Outcome After Modern Proton Beam Therapy in Childhood Craniopharyngioma: Results of the Prospective Registry Study KiProReg

Martin Bischoff; Dalia Ahmad Khalil; Sabine Frisch; Claus M Bäcker; Sarah Peters; Carsten Friedrich; Stephan Tippelt; Rolf-Dieter Kortmann; Brigitte Bison; Hermann L Müller; Beate Timmermann

doi:10.1016/j.ijrobp.2024.03.015

Outcome After Modern Proton Beam Therapy in Childhood Craniopharyngioma: Results of the Prospective Registry Study KiProReg

Int J Radiat Oncol Biol Phys. 2024 Mar 15:S0360-3016(24)00432-2. doi: 10.1016/j.ijrobp.2024.03.015. Online ahead of print.

Authors

Affiliations

¹ Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Centre (WTZ), Essen, Germany; Department of Radiation Oncology, Ruhr-University Bochum, Medical Faculty, Marien Hospital, Herne, Germany. Electronic address: martin.bischoff@ruhr-uni-bochum.de.
² Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Centre (WTZ), Essen, Germany.
³ West German Proton Therapy Centre Essen (WPE), West German Cancer Centre (WTZ), Essen, Germany.
⁴ Department of Pediatrics and Pediatric Hematology/Oncology, University Children's Hospital, Carl von Ossietzky University Oldenburg, Klinikum Oldenburg AöR, Oldenburg, Germany.
⁵ Department of Pediatrics III, Pediatric Oncology and Hematology, University Hospital Essen, Essen, Germany.
⁶ Department of Radiation Oncology, University of Leipzig, Leipzig, Germany.
⁷ Diagnostic and Interventional Neuroradiology, Faculty of Medicine, University of Augsburg, Augsburg, Germany.
⁸ Department of Particle Therapy, University Hospital Essen, West German Proton Therapy Centre Essen (WPE), West German Cancer Centre (WTZ), Essen, Germany; German Cancer Consortium (DKTK), Essen/Düsseldorf, University Hospital Essen, Essen, Germany.

PMID: 38492813
DOI: 10.1016/j.ijrobp.2024.03.015

Abstract

Purpose: Craniopharyngiomas (CPs) are rare tumors of the sellar region often leading to significant comorbidities due to their close proximity to critical structures. The aim of this study was to analyze survival outcome and late toxicities after surgery and proton beam therapy (PBT) in childhood CPs.

Methods and materials: Within the prospective registry study "KiProReg" (DRKS0000536), data of 74 childhood patients with CP, receiving PBT between August 2013 to June 2022 were eligible. Late toxicities were analyzed according to the grading system of the Common Terminology Criteria for Adverse Events, version 4.0.

Results: Median follow-up since first diagnosis was 4.3 years (range, 0.8-14.7). In addition, 75.7% of patients received PBT at time of disease progression or recurrence, whereas 24.3% as part of their primary therapy (definitive or adjuvant). Predominantly (85.1%), pencil beam scanning technique was used. The median total dose and initial tumor volume were 5400 cGy relative biologic effectiveness (RBE) and 17.64 cm³ (range, 3.07-300.59), respectively. The estimated (±SE) 3-year overall survival, progression-free, and cystic failure-free survival rate after PBT were 98.2% (±1.7), 94.7% (±3.0), and 76.8% (±5.4), respectively. All local failures (n = 3) were in-field relapses necessitating intervention and occurred exclusively in patients receiving PBT at progression or recurrence. Early cystic enlargements after PBT were typically asymptomatic and self-limiting. Fatigue, headaches, vision disorders, obesity, and endocrinopathies were the predominant late toxicities. No high-grade (≥3) new-onset visual impairment or cognitive deterioration occurred compared with baseline. The presence of cognitive impairments at the end of follow-up correlated with size of the planning target volume (P = .034), D_mean dose to the temporal lobes (P = .032, P = .045) and the number of surgical interventions before PBT (P = .029).

Conclusions: Our findings demonstrate favorable local control rates using modern PBT with acceptable late toxicities. Cyst growth within 12 months after radiation therapy is typically not associated with tumor progression. Longer follow-up must be awaited to confirm results.