Clinical efficacy and safety of a new hybrid radiofrequency electrode for treatment of liver malignancies-phase i and phase ii randomized clinical trial using radiofrequency versus microwave ablation
- Autores: Aleksandar Radosevic
- Directores de la Tesis: Fernando Burdio (dir. tes.), Rita Quesada Diez (codir. tes.)
- Lectura: En la Universitat Pompeu Fabra ( España ) en 2021
- Idioma: español
- Tribunal Calificador de la Tesis: María Angeles Garcia Criado (presid.), Joan Albanell Mestres (secret.), Xavier Serres Crèixams (voc.)
- Programa de doctorado: Programa de Doctorado en Biomedicina por la Universidad Pompeu Fabra
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
Treatment of liver malignancies is a constant challenge that multiple specialists face every day. Although surgery offers the best results when compared to other options, in the majority of cases it is not feasible for various reasons. Radiofrequency (RFA) and microwave (MWA) ablations are acceptable alternatives to surgery despite having a higher local progression rate compared to surgery. The constant improvement in techniques has led to it becoming the first option for selected patients. But there is still room for further improvement. One of these improvements, implemented by our team, has motivated the development of the present PhD thesis. The main objective of the present study is the clinical testing of a hybrid (cool-wet) radiofrequency electrode, Gnomon, which has been developed by our team.
A two-phase study was conducted between June-2014 and March 2015 (phase I, safety) and April 2015 and April 2020 (phase II, efficacy), respectively. We included only patients with liver tumor (hepatocellular carcinoma or liver metastases) in between 1.5 and 4 cm, unsuitable for surgical resection but eligible for ablative treatment.
In Phase I of the study, the first 20 consecutive patients to fulfill the inclusion criteria were included and their tumors were ablated by radiofrequency. All patients were strictly followed-up and all complications were registered. Once the results were reviewed and safety issues considered (a single patient with a major complication), we continued with phase II of the study.
Phase II of the study was conducted as a prospective, randomized, parallel-group, a single-blinded clinical trial with a total of 82 patients assigned to one of two groups: microwave ablation (control group) or radiofrequency ablation (experimental group). We compared this electrode with the selected, the latest generation microwave system (AMICA). For the per-protocol analysis, three patients were excluded. Median follow-up was 27 months (MWA group) and 23 months (RFA Group). The primary technical success was achieved in 98% (46/47) and 90 % (45/50) (p=0.108), and local tumor progression was observed in 21% (10/47) vs. 12% (6/50) (OR 1.9 [95% CI 0.66-5.3], p=0.238) of tumors in the MWA and RFA group, respectively. Major complications were found in 5 cases (11%) in the MWA Group vs. 2 cases (4%) in RFA, without statistical significance. The new hybrid electrode produces an ablation zone with a similar geometry to that produced when using the latest generation MWA systems. Although the long diameter of ablation zones, as well as volumes, produced using the Gnomon were shorter than with the MWA system, we did not observe an increase in the short-to-large diameter ratio.
In conclusion, the new hybrid electrode (Gnomon) is safe and effective for the treatment of liver malignancy of between 1.5-4 cm as the latest generation of MWA systems in terms of local tumor progression and technical failure. Moreover, after 2 years of follow-up we observed no significant differences in the rate of complications and residual unablated tumors, median time to progression or overall survival.
The research activity presented throughout the thesis has been funded by the Spanish Ministry of Health (grant numbers: FIS - PI12/00799). The randomized trial was officially registered under ISRCTN73194360 on https://www.isrctn.com.
