Another new code in 2005 that interventional radiologists welcome is 50391 (Instillation[s] of therapeutic agent into renal pelvis and/or ureter through established nephrostomy, pyelostomy or ureterostomy tube [eg, anticarcinogenic or antifungal agent]). This new code will be a great replacement for the unlisted code you've been forced to use for this procedure until now, according to coder Carolyn Artis with Eastern Radiology in Greenville, NC.