title: Protracted radiotherapy treatment duration in medulloblastoma.
abstract: From 1970 to 1997, 63 patients with medulloblastoma were treated with craniospinal irradiation followed by a posterior fossa boost. There were 38 males and 25 females with a median age of 9 years (range, 8 months to 53 years). Stage was T1-T3a in 50 (79%) and M0 in 38 patients (60%) according to the Chang staging system. Gross total resection of the primary tumor was achieved in 33 (52%) and median posterior fossa dose was 54 Gy, with 55 (87%) receiving > or =50 Gy. Median radiotherapy treatment duration was 49 days (range, 30-104 days) with 35 patients (56%) completing radiotherapy in <50 days. The most common reasons for a protracted radiotherapy treatment duration > or =50 days were hematologic toxicity (46%) and use of <1.6 Gy fraction size per day (29%). Chemotherapy was used in 22 (35%). Median follow-up time was 10.8 years (range, 2-28.5 years). The 5- and 10-year freedom from progression rates were 58% +/- 13% and 50% +/- 13%, respectively, whereas the 5- and 10-year posterior fossa control rates were 61% +/- 12% and 54% +/- 13%, respectively. On multivariate analysis, age > or =3 years, M0 status, > or =50 Gy PFB dose, radiotherapy treatment duration <50 days, and use of chemotherapy correlated with better freedom from progression and posterior fossa control rates. The 5- and 10-year freedom from progression rates were 67% +/- 15% and 64% +/- 16%, respectively, for patients with radiotherapy treatment duration <50 days and were 42% +/- 20% and 29% +/- 18%, respectively, for duration > or =50 days ( p= 0.0026, log-rank test). The 5- and 10-year posterior fossa control rates were 70% +/- 15% and 70% +/- 15%, respectively, for radiotherapy treatment duration <50 days and 46% +/- 20% and 33% +/- 19%, respectively, for duration > or =50 days ( p= 0.0037, log-rank test). In addition to age > or =3 years, M0 stage, use of adjuvant chemotherapy, and posterior fossa dose > or =50 Gy, our findings also reveal that radiotherapy treatment duration <50 days has a favorable prognostic outcome in patients with medulloblastoma.
authors.affiliation: Department of Radiation Oncology, the University of Iowa, College of Medicine and Children's Hospital of Iowa, Iowa City, Iowa, USA. arnold@radonc.emory.org
authors.forename: Arnold C
authors.initials: AC
authors.lastname: Paulino
authors.forename: B-Chen
authors.initials: BC
authors.lastname: Wen
authors.forename: Nina A
authors.initials: NA
authors.lastname: Mayr
authors.forename: Raymond
authors.initials: R
authors.lastname: Tannous
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Loew
authors.forename: Frederick D
authors.initials: FD
authors.lastname: Goldman
authors.forename: Sanford L
authors.initials: SL
authors.lastname: Meeks
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Ryken
authors.forename: John M
authors.initials: JM
authors.lastname: Buatti
mesh_terms: D000293:Adolescent; D000328:Adult; D002528:Cerebellar Neoplasms / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D003388:Cranial Fossa, Posterior; D016371:Cranial Irradiation; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000532:radiotherapy* / Q000601:surgery; D008875:Middle Aged; D011879:Radiotherapy Dosage; D016019:Survival Analysis; D016896:Treatment Outcome