Utility of the RENAL Nephrometry Scoring System in Predicting Adverse Events and Outcomes of Percutaneous Microwave Ablation of Renal Tumors

PurposeTo assess the utility of the radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, and location relative to polar lines (RENAL) nephrometry scoring system at predicting adverse events and outcomes in percutaneous microwave ablation (MWA) of renal tumors.Materials and MethodsA retrospective review of 116 patients who underwent MWA from 2004 to 2018 at 2 large university hospitals was conducted. Patient demographics and tumor characteristics were collected. The RENAL nephrometry scores were calculated, and procedure-related adverse events were stratified into minor and major (the Society of Interventional Radiology classification of class C or higher). Technical and oncologic outcomes were based on follow-up magnetic resonance imaging and computed tomography scans after ablation.ResultsThe mean RENAL score was 6.6 (range, 4–11), and the mean tumor size was 24 mm. Follow-up ranged between 16 and 161 weeks (median, 50 weeks; mean, 65 weeks). Oncologic control was achieved in 96% (n = 111) of patients. The major and minor adverse event rates were 8.6% (n = 10) and 17% (n = 19), respectively. The mean RENAL score for patients with recurrent and/or residual tumor (8.2 ± 2.7) was higher than that for patients without disease recurrence (6.5 ± 3.5, P = .05). However, in a multivariate analysis, the RENAL score was not found to be an independent predictor of oncologic outcomes (odds ratio, 1.548; P = .092).ConclusionsThe RENAL nephrometry score has minimal utility for predicting outcomes and adverse events in MWA of renal tumors. The inconsistent nature of RENAL nephrometry scoring in percutaneous ablation procedures underscores the need for an ablation-specific risk stratification system.     

Hepatic Hilar Nerve Block for Adjunctive Analgesia during Percutaneous Thermal Ablation of Hepatic Tumors: A Retrospective Analysis

PurposeTo determine whether hepatic hilar nerve block techniques reduce analgesic and sedation requirements during percutaneous image-guided thermal ablation of hepatic tumors.Materials and MethodsA single-center retrospective cohort analysis was performed of 177 patients (median age, 67 years; range, 33–86 years) who underwent percutaneous image-guided thermal ablation of liver tumors. All patients were treated utilizing local anesthetic and moderate sedation between November 2018 and November 2021 at a tertiary level hospital, with or without the administration of a hepatic hilar nerve block. Univariable and multivariable linear regression analyses were performed to determine the relationship between the administration of the hilar nerve block and fentanyl and midazolam dosages.ResultsA total of 114 (64%) patients received a hilar nerve block in addition to procedural sedation, and 63 (36%) patients received procedural sedation alone. There were no significant differences in the baseline demographic and tumor characteristics between the cohorts. The procedure duration was longer in the hilar block cohort than in the unblocked cohort (median, 95 vs 82 minutes; P = .0012). The technical success rate (98% in both the cohorts, P = .93) and adverse event rate (11% vs 3%, P = .14) were not significantly different between the cohorts. After adjusting for patient and tumor characteristics, ablation modality, and procedure and ablation durations, hilar nerve blocks were associated with lower fentanyl (?18.4%, P = .0045) and midazolam (?22.7%, P = .0007) dosages.ConclusionsHepatic hilar nerve blocks significantly decrease the fentanyl and midazolam requirements during thermal ablation of hepatic tumors, without a significant change in the technical success or adverse event rates.     

Stereotactic Body Radiotherapy for Stage I Renal Cell Carcinoma: National Treatment Trends and Outcomes Compared to Partial Nephrectomy and Thermal Ablation

