Microwave ablation for hepatic malignancies: a systematic review of the technology and differences in devices

Oncologic Outcomes after Percutaneous Ablation for Colorectal Liver Metastases: An Updated Comprehensive Review

Colorectal cancer is a major cause of cancer-related mortality, with liver metastases occurring in over a third of patients, and is correlated with poor prognosis. Despite surgical resection being the primary treatment option, only about 20% of patients qualify for surgery. Current guidelines recommend thermal ablation either alone or combined with surgery to treat limited hepatic metastases, provided that all visible disease can be effectively eradicated. Several ablation modalities, including radiofrequency ablation, microwave ablation, cryoablation, irreversible electroporation and histotripsy, are part of the percutaneous ablation armamentarium. Thermal ablation, including radiofrequency, microwave ablation and cryoablation, can offer local tumor control rates comparable to limited resection for selected tumors that can be ablated with margins. This review aims to encapsulate the current clinical evidence regarding the efficacy and oncologic outcomes after percutaneous ablation for the treatment of colorectal liver metastatic disease.

Robotic-assisted CT-guided percutaneous thermal ablation of abdominal tumors: An analysis of 41 patients

PURPOSE

Robotic assistance is rapidly evolving and may help physicians optimize needle guidance during percutaneous interventions. The purpose of the study was to report feasibility, safety, accuracy, immediate clinical success and short-term local tumor control after robotic-assisted computed tomography (CT)-guided thermal ablation of abdominal tumors.

MATERIALS AND METHODS

Forty-one patients who underwent percutaneous thermal ablation of abdominal tumors using robotic-assisted CT-guided were included. All ablations were performed with robotic assistance, using an optically-monitored robotic system with a needle guide sent to preplanned trajectories defined on three-dimensional-volumetric CT acquisitions with respiration monitoring. Endpoints were technical success, safety, distance from needle tip to planned trajectory and number of needle adjustments, and complete ablation rate.

RESULTS

Forty-one patients (31 men; mean age, 66.7 ± 9.9 [standard deviation (SD)] years [age range: 41-84 years]) were treated for 48 abdominal tumors, with 79 planned needles. Lesions treated were located in the liver (23/41; 56%), kidney (14/41;34%), adrenal gland (3/41; 7%) or retroperitoneum (1/41; 2%). Technical success was achieved in 39/41 (95%) patients, and 76/79 (96%) needle insertions. The mean lateral distance between the needle tip and planned trajectory was 3.2 ± 4.5 (SD) mm (range: 0-20 mm) before adjustments, and the mean three-dimensional distance was 1.6 ± 2.6 (SD) mm (range: 0-13 mm) after 29 manual depth adjustments (29/78; 37%) and 33 lateral adjustments (33/78; 42%). Two (2/79; 3%) needles required complete manual reinsertion. One grade 3 complication was reported in one patient (1/41; 2%). The overall clinical success rate was 100%. The 3-month local tumor control rate (progression free survival) was 95% (38/41).

CONCLUSION

These results provide further evidence on the use of robotic-assisted needle insertion regarding feasibility, safety, and accuracy, resulting in effective percutaneous thermal ablation of abdominal tumors.

Hepatic Ablation Technology: Assessment of Conflicts of Interest in Recent Literature

INTRODUCTION

Collaboration between the health care industry and surgeons is critical in modern medicine. Conflict of interest (COI) has the risk of introducing bias into research studies. We investigated the accuracy of self-disclosed COI for studies that researched the use of microwave ablation for liver metastasis.

METHODS

A literature search identified studies that investigated the use of microwave ablation for liver cancer between 2016 and 2022. We utilized the Open Payments Database to query individual authors' financial contributions from the industry. The accuracy of the disclosure statement and financial contribution for each study and author was calculated. We compared the amount of financial contribution authors received based on the accuracy of their COI statement.

RESULTS

Twenty-five studies of interest were identified. The mean number of authors was 8.24. A disclosure statement was present in 52% of studies. Of those, 28% had an incongruent disclosure statement. 9/25 (36%) of studies had a conflict of interest based on financial payments provided by industry. Overall, authors received an average of $440,483.41 (SD $1,889,375.34). We did not find a difference in the financial contribution's value based on the disclosure statement's accuracy (P = .55).

