Safety and oncologic efficacy of percutaneous MRI-guided cryoablation of intraparenchymal renal cancers

Renal Arteriography and C-arm CT-Guided Ablation (RenACAGA) for Thermal Ablation of Challenging Renal Tumors

PURPOSE

We present a technique that combines Renal arteriography with C-arm CT-Guided Ablation (RenACAGA) to improve tumor visualization, navigation and margin confirmation for percutaneous ablation of renal tumors.

MATERIALS AND METHODS

The RenACAGA technique was used for thermal ablation of challenging renal tumors (intraparenchymal or US-occult lesions). All patients treated with RenACAGA between January 1, 2022, and July 1, 2024, were retrospectively evaluated. Procedures were performed in the angiography suite, with catheterization of the renal artery for selective contrast infusion. C-arm CT and guidance software were used for tumor visualization and ablation needle placement. Pre- and post-ablation C-arm CTs were fused to assess ablation margins. Technical success and local tumor recurrence (LTR) rate were evaluated. Complications were graded according to the Common terminology criteria for adverse events (CTCAE) version 5.0.

RESULTS

Seven patients with 10 tumors were treated using the RenACAGA technique. All tumors were successfully identified, punctured and ablated (technical success 100%). During a median follow-up period of 8 months (range 7-25 months), no signs of tumor recurrence at the ablation site were observed (LTR rate 0%). One CTCAE grade 3 periprocedural complication was observed (urinary leakage through the needle tract), along with two CTCAE grade 1 complications (genitofemoral neuralgia (n = 1), and asymptomatic partial splenic infarction (n = 1)).

CONCLUSION

The RenACAGA technique was successfully used for renal tumor ablation. Further studies are warranted to establish the potential benefits of this technique in terms of superior tumor visualization, targeting, ablation margin assessment, and combination with embolization.

Profile and methodology of ancillary protective measures employed during percutaneous renal cryoablation in a single high-volume centre

OBJECTIVES

To evaluate the at-risk organs that require protection during percutaneous cryoablation (PCA) of renal tumours and the correlation with patient and target lesion characteristics, type of protective measure used and postoperative outcomes.

MATERIALS AND METHODS

Single-centre retrospective review of patients with renal tumours who underwent PCA between 2008 and 2020. Final analysis included 374 tumours. Patient, tumour, and procedure technical details were extracted and analysed. At-risk organs were classified according to tumour location relative to kidney side, pyelic axis, and polar lines.

RESULTS

There were 171 (46.0%) tumours in the left kidney, and 194 (52.0%) in the right. Cryoprotection was required for 272 (272/374; 73.0%) tumours, with hydrodissection (216/374; 58.0%) being the most common technique. Protective measures were used for 82 (82/93; 88.0%) tumours in under/normal-weight patients and 143 (143/196; 73.0%) in overweight/obese ones (P = 0.004). In the left kidney, colon was the most common at-risk organ (63/171; 37.0%), followed by spleen (21/171; 12.3%), small bowel (21/171; 12.3%), ureter (19/171; 11.1%), abdominal wall (15/171; 8.8%), psoas muscle (10/171; 5.8%), and pancreas (9/171; 5.3%). In the right kidney, common at-risk organs were the colon (67/194; 35.0%), liver (50/194; 25.7%), ureter (15/194; 15.5%), diaphragm (16/194; 8.2%), abdominal wall (14/194; 7.2%), and duodenum (12/194; 6.1%). No cryoinjuries to at-risk organs occurred.

CONCLUSION

Hydrodissection is the most common cryoprotective measure used for renal tumour PCA. Under/normal-weight patients are more likely to require cryoprotection. The colon is the most common adjacent at-risk organ requiring protection for both right- and left-sided tumours.

Comparative efficacy and safety of ablative therapies in the management of primary localised renal cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Non-invasive and minimally invasive ablative treatments, including stereotactic body radiotherapy (SBRT), radiofrequency ablation, microwave ablation, and cryoablation, have emerged as key treatment options for managing renal cell carcinoma, especially for patients who are unsuitable for surgery. We aimed to compare the clinical efficacy and safety of these emerging treatment methods in patients with localised renal cell carcinoma.

