With a median follow-up of 2.6 years, SABR provided 98 percent two-year local control and 98 percent two-year cancer-specific survival for RCC patients with a solitary kidney. These rates were not significantly different from those for patients with two kidneys treated with SABR: 97.8 percent local control (hazard ratio (HR) 0.89, p=0.923) and 94.3 percent cancer-specific survival (HR 0.16, p=0.082). Overall survival also did not differ between the cohorts, at 81 percent for the solitary group and 82 percent for the bilateral group (HR 0.75, p=0.445).
Renal function was modestly impacted by SABR. The decline in estimated glomerular filtration rate (eGFR) was similar for both cohorts, with average decreases of -5.8 (±10.8 mL/min) in the solitary cohort and -5.3 (±14.3 mL/min) in the bilateral cohort (p=0.984). None of the solitary kidney patients required dialysis, while six (4.2 percent) in the bilateral cohort did.
Ad Statistics
Times Displayed: 63870
Times Visited: 2092 Ampronix, a Top Master Distributor for Sony Medical, provides Sales, Service & Exchanges for Sony Surgical Displays, Printers, & More. Rely on Us for Expert Support Tailored to Your Needs. Email info@ampronix.com or Call 949-273-8000 for Premier Pricing.
“We were somewhat surprised that SABR could achieve such a high local control rate without more significantly impacting renal function in the solitary kidney setting,” said Dr. Correa. “While this is partly attributable to the technology of SABR — allowing very high radiation doses to be delivered with incredible precision, thus maximally sparing renal function — it is also important to acknowledge important differences in baseline characteristics between groups.”
Patients with a single kidney had smaller tumors on average than patients with two kidneys (mean 3.7 cm vs. 4.3 cm, p<0.001). They also exhibited slightly better baseline kidney function on average than those in the bilateral cohort (p=0.016).
The research team used Cox hazards regression analysis to look at factors predicting which patients had worse outcomes after SABR. Larger tumor size (>4.0 cm) correlated with more profound decreases in eGFR after SABR (hazard ratio (HR) 4.2, p=0.029). “From this, we concluded that proper patient selection will be important in optimizing outcomes for solitary kidney patients treated with SABR,” said Dr. Correa.
“Treatment of RCC in the solitary kidney setting poses a unique management challenge, since a careful balance of minimizing nephron loss and maximizing cancer control is essential,” concluded Dr. Correa. “Recognizing the challenges of randomized controlled trials in this unique and somewhat-rare population, we hope that our large, international dataset will significantly advance the paradigm of kidney SABR, increasing awareness and access for patients facing this challenging management scenario.”