PurposeTo assess use of stereotactic body radiotherapy (SBRT) for stage I renal cell carcinoma (RCC) and compare outcomes with thermal ablation and partial nephrectomy (PN).Materials and MethodsThe 2004–2015 National Cancer Database was investigated for histopathologically proven stage I RCC treated with PN, cryoablation, radiofrequency (RF) or microwave (MW) ablation, or SBRT. Patients were propensity score–matched to account for potential confounders, including patient age, sex, race, comorbidities, tumor size, histology, grade, tumor sequence, administration of systemic therapy, treatment in academic vs nonacademic centers, treatment location, and year of diagnosis. Overall survival (OS) was evaluated with Kaplan-Meier plots, log-rank tests, and Cox proportional hazards models.ResultsA total of 91,965 patients were identified (SBRT, n = 174; PN, n = 82,913; cryoablation, n = 5,446; RF/MW ablation, n = 3,432). Stage I patients who received SBRT tended to be older women with few comorbidities treated at nonacademic centers in New England states. After propensity score matching, a cohort of 636 patients was obtained with well-balanced confounders between treatment groups. In the matched cohort, OS after SBRT was inferior to OS after PN and thermal ablation (PN vs SBRT, hazard ratio [HR] = 0.29, 95% confidence interval [CI] 0.19–0.46, P < .001; cryoablation vs SBRT, HR = 0.40, 95% CI 0.26–0.60, P < .001; RF/MW ablation vs SBRT, HR = 0.46, 95% CI 0.31–0.67, P < .001). Compared with PN, neither cryoablation nor RF/MW ablation showed significant difference in OS (cryoablation vs PN, HR = 1.35, 95% CI 0.80–2.28, P = .258; RF/MW ablation vs PN, HR = 0.64, 95% CI 0.95–2.55, P = .079).ConclusionsCurrent SBRT protocols show lower OS compared with thermal ablation and PN, whereas thermal ablation and PN demonstrate comparable outcomes.     

Long-Term Survival after Percutaneous Radiofrequency Ablation of Pathologically Proven Renal Cell Carcinoma in 100 Patients

PurposeTo determine the long-term survival of patients treated with percutaneous radiofrequency (RF) ablation for pathologically proven renal cell carcinoma (RCC).Materials and MethodsIn this single-center retrospective study, 100 patients with 125 RCCs (100 clear-cell, 19 papillary, and 6 chromophobe) 0.8–8 cm in size treated with RF ablation were evaluated at a single large tertiary-care center between 2004 and 2015. Technical success, primary and secondary technique efficacy, and pre- and postprocedural estimated glomerular filtration rate (eGFR) at 3–6 months and 2–3 years were recorded. Overall survival, cancer-specific survival, and local tumor progression–free survival were calculated by Kaplan–Meier survival curves. Complications were classified per the Clavien–Dindo system. Statistical testing was done via χ² tests for proportions and paired t test for changes in eGFR. Statistical significance was set at α = 0.05.ResultsOverall technical success rate was 100%, and primary and secondary technique efficacy rates were 90% and 100%, respectively. Median follow-up was 62.8 months, ranging from 1 to 120 months. The 10-year overall, cancer-specific, and local progression–free survival rates were 32%, 86%, and 92%, respectively. The number of ablation probes used was predictive of residual unablated tumor (P < .001). There were no significant changes in preprocedure vs 2–3-years postprocedure eGFR (65.2 vs 62.1 mL/min/1.73 m²; P = .443). There was a 9% overall incidence of complications, the majority of which were grade I.ConclusionsImage-guided percutaneous RF ablation of RCCs is effective at achieving local control and preventing cancer-specific death within 10 years from initial treatment.     

Creation of an Ex Vivo Renal Perfusion Model to Investigate Microwave Ablation

This study hypothesized that an ex vivo renal perfusion model can create smaller microwave ablation (MWA) measurements during perfused states compared with nonperfused states across multiple device settings. Nine bovine kidneys, a fluoroscopic compatible perfusion model, and a commercially-available clinical MWA system were used to perform 72 ablations (36 perfused and 36 nonperfused) at 9 different device settings. Comparing perfused and nonperfused ablations at each device setting, significant differences in volume existed for 6 of 9 settings (P < .05). Collapsed across time settings, the ablation volumes by power were the following (perfused and nonperfused, P value): 60 W, 2.3 cm³ ± 1.0 and 7.2 cm³ ± 2.7, P < .001; 100 W, 5.4 cm³ ± 2.1 and 11.5 cm³ ± 5.6, P < .01; and 140 W, 11.2 cm³ ± 3.7 and 18.7 cm³ ± 6.3, P < .01. Applied power correlated with ablation volume: perfused, 0.021 cm³/W and R = 0.462, P = .004, and nonperfused, 0.029 cm³/W and R = 0.565, P < .001. These results support that an ex vivo perfused organ system can evaluate MWA systems and demonstrate heat sink perfusion effects of decreased ablation size.     