METHODS

In this systematic review and meta-analysis, we searched PubMed (MEDLINE), Embase, and the Cochrane Library for publications between Jan 1, 2000, and March 1, 2024. Eligible articles were observational studies and randomised controlled trials including at least five adult patients (age ≥18 years) with primary and localised renal cell carcinoma treated with SBRT, radiofrequency ablation, microwave ablation, or cryoablation and that reported on local control outcomes. Two reviewers independently screened titles and abstracts and then full texts of eligible studies were independently evaluated by the same reviewers, with disagreements resolved via discussion or consultation with a third reviewer. Summary estimates were extracted from published reports manually using a standardised data extraction form. The primary endpoint was local control rate at 1 year, 2 years, and 5 years after start of treatment. A meta-analysis was conducted using a DerSimonian and Laird model to summarise local control rates. Publication bias was evaluated using funnel plots and Egger's test. We also recorded the frequency and severity of adverse events after treatment on the basis of the Common Terminology Criteria for Adverse Events (version 5.0) and Clavien-Dindo complication index. The study protocol was prospectively registered with PROSPERO, CRD42024511840.

FINDINGS

We identified 6668 records, of which 330 were assessed via full-text review, and 133 were included in our systematic review and meta-analysis. The eligible studies included data for 8910 patients (mean age 67·9 years [SD 7·3], 2518 [31·4%] of 8018 patients with available data were female and 5500 [68·6%] were male). Local control rates for SBRT were 99% (95% CI 97-100; I2=6%) at 1 year, 97% (95-99; I2=0%) at 2 years, and 95% (89-98; I2=42%) at 5 years; for radiofrequency ablation were 96% (94-98; I2=73%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 92% (88-96; I2=78%) at 5 years; for microwave ablation were 97% (95-99; I2=74%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 86% (75-94; I2=66%) at 5 years; and for cryoablation were 95% (93-96; I2=61%) at 1 year, 94% (91-96; I2=69%) at 2 years, and 90% (87-93; I2=74%) at 5 years. The proportion of patients who reported grade 3-4 adverse events was 3% (121 of 3726) after cryoablation, 2% (39 of 2503) after radiofrequency ablation, 1% (22 of 2069) after microwave ablation, and 2% (11 of 612) after SBRT. Risk of bias was moderate in most studies (70 [53%] of 133) and no publication bias was observed.

INTERPRETATION

All investigated ablative methods continue to represent effective treatment choices in renal cell carcinoma, and these findings support multi-disciplinary discussions of these treatment methods, along with surgery and surveillance, to individualise treatment decisions in these patients. Future research should aim to conduct randomised controlled trials across larger patient populations to further elucidate the long-term oncological and survival outcomes associated with these treatments.

FUNDING

None.

Impact of Percutaneous Cryoablation on Renal Function in Patients with Stage I Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

PURPOSE

To assess the effect of cryoablation on renal function (measured by estimated glomerular filtration rate [eGFR] or serum creatinine) for treating Stage I renal cancer.

MATERIALS AND METHODS

The MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were systematically searched from inception to May 1, 2023. Cohort studies that included data on change of eGFR and serum creatinine increase were included. Meta-analysis was performed by measuring the weighted mean difference and by fitting random-effect models.

RESULTS

Overall, 38 studies were included, comprising 3,202 participants. Percutaneous cryoablation was associated with an absolute eGFR reduction of -3.06 mL/min/1.73 m2 (95% CI, -4.12 to -2.01; P < .001) and serum creatinine increase of 0.05 mg/dL (95% CI, -0.02 to 0.11; P > .05). The weighted absolute mean difference of percutaneous cryoablation for treating Stage T1b renal cell carcinoma was estimated at -5.19 mL/min/1.73 m2 (95% CI, -11.1 to 0.72; P > .05). Lastly, when analyzing studies that included cohorts with solitary kidneys, the pooled weighted mean difference was estimated as -3.27 mL/min/1.73 m2 (95% CI, -6.79 to 0.25; P > .05).

