Methods and apparatus are provided for delivering a bioactive agent in a needle track formed in a target tissue mass, following formation of the needle track, by avoiding impingement of the agent against target tissue at high velocity or by using capillary action to draw the bioactive agent out of the needle during needle withdrawal. The apparatus comprises a catheter and a needle disposed within the catheter and configured to be selectively extended into the tissue mass to a predetermined depth, while dispensing the agent simultaneously with retraction of the needle along the needle track. Alternatively, or in addition, the needle may be configured to create a tissue space surrounding a distal or lateral surface of the needle, into which the bioactive agent to be infused.