled who underwent 90Y-microsphere treatment (M : F = 23 : 10, Age 58.8 ± 11.6 y). Patients underwent 99mTc-MAA SPECT as pretreatment evaluation. In cases of abnormally high gastrointestinal activity in SPECT image, coil embolization and/or changing the position of the microcatheter tip were considered. After administration of 90Y microsphere, patients underwent post-treatment 90Y-PET/CT images within 24 hours. Quantitative analysis and comparison using tumor-to-normal uptake ratios (TNRs) were done for 99mTc-MAA SPECT (TNS) and 90Y-PET/CT (TNP) by two nuclear medicine physicians. Results Both PET/CT and SPECT images demonstrated distribution of radiopharmaceuticals in the liver of forty-six tumor lesions from thirty-three patients. Thirteen patients underwent coil embolization and fourteen patients underwent tip relocation before 90Y-microsphere administration. Quantitative analysis showed TNP was positively correlated with TNS (p<0.001). However, TNP (3.70 ± 3.62) was significantly higher than TNS (2.46 ± 2.33). TNRs between coiled and non-coiled, tip relocated and non-relocated group were not significantly different. Conclusions 90Y-microsphere PET/CT provide good image quality and low background scatter. It could be useful for evaluation of 90Y-microsphere treatment for advanced liver malignancy. Further studies about discrepancies between 90Y-PET/CT and 99mTc-MAA SPECT is needed.