title: The value of positron emission tomography and proliferation index in predicting progression in low-grade astrocytomas of childhood.
abstract: Astrocytomas are the most common brain tumors of childhood and adolescence. Low-grade astrocytomas (LGAs), in general, have favorable prognosis, but recurrence or progressive disease with dissemination, malignant transformation, and death occur in some cases. Current clinical and pathological measures including age, sex, imaging characteristics, location and size of the tumor, histopathology, and degree of resection cannot predict with certainty which tumors will demonstrate aggressive behavior. The objective of the study is to determine the predictive value of positron emission tomography (PET) and a proliferation index (PI) in identifying high risk LGAs. We reviewed 46 cases ages 5 months to 17 years with low-grade (WHO I-II) astrocytomas. All patients had PET scans utilizing [(18)F] fluorodeoxyglucose (FDG) and 24 cases had measurements with Ki-67/MIB-1 immunohistochemistry. Review of our data confirmed progressive disease (PD) in 18/46 (39%) of cases with 9/21 (42%) occurring after subtotal resection and 9/25 (36%) after gross total resection. The mortality rate was 5/46 (10.8%). Tumors with FDG hypermetabolism were significantly more likely to demonstrate aggressive behavior and PD. Increased PI values also suggested PD. Progression-free survival and time to progression were significantly longer for patients with hypometabolic scans. Time to progression was significantly longer with lower PI values. Results demonstrate that PET and PI are useful measures in the identification and stratification of high risk LGAs. The ability to identify a subset of progressive LGAs earlier may suggest the need for second-look neurosurgical procedures or more intensified adjuvant treatment that may ultimately improve outcome and survival.
authors.affiliation: Division of Pediatrics, Phoenix Children's Hospital, Phoenix, AZ, 85016, USA.|Divisions of Pediatric Neurology and Developmental Pediatrics, Child Development and Rehabilitation Center, Oregon Health & Science University, Portland, OR, 97239, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Kruer
authors.affiliation: Division of Child Neurology, Phoenix Children's Hospital, 1919 E. Thomas Road, Phoenix, AZ, 85016, USA. akaplan@phoenixchildrens.com.
authors.forename: Allen M
authors.initials: AM
authors.lastname: Kaplan
authors.affiliation: Division of Hematology/Oncology, Phoenix Children's Hospital, Phoenix, AZ, 85016, USA.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Etzl
authors.affiliation: Division of Pathology, Phoenix Children's Hospital, Phoenix, AZ, 85016, USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Carpentieri
authors.affiliation: Division of Pathology, Phoenix Children's Hospital, Phoenix, AZ, 85016, USA.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Dickman
authors.affiliation: Banner Samaritan PET Center, Phoenix, AZ, 85015, USA.
authors.forename: Kewei
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Mathematics and Statistics, Arizona State University, Tempe, AZ, 85287, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Mathieson
authors.affiliation: Banner Samaritan PET Center, Phoenix, AZ, 85015, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Irving
mesh_terms: D000293:Adolescent; D001254:Astrocytoma / Q000000981:diagnostic imaging* / Q000378:metabolism; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D011379:Prognosis; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D015996:Survival Rate; D014018:Tissue Distribution
chemical_list: D019394:Ki-67 Antigen; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18