Resumen
From April 2017 to December 2020, 29 patients with prostate cancer recurrence were selected. They received Cyberknife® (CK) treatment (17 pts) or alternatively VMAT (Volumetric Modulated Arc Technique) therapy by IGRT (Image-Guided Radiation Therapy)/Clarity® (12 pts). Urinary (GU), rectal (GI) toxicities, and biochemical control were investigated. Further, the two techniques were dosimetrically compared by rival plans. The VMAT-IGRT Clarity® treatments were replanned applying a template developed for prostate VMAT-SBRT in FFF mode, keeping the same dose/fractionation scheduled for the CK Group (30 Gy in 5 fx at 80% isodose). In the CK group, 23% of patients experienced grade 2 acute GU, while 6% showed grade 2 acute GI. In the VMAT-Clarity® group, 17% of patients showed acute GU toxicity, while for 8% grade 2 late toxicity was recorded. The dosimetric analysis shows that VMAT-FFF allows to deliver a biological equivalent dose to CK, with the advantage of reducing the likelihood of toxicities arising.