Comparison of iodine-123 metaiodobenzylguanidine (MIBG) scan and [18F]fluorodeoxyglucose positron emission tomography to evaluate response after iodine-131 MIBG therapy for relapsed neuroblastoma.
OBJECTIVE
Children with relapsed neuroblastoma have poor survival. It is crucial to have a reliable method for evaluating functional response to new therapies. In this study, we compared two functional imaging modalities for neuroblastoma: metaiodobenzylguanidine (MIBG) scan for uptake by the norepinephrine transporter and [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) uptake for glucose metabolic activity.


METHODS
Patients enrolled onto a phase I study of sequential infusion of iodine-131 ((131)I) MIBG (NANT-2000-01) were eligible for inclusion if they had concomitant FDG-PET and MIBG scans. (131)I-MIBG therapy was administered on days 0 and 14. For each patient, we compared all lesions identified on concomitant FDG-PET and MIBG scans and gave scans a semiquantitative score.


RESULTS
The overall concordance of positive lesions on concomitant MIBG and FDG-PET scans was 39.6% when examining the 139 unique anatomic lesions. MIBG imaging was significantly more sensitive than FDG-PET overall and for the detection of bone lesions (P < .001). There was a trend for increased sensitivity of FDG-PET for detection of soft tissue lesions. Both modalities showed similar improvement in number of lesions identified from day 0 to day 56 scan and in semiquantitative scores that correlated with overall response. FDG-PET scans became completely negative more often than MIBG scans after treatment.


CONCLUSIONS
MIBG scan is significantly more sensitive for individual lesion detection in relapsed neuroblastoma than FDG-PET, though FDG-PET can sometimes play a complementary role, particularly in soft tissue lesions. Complete response by FDG-PET metabolic evaluation did not always correlate with complete response by MIBG uptake.
Taggart
Denah R
DR
Department of Pediatrics and Nuclear Medicine, University of California, San Francisco, CA 94143-0106, USA.
Han
Myo M
MM
Quach
Alekist
A
Groshen
Susan
S
Ye
Wei
W
Villablanca
Judith G
JG
Jackson
Hollie A
HA
Mari Aparici
Carina
C
Carlson
David
D
Maris
John
J
Hawkins
Randall
R
Matthay
Katherine K
KK
D019797:3-Iodobenzylguanidine; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D017321:Clinical Trials, Phase I as Topic; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D009364:Neoplasm Recurrence, Local; D009447:Neuroblastoma / Q000175:diagnosis* / Q000532:radiotherapy; D017063:Outcome Assessment, Health Care / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D007457:Iodine Radioisotopes; D019788:Fluorodeoxyglucose F18; D019797:3-Iodobenzylguanidine