99mTc-Macroaggregated Albumin Poorly Predicts the Intrahepatic Distribution of 90Y Resin Microspheres in Hepatic Radioembolization

Journal of Nuclear Medicine

Maurits Wondergem¹  Maurice A.A.J. van den Bosch¹  Johannes F.W. Nijsen¹  Marnix G.E.H. Lam¹  Mattijs Elschot¹  Hugo W.A.M. de Jong¹  Helena M. Verkooijen¹  Maarten L.J. Smits¹ 

[1] Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands Department of Radiology and Nuclear Medicine, UMC Utrecht, Utrecht, The Netherlands

关键词: ^99mTc-MAA;    ⁹⁰Y microspheres;    radioembolization;    dosimetry;    liver;   

DOI  :  10.2967/jnumed.112.117614

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

In hepatic 90Y radioembolization, pretreatment 99mTc-macroaggregated albumin (99mTc-MAA) nuclear imaging is used for lung shunt analysis, evaluation of extrahepatic deposition, and sometimes for treatment planning, using a partition model. A high level of agreement between pretreatment 99mTc-MAA distribution and final 90Y-microsphere distribution is assumed. The aim of this study was to investigate the value of pretreatment 99mTc-MAA SPECT to predict intrahepatic posttreatment 90Y-microsphere distribution. Methods: Volumes of interest (VOIs) were delineated on pretreatment contrast-enhanced CT or MR images according to Couinaud liver segmentation. All VOIs were registered to the 99mTc-MAA SPECT and 90Y SPECT images. The 99mTc-MAA SPECT and 90Y SPECT activity counts were normalized to the total administered activity of 90Y. For each VOI, this practice resulted in a predictive amount of 90Y (MBq/cm3) based on 99mTc-MAA SPECT in comparison with an actual amount of 90Y based on 90Y SPECT. Bland–Altman analysis was used to investigate the agreement of the activity distribution between 99mTc-MAA SPECT and 90Y SPECT. Results: A total of 39 procedures (225 VOIs) in 31 patients were included for analysis. The overall mean difference between pretreatment and posttreatment distribution of activity concentration for all segments was −0.022 MBq/cm3 with 95% limits of agreement of −0.581 to 0.537 MBq/cm3 (−28.9 to 26.7 Gy absorbed dose). A difference of >10%, >20%, and >30% of the mean activity per milliliter was found in, respectively, 153 (68%), 97 (43%), and 72 (32%) of the 225 segments. In every 99mTc-MAA procedure, at least 1 segment showed an under- or overestimation of >10%. The position of the catheter tip during administrations, as well as the tumor load of the liver segments, significantly influenced the disagreement. Conclusion: In current clinical practice, 99mTc-MAA distribution does not accurately predict final 90Y activity distribution. Awareness of the importance of catheter positioning and adherence to specific recommendations may lead to optimization of individualized treatment planning based on pretreatment imaging.

【 授权许可】

Unknown