The effectiveness of ablation treatment is significantly dependent on tumor size.
Lesions up to 3 cm undergo complete ablation,
while a larger lesions may require multiple RFA treatment to prevent recurrence.
The patient are put into the prone position on CT scanner examination table after deep sedation with continuous monitoring of blood pressure,
heart rate,
electrocardiography (ECG) tracing,
and oxygen saturation.
During the procedure,
hypertensive peaks can occur and are treated by the anesthesiologists who are following the process.
After deep sedation,
a single Cool-tip radiofrequency needle electrode with 2 cm tip exposure penetration is inserted into the adrenal adenoma in a step-wise manner under CT guidance.
Once a successful puncture was achieved,
a standard 2,
4 or 6 minutes cycle of ablation and impedance-control algorithm is applied with the patient in the same position. The ablation time is adjusted by the size of the lesion,
as described in next table (Fig.
6).
Fig. 6: Adjustment of power and time according to lesion size.
References: Solero Microwave Tissue Applicator - Angiodynamics
For the adequate destruction of tumors,
the entire volume of a lesion should be subjected to cytotoxic temperatures.
Tissue destruction is achieved once the temperature threshold for cell death of 50–60 °C has been reached,
using for this powers between 60 and 140 W.
The extent of tumor ablation should be immediately assessed by CT scan which may show the completeness of ablation and possible bleeding complication.
Within 1 month,
3 months ,
6 months,
12 months and anually after the procedure,
a contrast-enhanced computed tomography (CT) scan may be performed to check the integrity of tumor ablation.
Complete responses is considered when there is no positive contrast enhancement on the residual adrenal lesion in the follow-up CT scan.