Preliminary Study of Microwave Ablation for Multifocal Papillary Thyroid Microcarcinoma in Nonoperative Candidates

PurposeTo study the feasibility, safety, and effectiveness of microwave ablation (MWA) in patients with multifocal papillary thyroid microcarcinoma (PTMC).Materials and MethodsThis retrospective study included patients who underwent MWA for multifocal PTMC (number of nodules ≤3). A total of 44 patients were included, and the mean age was 43 years (SD ± 11). After ablation, progression-free survival (PFS) at 6, 12, 24, 36, and 48 months; disease progression; change in tumor size and volume; tumor disappearance rate; and adverse events (AEs) were assessed, and the feasibility, safety, and effectiveness of MWA for PTMC were evaluated on the basis of statistical analysis.ResultsThe median follow-up period was 18 months (interquartile range, 12–33 months). The PFS rates at 6, 12, 24, 36, and 48 months were 100.0%, 96.4%, 96.4%, 70.3%, and 52.7%, respectively. The disease progression rate was 11.4% (5 of 44 patients). The maximum diameter (MD) and volume of the ablation zone were larger at the 3-month follow-up than before ablation (median MD, 13.0 vs 7.0 mm; P < .001; median volume, 503.8 vs 113.0 mm³; P < .001). Subsequently, the tumors exhibited a reduction in both size and volume after 18 months (median MD, 4.0 vs 7.0 mm; P = .04; median volume, 12.6 vs 113.0 mm³; P = .055). At the end of the follow-up period, the complete response rate was 59% (26 of 44 patients). The overall AE rate was 6.8%.ConclusionsMWA is a feasible treatment for PTMC (number of nodules ≤3), and this study preliminarily demonstrated the safety and effectiveness of this technique.     

Transarterial Radioembolization versus Transarterial Chemoembolization Plus Percutaneous Ablation for Unresectable,Solitary Hepatocellular Carcinoma of ≥3 cm: A Propensity Score–Matched Study

PurposeTo compare the safety and effectiveness of transarterial radioembolization (TARE) and transarterial chemoembolization with drug-eluting embolic agents combined with percutaneous ablation (transarterial chemoembolization [TACE] + ablation) in the treatment of treatment-naïve, unresectable, solitary hepatocellular carcinoma (HCC) of ≥3 cm.Materials and MethodsTwenty-nine patients with treatment-naïve, unresectable, solitary HCC of ≥3 cm received combined TACE + ablation, and 40 patients received TARE at a single institution. Local tumor response, tumor progression-free survival (PFS), overall survival, need for reintervention, bridge to transplant, and major complications were compared. Clinical variables and outcomes were compared before and after propensity score matching (PSM).ResultsBefore PSM, patients who underwent TARE had a larger tumor size (3.7 vs 5.5 cm; P = .0005) and were older (61.5 vs 69.3 years; P = .0014). After PSM, there was no difference in baseline characteristics between the 2 groups, with the mean tumor sizes measuring 3.9 and 4.1 cm in the TACE + ablation and TARE cohorts, respectively. After PSM (n = 19 in each group), no statistically significant difference was observed in local radiological response (disease control rates, 100% vs 94.7%; P = .31), survival (subdistribution hazard ratio [SHR], 0.71; 95% confidence interval [CI], 0.28–1.80; P = .469), PFS (SHR, 0.61; 95% CI, 0.21–1.71; P = .342), bridge to transplant (21.1% vs 31.6%, P = .46), and major adverse event rates (15.8% vs 10.5%, P = .63) between the 2 groups. The mean total number of locoregional interventions was higher in the TACE + ablation cohort (1.9 vs 1.3 sessions, P = .02), with an earlier median reintervention trend (SHR, 0.61; 95% CI, 0.20–1.32; P = .167).ConclusionsThe present study showed that TARE and the combination of TACE and ablation are comparable in safety and effectiveness for treating treatment-naïve, unresectable, solitary HCC of ≥3 cm.     

Radiofrequency Ablation,Cryoablation, and Microwave Ablation for T1a Renal Cell Carcinoma: A Comparative Evaluation of Therapeutic and Renal Function Outcomes

