Abstract: A needle assembly particularly suitable for prostate brachytherapy anesthesia and biopsy anesthesia procedure. The needle assembly has a cannula with a tapered distal end and a hub attached to a proximal end of the cannula. The cannula is provided with a plurality of spaced-apart openings extending through a wall of the cannula between the proximal end and the distal end for creating a pre-determined pattern of distribution in variable cylindrical patterns along the needle tract.