 This is a dose finding Phase III study of combined focused LDR brachytherapy boost with whole gland single fraction HDR for men with low and intermediate risk prostate cancer and Dominant Intraprostatic Lesion DIL visible on multi parametric MRI. Patients will receive 19 Gy HDR to the whole gland with concurrent LDR brachytherapy boost to the DIL, in a sequential dose escalation manner. Primary endpoints are early toxicity. 