Image-Guided Thermal Ablation for Non-resectable Recurrence of Renal Cell Cancer Following Nephrectomy: Clinical Experience with Eleven Patients

Current strategies to diagnose and manage of positive surgical margins and local recurrence after partial nephrectomy

Objective

No standard strategy for diagnosis and management of positive surgical margin (PSM) and local recurrence after partial nephrectomy (PN) are reported in literature. This review aims to provide an overview of the current strategies and further perspectives on this patient setting.

Methods

A non-systematic review of the literature was completed. The research included the most updated articles (about the last 10 years).

Results

Techniques for diagnosing PSMs during PN include intraoperative frozen section, imprinting cytology, and other specific tools. No clear evidence is reported about these methods. Regarding PSM management, active surveillance with a combination of imaging and laboratory evaluation is the first option line followed by surgery. Regarding local recurrence management, surgery is the primary curative approach when possible but it may be technically difficult due to anatomy resultant from previous PN. In this scenario, thermal ablation (TA) may have the potential to circumvent these limitations representing a less invasive alternative. Salvage surgery represents a valid option; six studies analyzed the outcomes of nephrectomy on local recurrence after PN with three of these focused on robotic approach. Overall, complication rates of salvage surgery are higher compared to TA but ablation presents a higher recurrence rate up to 25% of cases that can often be managed with repeat ablation.

Conclusion

Controversy still exists surrounding the best strategy for management and diagnosis of patients with PSMs or local recurrence after PN. Active surveillance is likely to be the optimal first-line management option for most patients with PSMs. Ablation and salvage surgery both represent valid options in patients with local recurrence after PN. Conversely, salvage PN and radical nephrectomy have fewer recurrences but are associated with a higher complication rate compared to TA. In this scenario, robotic surgery plays an important role in improving salvage PN and radical nephrectomy outcomes.

Percutaneous Ablation Versus Surgical Resection for Local Recurrence Following Partial Nephrectomy for Renal Cell Cancer: A Propensity Score Analysis (REPART Study-UroCCR 71)

BACKGROUND

Data comparing percutaneous ablation (PCA) and surgical resection (SR) for an isolated local recurrence (LR) following partial nephrectomy (PN) for renal cell carcinoma (RCC) are lacking.

OBJECTIVE

To examine the outcomes between PCA and SR for an isolated LR following PN for RCC.

DESIGN, SETTING, AND PARTICIPANTS

Patients who underwent PN for RCC and developed an LR between 2013 and 2019 were included. An LR was defined as the appearance of a mass in contact with the resection bed or the development of a tumor in the same region of the homolateral kidney as the original site.

INTERVENTION

PCA or SR.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

To achieve balance in baseline characteristics, we used inverse probability of treatment weighting (IPTW) based on propensity to receive treatment. Oncological outcomes, complications, and renal function were evaluated between groups using logistic, linear, and Cox proportional hazard regression models.

RESULTS AND LIMITATIONS

A total of 81 patients with an isolated LR were included (PCA: 42; SR: 39). The median follow-up was 23 mo. After adjustment, excellent balance was achieved for the majority of propensity score variables. In IPTW analysis, PCA was associated with a lower risk of postoperative complications (odds ratio=0.22; p=0.006) and a smaller change in eGFR (beta=-16.18; p=0.001). There were no significant differences in the risk of disease recurrence (hazard ratio [HR]=0.72; p=0.61), new LR (HR=1.51; p=0.59), and distant metastasis (HR=0.19; p=0.09). Limitations include the sample size and unmeasured confounding factors.

CONCLUSIONS

Our results suggest that PCA provides comparable oncological outcomes to repeat surgery with fewer complications and better renal function preservation for the management of an LR after PN.

PATIENT SUMMARY

This report shows that percutaneous ablation can be used for treating a local recurrence of renal cell carcinoma after partial nephrectomy, without significantly compromising cancer control.

Impact of Body Mass Index on Perioperative Complications and Oncologic Outcomes in Patients Undergoing Thermal Ablation for Renal Cell Carcinoma

PURPOSE

To determine effect of body mass index (BMI) on safety and cancer-related outcomes of thermal ablation for renal cell carcinoma (RRC).

MATERIALS AND METHODS

This retrospective study evaluated 427 patients (287 men and 140 women; mean [SD] age, 72 [12] y) who were treated with thermal ablation for RCC between October 2006 and December 2017. Patients were stratified by BMI into 3 categories: normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), and obese (≥ 30 kg/m²). Of 427 patients, 71 (16%) were normal weight, 157 (37%) were overweight, and 199 (47%) were obese. Complication rates, local recurrence, and residual disease were compared in the 3 cohorts.