CONCLUSIONS

Percutaneous cryoablation for Stage 1 renal cell carcinoma has minimal significant impact on renal function (measured by eGFR or serum creatinine). The same outcome was observed in patients with larger tumors (T1b) and those with solitary kidneys.

Magnetic-Resonance-Imaging-Guided Cryoablation for Solitary-Biopsy-Proven Renal Cell Carcinoma: A Tertiary Cancer Center Experience

BACKGROUND

Our purpose is to evaluate the long-term oncologic efficacy and survival rates of MRI-guided cryoablation for patients with biopsy-proven cT1a renal cell carcinoma (RCC).

MATERIALS AND METHODS

We retrospectively reviewed our renal ablation database between January 2007 and June 2021 and only included patients with solitary-biopsy-proven cT1a RCC (≤4 cm) who underwent MRI-guided cryoablation. We excluded patients with genetic syndromes, bilateral RCC, recurrent RCC or benign lesions, those without pathologically proven RCC lesions and patients who underwent radiofrequency ablation or CT-guided cryoablation. For each patient, we collected the following: age, sex, lesion size, right- or left-sided, pathology, ablation zone tumor recurrence, development of new tumor in the kidney other than ablation zone, development of metastatic disease, patient alive or not, date and cause of death. We used the Kaplan and Meier product limit estimator to estimate the survival outcomes.

RESULTS

Twenty-nine patients (median age 70 years) met our inclusion criteria. Twenty-nine MRI-guided cryoablation procedures were performed for twenty-nine tumor lesions with a median size of 2.2 cm. A Clavien-Dindo grade III complication developed in one patient (3.4%). Clear cell RCC was the most reported histology (n = 19). The median follow up was 4.5 years. No tumor recurrence or metastatic disease developed in any of the patients. Two patients developed new renal lesions separate from the ablation zone. The 5- and 10-year OS were 72% and 55.6%, respectively. The 5- and 10-year DFS were 90.5% and the 5-year and 10-year LRFS, MFS and CSS were all 100%.

CONCLUSIONS

MRI-guided cryoablation is a safe treatment with a low complication rate. Long-term follow-up data revealed long-standing oncologic control.

Ablation of Kidney Tumors in Patients with Substantial Kidney Impairment: Current Status

PURPOSE OF REVIEW

To review the current status of kidney tumor ablation in patients with substantial kidney impairment.

RECENT FINDINGS

Few reports of kidney tumor ablation in such patients have recently been published. The reported prevalence of patients with stage 4 or 5 chronic kidney disease (CKD) among patients undergoing ablation is 2.0%-10%. In patients with stage 4 or 5 CKD, local tumor control rates were 88%-100%. The effect of ablation on CKD stage is unclear, and the observed deteriorations in kidney function are consistent with both the effect of cryoablation and the natural course of advanced CKD. According to guidelines, active surveillance may be selected. The goals of treatment are complete tumor removal and maintenance of kidney function, both of which can be met by ablation. Given the limited treatment options, ablation may play a pivotal role in the management of patients with advanced CKD.

Percutaneous Image-Guided Cryoablation of Endophytic Renal Cell Carcinoma

PURPOSE

Endophytic renal cancer treatment is a challenge. Due to difficulties in endophytic tumor visualization during surgical extirpation, image-guided percutaneous cryoablation (PCA) is an attractive alternative. The minimally invasive nature of PCA makes it favorable for comorbid patients as well as patients in which surgery is contraindicated. Oncological outcomes and complications after PCA of endophytic biopsy-proven renal cell carcinoma (RCC) were reviewed in this study.

MATERIALS AND METHODS

Patients were included after a multidisciplinary team conference from January 2015 to November 2021. Inclusion criteria were endophytic biopsy-proven T1 RCC treated with PCA with one year of follow-up. Complications were reported according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification system and the Clavien-Dindo classification (CDC) system. Major complications were defined as a grade ≥ 3 according to the CDC.

RESULTS

Fifty-six patients were included with a total of 56 endophytic tumors treated during 61 PCA sessions. The median RENAL nephrometry score was 9 (IQR 2), and the mean tumor size was 25.7 mm (SD ± 8.9 mm). Mean hospitalization time was 0.39 (SD ± 1.1) days. At a mean follow-up of 996 days (SD ± 559), 86% of tumors were recurrence free after one PCA. No patients progressed to metastatic disease. According to the CIRSE classification, 10.7% (n = 6) had grade 3 complications, and 5.4% (n = 3) had CDC major complications.