PurposeTo compare the therapeutic and renal function outcomes of radiofrequency (RF) ablation, cryoablation, and microwave (MW) ablation for treatment of T1a renal cell carcinoma (RCC).Materials and MethodsA retrospective assessment of 297 patients (mean age 72 years range 24–90 years) with biopsy-proven RCC treated with image-guided percutaneous thermal ablation was performed between October 2006 and December 2016. Mean tumor size was 2.4 cm; mean radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, hilar tumor touching the main renal artery or vein, and location relative to polar lines; Preoperative Aspects and Dimensions Used for an Anatomical; and c-centrality scores were 6.0, 7.0, and 2.8, respectively. Assessments of adverse events, treatment efficacy, and therapeutic outcomes were performed among RF ablation, cryoablation, and MW ablation. The 2-year disease-free, metastatic-free, and cancer-specific survival rates were tabulated. Estimated glomerular filtration rate was used to assess for treatment related changes in renal function.ResultsA total of 297 T1aN0M0 biopsy-proven RCCs measuring 1.2–3.9 cm were treated with computed tomography–guided RF ablation (n = 244, 82%), cryoablation (n = 26, 9%), and MW ablation (n = 27, 9%). There were no significant differences in patient demographics among the 3 groups (P = .09). Technical success rates were similar among the 3 treatments (P = .33). Primary efficacy at 1 month postablation was more likely to be achieved with RF ablation and MW ablation than with cryoablation. At 2 years’ follow-up, there was no local recurrence, metastatic progression, or RCC-related death observed in the 3 groups. There was no significant change in estimated glomerular filtration rate among the 3 ablation groups compared with baseline at 2-year follow-up (P = .71).ConclusionRF ablation, cryoablation, and MW ablation are equivalent at 2 years for treatment of T1a RCC for therapeutic outcome, stability of renal function, and low adverse event rate.     

Factors Associated with Hospital Length of Stay and Adverse Events following Percutaneous Ablation of Lung Tumors

PurposeTo explore the association between risk factors established in the surgical literature and hospital length of stay (HLOS), adverse events, and hospital readmission within 30 days after percutaneous image-guided thermal ablation of lung tumors.Materials and MethodsThis bi-institutional retrospective cohort study included 131 consecutive adult patients (67 men [51%]; median age, 65 years) with 180 primary or metastatic lung tumors treated in 131 sessions (74 cryoablation and 57 microwave ablation) from 2006 to 2019. Age-adjusted Charlson Comorbidity Index, sex, performance status, smoking status, chronic obstructive pulmonary disease (COPD), primary lung cancer versus pulmonary metastases, number of tumors treated per session, maximum axial tumor diameter, ablation modality, number of pleural punctures, anesthesia type, pulmonary artery–to–aorta ratio, lung densitometry, sarcopenia, and adipopenia were evaluated. Associations between risk factors and outcomes were assessed using univariable and multivariable generalized linear models.ResultsIn univariable analysis, HLOS was associated with current smoking (incidence rate ratio [IRR], 4.54 [1.23–16.8]; P = .02), COPD (IRR, 3.56 [1.40–9.04]; P = .01), cryoablations with ≥3 pleural punctures (IRR, 3.13 [1.07–9.14]; P = .04), general anesthesia (IRR, 10.8 [4.18–27.8]; P < .001), and sarcopenia (IRR, 2.66 [1.10–6.44]; P = .03). After multivariable adjustment, COPD (IRR, 3.56 [1.57–8.11]; P = .003) and general anesthesia (IRR, 12.1 [4.39–33.5]; P < .001) were the only risk factors associated with longer HLOS. No associations were observed between risk factors and adverse events in multivariable analysis. Tumors treated per session were associated with risk of hospital readmission (P = .03).ConclusionsIdentified preprocedural risk factors from the surgical literature may aid in risk stratification for HLOS after percutaneous ablation of lung tumors, but were not associated with adverse events.     

Partial Nephrectomy versus Percutaneous Cryoablation of Small Renal Cell Carcinomas: A Comparison of Adverse Events in a Prospective Multicenter Cohort Study

