title: Dosimetric advantages of proton therapy over conventional radiotherapy with photons in young patients and adults with low-grade glioma.
abstract: OBJECTIVE
  Low-grade glioma (LGG) is a very common brain tumor in pediatric patients typically associated with a very good prognosis. This prognosis makes it imperative that the risk of long-term treatment-related side effects be kept at an absolute minimum. Proton therapy (PRT) provides a radiation technique that has the potential to further reduce the genesis of radiogenic impairment.
  
  
  METHODS
  We retrospectively assessed 74 patients with LGG who underwent PRT. Conventional three-dimensional photon and PRT plans were generated after contouring structures of neurogenesis, crucial neuronal structures, and areas susceptible to secondary malignancies. Target volume coverage was evaluated using the homogeneity index (HI) and inhomogeneity coefficient (IC). Results were compared using the Wilcoxon-signed rank test, with p < 0.05 being statistically significant.
  
  
  RESULTS
  Target volume coverage was comparable for the photon and proton plans. Overall, we could show an essential reduction in maximal, mean, and integral doses in critical neurologic structures, areas of neurogenesis, and structures of neurocognitive function. The study indicated specifically how contralaterally located structures could be spared with PRT.
  
  
  CONCLUSIONS
  PRT is a highly conformal radiation technique offering superior dosimetric advantages over conventional radiotherapy by allowing significant dose reduction for organs at risk (OAR) that are essential for neurologic function, neurocognition, and quality of life, thus demonstrating the potential of this technique for minimizing long-term sequelae.
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
authors.forename: S B
authors.initials: SB
authors.lastname: Harrabi
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Bougatf
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Mohr
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Haberer
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Herfarth
authors.affiliation: Department of Radiation Sciences (DRS), Institute of Innovative Radiotherapy (iRT), Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Oberschleißheim, Germany.|Partner Site Munich, Deutsches Konsortium für Translationale Krebsforschung (dktk), Munich, Germany.
authors.forename: S E
authors.initials: SE
authors.lastname: Combs
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.|Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Debus
authors.affiliation: Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. sebastian.adeberg@med.uni-heidelberg.de.|Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany. sebastian.adeberg@med.uni-heidelberg.de.|Dept. of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. sebastian.adeberg@med.uni-heidelberg.de.|Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. sebastian.adeberg@med.uni-heidelberg.de.
authors.forename: S
authors.initials: S
authors.lastname: Adeberg
mesh_terms: D000293:Adolescent; D000328:Adult; D001932:Brain Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D016371:Cranial Irradiation / Q000379:methods; D005260:Female; D005910:Glioma / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D058958:Organs at Risk / Q000528:radiation effects; D061766:Proton Therapy / Q000009:adverse effects / Q000379:methods*; D011835:Radiation Protection / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000009:adverse effects / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult; D011522:Protons
chemical_list: D011522:Protons
keywords: Brain tumors; Children; Neurogenesis; Organs at risk; Quality of life