Intraprocedural contrast-enhanced ultrasound (CEUS) in liver percutaneous radiofrequency ablation: clinical impact and health technology assessment

Abstract

Objectives: To assess the clinical and the economic impacts of intraprocedural use of contrast-enhanced ultrasound (CEUS) in patients undergoing percutaneous radiofrequency ablation for small (<2.5 cm) hepatocellular carcinomas.

Methods: One hundred and forty-eight hepatocellular carcinomas in 93 patients were treated by percutaneous radiofrequency ablation and immediate assessment by intraprocedural CEUS. Clinical impact, cost effectiveness, and budget, organisational and equity impacts were evaluated and compared with standard treatment without intraprocedural CEUS using the health technology assessment approach.

Results: Intraprocedural CEUS detected incomplete ablation in 34/93 (36.5 %) patients, who underwent additional treatment during the same session. At 24-h, complete ablation was found in 88/93 (94.6 %) patients. Thus, a second session of treatment was spared in 29/93 (31.1 %) patients. Cost-effectiveness analysis revealed an advantage for the use of intraprocedural CEUS in comparison with standard treatment (4,639 vs 6,592) with a 21.9 % reduction of the costs to treat the whole sample. Cost per patient for complete treatment was <euro> 4,609 versus <euro> 5,872 respectively. The introduction of intraprocedural CEUS resulted in a low organisational impact, and in a positive impact on equity

Conclusions: Intraprocedural use of CEUS has a relevant clinical impact, reducing the number of re-treatments and the related costs per patient.

Teaching points: • CEUS allows to immediately asses the result of ablation. • Intraprocedural CEUS decreases the number of second ablative sessions. • Intraprocedural CEUS may reduce cost per patient for complete treatment. • Use of intraprocedural CEUS may reduce hospital budget. • Its introduction has low organisational impact, and relevant impact on equity.

Fig. 1

The case of a single HCC that had undergone RFA and immediate re-treatment because of the detection of residual unablated tumour with intraprocedural CEUS. In the left hepatic lobe pre-treatment CE-CT (a) and CEUS (b) show an HCC with typical hypervascularity in arterial phase (arrowheads). c The HCC is treated with single insertion of RF electrode (arrowheads). d Gas produced by heating during ablation (arrowheads) seems to diffuse beyond the tumour margins. e Intraprocedural CEUS performed few minutes after electrode withdrawal demonstrates residual enhancing viable tumour (arrows) at the periphery of the volume of necrosis (arrowheads). f Second insertion of RF electrode is performed aiming at the area of residual enhancement (arrows) (dotted line path of the electrode). g Post-ablation CEUS demonstrates large volume of necrosis (arrowheads) with complete ablation of the residual tumour previously detected (arrows). h Twenty-four-hour post-ablation CE-CT confirms that treatment is complete (arrowheads ablated zone)

Fig. 2

Incremental cost-effectiveness plan. The plan shows the incremental cost and effectiveness of the procedure with intraoperational CEUS, compared with the standard procedure. There is an increase in effectiveness and in costs, the procedure being located in the North-East quadrant. The acceptability of the use of the procedure depends on the willingness to pay of the payer

Fig. 3

Incremental cost-effectiveness ratio (ICER) sensitivity analysis results. The figure shows the percentage of the 1,000 ICERs calculated with the sensitivity analysis performed, which are cost effective (compared with the other procedure), considering hypothetical willingness to pay values for the regional healthcare service to increase the effectiveness of 1 unit. The cost effectiveness acceptability curve shows a probability higher than 50 % for the procedure with intraprocedural CEUS to be cost-effective, with a willingness to pay per additional effectiveness unit of € 575

Fig. 4

Perceived short-term organisational impact. The use of intraprocedural CEUS leads to a short-term medium negative impact on learning time, and a low negative impact on training for personnel directly involved in the procedure, support personnel, meetings within the department and software update. It leads to a positive medium impact on the internal processes of the ward and appropriateness of requests for diagnostic exams, leading to a reduction in terms of further interventions or investigations needed for the same patient