A flexible and kink-proof intra-cavity delivery catheter for precise placement and injection of therapeutic agent(s) into and/or through the wall of a body cavity at a precise treatment site with even distribution throughout. One or more needle assemblies are disposed around a calibrated balloon which, when inflated, brings each needle assembly into contact with and enables the piercing of the cavity wall to a calibrated depth. Each needle assembly consists of a plurality of tissue insertion needles along the longitudinal axis of the needle assembly. Precise amounts of the therapeutic agent are then quickly delivered through the needle assembly directly into the diseased body tissue. When the calibrated balloon is deflated, retraction members pull the needle assemblies back into the catheter body for catheter repositioning or catheter withdrawal. The problems of overtreatment and undertreatment of the treatment site and the body with therapeutic agents, uneven distribution of therapeutic agents within the diseased treatment site, additional trauma to the treatment site, and long term blockage of body fluid distal to the treatment site via known drug delivery catheters are thereby eliminated.