Percutaneous microwave ablation for local control of metastatic renal cell carcinoma

Multidisciplinary systemic and local therapies for metastatic renal cell carcinoma: a narrative review

INTRODUCTION

Systemic and local therapies for patients with metastatic renal cell carcinoma (mRCC) are often challenging despite the evolution of multimodal cancer therapies in the last decade. In this review, we will focus on recent multidisciplinary approaches for patients with mRCC.

AREAS COVERED

Systemic therapies for patients with mRCC have been garnering attention particularly after the approval of immuno-oncology (IO) agents, including anti-programmed death 1/programmed death-ligand 1. IO combinations have significantly prolonged overall survival in patients with mRCC in the first-line setting. Regarding local therapies, cytoreductive nephrectomy (CN) has become less common in the post-Cancer du Rein Metastatique Nephrectomie et Antiangiogéniques (CARMENA) trial era, even though CN may still benefit selected patients with mRCC. In addition, metastasis-directed local therapies, namely metastasectomy or stereotactic radiotherapy, particularly for oligo-metastatic lesions or brain metastases, may have a prognostic impact. Several ablative techniques are also evolving while maintaining high local control rates with acceptable safety.

EXPERT OPINION

Multimodal cancer therapies are essential for conquering complex cases of mRCC. Modern systemic therapies including IO-based combination therapy as well as local therapies including CN, metastasectomy, stereotactic radiotherapy, and ablative techniques appear to improve oncologic outcomes of patients with mRCC, although appropriate patient selection is indispensable.

Percutaneous Microwave Ablation for Treatment of Retroperitoneal Tumors

Purpose To determine if microwave ablation (MWA) of retroperitoneal tumors can safely provide high rates of local tumor control. Materials and Methods This retrospective study included 19 patients (median age, 65 years [range = 46-78 years]; 13 [68.4%] men and six [31.6%] women) with 29 retroperitoneal tumors treated over 22 MWA procedures. Hydrodissection (0.9% saline with 2% iohexol) was injected in 17 of 22 (77.3%) procedures to protect nontarget anatomy. The primary outcomes evaluated were local tumor progression (LTP) and complication rates. Oncologic outcomes, including overall survival (OS), progression-free survival (PFS), and treatment-free interval (TFI), were examined as secondary outcome measures. Results Median follow-up was 18 months (range = 0.5-113). Hydrodissection was successful in displacing nontarget anatomy in 16 of 17 (94.1%) procedures. The LTP rate was 3.4% (one of 29; 95% CI: 0.1, 17.8) per tumor and 5.3% (one of 19; 95% CI: 0.1, 26.0) per patient. The overall complication rate per patient was 15.8% (three of 19), including two minor complications and one major complication. The OS rate at 1, 2, and 3 years was 81.8%, 81.8%, and 72.7%, respectively, with a median OS estimated at greater than 7 years. There was no evidence of a difference in OS (P = .34) and PFS (P = .56) between patients with renal cell carcinoma (six of 19 [31.6%]) versus other tumors (13 of 19 [68.4%]) and patients treated with no evidence of disease (15 of 22 [68.2%]) versus patients with residual tumors (seven of 22 [31.8%]). Median TFI was 18 months (range = 0.5-108). Conclusion Treatment of retroperitoneal tumors with MWA combined with hydrodissection provided high rates of local control, prolonged systemic therapy-free intervals, and few serious complications. Keywords: Ablation Techniques (ie, Radiofrequency, Thermal, Chemical), Retroperitoneum, Microwave Ablation, Hydrodissection © RSNA, 2024.

Beyond the Knife in Renal Cell Carcinoma: A Systematic Review-To Ablate or Not to Ablate?

Intensified systemic therapy in metastatic renal cell carcinoma (mRCC) has led to improved patient outcomes. Patients commonly require local control of one or a few metastases. The aim was to evaluate metastasis-directed ablative therapies in extracranial mRCC. Two databases and one registry were searched, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) approach, for all prospective and matched-pair case-control mRCC studies of radiofrequency ablation (RFA), cryotherapy, microwave ablation (MWA), and stereotactic body radiotherapy (SBRT). Eighteen studies were identified. Fourteen investigated SBRT in 424 patients. Four thermal ablation studies were identified: two cryotherapy (56 patients) and two RFA studies (90 patients). The median participant number was 30 (range 12-69). The combined median follow-up was 17.3 months (range 8-52). Four SBRT studies reported local control (LC) at 12 months, median 84.4% (range 82.5-93). Seven studies (six SBRT and one cryotherapy) reported an LC rate of median 87% (79-100%). Median overall survival (OS) was reported in eight studies (five SBRT, two cryotherapy, and one RFA) with a median of 22.7 months (range 6.7-not reached). Median progression-free survival was reported in seven studies (five SBRT, one cryotherapy, and one RFA); the median was 9.3 months (range 3.0-22.7 months). Grade ≥ 3 toxicity ranged from 1.7% to 10%. SBRT has excellent local control outcomes and acceptable toxicity. Only four eligible thermal ablative studies were identified and could not be compared with SBRT. Translationally rich definitive studies are warranted.

