Percutaenous renal tumor ablation

Percutaneous ablation in the kidney is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection. It is performed via radiofrequency ablation or cryoablation.

Follow-up time frame

Can vary according to center but usually includes contrast-enhanced CT or MR imaging at approximately 3-, 6-, and 12-months after ablation and at 6–9-month intervals thereafter ².

Postoperative imaging

In general, the ablated region frequently decreases in size over time.

CT 

The use of intravenous contrast material is often essential for the evaluation of possible residual or recurrent tumor. Ablated regions, (regardless of RF ablation) appear as low-attenuation regions without enhancement.

MRI

Local stranding in the perinephric fat adjacent to the ablation site may be present.

The usual signal relative to renal parenchyma of ablated regions are:

• T1: iso- to hyperintense

• T2: generally hypointense

• T1 C+ GAD: post-ablation beds often show a thin rim of peripheral enhancement ⁵

Complications

• genitofemoral nerve injury ⁶ - emerging from the surface of the psoas major muscle, the nerve may be injured when the lesion is too close to the psoas muscle