The RENAL nephrometry scoring system is one of many nephrotomy scoring systems ₄. It was developed to categorise renal masses into low, intermediate, and high complexity and was originally developed for renal masses based on MDCT features utilising a CT IVU protocol but can also be calculated from MRI features ^1-3.

Usage

Its purpose is to aid decision-making, patient counselling, surgical planning, patient follow-up, and academic reporting ^1-3.

Classification

RENAL is an easy-to-remember mnemonic of the five features scored as follows ^1-3:

• Radius (maximum diameter) in centimetres (cm) in any axis:

  • ≤4: 1 point

  • 4-7: 2 points

  • ≥7: 3 points

• Exophytic/endophytic tumour location:

  • ≥50% exophytic: 1 point

  • <50% exophytic: 2 points

  • 100% endophytic: 3 points

• Nearness to the renal collecting system or renal sinus measured in millimetres (mm) as the shortest distance from the deepest point of the tumour:

  • ≥7: 1 point

  • 4-7: 2 points

  • ≤4: 3 points

• Anterior or posterior location - assessed on the axial view:

  • no points are allocated

  • descriptors: “a” (anterior), “p” (posterior) or “x” (neither)

• ​​Location relative to the renal poles

  • entirely below the inferior pole or above the superior pole: 1 point

  • mass crosses the polar line: 2 points

  • >50% of mass lies across the polar line or is entirely between the polar lines or crosses the axial midline: 3 points

  • h: assigned as a suffix if the mass touches the main renal artery or vein

Nephrometry score grading

• score of 4-6: low complexity

• score of 7-9: moderate complexity

• score of 10-12: high complexity

History and etymology

Alexander Kutikov and Robert G Uzzo, American urologists working at Temple University School of Medicine, in Philadelphia, USA, published their scoring system in 2009 ³.

External links

• RENAL nephrometry score calculator - Rad At Hand

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