title: Tumor control and QoL outcomes of very young children with atypical teratoid/rhabdoid tumor treated with focal only chemo-radiation therapy using pencil beam scanning proton therapy.
abstract: The aim of this analysis was to assess the early clinical results of pencil beam scanning proton therapy (PT) in the treatment of young children with non-metastatic atypical teratoid/rhabdoid tumor (ATRT) of the CNS. Fifteen children (male, n = 8, 53 %) were treated with PT between May 2008 and January 2013. Mean age at diagnosis was 17.4 ± 7.0 months. The localization was infratentorial in 9 (60 %) patients. Gross total resection of the primary tumors was achieved in 7 (47 %) patients. The dose administered focally under sedation was 54 Gy (RBE). After a median follow-up of 33.4 months (range 9.7-69.2), 3 (20 %), 4 (27 %) and 2 (13 %) patients presented with local failure (LF), distant brain failure (DBF) and spinal failure (SF), respectively. Six patients died, all of tumor progression. The 2-year overall- and progression-free survival was 64.6 and 66.0 %. Tumor location (supratentorial) and the extent of surgical resection (non-gross total resection) were negative prognostic factors for both OS and PFS. PT was well tolerated. No grade >2 acute toxicity was observed. The estimated 2-year toxicity-free survival was 90 %. As assessed by the PedsQoL proxy, no decrease in QoL was observed after PT. We conclude that PBS PT is an effective treatment for young children with ATRT. After PT, with or without concomitant chemotherapy, two third of the patients survived >2 years. Acute toxicity was manageable. Longer follow-up and larger numbers of patients are needed to assess long-term outcomes and treatment-induced toxicity.
authors.affiliation: Center for Proton Therapy, Paul Scherrer Institute, WPTA 144, CH-5232, Villigen West, Switzerland, damien.weber@psi.ch.
authors.forename: Damien C
authors.initials: DC
authors.lastname: Weber
authors.forename: Carmen
authors.initials: C
authors.lastname: Ares
authors.forename: Robert
authors.initials: R
authors.lastname: Malyapa
authors.forename: Francesca
authors.initials: F
authors.lastname: Albertini
authors.forename: Gabriele
authors.initials: G
authors.lastname: Calaminus
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kliebsch
authors.forename: Lorentzos
authors.initials: L
authors.lastname: Mikroutsikos
authors.forename: Petra
authors.initials: P
authors.lastname: Morach
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bolsi
authors.forename: Tony
authors.initials: T
authors.lastname: Lomax
authors.forename: Ralf
authors.initials: R
authors.lastname: Schneider
mesh_terms: D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects / Q000601:surgery; D016543:Central Nervous System Neoplasms / Q000188:drug therapy* / Q000523:psychology / Q000532:radiotherapy* / Q000601:surgery; D002675:Child, Preschool; D003131:Combined Modality Therapy / Q000009:adverse effects; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D011379:Prognosis; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods; D011788:Quality of Life; D011880:Radiotherapy Planning, Computer-Assisted; D018335:Rhabdoid Tumor / Q000188:drug therapy* / Q000523:psychology / Q000532:radiotherapy* / Q000601:surgery; D016896:Treatment Outcome