CONCLUSIONS

Over a quarter of studies in our review of microwave ablation literature had discrepancies in the reporting of conflicts of interest, highlighting the need for improved reporting of potential conflicts of interest to protect the integrity of clinical research. Compared to other fields of surgery, we found a lower rate of undisclosed COI, suggesting that the scope of cancer-directed surgery may be more resistant to industry influence.

Construction of BaTiO3-TiO2 hollow sphere heterojunctions for enhanced microwave dynamic therapy in cancer treatment

Cancer is one of the primary health concerns among humans due to its high incidence rate and lack of effective treatment. Currently, medical techniques to achieve the precise elimination of local cancer lesions with negligible damage to normal tissues are still intensely desired. Herein, we synthesized BaTiO3-TiO2 hollow spheres (BTHSs) for use in microwave dynamic therapy (MWDT) for cancer. Under UV irradiation, BTHSs can mediate the production of multiple reactive oxygen species (ROS), mainly 1O2, which results in a rapid photocatalytic degradation rate (97%), 1.6-fold that of commercial P25. Importantly, the ROS production process can be triggered by microwaves to effectively execute MWDT for cancer. Under microwave irradiation, BTHSs exhibit a remarkable therapeutic effect and slight cytotoxicity. In terms of mechanism, the enhanced ROS production efficiency of BTHSs can be attributed to their unique hollow structure and the formation of a type-II heterojunction by the incorporation of BaTiO3. The hollow structure increases the availability of active sites and enhances light scattering, while the BaTiO3-TiO2 heterojunction enhances the photocatalytic activity of TiO2 through charge transfer and electron-hole separation. Overall, this study provides important insights into the design and optimization of sensitizers for MWDT applications.

TACE sequential MWA guided by cone-beam computed tomography in the treatment of small hepatocellular carcinoma under the hepatic dome

PURPOSE

An assessment is being conducted to determine the safety and effectiveness of using Cone-beam computed tomography (CBCT)-guided transcatheter arterial chemoembolization (TACE) and microwave ablation (MWA) sequentially to treat small hepatocellular carcinomas (HCCs) located in the hepatic dome.

MATERIALS AND METHODS

Fifty-three patients with small HCCs in the hepatic dome who underwent TACE combined with simultaneous CBCT-guided MWA were studied. Inclusion criteria were a single HCCs ≤ 5.0 cm or a maximum of three. The safety and interventional-related complications were monitored, and local tumor progression (LTP), overall survival (OS), and prognostic factors for LTP/OS were evaluated.

RESULTS

The procedures were successfully accomplished in all patients. According to Common Terminology Criteria for Adverse Events (CTCAE), adverse reactions and complications are mainly Grade 1 or 2 (mild symptoms, no or local/noninvasive intervention indicated). Liver and kidney function and alpha-fetoprotein (AFP) levels remained within a reasonable range after 4 weeks of treatment (both p < 0.001). The mean LTP was 44.406 months (95% CI: 39.429, 49.383) and the mean OS rate was 55.157 months (95% CI: 52.559, 57.754). The combination treatment achieved 1-, 3-, and 5-year LTP rates of 92.5%, 69.6%, and 34.5%, respectively; and 1-, 3-, and 5-year OS rates of 100.0%, 88.4%, and 70.2%, respectively. Results from both univariate and multivariate Cox regression analyses showed that the tumor diameter (< 3 cm) and the distance to the hepatic dome (≥ 5 mm, < 10 mm) had a significant impact on the patient's LTP and OS, and were related to better survival.

CONCLUSION

CBCT-guided TACE combined with simultaneous MWA was a safe and successful treatment of HCCs located under the hepatic dome.

Uncooled TATO microwave system for liver ablation

Aim: To evaluate the safety and efficacy of uncooled TATO microwave ablation (MWA) for primary and metastatic liver cancer. Materials & methods: This was a retrospective study on percutaneous liver ablations performed with TATO MWA. Twenty-five ablations were performed; 11 (44%) were performed for hepatocellular carcinoma, 14 (56%) for colorectal carcinoma, gastric and pancreatic metastases. Results: Adverse events were reported only in one (4%) ablation: an abscess that was observed in the ablated area and was resolved with a percutaneous drainage and antibiotic therapy. Local tumor control rate was 92% at the 3-month follow-up. Conclusion: TATO MWA was safe and effective with high reproducibility in treating primary and secondary liver cancer with satisfactory technical and clinical outcomes.