CONCLUSION

This study demonstrates that PCA of endophytic biopsy-proven T1 RCC is safe with few major complications and excellent local tumor control rates at almost three-year mean follow-up. LEVEL OF EVIDENCE 3: Retrospective cohort study.

Minimally invasive nephron-sparing treatments for T1 renal cell cancer in patients over 75 years: a comparison of outcomes after robot-assisted partial nephrectomy and percutaneous ablation

PURPOSE

To compare the oncological and perioperative outcomes of robot-assisted partial nephrectomy (RPN) and percutaneous thermal ablation (PTA) for treatment of T1 renal cell cancer (RCC) in patients older than 75 years.

MATERIALS AND METHODS

Retrospective national multicenter study included all patients older than 75 years treated for a T1 RCC by RPN or PTA between January 2010 and January 2021. Patients' characteristics, tumor data, and perioperative and oncological outcomes were compared.

RESULTS

A total of 205 patients for 209 procedures (143 RPN and 66 PTA) were included. In the PTA group, patients were older (80.4 ± 3.7 vs. 79 ± 3.7 years (p = 0.01)); frailer (ASA score (2.43 ± 0.6 vs. 2.17 ± 0.6 (p < 0.01)); and more frequently had a history of kidney surgery (16.7% [11/66] vs. 5.6% [8/143] (p = 0.01)) than in the RPN group. Tumors were larger in the RPN group (2.7 ± 0.7 vs. 3.2 ± 0.9 cm (p < 0.01)). Operation time, length of hospital stay, and increase of creatinine serum level were higher in RPN (respectively 92.1 ± 42.7 vs. 150.7 ± 61.3 min (p < 0.01); 1.7 ± 1.4 vs. 4.2 ± 3.4 days (p < 0.01); 1.9 ± 19.3% vs. 10.1 ± 23.7 (p = 0.03)). Disease-free survival and time to progression were similar (respectively, HR 2.2; 95% CI 0.88-5.5; p = 0.09; HR 2.1; 95% CI 0.86-5.2; p = 0.1). Overall survival was shorter for PTA that disappeared after Cox adjusting model (HR 3.3; 95% CI 0.87-12.72; p = 0.08).

CONCLUSION

Similar oncological outcomes are observed after PTA and RPN for T1 RCC in elderly patients.

CLINICAL RELEVANCE STATEMENT

Robot-assisted partial nephrectomy and percutaneous thermal ablation have similar oncological outcomes for T1a kidney cancer in patients over 75 years; however, operative time, decrease in renal function, and length of hospital stay were lower with ablation.

KEY POINTS

• After adjusting model for age and ASA score, similar oncological outcomes are observed after percutaneous thermal ablation and robot-assisted partial nephrectomy for T1 renal cell cancer in elderly patients. • Operation time, length of hospital stay, and increase of creatinine serum level were higher in the robot-assisted partial nephrectomy group.

Simultaneous T2 -weighted real-time MRI of two orthogonal slices

PURPOSE

MR guidance is used during therapy to detect and compensate for lesion motion. T2 -weighted MRI often has a superior lesion contrast in comparison to T1 -weighted real-time imaging. The purpose of this work was to design a fast T2 -weighted sequence capable of simultaneously acquiring two orthogonal slices, enabling real-time tracking of lesions.

METHODS

To generate a T2 contrast in two orthogonal slices simultaneously, a sequence (Ortho-SFFP-Echo) was designed that samples the T2 -weighted spin echo (S- ) signal in a TR-interleaved acquisition of two slices. Slice selection and phase-encoding directions are swapped between the slices, leading to a unique set of spin-echo signal conditions. To minimize motion-related signal dephasing, additional flow-compensation strategies are implemented. In both the abdominal breathing phantom and in vivo experiments, a time series was acquired using Ortho-SSFP-Echo. The centroid of the target was tracked in postprocessing steps.

