MRI technology lets patients skip biopsy

Researchers have developed a new MRI technology that allows patients with suspected kidney tumors to bypass biopsies. The team also developed multiparametric MRI (mpMRI) protocols capable of determining whether a tumor is aggressive or not.

The researchers, led by Ivan Pedrosa, MD and Jeffrey Cadeddu, MD with the Kidney Cancer Program at the University of Texas Southwestern Harold C. Simmons Comprehensive Cancer Center, discussed their findings in a study published online Jan. 2 in The Journal of Urology.

“Among malignant masses clear cell renal cell carcinoma [ccRCC] is the most prevalent and aggressive subtype. A method to identify such histology would aid in risk stratification,” wrote Pedrosa and colleagues. “Our goal was to evaluate a likelihood scale for multi-parametric magnetic resonance imaging in the diagnosis of clear cell histology.”

The mpMRI protocols help inform physicians whether or not a tumor is aggressive.

“To our knowledge our series is the first to specifically evaluate the diagnostic accuracy of mpMRI for ccRCC in cT1a lesions,” wrote Pedrosa et al.

Team members retrospectively reviewed records of 110 patients with cT1a masses who underwent MRI and partial or radical nephrectomy from Dec. 2011 to July 2015. They applied clear cell likelihood scores of 1 (definitely not) through 5 (definitely) to their cases.

Mean tumor size was 2.4 cm and 50 percent of lesions were clear cell. Histology showed ccRCC in 61 cases, nonclear cell RCC in 40 and benign lesions in 20. Defining clear cell as scores of 4 or greater demonstrated 78 percent sensitivity and 80 percent specificity while scores of 3 or greater showed 95 percent sensitivity and 58 percent specificity.

“A clear cell likelihood score used with magnetic resonance imaging can reasonably identify clear cell histology in small renal masses and may decrease the number of diagnostic renal mass biopsies,” wrote the authors.