Approaches to Oligometastatic Renal Cell Carcinoma

PURPOSE OF REVIEW

This study aims to gather the current state of the literature about therapeutic approaches and management of oligometastatic renal cell carcinoma.

RECENT FINDINGS

Two recent stereotactic body radiotherapy (SBRT) studies gained attention and offered a promising outcome alone or in association with antineoplastic drugs especially in oligometastatic renal cell carcinoma. If one can consider evidence-based medicine as the sole therapeutic option, many unresolved questions are still pending. Thus, therapeutic approaches in oligometastatic renal cell carcinoma are still working. Further phase III clinical trials are urgently needed to validate the last 2 phase II involving SBRT and improve knowledge for defining the right care to the right patient at the right time. In addition, a discussion in a disciplinary consultation meeting remains essential to validate the arrangement between systemic treatments and focal treatments that will best benefit the patient.

Evaluation of the performance of designed coaxial antennas for hyperthermia using simulation and experimental methods

Introduction: Antenna geometries and tissue properties affect microwave energy distributions during microwave ablation procedures. There is paucity information on the potential of antenna fabricated from a thick semi-rigid coaxial cable in the field of microwave thermal therapy. This study aimed at comparing the performance of two dual-slot antennas designed from different semi-rigid coaxial cables for the ablation of a liver tumour using numerical simulation and experimental validation methods.

Materials and Methods: COMSOL Multiphysics software was used for designing dual-slot antennas and as well as to evaluate microwave energy deposition and heat distribution in the liver tissue. Experimental validations were conducted on the ex-vivo bovine livers to validate the simulation results.

Results: Thick antenna developed in this study produced a higher sphericity index, larger ablation diameter and reduced backward heating along the antenna shaft than the existing one. The experimental validation results also indicate significant differences between the two antennas in terms of ablation diameters (p = 0.04), ablation lengths (p = 0.02) and aspect ratios (p = 0.02).

Conclusion: Based on the findings in this study, antenna fabricated from a thick coaxial cable has a higher potential of localizing microwave energy in the liver than conventional antennas.

Percutaneous microwave ablation versus surgical resection for ovarian cancer liver metastasis

Objective: To compare the oncological outcomes between microwave ablation (MWA) and surgical resection (SR) in patients with ovarian cancer liver metastasis (OCLM).Materials and methods: In this retrospective study, a total of 29 female patients (mean age, 47.8 ± 12.9 years; range, 21-65 years) diagnosed with forty-three OCLM nodules between September 2008 and July 2016 were included. All patients with ovarian cancer received chemotherapy and cytoreductive surgery (CRS). Fifteen patients with 22 nodules underwent MWA, and 14 patients with 21 nodules underwent SR. Overall survival (OS), local tumor recurrence-free survival (LTRS), and operation-related parameters were compared between the two groups. Multivariate analyses were performed on clinicopathological variables to identify factors affecting OS and LTRS.Results: The median follow-up time was 70.2 months (range, 12.1-107.2 months). Fourteen patients died during this period. The 1-, 3-, and 5-year OS and LTRS rates after MWA were comparable to those after SR (p = .198 and p = .889, respectively). Compared with the SR group, the MWA group had a shorter surgical time (p < .001), less estimated blood loss (p < .001), shorter postoperative hospitalization (p < .001) and fewer costs (p = .015). The multivariate analysis showed that old age (p = .001) was a predictor of poor OS and that intrahepatic tumor size (p = .005) and intrahepatic tumor number (p = .001) were predictors of poor LTRS.Conclusion: Percutaneous MWA had comparable oncologic outcomes with those of SR and could be a safe and effective treatment for OCLM.

The Evolving Role of Metastasectomy for Patients with Metastatic Renal Cell Carcinoma

Surgical metastasectomy continues to be utilized for patients with solitary or low-volume metastatic renal cell carcinoma (mRCC). Although few high-quality data are available to evaluate outcomes, local treatment is recommended when feasible because it may allow a subset of patients to delay or avoid systemic treatments. With the development of improved mRCC therapies, utilization of metastasectomy has increased because most patients have incomplete responses to systemic treatment of their metastases. This review discusses the rationale and history of metastasectomy, trends in utilization, prognostic factors for patient selection, site-specific considerations, alternatives for nonsurgical local treatment, and risk of morbidity associated with metastasectomy.

An overview of interventional strategies for the management of oncologic pain

Pain is a ubiquitous part of the cancer experience. Often the presenting symptom of malignancy, pain becomes more prevalent in advanced or metastatic disease and often persists despite curative treatment. Although management of cancer pain improved following publication of the WHO's analgesic ladder, when used in isolation, conservative approaches often fail to control pain and are limited by intolerable side effects. Interventional strategies provide an option for managing cancer pain that remains refractory to pharmacologic therapy. The purpose of this review is to investigate these strategies and discuss the risks and benefits which must be weighed when considering their use. Therapies anticipated to have an increasingly important role in the future of cancer pain management are also discussed.