RESULTS

In the phantom, the lesion could be identified and delineated in the dynamic images. In the volunteer experiments, the kidney was visualized with a T2 contrast at a temporal resolution of 0.45 s under free-breathing conditions. A respiratory belt demonstrated a strong correlation with the time course of the kidney centroid in the head-foot direction. A hypointense saturation band at the slice overlap did not inhibit lesion tracking in the semi-automatic postprocessing steps.

CONCLUSION

The Ortho-SFFP-Echo sequence delivers real-time images with a T2 -weighted contrast in two orthogonal slices. The sequence allows for simultaneous acquisition, which could be beneficial for real-time motion tracking in radiotherapy or interventional MRI.

What is the benefit of gadolinium-chelate injection for the diagnosis of local recurrence of clear cell renal cell carcinoma after percutaneous thermal ablation with MRI?

PURPOSE

The purpose of this study was to compare the diagnostic capabilities of contrast-enhanced (CE)-MRI to those of non-CE-MRI to diagnose local recurrence of clear cell renal cell carcinoma (ccRCC) after percutaneous thermal ablation (TA).

MATERIALS AND METHODS

This institutional, review board-approved, case-control, single-center retrospective study included all consecutive adult patients with at least two post-TA MRIs showing local recurrence of ccRCC after TA validated by multidisciplinary board. 'Control' patients without recurrence were randomly-selected with a case:control ratio of 2/3. Four senior radiologists reviewed in a double-blinded fashion non-CE sequences of last two consecutive MRI examinations (non-CE-MRIs), assessed the presence of recurrence of ccRCC, then reviewed the CE sequences (CE-MRI) and determined again the presence of a recurrence. Area under the receiver operating characteristic curve (AUROC), sensitivity, specificity and accuracy were compared for each reader for non-CE-MRI and CE-MRI.

RESULTS

Fifty-one patients (41 men; mean age, 77.5 years) who underwent percutaneous TA for ccRCC were included. There were a total of 21 recurrences and 35 scars. Whoever the reader, AUROC was not significantly different (mean, 0.86 with-CE-MRI vs. 0.81 with non-CE-MRI; P values ranging between 0.08 and 0.98), neither sensitivity (mean, 76.2% with CE-MRI vs. 71.4% with non-CE-MRI; P values ranging between 0.06 and >0.99), nor accuracy (85.8% with CE-MRI vs. 80.8% with non-CE-MRI; P values ranging between 0.07 and >0.99). Change in specificity depended on the reader with a significant increase for one reader (+20%; P = 0.02) and a significant decrease for another reader (-17.2%; P = 0.03).

CONCLUSION

Non-CE MRI has good diagnostic performance for the follow-up of patients with ccRCC treated using percutaneous TA, questioning the systematic use of GBCA injection.

Leveraging cryoablation and checkpoint inhibitors for high-risk triple negative breast cancer

Breast cancer is the second most common cancer among women in the United States in which the standard of care treatment is surgery with adjunctive therapy. Cryoablation, which destroys the tumor using extremely cold temperatures while preserving the potential tumor antigens, is a promising alternative to surgical resection. It is less invasive, cosmetically appeasing, cost-effective, and capable of contributing to the abscopal effect - the immune response targeting potential distant metastasis. However, to maximize the immunologic benefit of cryoablation in biologically high-risk breast cancers, combination with therapies that enhance immune activation, such as immune checkpoint inhibitors (ICIs) may be necessary. This mini review describes the fundamentals of cryoablation and treatment with ICIs, as well as discuss the caveats in both strategies and current clinical trials aimed to improve this approach to benefit patients.

A Comparison of Microwave Ablation and Cryoablation for the Treatment of Renal Cell Carcinoma: A Systematic Literature Review and Meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis comparing microwave ablation (MWA) and cryoablation for renal cell carcinoma (RCC).

METHODS

The systematic search was performed in MEDLINE, Embase, and Cochrane databases. Studies published in English from January 2006 to February 2022 that assessed adults with primary RCC who received MWA or cryoablation were included. Study arms from RCTs, comparative observational, and single-arm studies were eligible. The outcomes included local tumor recurrence (LTR), overall survival, disease-free survival, overall/major complications, procedure/ablation time, 1- to 3-month primary technique efficacy, and technical success. Single-arm meta-analyses were performed using the random effects model. Sensitivity analyses excluding low-quality studies assessed using the MINORs scale were performed. Univariable and multivariable examined the effects of prognostic factors.

