Advances in nephron-sparing surgery for low-grade UTUC

At a recent Urology Times Clinical Forum in New York City, moderated by Katie S. Murray, DO, MS, a panel of health care professionals examined how evolving technology and new therapeutic options are reshaping management of low-grade upper tract urothelial carcinoma (UTUC). The discussion focused on preserving renal function while maintaining oncologic safety, with special attention to mitomycin reverse thermal gel (UGN-101 or Jelmyto) and contemporary laser-based surgical techniques.

Shifting paradigms in surgical management

Historically, radical nephroureterectomy was the mainstay of treatment for UTUC due to high recurrence rates and limited endoscopic tools. Panelists reflected on how the field has transitioned from that surgical default to a more nuanced, risk-stratified approach.

The group emphasized that nephron-sparing surgery is now a cornerstone of care for patients with solitary kidneys, borderline renal function, or limited tumor burden. Yet, as several participants acknowledged, case selection remains critical—large, multifocal, or high-grade lesions still carry significant recurrence risk and may ultimately require nephroureterectomy.

Technology and technique: Lasers in UTUC treatment

A detailed comparison of laser systems underscored the technological diversity among institutions.

Most panelists favored holmium or thulium lasers, citing precision and low risk of perforation. However, one participant championed a dual-wavelength neodymium-holmium laser, describing it as uniquely capable of achieving deep coagulation and excellent hemostasis in the renal pelvis. The group acknowledged that compatibility issues with modern digital ureteroscopes have limited its broader use.

Technical preferences also extended to access strategies. Most surgeons employ a ureteral access sheath, which reduces intrapelvic pressure and potential tumor seeding. A few rely on direct flexible ureteroscopy when the sheath cannot be safely advanced. Others noted that older techniques such as a Bugbee electrode can still be useful in select bleeding or broad-based lesions, especially when laser access is limited.

Intracavitary chemotherapy and mitomycin hydrogel

A central focus of the discussion was mitomycin reverse thermal gel, a hydrogel that transitions from liquid to gel at body temperature, allowing the agent to dwell within the upper collecting system.

Panelists reviewed outcomes from the OLYMPUS trial, which evaluated this formulation as a primary chemoablative therapy for biopsy-proven, low-grade, non-invasive tumors ≤1.5 cm. The study demonstrated a 58% complete response rate at first follow-up ureteroscopy and sustained responses in over half of patients at 12 months.

Several clinicians noted that these findings, reinforced by emerging real-world data, validate mitomycin reverse thermal gel as both an induction and adjuvant therapy in patients undergoing kidney-sparing procedures. For many, it represents the first reliable pharmacologic tool to complement surgical ablation in the upper tract.

Delivery methods and complication management

A lively discussion surrounded the optimal route of administration. The panel reached broad consensus that antegrade delivery through a nephrostomy tube is preferred over retrograde ureteral catheterization.

This approach minimizes the need for repeated anesthesia, simplifies logistics, and appears to reduce the risk of ureteral stenosis, a known but often subclinical complication.

Speakers stressed the importance of careful technique: allowing 1 week for tract healing before instillation, confirming proper placement with a nephrostogram, and ensuring no contrast extravasation. The hydrogel typically remains in place for approximately 6 hours before liquefying and draining naturally through the ureter.

Although some stenoses have been reported, most are mild or asymptomatic. The group agreed that trauma from instrumentation may play a larger role in stricture formation than the drug itself.

Case-based learning: Applying evidence in practice

Two patient cases anchored the discussion in real-world clinical reasoning.

Case 1: Solitary 1.5 cm Low-Grade Lesion

A patient underwent endoscopic ablation with complete tumor removal and was subsequently treated with 6 weekly doses of mitomycin hydrogel via nephrostomy. The group endorsed this plan as a prototypical example of kidney-sparing, evidence-based care.

Panelists emphasized measuring renal pelvic volume at the time of initial ureteroscopy to guide precise dosing in future treatments.

Case 2: Multifocal Distal Ureter and Renal Pelvis Disease

In contrast, the second scenario—multifocal, low-grade recurrence in both the ureter and renal pelvis—sparked debate. Some clinicians advocated for nephroureterectomy to achieve definitive control, citing multifocality as a predictor of failure with conservative management. Others favored continued endoscopic management and adjuvant hydrogel therapy, especially for patients with comorbidities or reduced renal reserve.

The conversation underscored that even within the framework of guideline-supported care, clinical judgment and patient preference remain decisive factors. Importantly, participants noted that the FDA indication for mitomycin reverse thermal gel encompasses “upper tract urothelial carcinoma,” which by definition includes both renal pelvis and ureteral locations—supporting its use in multifocal cases.

Surveillance and long-term follow-up

Monitoring strategies varied but generally included ureteroscopy at 3 months post-treatment, followed by alternating ureteroscopy and CT urography every 3 to 6 months depending on risk factors and prior recurrence.

This approach aims to detect early recurrences amenable to repeat ablation before they progress to invasive disease.

Panelists also highlighted the value of patient counseling—helping individuals understand the chronic nature of low-grade UTUC and the potential need for iterative procedures over time.

Key takeaways and evolving standards

The panel’s dialogue reflected both the maturity and dynamism of kidney-sparing therapy for upper tract disease.

Collectively, the experts agreed that:

• Endoscopic ablation is appropriate for most small, low-grade tumors.

• Mitomycin hydrogel therapy enhances local control and may extend disease-free intervals.

• Antegrade administration via nephrostomy is favored for safety and practicality.

• Recurrence management requires flexibility, balancing oncologic control with quality of life.

• Above all, participants emphasized the importance of individualized, evidence-informed care—where patient comorbidity, renal function, and preferences guide every decision.