PurposeTo assess and compare complications and readmissions after partial nephrectomy and percutaneous cryoablation of cT1 renal cell carcinoma (RCC).Materials and MethodsPatients treated for cT1 RCC between 2019 and 2021 were prospectively and consecutively enrolled. Complications recorded within 30 and 90 days were graded according to the Clavien-Dindo classification, and percutaneous cryoablation was graded according to the Society of Interventional Radiology classification of adverse events. Major complications were defined as complications with a grade of ≥3 based on the Clavien-Dindo classification. Readmission within 30 days was recorded.ResultsThe cohort included 86 partial nephrectomies and 104 cryoablations. The complication rate within 90 days was 23% after partial nephrectomy and cryoablation (P = .98), with major complication rates of 3% after partial nephrectomy and 10% after cryoablation (P = .15). The readmission rates were 14% and 11% after partial nephrectomy and cryoablation, respectively (P = .48). Double-J stents were associated with overall complications (odds ratio [OR], 9.88; 95% confidence interval [CI], 2.18–44.68; P = .003) and readmissions (OR, 5.39; 95% CI, 1.37–21.06; P = .015) after cryoablation. A high versus low radius-endophytic-nearness-anterior-location score (OR, 5.86; 95% CI, 1.08–31.81; P = .040) and endophytic location (OR, 7.70; 95% CI, 1.72–34.50; P = .008) were associated with a higher complication rate after cryoablation. The Charlson Comorbidity Index (CCI) was associated with major complications after partial nephrectomy (OR, 2.12; 95% CI, 1.05–4.30; P = .036).ConclusionsPartial nephrectomy and cryoablation are comparable regarding complications within 90 days after treatment. Tumor complexity and double-J stents were associated with complications after cryoablation, and a high CCI was associated with complications after partial nephrectomy.     

Radiofrequency Ablation for the Palliative Treatment of Bone Metastases: Outcomes from the Multicenter OsteoCool Tumor Ablation Post-Market Study (OPuS One Study) in 100 Patients

PurposeTo evaluate the effectiveness of radiofrequency (RF) ablation as measured by change in worst pain score from baseline to 3 mo after RF ablation for the palliative treatment of painful bone metastases.Materials and MethodsOne hundred patients (mean age, 64.6 y) underwent RF ablation for metastatic bone disease and were followed up to 6 mo. Subjects’ pain and quality of life were measured before RF ablation and postoperatively by using the Brief Pain Index and European Quality of Life questionnaires. Opioid agent use and device-, procedure-, and/or therapy-related adverse events (AEs) were collected.ResultsEighty-seven patients were treated for tumors involving the thoracolumbar spine and 13 for tumors located in the pelvis and/or sacrum. All ablations were technically successful, and 97% were followed by cementoplasty. Mean worst pain score decreased from 8.2 ± 1.7 at baseline to 3.5 ± 3.2 at 6 mo (n = 22; P < 0.0001 for all visits). Subjects experienced significant improvement for all visits in average pain (P < .0001), pain interference (P < .0001), and quality of life (P < .003). Four AEs were reported, of which 2 resulted in hospitalization for pneumonia and respiratory failure. All 30 deaths reported during the study were attributed to the underlying malignancy and not related to the study procedure.ConclusionsResults from this study show rapid (within 3 d) and statistically significant pain improvement with sustained long-term relief through 6 mo in patients treated with RF ablation for metastatic bone disease.     

Transcatheter CT Hepatic Arteriography Compared with Conventional CT Fluoroscopy Guidance in Percutaneous Thermal Ablation to Treat Colorectal Liver Metastases: A Single-Center Comparative Analysis of 2 Historical Cohorts

PurposeTo evaluate safety and efficacy of CT hepatic arteriography compared with conventional CT fluoroscopy guidance in percutaneous radiofrequency (RF) and microwave (MW) ablation to treat colorectal liver metastases (CRLM).Materials and MethodsThis single-center comparative, retrospective study analyzed data of 108 patients treated with 156 percutaneous ablation procedures (42 CT fluoroscopy guidance [25 RF ablation, 17 MW ablation]; 114 CT hepatic arteriography guidance [18 RF ablation, 96 MW ablation]) for 260 CRLM between January 2009 and May 2019. Local tumor progression-free survival (LTPFS) was assessed using univariate and multivariate Cox proportional hazard regression analyses. LTPFS and overall survival (OS) were estimated using the Kaplan-Meier method.ResultsThere were no complications related to the transarterial catheter procedure. CT hepatic arteriography proved superior to CT fluoroscopy regarding 2-year LTPFS (18/202 [8.9%] vs 19/58 [32.8%]; P < .001, respectively). CT hepatic arteriography versus CT fluoroscopy (hazard ratio = 0.28; 95% confidence interval, 0.15–0.54; P < .001) and MW ablation versus RF ablation (hazard ratio = 0.52; 95% confidence interval, 0.24–1.12; P = .094) were positive predictors for longer LTPFS. Multivariate analysis revealed that CT hepatic arteriography versus CT fluoroscopy (hazard ratio = 0.41; 95% confidence interval, 0.19–0.90; P = .025) was associated with a significantly superior LTPFS. OS was similar between the 2 cohorts (P = .3).ConclusionsWhile adding procedure time and marginal patient burden, transcatheter CT hepatic arteriography–guided ablation was associated with increased local disease control and superior LTPFS compared with conventional CT fluoroscopy. CT hepatic arteriography represents a safe and valid alternative to CT fluoroscopy, as it reduces the number of repeat ablations required without adding risk or detrimental effect on survival.     

