A case of CRPC with multiple bladder invasions treated with EBRT followed by HDR-BT boost

We report a case of post-operative local recurrence of castration-resistant prostate cancer with multiple bulky bladder invasions treated using external beam radiotherapy (EBRT) followed by a high-dose-rate brachytherapy (HDR-BT) boost. The EBRT dose was 46 Gy delivered in 23 fractions with intensity-modulated radiotherapy to the entire pelvis. The HDR-BT dose was 15 Gy delivered in 1 fraction using ultrasound, CT, and MRI-guided brachytherapy with 18 interstitial needles. We achieved excellent local control of cancer in the prostate bed and multiple bulky bladder invasions. EBRT plus HDR-BT boost can allow higher doses to be delivered than EBRT alone for locally recurrent bulky prostate cancer following prostatectomy.