Retrospective Prostate Treatment Plan Comparison for Proton, Tomotherapy, and Cyberknife Therapy

Abstract Background: Twenty-eight cases from patients previously treated for prostate cancer using helical tomotherapy (22 patients) or Cyberknife (6 patients; Accuray, Sunnyvale, California) linear accelerators were selected chronologically between 2009 and 2011 and were replanned using parallel-opposed beam geometry for proton therapy (PT). Methods: Proton data used an IBA (Louvain-La-Neuve, Belgium) beam model that was made available from the Philips Radiation Oncology System (Fitchburg, Wisconsin) as a pre-510(k)–approved Pinnacle treatment planning system. Comparison for the coverage of the planned target volume (expanded clinical target volume) and doses to bladder, rectum, and femoral heads were used to evaluate the plans. Radiation Therapy Oncology Group (RTOG, Philadelphia, Pennsylvania) trial 0815, a prostate intensity-modulated radiation therapy protocol, and trial 0938, a prostate stereotactic radiation therapy protocol, were used as an independent “benchmark” for plan robustness. Results: In ...