PET for staging in rhabdomyosarcoma: an evaluation of PET as an adjunct to current staging tools.
BACKGROUND
Complete staging of rhabdomyosarcoma is critical to deliver appropriate therapy. We evaluated the role of F-fluorodeoxyglucose positron emission tomography (PET) in the staging of patients with rhabdomyosarcoma.


METHODS
Twenty-four patients with rhabdomyosarcoma had a PET scan during staging evaluation, before or within 13 days of initiation of therapy. PET was compared with computed tomography (CT), magnetic resonance imaging (MRI), bone scan, and pathology.


RESULTS
Ninety-six sites were evaluated. All patients had positive PET scans at the primary site. Thirty-one PET positive sites at primary, regional, or distant sites were biopsied. Pathology in all 31 confirmed disease. Standardized uptake value for the primary site at diagnosis ranged from 2.4 to 12.7 (mean 6.4). At 23 sites, CT or MRI was equivocal for the detection of regional or distant spread. In these cases, a negative PET helped to exclude disease in 21 of 23 patients. PET failed to capture sites of disease visualized by CT, MRI, or bone scan at 10 sites. When comparing PET with the final clinical determination of disease extent, PET was 77% sensitive and 95% specific.


CONCLUSIONS
These preliminary data indicate that PET is a useful adjunct in staging rhabdomyosarcoma. A prospective study of PET for staging of rhabdomyosarcoma is warranted.
Klem
Michelle L
ML
Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA.
Grewal
Ravinder K
RK
Wexler
Leonard H
LH
Schöder
Heiko
H
Meyers
Paul A
PA
Wolden
Suzanne L
SL
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D012189:Retrospective Studies; D012208:Rhabdomyosarcoma / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18