Combined Radiofrequency Ablation and Double Anti-Angiogenic Protein Therapy to Increase Coagulation Efficacy: An Experimental Study in a Murine Renal Carcinoma Model

Basic Knowledge in Soft Tissue Sarcoma

Sarcoma is rare and heterogenous with various subtypes having a different prognostic. Desmoid is a tumour with a local aggressiveness; GIST with KIT mutation responds massively to target treatment as IMATINIB, whereas soft tissue sarcoma and leiomyosarcoma are very aggressive with poor response to systemic therapies. Interventional radiology plays an important role in the diagnosis of sarcomas with image-guided percutaneous core needle biopsy being the most commonly used biopsy technique in the diagnosis of sarcomas. Biopsy access routes discussed with the surgeon, and skin access is tattooed. Surgery is a mainstay of sarcoma treatment; the resection can be large. Indeed, resection objective is R0 because quality of surgical margins impacts local control and survival. Radiotherapy is possible in neoadjuvant or in adjuvant treatment to improve local control rate. Recently radiotherapy enhancer injected percutaneously in soft tissue sarcoma has proven benefit in increasing the rate of R0 complete surgical resection. Several studies showed better local control rate linked with post-operative radiotherapy. In patients affected by oligometastatic disease, complete surgical resection of all metastatic sites is in fact considered the primary treatment because complete remission is critical for cure. The decision making to use local therapies is complex, depends upon diverse presentations and histologies, and should always be taken in a multidisciplinary discussion. Today, percutaneous image-guided treatments with ablation technologies (radiofrequency ablation, cryotherapy, microwaves ablation) provide high rate of durable local control for small-sized malignant deposit in many organs including lung, liver and bones. Sarcoma must be managed by multimodality treatment in expert reference centres. Such management has a considerable impact on the prognosis.

Combined microwave ablation and antiangiogenic therapy to increase local efficacy

Purpose: We aim to evaluate the efficacy, safety and survival time of microwave ablation (MWA) with adjuvant antiangiogenic therapy-endostatin in animal models.Material and methods: A total of 40 rabbits successfully implanted with VX2 tumors were randomly assigned to four experimental groups: Group A underwent only microwave ablation of the tumors; Group B received only antiangiogenic drugs endostatin; Group C received endostatin immediately after MWA; Group D followed up without treatment.Results: Two months post-treatment, tumor sizes of Group A and Group C were reduced to 1.936 ± 0.373 cm³ and 1.592 ± 0.382 cm³, respectively. However, tumors grew to 15.091 ± 1.735 cm³ and 47.825 ± 7.664 cm³ in Group B and the control group. Three months post-treatment, tumor sizes in Group A and Group C maintained as 1.395 ± 0.394 cm³ and 1.482 ± 0.305 cm³, significantly smaller than Group B (35.277 ± 6.019 cm³). All animals in the control group died, while four (40%) survived in Group B (Endo Group). The numbers of survivals in Groups A and C were seven (70%) and eight (80%), respectively. The lowest metastasis rate (2/10, 20%) was observed in Group C (combination therapy).Conclusion: The combination of MWA and antiangiogenic therapy triggered a significant reduction in the growth rate and metastases of tumors and may potentially improve survivals.

Experimental murine model of renal cancer

INTRODUCTION

The objective of this study was to determine the reproducibility in a murine model of renal tumours of various histological strains that could be useful for investigating the response to target drugs.

MATERIAL AND METHODS

Development and analysis of the "in vivo" model: tumour xenograft of renal cell carcinomas with Balb/c nude athymic mice. Nontumourous human renal tissue was implanted in the interscapular region of 5 mice, chromophobe renal cell carcinoma was implanted in 5 mice (which, after checking its growth, was prepared for implantation in another 10 mice) and Fuhrman grade 2 clear cell renal cell carcinoma (CCRCC) was implanted in 5 mice (which was also subsequently implanted in 10 mice). We monitored the tumour size, onset of metastases and increase in size and number of tumours. When the size had reached a point greater than or equal to locally advanced or metastatic carcinoma, the animals were euthanised for a pathological and immunohistochemical study and a second phase of implantation.