Combination of Microwave Ablation and Percutaneous Osteoplasty for Treatment of Painful Extraspinal Bone Metastasis

PurposeTo evaluate the efficacy and safety of microwave (MW) ablation combined with percutaneous osteoplasty (POP) on painful extraspinal bone metastases.Materials and MethodsIn this retrospective study, 50 adult patients with 56 extraspinal bone metastasis lesions, who suffered from refractory moderate to severe pain, were treated with MW ablation and POP. Changes in quality of life were evaluated based on the Visual Analog Scale (VAS), daily morphine consumption, and the Oswestry Disability Index (ODI) before and immediately after the procedure and during follow-up times.ResultsTechnical success was achieved in all patients. Mean preoperative VAS score and morphine dose were 7.0 ± 2.6 (range, 3–10) and 66.7 ± 33.2 mg (range, 10–120 mg), respectively. Mean postoperative VAS scores and daily morphine doses were as follows: 1 day, 3.5 ± 2.1 and 36.1 ± 25.8 mg (P < .05); 1 week, 1.5 ± 1.7 and 12.2 ± 14.8 mg (P < .001); 1 month, 0.9 ± 1.4 and 5.7 ± 10.0 mg (P < .001); and 3 months, 0.6 ± 1.2 and 4.7 ± 8.4 mg (P < .001). A significant decrease in the ODI score was also observed (P < .05). Periprocedural death was not observed. A pathologic fracture occurred in 1 (2%) patient with femoral metastasis, and local infection was observed in 2 (4%) patients. Minor cement leakage occurred in 4 (8%) patients with no symptomatic or intra-articular extravasation. No local tumor progression occurred in patients with imaging follow-up.ConclusionsMW ablation combined with POP is an effective and safe treatment for painful extraspinal bone metastases, which can significantly relieve pain and improve quality of life.     

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

PurposeTo determine effect of body mass index (BMI) on safety and cancer-related outcomes of thermal ablation for renal cell carcinoma (RRC).Materials and MethodsThis 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.ResultsNo 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).ConclusionsCT-guided renal ablation is safe, feasible, and effective regardless of BMI.     

Percutaneous Radiofrequency Ablation of Appendicular Skeleton Chondroblastoma—an Experience from a Tertiary Care Cancer Center

PurposeTo evaluate safety and long-term efficacy of radiofrequency (RF) ablation in treatment of chondroblastoma.Materials and MethodsThis retrospective analysis comprised 27 consecutive patients with histopathologically proven chondroblastoma treated by RF ablation. The tumors were located in the proximal humerus (n = 6), proximal tibia (n = 8), proximal femur (n = 6), distal femur (n = 5), acromion process (n = 1), and lunate (n = 1). In 19 patients (70.3%), the tumor was in the weight-bearing area of the bone. Clinical response was assessed by comparing pain scores and functional assessment by Musculoskeletal Tumor Society (MSTS) score before and after ablation. Patients were followed for a minimum of 1 year to rule out complications and recurrence.ResultsTechnical success rate was 100%. Mean pain score before the procedure was 7.34 (range, 7–9); all patients experienced a reduction in pain, with 25 (92.6%) patients reporting complete pain relief at 6 weeks. Mean MSTS score before the procedure was 15.4, whereas mean MSTS score at 6 weeks after the procedure was 28.6, suggesting significant functional improvement (P < .0001). Two patients developed osteonecrosis and collapse of the treated bone. There were no recurrences.ConclusionsPercutaneous RF ablation is a safe and effective option for treating chondroblastoma of the appendicular skeleton.     

