Effectiveness and Safety of Spot Scanning Proton Radiation Therapy for Chordomas and Chondrosarcomas of the Skull Base: First Long-Term Report

Journal Article · Sun Nov 15 04:00:00 EST 2009 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2008.12.055· OSTI ID:21367509

Ares, Carmen ^[1]; Hug, Eugen B; Lomax, Antony J; Bolsi, Alessandra; Timmermann, Beate; Rutz, Hans Peter ^[1]; Schuller, Jan C ^[2]; Pedroni, Eros; Goitein, Gudrun ^[1]

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1. Center for Proton Radiation Therapy, Paul Scherrer Institute, Villigen (Switzerland)
2. Statistics Department, Swiss Group for Clinical Cancer Research, Bern (Switzerland)

Purpose: To evaluate effectiveness and safety of spot-scanning-based proton radiotherapy (PT) in skull-base chordomas and chondrosarcomas. Methods and Materials: Between October 1998 and November 2005, 64 patients with skull-base chordomas (n = 42) and chondrosarcomas (n = 22) were treated at Paul Scherrer Institute with PT using spot-scanning technique. Median total dose for chordomas was 73.5 Gy(RBE) and 68.4 Gy(RBE) for chondrosarcomas at 1.8-2.0 Gy(RBE) dose per fraction. Local control (LC), disease specific survival (DSS), and overall survival (OS) rates were calculated. Toxicity was assessed according to CTCAE, v. 3.0. Results: Mean follow-up period was 38 months (range, 14-92 months). Five patients with chordoma and one patient with chondrosarcoma experienced local recurrence. Actuarial 5-year LC rates were 81% for chordomas and 94% for chondrosarcomas. Brainstem compression at the time of PT (p = 0.007) and gross tumor volume >25 mL (p = 0.03) were associated with lower LC rates. Five years rates of DSS and OS were 81% and 62% for chordomas and 100% and 91% for chondrosarcomas, respectively. High-grade late toxicity consisted of one patient with Grade 3 and one patient with Grade 4 unilateral optic neuropathy, and two patients with Grade 3 central nervous system necrosis. No patient experienced brainstem toxicity. Actuarial 5-year freedom from high-grade toxicity was 94%. Conclusions: Our data indicate safety and efficacy of spot-scanning based PT for skull-base chordomas and chondrosarcomas. With target definition, dose prescription and normal organ tolerance levels similar to passive-scattering based PT series, complication-free, tumor control and survival rates are at present comparable.

• OSTI ID: 21367509
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 75; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BARYONS
BODY
DISEASES
ELEMENTARY PARTICLES
FERMIONS
HADRONS
MEDICINE
NEOPLASMS
NUCLEAR MEDICINE
NUCLEONS
ORGANS
PROTONS
RADIOLOGY
RADIOTHERAPY
SARCOMAS
SKELETAL DISEASES
SKELETON
SKULL
SURVIVAL CURVES
THERAPY
TOXICITY