gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Dose-escalation with photon/proton irradiation for lower-grade glioma in the pediatric age: the Orsay experience

Meeting Abstract

  • J.-L. Habrand - Radiation Oncology, I Curie-Centre de Protonthérapie d'Orsay, Orsay, France
  • J. Datchary - Radiation Oncology, I Curie-Centre de Protonthérapie d'Orsay, Orsay, France
  • C. Alapetite - Radiation Oncology, I Curie-Centre de Protonthérapie d'Orsay, Orsay, France
  • S. Bolle - Radiation Oncology, I Curie-Centre de Protonthérapie d'Orsay, Orsay, France
  • S. Petras - Radiology, I Curie, Paris, France
  • F. Dhermain - Radiation Oncology, I Gustave-Roussy, Villejuif, France
  • R. Ferrand - Biophysics, I Curie-Centre de Protonthérapie d'Orsay, Orsay, France
  • J. Grill - Pediatric Oncology, I Gustave-Roussy, Villejuif, France
  • P. Bey - Director, I Curie, Paris, France

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog080

DOI: 10.3205/09ptcog080, URN: urn:nbn:de:0183-09ptcog0804

Published: September 24, 2009

© 2009 Habrand et al.
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Outline

Text

Background: To assess the local control, survival, and toxicity in symptomatic and/or progressive gliomas treated with sophisticated 3D Photon /proton conformal radiotherapy.

Material and methods: From 08/1994 through 05/2008, 18 children (Med. 10 years, range 6–16 ) with a low grade glioma were treated with radiotherapy upfront (10 cases) or at the time of progression, following an initial chemotherapy course (8 cases). One additional 5-year old boy was excluded due to poor compliance to radiotherapy. None of them presented with neurofibromatosis. Site of the primary was the optic pathway in 8, IIIrd ventricle in 3, hypothalamo-chiasmatic in 3, sellar/supra sellar in 2, and tectal in 2. Med. prescribed total dose to gross tumor volume (GTV) was escalated from the conventional 45–50 Gy up to 54 Cobalt-Gray Equivalent (CGE = physical dose x 1.1 RBE). Fractionation was conventional, with 1.8 CGE delivered once a day. Protons alone were employed in 14/18, and combined photons/protons in 4/18 early cases. Stereotactic alignment based on fiducial intra cranial markers, and immobilisation thick thermoplastic masks were used in all.

Results: 13/18 (72%) patients underwent a biopsy, or a sub total resection, and 5/18 (28%) no surgical approach. Chemotherapy administered before radiations in younger children consisted in combinations of VCR,VLB, CDDP, CBDCA according to BB-SFOP, Packer, or SIOP-LGG protocols. With a 31 months follow-up (3–145), 18/18 patients are alive: 15/18 (83%) with stable or improved clinical symptoms and radiological tumor size, and 3/18 (17%) with clinical/radiological deterioration at 12, 23, and 31 months post RT salvaged with chemotherapy or surgery; none had progressive disease at the time of analysis. No patients experienced severe immediate toxicity but one with glioma of the optic nerve had documented further visual deterioration and one with tectal glioma had 6 months post radiotherapy radiological aspects of radiation-necrosis and pseudo progression. Cognitive function appeared well preserved in all.

Conclusion: Highly conformal proton-based RT can be used either upfront in older children or at the time of progression following an initial chemotherapy regimen in younger ones with excellent local control and quality of life preservation. Moderate dose-escalation on this tumor-type seems warranted.