Risk Factors for Hemorrhagic Adverse Events in Percutaneous Transhepatic Biliary Drainage: A Prospective Multicenter Study

PurposeTo determine risk factors (RFs) for hemorrhagic adverse events (AEs) associated with percutaneous transhepatic biliary drainage (PTBD) and to develop a risk assessment model.Materials and MethodsThis was a multicenter, prospective, case control study between 2015 and 2020. Adults with an indication for PTBD were included. Patients who had undergone recent previous drainage procedures were excluded. Multiple variables were controlled. The exposure variables were the number of capsular punctures and passes (using the same puncture). A multivariate analysis was performed (logistic regression analysis).ResultsA total of 304 patients (mean age, 63 years ± 14 [range, 23–87 years]; female, 53.5%) were included. Hemorrhagic AEs occurred in 13.5% (n = 41) of the patients, and 3.0% (n = 9) of the cases were severe. Univariate analysis showed that the following variables were not associated with hemorrhagic AEs: age, sex, bilirubin and hemoglobin levels, type of pathology, portal hypertension, location of vascular punctures, ascites, nondilated bile duct, intrahepatic tumors, catheter features, blood pressure, antiplatelet drug use, and tract embolization. Multivariate analysis showed that number of punctures (odds ratio [OR], 2.5; P = .055), vascular punctures (OR, 4.1; P = .007), fatty liver or cirrhosis (OR, 3.7; P = .021), and intrahepatic tumor obstruction (Bismuth ≥ 2; OR, 2.4; P = .064) were associated with hemorrhagic AEs. Patients with corrected coagulopathies had fewer hemorrhagic AEs (OR, ?5.5; P = .026). The predictability was 88.2%. The area under the curve was 0.56 (95% confidence interval, 0.50–0.61).ConclusionsPreprocedural and intraprocedural RFs were identified in relation to hemorrhage with PTBD. AE risk assessment information may be valuable for prediction and management of hemorrhagic AEs.     

Dual-Applicator MR Imaging–Guided Microwave Ablation with Real-Time MR Thermometry: Phantom and Porcine Tissue Model Experiments

PurposeTo investigate the effect of simultaneous use of dual applicators on the image quality of real-time magnetic resonance (MR) thermometry and to characterize the dual-applicator treatment zone pattern during MR imaging–guided microwave ablation (MWA).Materials and MethodsMWA experiments were performed on a 1.5-T MR scanner with 2 commercial microwave systems (902–928 MHz). Phantom experiments were first performed to evaluate the effect of dual-applicator MWA on the image quality of MR. Then, porcine tissue model experiments were conducted with real-time MR thermometry using either a single applicator or dual applicators inserted 2.6, 3.6, and 4.6 cm apart. Fiberoptic thermal probes were used to measure the temperature changes at the tissue surface.ResultsSimultaneous use of dual applicators resulted in a decrease in the relative signal-to-noise ratio (SNR) in the MR thermometry images to 55% ± 2.9% when compared with that of a single applicator (86.2% ± 2.0%). Despite the lower SNR, the temperature and ablation zone maps were of adequate quality to allow visualization of the ablation zone(s). The extents of increase in the temperature at the tissue surface using dual applicators (19.7 °C ± 2.6 °C) and a single applicator (18.2 °C ± 3.3 °C) were not significantly different (P = .40). Treatment zones were significantly larger (P < .05) in dual-applicator ablations (29.4 ± 0.4, 39.9 ± 0.6, and 42.6 ± 0.9 cm² with 2.6-, 3.6-, and 4.6-cm spacing, respectively) at the end of the ablation procedure than in the single-applicator MWA (18.6 ± 0.9 cm²).ConclusionsMR imaging–guided dual-applicator MWA produced larger ablation zones while allowing adequate real-time MR thermometry image quality for monitoring the evolution of the treatment zone.     

Long-term Outcomes of Patients with Hepatocellular Carcinoma Who Underwent Microwave Ablation after Downstaging with Transarterial Chemoembolization to Barcelona Clinic Liver Cancer Stage A

PurposeTo compare the clinical results of microwave ablation (MWA) between patients downstaged to Barcelona Clinic Liver Cancer (BCLC) Stage A with transarterial chemoembolization (TACE) and those initially classified as BCLC Stage A.Materials and MethodsFrom January 2012 to May 2017, 1,087 patients were reviewed retrospectively using propensity score matching (1:1): 86 patients underwent MWA as a curative treatment after downstaging to BCLC Stage A by TACE (downstaging group) and 86 patients initially classified as BCLC Stage A underwent MWA (control group). The overall survival (OS) and disease-free survival (DFS) between the 2 groups were compared.ResultsThe 1-, 3-, and 5-year OS rates were 95.3%, 79.1%, and 58.1%, respectively, in the downstaging group and 93.0%, 81.4%, and 61.6%, respectively, in the control group (hazard ratio [HR], 0.75; 95% CI, 0.50–1.13; P = .162). The 1-, 3-, and 5-year DFS rates were 80.2%, 50.0%, and 24.4%, respectively, in the downstaging group and 77.9%, 52.3%, and 27.9%, respectively, in the control group (HR, 1.08; 95% CI, 0.76–1.53; P = .678). No significant differences were found in OS and DFS.ConclusionsThe long-term prognosis in patients with HCC who underwent MWA after downstaging to BCLC Stage A using TACE was similar to that in patients with initial BCLC Stage A.     

