Three-Dimensional Ultrasound-Based Image-Guided Hypofractionated Radiotherapy for Intermediate-Risk Prostate Cancer: Results of a Consecutive Case Series

External beam radiotherapy (EBRT) is a standard of care in the treatment of prostate cancer. Hypofractionation is a valid option either radiobiologically and logistically in this context. Image-guidance procedures are strongly needed to provide ballistic precision to radiation delivery. The Clarity platform allows for the acquisition of three-dimensional ultrasound scans (3D-US) to perform image-guided radiotherapy. We treated a consecutive series of intermediate-risk prostate cancer patients (according to NCCN stratification) with a hypofractionated schedule (70.2 Gy/26 fractions at 2.7 Gy/daily to the prostate gland excluding the seminal vesicles at 62.1 Gy) under 3D-US guidance with the Clarity platform. The 3-year biochemical-relapse-free survival, distant-metastases-free, cancer-specific and overall survival were 98.6% (CI: 91.1–99.6%), 98.6% (CI: 91.1–99.6%), 97.5% (CI: 94.5–99.1%), and 94.3% (CI: 90.4–96.7%), respectively. Maximum detected acute GU toxicity was G0 in 22 patients (29.7%), G1 in 30 (...