RESULTS

Baseline characteristics were similar between groups and mean tumor size for MWA and cryoablation were 2.74 and 2.69 cm. Single-arm meta-analyses were similar for LTR and secondary outcomes between cryoablation and MWA. Ablation time was significantly shorter with MWA than with cryoablation (meta-regression weighted mean difference 24.55 minutes, 95% confidence interval -31.71, -17.38, P < .0001). One-year LTR was significantly lower with MWA than cryoablation (odds ratio 0.33, 95% confidence interval 0.10-0.93, P = .04). There were no significant differences for other outcomes.

CONCLUSION

MWA provides significantly improved 1-year LTR and ablation time compared with cryoablation for patients with RCC. Other outcomes appeared similar or favorable for MWA; however, results were not statistically significant. MWA of primary RCC is as safe and effective as cryoablation, which should be confirmed with future comparative studies.

MRI- Versus CT-Guided Renal Tumor Cryoablation: Is There a Difference?

PURPOSE

To compare procedure-related variables, safety, renal function, and oncologic outcomes in patients undergoing percutaneous cryoablation (CA) of renal tumors with MRI- or CT-guidance.

MATERIALS AND METHODS

Patient, tumour, procedure, and follow-up data were collected and analysed. MRI and CT groups were matched using a coarsened exact approach according to patient's gender and age, tumour grade, size and location. P < 0.05 was considered statistically significant.

RESULTS

Two-hundred fifty-three patients (266 tumors) were retrospectively selected. Following the coarsened exact matching 46 patients (46 tumors) in the MRI group and 42 patients (42 tumors) in the CT group were matched. There were no significant baseline differences between the two populations except for the duration of follow-up (P = 0.002) and renal function (P = 0.002). On average MRI-guided CA lasted 21 min longer than CT-guided ones (P = 0.005). Following CA, complication rates (6.5% for MRI vs 14.3% for CT; P = 0.30) and GFR decline (mean - 13.1 ± 15.8%; range - 64.5-15.0 for MRI; mean - 8.1 ± 14.8%; range - 52.5-20.4; for CT; P = 0.13) were similar in both groups. The 5-year local progression-free, cancer-specific and overall survivals in the MRI and CT groups were 94.0% (95% CI 86.3%-100.0%) and 90.8% (95% CI 81.3%-100.0%; P = 0.55), 100.0% (95% CI 100.0%-100.0%) and 100.0% (95% CI 100.0%-100.0%; P = 1), and 83.7% (95% CI 64.0%-100.0%) and 76.2% (95% CI 62.0%-93.6%; P = 0.41), respectively.

CONCLUSIONS

Apart from increased procedural times associated with MRI-guided CA of renal tumors compared to CT-guidance, both modalities demonstrate similar safety, GFR decline and oncologic outcomes.

Role of MRI at 1- and 3-Month Follow-up in Predicting the Likelihood of Tumor Recurrence Following Percutaneous Cryoablation of Renal Tumors

PURPOSE

To evaluate whether ablation volume difference relatively to tumoral volume, minimal distance between ablation area and necrotic tumor, or apparent diffusion coefficient (ADC) within the ablation area, measured on 1- and 3-month follow-up MRI following cryoablation of renal tumors, are associated with tumor recurrence.

MATERIALS AND METHODS

136 renal tumors were retrospectively identified. Patients, tumor characteristics and follow-up MRI (1-, 3-, 6-month, and thereafter annually) were collected. Uni- and multivariate analyses were performed to assess the association between the investigated parameters and tumor recurrence.

