The significance of 99mTc-MAA SPECT/CT liver perfusion imaging in treatment planning for 90Y-microsphere selective internal radiation treatment.
Selective internal radiation therapy (SIRT), a catheter-based liver-directed modality for treating primary and metastatic liver cancer, requires appropriate planning to maximize its therapeutic response and minimize its side effects. (99m)Tc-macroaggregated albumin (MAA) scanning should precede the therapy to detect any extrahepatic shunting to the lung or gastrointestinal tract. Our aim was to compare the ability of SPECT/CT with that of planar imaging and SPECT in the detection and localization of extrahepatic (99m)Tc-MAA accumulation and to evaluate the impact of SPECT/CT on SIRT treatment planning and its added value to angiography in this setting.


METHODS
Ninety diagnostic hepatic angiograms with (99m)Tc-MAA were obtained for 76 patients with different types of cancer. All images were reviewed retrospectively for extrahepatic MAA deposition in the following order: planar, non-attenuation-corrected SPECT, and SPECT/CT. Review of angiograms and follow-up of patients with abdominal shunting served as reference standards.


RESULTS
Extrahepatic accumulation was detected by planar imaging, SPECT, and SPECT/CT in 12%, 17%, and 42% of examinations, respectively. The sensitivity for detecting extrahepatic shunting with planar imaging, SPECT, and SPECT/CT was 32%, 41%, and 100%, respectively; specificity was 98%, 98%, and 93%, respectively. The respective positive predictive values were 92%, 93%, and 89%, and the respective negative predictive values were 71%, 73%, and 100%. The therapy plan was changed according to the results of planar imaging, SPECT, and SPECT/CT in 7.8%, 8.9%, and 29% of patients, respectively.


CONCLUSIONS
In pre-SIRT planning, (99m)Tc-MAA SPECT/CT is valuable for identifying extrahepatic visceral sites at risk for postradioembolization complications.
Ahmadzadehfar
Hojjat
H
Department of Nuclear Medicine, University Hospital Bonn, Bonn, Germany. Hojjat.ahmadzadehfar@ukb.uni-bonn.de
Sabet
Amir
A
Biermann
Kim
K
Muckle
Marianne
M
Brockmann
Holger
H
Kuhl
Christiane
C
Wilhelm
Kai
K
Biersack
Hans-Jürgen
HJ
Ezziddin
Samer
S
D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003627:Data Interpretation, Statistical; D004621:Embolization, Therapeutic; D005260:Female; D005704:Gallbladder / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging*; D008102:Liver Circulation / Q000502:physiology*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D010347:Patient Care Planning; D011875:Radionuclide Angiography; D019275:Radiopharmaceuticals; D012015:Reference Standards; D013668:Technetium Tc 99m Aggregated Albumin; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon; D015021:Yttrium Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*
D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin; D015021:Yttrium Radioisotopes