RESULTS

The subcutaneous xenograft of the healthy tissue did not grow. The animals were euthanised at 6 months and no renal tissue was found. The chromophobe renal cell carcinoma cells grew in the initial phase (100%); however, in the second phase, we observed a chronic lymphomonocyte inflammatory reaction and a foreign body reaction. The CCRCC grew at 5-8 months both in the first and second phase (100%), maintaining the tumour type and grade.

CONCLUSIONS

The model with athymic Balb/c nude mice is useful for reproducing CCRCC, with the same histological characteristics and aggressiveness as native human tumours, promoting the development of the second experimental phase.

Percutaneous Dual-Switching Monopolar Radiofrequency Ablation Using a Separable Clustered Electrode: A Preliminary Study

Objective

To prospectively evaluate the safety and therapeutic effectiveness of dual-switching monopolar (DSM) radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC), and to retrospectively compare the results with those of single-switching monopolar (SSM) RFA in a historical control group.

Materials and Methods

This study was approved by the Institutional Review Board, with informed consent obtained from all patients. Fifty-two HCC patients who underwent DSM-RFA using a separable clustered electrode and dual-generators were prospectively enrolled. Technical parameters, complications, technical success, technical effectiveness, and local tumor progression (LTP) rates were evaluated by means of post-procedural and follow-up imaging. Thereafter, the outcome of DSM-RFA was compared with those of 249 retrospectively included HCC patients treated with SSM-RFA.

Results

There were two major complications (3.8%, 2/52) including pleural and pericardial effusion in the DSM-RFA group. The DSM-RFA yielded a 100% technical success rate, a 98.1% technical effectiveness rate, and a 4.3% 2-year LTP rate. In a retrospective comparison between the two groups, DSM-RFA created significantly larger ablation volume (4.20 ± 2.07 cm³/min vs. 3.03 ± 1.99 cm³/min, p < 0.01), and delivered higher energy (1.43 ± 0.37 kcal/min vs. 1.25 ± 0.50 kcal/min, p < 0.01) per given time, than SSM-RFA. There was no significant difference in major procedure-related complications (3.8% vs. 4.4%) and technical effectiveness rate (98.1% vs. 96.4%) between the two groups (p = 1.00). In addition, the 2-year LTP rate of DSM-RFA and SSM-RFA were 4.3% and 10.1%, respectively (p = 0.15).

Conclusion

DSM-RFA using a separable clustered electrode is safe and provides high local tumor control and good preliminary clinical outcome for small HCCs, which are at least comparable to those of SSM-RFA.

Safety and effectiveness of percutaneous radiofrequency ablation in early stage renal cell carcinoma

The purpose of this study was to analyze the safety and effectiveness of percutaneous radiofrequency ablation (RFA) in early stage renal cell carcinoma. A total of 76 patients suffering from early stage renal cell carcinoma were selected and randomly assigned into the observation group (41 cases) or the control group (35 cases). Percutaneous RFA was used in the observation group, while retroperitoneoscopic radical operation of renal cell carcinoma was used in the control group, and the operative effects were compared. In the observation group, operation time, blood loss during operation, length of stay and incidence rate of complications were lower than those in control group (P<0.05). For both groups, serum C-reactive protein, interleukin-6 and T lymphocyte counts at 1, 2 and 3 days after operation were all increased; however, the control group had significantly greater increase for all the time points (P<0.05). For total effective rates, tumour-free survival times and survival rates, there were no statistically significant differences between the two groups (P>0.05). Percutaneous RFA has a reduced size of operation wound and a quick postoperative recovery time in the treatment of early stage renal cell carcinoma. It results in less inflammation and immunity-based injuries in the body and achieves the same clinical outcomes as retroperitoneoscopic radical operation of renal cell carcinoma.