RESULTS

No differences in technical success between normal-weight, overweight, and obese patients were identified (P = .72). Primary technique efficacy rates for normal-weight, overweight, and obese patients were 91%, 94%, and 93% (P = .71). There was no significant difference in RCC specific-free survival, disease-free survival, and metastasis-free survival between obese, overweight, and normal-weight groups (P = .72, P = .43, P = .99). Complication rates between the 3 cohorts were similar (normal weight 4%, overweight 2%, obese 3%; P = .71).

CONCLUSIONS

CT-guided renal ablation is safe, feasible, and effective regardless of BMI.

Cryoablation for Secondary Renal Cell Carcinoma After Surgical Nephrectomy

PURPOSE

To retrospectively evaluate the clinical outcomes of cryoablation for secondary renal cell carcinoma for patients with a history of nephrectomy for initial renal cell carcinoma.

MATERIALS AND METHODS

Thirty patients with 40 renal tumors who had undergone a nephrectomy for initial renal cell carcinoma and cryoablation for renal cell carcinoma as a secondary treatment during the period from April 2014 to December 2018 at a single center institution were enrolled. The patients' overall survival, local control, relapse-free survival, change of renal function, and complications were evaluated. The clinical factors of relapse-free survival were also evaluated.

RESULTS

The 5 year overall survival rate was 94.5%, the 5 year local control rate was 89.3%, and the 5 year relapse-free survival rate (RFSR) was 56.3%. There was an average reduction in renal function of 8.5% after 1 year, and > grade 3 complications occurred in only one case. The RFSR in the patients whose initial stage was T3 was 0%, significantly lower than the 70.4% RFSR in the patients whose initial stage was T1 or T2.

CONCLUSION

Cryoablation for secondary renal cell carcinoma after nephrectomy was safe and provided good local control with preserved renal function. However, the indications for cryoablation should be carefully considered for patients with T3-stage initial renal cell carcinoma, because of the high risk of relapse.

LEVEL OF EVIDENCE

III.

Thermal Ablation of Renal Cell Carcinoma in Patients With Morbid Obesity: Assessment of Technique, Safety, and Oncologic Outcomes

BACKGROUND. Obesity is a worldwide problem that impacts patient health as well as the morbidity associated with surgical procedures. Thus, patients with morbid obesity may not be suitable candidates for curative surgery. For this patient population, thermal ablation may be an effective alternative to nephrectomy. OBJECTIVE. The purpose of this study was to determine the feasibility, oncologic outcomes, and survival of patients with morbid obesity and renal cell carcinoma treated with thermal ablation. MATERIALS AND METHODS. A retrospective analysis was performed of 107 patients treated with CT-guided renal ablation for clinical T1 renal cell carcinoma between February 2005 and December 2017. Patients were stratified into two cohorts on body mass index of ≥ 40 kg/m² (morbidly obese) and body mass index (weight in kilograms divided by the square of height in meters) of ≥ 40 (morbidly obese) and 18.5-24.9 (normal weight). Anesthetic and radiation dosages, procedure time, residual disease, and local recurrence, and adverse events were analyzed between the two groups. Kaplan-Meier statistics were used to evaluate cancer-related outcomes for each group. RESULTS. Thirty-four patients were morbidly obese, and 73 patients had normal weight. Morbid obesity was associated with longer procedural duration (p = .001), sedative doses (p = .002) and radiation exposure (p = .001) than normal weight. Hematomas were more prevalent in patients with morbid obesity than in those of normal weight (p = .01), but treatment efficacy and local recurrences were comparable with those for normal-weight individuals (p = .81 and p = .12, respectively). Cancer-related outcomes were equivalent between the two groups based on 5 years of imaging observation data. CONCLUSION. CT-guided thermal ablation remains technically feasible, well-tolerated, and effective in patients with morbid obesity and renal cell carcinoma, with the caveat of increased risk of perinephric hematoma, anesthesia dose, and radiation exposure. CLINICAL IMPACT. CT-guided thermal ablation can be considered a safe and effective treatment for renal cell carcinoma in patients with morbid obesity.