Percutaneous MR Imaging-Guided Laser Ablation and Cryoablation for the Treatment of Pediatric and Adult Symptomatic Peripheral Soft Tissue Vascular Anomalies

PurposeTo evaluate the safety and effectiveness of percutaneous magnetic resonance (MR) imaging-guided laser ablation and cryoablation for the treatment of symptomatic soft tissue vascular anomalies (VAs) of the trunk and extremities.Materials and MethodsAn institutional review board-approved retrospective review was undertaken of all pediatric and adult patients who underwent MR imaging-guided and monitored laser ablation and/or cryoablation for the treatment of symptomatic peripheral soft tissue VA. Preablation and postablation MR imaging was independently reviewed. Pain scores on the visual analog scale (0 to 10) and self-reported subjective symptomatic improvement were assessed. Change in VA size and pain scores were compared using a paired t test.ResultsThirty patients (24 females; age, 10–75 years) with 34 VAs were treated for moderate to severe pain (n = 27) or swelling/mass effect (n = 3) with 60 total ablation sessions. The baseline maximum VA diameter was 9.5 cm ± 8.6. At baseline, all VAs (100%) demonstrated variable T2-weighted signal hyperintensity and enhancement. The baseline pain score was 6.4 ± 1.6. Clinical follow-up was available for 23 patients. At a mean follow-up time of 12.2 months ± 10.1, 19 of 20 (95%) patients treated for pain and 2 of 3 (67%) patients treated for swelling/mass effect reported partial or complete symptomatic relief. There was a significant decrease in the postablation pain scores (−5.7 ± 1.0, P < .001) and maximum VA size (−2.3 cm ± 2.7, P = .004), with >50% reduction in VA T2 signal (59%) and enhancement (73%). Nine of 30 (30%) patients experienced minor complications.ConclusionsMR imaging-guided and monitored percutaneous laser ablation and cryoablation appear to be safe and effective for the treatment of symptomatic peripheral soft tissue VAs.     

Hypertensive Crisis during Microwave Ablation of Adrenal Neoplasms: A Retrospective Analysis of Predictive Factors

PurposeTo identify risk factors for hypertensive crisis (HC) during ultrasound-guided percutaneous microwave (MW) ablation of adrenal neoplasms.Materials and MethodsPatients who underwent MW ablation for adrenal tumors between April 2006 and November 2017 were retrospectively identified for this study (51 consecutive patients; 35 males, 16 females; mean age, 55 years; range, 15–85 years). A total of 77 MW ablation treatments were performed for 67 tumors (24 primary [9 pheochromocytomas, 8 adenomas, and 7 cortical carcinomas]; and 43 metastases [22 hepatocellular carcinoma, 8 renal cell carcinoma, 5 non-small cell lung cancer, 4 colorectal cancer, 3 liposarcoma, and 1 malignant fibrous histiocytoma]). The mean diameter of the adrenal tumors was 4.6 cm (range, 1.2–16.2 cm). Information about patient demographics, imaging studies, pathology and laboratory results, procedure records, and clinical outcomes was retrieved and analyzed. Statistical analysis was then performed to determine potential risk factors for HC.ResultsOf the 77 MW ablation procedures, HC occurred in 13 (16.9%). A significantly higher risk of HC was observed in patients with pheochromocytoma (odds ratio [OR], 9.037; 95% confidence interval [CI], 1.731–47.172; P = .009), body mass index <24 kg/m² (OR, 5.167; 95% CI, 1.060–25.194; P = .042), dominant tumor size ≤4.5 cm (OR, 4.023; 95% CI, 1.011–16.005; P = .048), and pre-procedural systolic blood pressure ≥130 mmHg (OR, 0.242; 95% CI, 0.068–0.861; P = .029).ConclusionHC can occur during MW ablation in patients with either primary or metastatic adrenal tumors. Pheochromocytoma, body mass index, tumor size, and pre-procedural systolic blood pressure appear to be significant risk factors for the occurrence of HC.