Keywords:
Abdomen, Oncology, Interventional non-vascular, CT, Ultrasound, Ablation procedures, Biopsy
Authors:
L. Ingram, A. Abbas, B. Shepherd, S. George, D. J. Breen; Southampton/UK
DOI:
10.1594/ecr2013/C-1434
Methods and Materials
A retrospective review of histologically (via biopsy) - proven renal cell carcinomas treated with pCRA at our institution between May 2007 and November 2011 was performed.
The pre-ablation R.E.N.A.L nephrometry score was derived for each patient and correlated with treatment outcomes and complication rates.
The R.E.N.A.L score is calculated using: maximum tumour radius (R),
exophytic or endophytic (E),
as shown in images 1,
nearness to renal collecting system (N),
as shown in image 2,
anterior or posterior location (A) and location of tumour relative to the polar line (L).
The polar lines are shown in image 3 and defined as the portion of kidney where the concentric rim of the renal parenchyma is interrupted by the renal hilar vessels,
pelvis or fat.
Components are scored out of 3 points and the position is given a descriptor letter,
as shown in Table 1.
The score is then calculated and categorized into degrees of complexity as low (4-6),
medium (7-9) and high (10-12).
Cryoablations were performed percutaneously under general anaesthesia with combined CT/ultrasound guidance.
Image 5 shows a typical case with probe in situ.
Patients were followed-up with contrast-enhanced CT (<1 month,
6-monthly to 2 years and then annually).
Table 1: R.E.N.A.L nephrometry scoring system.
|
1 pt
|
2 pts
|
3pts
|
Radius (R) / cm
|
<4
|
>4 but <7
|
>7
|
Exophytic/endophytic (E)
|
>50% exophytic
|
<50% exophytic
|
Entirely endophytic
|
Nearness to collecting system (N) / mm
|
>7
|
>4 but <7
|
<4
|
Anterior / posterior (A)
|
No points given.
Mass assigned a,
p or x
|
Location relative to polar lines (L)*
* - suffix ‘h’ given if tumour touches main renal vein or artery
|
Entirely above or below polar lines
|
Mass crosses polar lines
|
>50% mass crosses polar lines or mass crosses axial midline
|