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

Spot-Scanning Proton Radiation Therapy for Extra-Cranial Chondrosarcoma

Meeting Abstract

  • A. Staab - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • H. P. Rutz - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • G. Goitein - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • B. Timmermann - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • C. Ares - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • R. Schneider - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • T. Lomax - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland
  • E. Hug - Center for Proton Therapy, Paul Scherrer Institute, Villigen, Switzerland

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog193

DOI: 10.3205/09ptcog193, URN: urn:nbn:de:0183-09ptcog1930

Published: September 24, 2009

© 2009 Staab et al.
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Outline

Text

Background: Extra-cranial chondrosarcoma (ECC) require high dose radiotherapy to achieve satisfactory local control (LC). Tumor proximity to critical organs at risk poses significant dose constraints. Proton Radiotherapy (PT) has been employed at the Center for Proton Therapy at Paul Scherrer Institute (PSI) since 1996.

Material and methods: Between 1999–2005, 14 patients with chondrosarcoma of C-, T-, L-spine and Sacrum underwent PT. Six patients with gross residual diseases were not considered suitable for further tumor resection (GTV, range: 2.18–2846.06 ml). Seven patients underwent prior surgical stabilization (SS) of the axial skeleton. Median total dose applied was 68 Gy(RBE). Median follow-up time was 47 months. Two patients had metastatic desease prior to PT.

Results: Five local failures were diagnosed in 14 patients with chondrosarcoma of C-, T-, L-spine and sacrum yielding a 5 year LC rate of 50%. Two failures occurred in 7 patients without SS after 5 years and 3 failures were diagnosed in 7 patients with SS (p=0.682). Five-year OS for the entire cohort was 73% and 3 patients died during follow up time (2 patients due to metastatic disease). One patient with sacral chondrosarcoma, lung metastasis and bulky disease (GTV= 2846ml prior PT) died 16 months after PT due to a infected tumor necrosis and the formation of fistula. One patient suffering from a sacral chondrosarcoma and a huge residual tumor prior to PT (GTV= 785ml) developed an osteonecrosis of the right hip joint 9 months after PT. In this patient the right hip joint was in parts included in the PTV. No high grade neurotoxicity was observed in the entire cohort.

Conclusion: Spot scanning based PT at PSI delivered subsequently after function-preserving surgery is a safe and effective treatment modality in ECC patients. Although two high grade toxicities were observed (Grade 4 and 5). All high grade toxicities (osteonecrosis, tumor necrosis) were noticed in patients with unfavorable prognosis and huge gross tumor volume prior PT.