RESULTS

Over the follow-up period (27.7 ± 21.9 months), 13 recurrences were identified at 20.5 ± 19.4 months. At 1- and 3-month, the mean volume difference between the ablation zone and the tumor volume were + 577.5 ± 511.3% vs + 251.4 ± 209.8% (p = 0.003), and + 268.8 ± 291.1% vs + 103.8 ± 94.6% (p = 0.023) in patients without and with tumor recurrence, respectively. At 1- and 3-month, the minimum distance between the necrotic tumor and the edge of the ablation area was 3.4 ± 2.5 vs 1.8 ± 1.9 mm (p = 0.019), and 2.4 ± 2.3 vs 1.4 ± 1.8 mm (p = 0.13) in patients without and with tumor recurrence, respectively. Analysis of ADC values was not associated with tumor recurrence. After performing the multivariate analysis, only volume difference of the ablation area compared to tumor volume was associated with absence of tumor recurrence at 1- (OR = 14.1; p = 0.001) and 3-month (OR = 8.2; p = 0.01).

CONCLUSIONS

Evaluation of volume difference between the ablation area and tumor volume on early (≤ 3 months) MRI follow-up identifies patients at risk of tumor recurrence.

Percutaneous image-guided cryoablation with temporary balloon occlusion of the renal artery for the treatment of central renal tumors

PURPOSE

The purpose of this study was to report the technical feasibility and outcomes of percutaneous image-guided cryoablation with temporary balloon occlusion of the renal artery for the treatment of central renal tumors.

MATERIALS AND METHODS

All consecutive patients with central renal tumors treated with cryoablation and temporary renal artery occlusion from January 2017 to October 2021 were retrospectively included. Patient demographics, tumor's characteristics, procedural data, technical success, primary and secondary clinical efficacy, complications (according to Cardiovascular and Interventional Radiology Society of Europe [CIRSE] classification) and follow-up were investigated.

RESULTS

A total of 14 patients (8 men, 6 women; mean age 72.4 years ± 21.4 [SD] years; age range: 42-93 years) with 14 central renal tumors (median size, 32 mm; IQR: 23.5, 39.5 mm; range: 13-50 mm) were treated with percutaneous image-guided cryoablation and temporary balloon occlusion of the renal artery. Technical success was 13/14 (93%), with 1/14 (7%) failure of vascular access. A median of 4 cryoprobes (IQR: 3, 4.75) were inserted and protective hydrodissection was performed in 11/14 (79%) patients. Median time to perform cryoprobes insertion, hydrodissection and vascular access was 26.5 min (IQR: 18, 35 min), 10 min (IQR: 10, 17 min) and 30 min (IQR: 20, 45 min) respectively. Median duration of the whole intervention was 150 min (IQR: 129, 180 min; range: 100-270 min). Median hospital stay was 2.5 days (IQR: 2, 4 days; range: 2-14 days). Major complications occurred in 3/14 (21%) patients. Primary efficacy rate was 93% (13/14 patients). Median oncological follow-up was 25 months (IQR: 11, 33 months; range: 6-39 months). One patient experienced renal tumor recurrence at 14-months of follow-up, which was successfully treated with repeat cryoablation.

CONCLUSION

Percutaneous image-guided cryoablation of renal tumors with temporary balloon occlusion of the renal artery is technically feasible, with a high technical success rate and paths the way for percutaneous treatment of central renal tumors.

Precision Imaging Guidance in the Era of Precision Oncology: An Update of Imaging Tools for Interventional Procedures

Interventional oncology (IO) procedures have become extremely popular in interventional radiology (IR) and play an essential role in the diagnosis, treatment, and supportive care of oncologic patients through new and safe procedures. IR procedures can be divided into two main groups: vascular and non-vascular. Vascular approaches are mainly based on embolization and concomitant injection of chemotherapeutics directly into the tumor-feeding vessels. Percutaneous approaches are a type of non-vascular procedures and include percutaneous image-guided biopsies and different ablation techniques with radiofrequency, microwaves, cryoablation, and focused ultrasound. The use of these techniques requires precise imaging pretreatment planning and guidance that can be provided through different imaging techniques: ultrasound, computed tomography, cone-beam computed tomography, and magnetic resonance. These imaging modalities can be used alone or in combination, thanks to fusion imaging, to further improve the confidence of the operators and the efficacy and safety of the procedures. This article aims is to provide an overview of the available IO procedures based on clinical imaging guidance to develop a targeted and optimal approach to cancer patients.