Outcomes following minimally invasive imagine-guided percutaneous ablation of adrenal glands

Whilst surgery represents the gold standard for the treatment of adrenal primary malignant tumors, metastatic involvement of the adrenal glands is generally approached conservatively; however, surgery for local control has been controversial, and several reports have described the utility of surgical removal in terms of prolonged survival in selected patients. Different techniques, including radiofrequency ablation (RFA), microwave ablation (MWA), laser induced thermal therapy (LITT), cryoablation (CRA), and chemical ablation, are employed in percutaneous image-guided ablation for primary and metastatic malignancies of the adrenal glands, in case of patients with multiple comorbidities or who refuse surgery. Technical success, clinical success and safety were analysed and discussed in this systematic review. Tumor size was found a significant determinant for local disease control; histology of the primary malignancy and coexistence of tumor elsewhere were correlated with prognosis. These procedures resulted to be feasible and safe, with hypertensive crisis representing the most common complication. Although there is lack of evidence in the literature concerning outcomes compared with surgery, percutaneous ablation may represent a useful therapeutic option for controlling unresectable adrenal metastases, offering patients opportunities for improved survival.

Percutaneous microwave ablation therapy of renal cancer local relapse after radical nephrectomy: a feasibility and efficacy study

Renal cell carcinoma (RCC) local recurrence after radical nephrectomy is uncommon. When feasible, surgical removal remains the primary treatment strategy; nevertheless, local RCC relapse management is controversial, and less invasive procedures may represent an attractive option to achieve oncologic control. The aim of our study was to assess the feasibility, safety, and clinical outcomes of image-guided percutaneous microwave ablation (MWA) for RCC local recurrence in patients initially treated with nephrectomy with curative intent. 10 consecutive patients underwent CT-guided percutaneous MWA of a total of 10 retroperitoneal nodules. Inclusion criteria were: histologically verified retroperitoneal metastases, previous radical nephrectomy, lesion no larger than 3 cm, no other metastatic site elsewhere. All the procedures were performed under moderate sedation choosing the most favorable patient decubitus. If deemed necessary, pneumodissection was induced before ablation. After the antenna placement inside the target lesion, thermal ablation was achieved by maintenance of a power of 100 W for a total time between 2 and 4 min. All patients were observed overnight and discharged the following day if clinically stable. Technical success was obtained in 100% of patients. One patient was re-treated to complete oncologic response with repeat MWA. No major complications were observed. No patients demonstrated local recurrence at a mean follow-up of 26 months. MWA is a safe and effective treatment strategy for loco-regional relapse of RCC following radical nephrectomy. This technique may represent a valuable approach for patients who are not eligible for surgery.

Image-guided laser ablation in the treatment of recurrence of renal tumours: technique and preliminary results

Abdominal recurrences of renal cell carcinoma (RCC) after surgery might represent a challenge for treatment, often requiring difficult surgeries or anticipated systemic therapy. Our aim is to illustrate a novel application of laser ablation for the treatment of abdominal recurrences of RCC. Patients with abdominal recurrences of renal cancer were treated under ultrasound/computed tomography guidance with a diode laser inserted into the lesion through a thin 21-G needle. A fixed 3-W power protocol was used, changing the illumination time according to lesion dimension and shape. Also, technical success, technical efficacy, local tumour progression, and major and minor complications were retrospectively analysed. Three patients were treated with image-guided laser ablation for abdominal recurrences of RCC. In all cases, it was possible to perform ablation as preoperatively planned and all three nodules (size of 6, 8, and 12 mm) were completely ablated with no evidence of residual enhancement after 6 weeks at contrast-enhanced CT. No minor or major complications were observed. No local tumour progression was reported up to 12 months from ablation. Image-guided laser ablation holds the potential to offer a minimally invasive treatment to patients with abdominal recurrence of RCC. Further studies are needed to evaluate the clinical role of this technique.

Imaging of Small Renal Masses before and after Thermal Ablation

Thermal ablation of small renal masses is increasingly accepted as an alternative to partial nephrectomy, particularly in patients with multiple comorbidities. Many professional societies support this alternate treatment with updated guidelines. Before performing thermal ablation, it is important to stratify risk and assess technical feasibility by evaluating tumor imaging features such as size, location, and centrality. Routine postablation imaging with CT or MRI is necessary for assessment of residual or recurrent tumor, evidence of complications, or new renal masses outside the ablation zone. The normal spectrum and evolution of findings at CT and MRI include a halo appearance of the ablation zone, ablation zone contraction, and ablation zone calcifications. Tumor recurrence frequently manifests at CT or MRI as new nodular enhancement at the periphery of an expanding ablation zone, although it is normal for the ablation zone to enlarge within the first few months. Recognizing early tumor recurrence is important, as small renal masses are often easily treated with repeat ablations. Potential complications of thermal ablation include vascular injury, urine leak, ureteral stricture, nerve injury, and bowel perforation. The risk of these complications may be related to tumor size and location.^©RSNA, 2019.