Reduction of metastatic load to liver after intraarterial hepatic yttrium-90 radioembolization as evaluated by [18F]fluorodeoxyglucose positron emission tomographic imaging.
OBJECTIVE
To assess the response of hepatic metastases after treatment with intraarterial yttrium 90 radioembolization (ie, use of SIR-Spheres) with use of [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET).


METHODS
Nineteen patients with metastatic cancer to the liver from various solid tumors with progression despite polychemotherapy were included. All patients underwent baseline computed tomography, FDG PET, hepatic angiography, and intraarterial technetium 99 m macroaggregated albumin scan for assessment of lung shunting fraction. Patients were treated with 90Y resin microspheres on a lobar basis and were monitored for 3 months with use of dedicated attenuation-corrected PET. For each patient, regions of interest were drawn along the liver edge to measure total liver standard uptake value (SUV) on axial images, covering the entire liver. Visual estimates were also performed and graded as +1, 0, -1, -2, or -3 for progression, no change, and mild, moderate, and dramatic improvement by posttreatment PET.


RESULTS
The median absorbed dose for the tumor was 76 Gy. There was a significant overall decrease in total liver SUV after treatment (baseline, 71,134 +/- 38,055; after SIR-Sphere treatment, 59,941 +/- 26,509; P = .028) for the entire group. Visual estimates placed 15 patients (79%) in response categories (-3 to -1) and four patients (21%) in nonresponse categories (0 to +1) for the liver. The percentage change of total liver SUV after treatment in the response group (-19%) was significantly greater and different in direction than that in the nonresponse group (+27%; P = .03). This percentage change was also correlated significantly with the respective visual estimates (r = 0.72; P < .0005) for each individual patient. Three patients had major complications related to hyperbilirubinemia (transient, n = 1; permanent, n= 2).


CONCLUSIONS
The results suggest that there is significant reduction of hepatic metastatic load as evaluated objectively by PET after 90Y radioembolization for the treatment of unresectable metastatic disease to the liver. 90Y radioembolization provides encouraging results by arresting progression of metastatic cancer to the liver.
Wong
Ching-Yee Oliver
CY
Positron Diagnostic Center and Medical Cyclotron, Department of Nuclear Medicine, William Beaumont Hospital, 3601 West 13 Mile Road, Royal Oak, MI 48073-6769, USA.
Qing
Feng
F
Savin
Michael
M
Campbell
Janice
J
Gates
Vanessa L
VL
Sherpa
Kanchi M
KM
Lewandowski
Robert J
RJ
Nagle
Conrad
C
Salem
Riad
R
D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D006499:Hepatic Artery; D006801:Humans; D007269:Injections, Intra-Arterial; D008099:Liver / Q000528:radiation effects; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D008168:Lung / Q000528:radiation effects; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D011879:Radiotherapy Dosage; D015021:Yttrium Radioisotopes / Q000008:administration & dosage*
D019275:Radiopharmaceuticals; D015021:Yttrium Radioisotopes; D019788:Fluorodeoxyglucose F18