Incorporating cone-beam CT into the treatment planning for yttrium-90 radioembolization.
OBJECTIVE
To prepare for yttrium-90 ((90)Y) microsphere radioembolization therapy, digital subtraction angiography (DSA) and technetium- 99m-labeled macroaggregated albumin ((99m)Tc MAA) scintigraphy are used for treatment planning and detection of potential nontarget embolization. The present study was performed to determine if cone-beam computed tomography (CBCT) affects treatment planning as an adjunct to these conventional imaging modalities.


METHODS
From March 2007 to August 2008, 42 consecutive patients (21 men, 21 women; mean age, 59 years; range, 21-75 y) who underwent radioembolization were evaluated by CBCT in addition to DSA and (99m)Tc MAA scintigraphy during treatment planning, and their records were retrospectively reviewed. The contrast-enhanced territories shown by CBCT with selective intraarterial contrast agent administration were used to predict intrahepatic and possible extrahepatic distribution of microspheres.


RESULTS
In 22 of 42 cases (52%), extrahepatic enhancement or incomplete tumor perfusion seen on CBCT affected the treatment plan. In 14 patients (33%), the findings were evident exclusively on CBCT and not detected by DSA. When comparing CBCT versus (99m)Tc MAA scintigraphy, CBCT showed eight cases of extrahepatic enhancement (19%) that were not evident on (99m)Tc MAA imaging. CBCT findings directed the additional embolization of vessels or repositioning of the catheter for better contrast agent and microsphere distribution. One case of gastric ulcer from nontarget embolization caused by reader error was observed.


CONCLUSIONS
CBCT can provide additional information about tumor and tissue perfusion not currently detectable by DSA or (99m)Tc MAA imaging, which should optimize (90)Y microsphere delivery and reduce nontarget embolization.
Louie
John D
JD
Department of Radiology, Stanford University Medical Center, CA 94305-5642, USA. jdlouie@stanford.edu
Kothary
Nishita
N
Kuo
William T
WT
Hwang
Gloria L
GL
Hofmann
Lawrence V
LV
Goris
Michael L
ML
Iagaru
Andrei H
AH
Sze
Daniel Y
DY
D000328:Adult; D000368:Aged; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional / Q000379:methods*; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome; D015021:Yttrium Radioisotopes / Q000627:therapeutic use*
D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes