Randomised Trial of Proton vs. Carbon Ion Radiation Therapy in Patients With Chordoma of the Skull Base -Clinical Phase III Study-
The study is a prospective randomised clinical phase III trial. The trial will be carried
out at Heidelberger Ionenstrahl-Therapie (HIT) centre as monocentric trial.
Proton therapy is the gold standard in the treatment of skull base chordomas. However,
high-LET beams such as carbon ions theoretically offer biologic advantages by enhanced
biologic effectiveness in slow-growing tumors. Up until now it was impossible to compare two
different particle therapies, i.e. proton and carbon ion therapy directly with each other.
The aim of this study is to find out, whether the biological advantages of carbon ion
therapy mentioned above can also be clinically confirmed.
Patients with skull base chordoma will be randomised to either proton or carbon ion
radiation therapy. As a standard, patients will undergo non-invasive, rigid immobilization
and target volume delineation will be carried out based on CT and MRI data. The biologically
isoeffective target dose to the PTV in carbon ion treatment (accelerated dose) will be 63 Gy
E ± 5% and 72 Gy E ± 5% (standard dose) in proton therapy respectively. Local-progression
free survival (LPFS) will be analysed as primary end point. Toxicity and survival are the
secondary end points. Also matters of interest are patterns of recurrence, prognostic
factors and plan quality.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
local-progression free survival (LPFS)
The primary objective of this study is to evaluate, if the innovative therapy (carbon ion irradiation) in chordomas is superior to the standard proton treatment with respect to the LPFS defined as time from the randomisation to observed local reccurrence or death from any cause in the absence of documented local disease progression. Lo-cal recurrence defined as MRT or CT - morphological tumor progress in the former irradiated region. A 10% increase in the LPFS is considered clinically relevant as-suming that the LPFS rate for the proton therapy is 70%.
Juergen Debus, MD PhD
University of Heidelberg
Germany: "Bundesamt für Strahlenschutz" (German Radiation Protection Authority)