Risk Of Local Tumor Progression Research Articles

Precise liver tumor ablation: the clinical potential of US-US overlay fusion guidance.

Image-guided thermal ablation is a minimally invasive option for patients with early-stage hepatocellular carcinoma (HCC). However, the risk of local recurrence remains substantial because ultrasound (US) artifacts have a negative impact on the assessment of ablative margins during and immediately after ablation. Precise, real-time assessment of the ablation zone is key to reducing the risk of local tumor progression. With the advent of US image fusion technology, ablative margins can now be assessed three-dimensionally with greater accuracy. Therefore, US-US overlay fusion guidance has the potential to improve the local controllability of ablation in patients with HCC. This review discusses the US-US fusion guidance technique and its current clinical applications for hepatic interventions, with descriptions of its concept, methodology, and efficacy.

Comparative Efficacy of Microwave versus Radiofrequency Ablation in Hepatocellular Carcinoma: Systematic Review and Meta-Analysis of Randomized-Controlled Trials.

Introduction: Hepatocellular carcinoma (HCC) is a leading global cause of cancer-related deaths. Thermal ablation techniques, especially radiofrequency ablation (RFA) and microwave ablation (MWA), have become pivotal treatments for HCC. This systematic review and meta-analysis aim to compare these modalities, highlighting their efficacy, strengths, and limitations in treating HCC. Methods: A comprehensive literature search was conducted across major databases (PubMed, MEDLINE, Springer, ProQuest, EBSCOhost, Cochrane, and EMBASE) targeting studies on hepatocellular carcinoma with RFA and MWA. Heterogeneity analyses and pooled outcomes using random-effect models with were evaluated to compare both thermal ablation methods. Results: Nine studies, which consists of 368 patients underwent RFA and 387 patients underwent MWA, were included in review. The findings showed no significant differences in pooled analysis of volume of ablation, complete ablation rate, local tumor progression, survival rates, major complications, and adverse events. Subgroup analysis showed significantly higher risk of local tumor progression in RFA in African populations. Conclusion: No statistically significant difference was seen between outcomes across studies. MWA may offer a potential for longer therapeutic response with comparable risk of complications and adverse outcomes.

Clinical implications of DNA methylation-based integrated classification of histologically defined grade 2 meningiomas

The combination of DNA methylation analysis with histopathological and genetic features allows for a more accurate risk stratification and classification of meningiomas. Nevertheless, the implications of this classification for patients with grade 2 meningiomas, a particularly heterogeneous tumor entity, are only partially understood. We correlate the outcomes of histopathologically confirmed grade 2 meningioma with an integrated molecular-morphologic risk stratification and determine its clinical implications. Grade 2 meningioma patients treated at our institution were re-classified using an integrated risk stratification involving DNA methylation array-based data, copy number assessment and TERT promoter mutation analyses. Grade 2 meningioma cases according to the WHO 2021 criteria treated between 2007 and 2021 (n = 100) were retrospectively analyzed. The median clinical and radiographic follow-up periods were 59.8 and 54.4 months. A total of 38 recurrences and 17 deaths were observed. The local control rates of the entire cohort after 2-, 4-, and 6-years were 84.3%, 68.5%, and 50.8%, with a median local control time of 77.2 months. The distribution of the integrated risk groups were as follows: 31 low, 54 intermediate, and 15 high risk cases. In the multivariable Cox regression analysis, integrated risk groups were significantly associated with the risk of local recurrence (hazard ratio (HR) intermediate: 9.91, HR high-risk: 7.29, p < 0.01). Gross total resections decreased the risk of local tumor progression (HR gross total resection: 0.19, p < 0.01). The comparison of 1p status and integrated risk groups (low vs. intermediate/high) revealed nearly identical local control rates within their respective subgroups. In summary, only around 50% of WHO 2021 grade 2 meningiomas have an intermediate risk profile. Integrated molecular risk stratification is crucial to guide the management of patients with grade 2 tumors and should be routinely applied to avoid over- and undertreatment, especially concerning the use of adjuvant radiotherapy.

The prediction value of lipiodol retention pattern on post-TACE CT scan for local progression of HCC after complete response

BackgroundHepatocellular carcinoma (HCC) is classified as the sixth commonest cancer over the world and the fourth common in Egypt, representing the third leading cause of cancer-related mortality. Trans-arterial chemoembolization (TACE) is considered as one of the most effective treatment option for intermediate stage HCC. Lesions showing complete response (CR) after TACE can be classified according to their lipiodol retention pattern into complete (C-Lip, covering the entire tumor volume) or incomplete (I-Lip). The purpose of this study was to assess the prediction value of post-TACE lipiodol retention pattern on the local disease progression after complete response and thus to decide which patient should be carefully observed and considered to be incompletely treated.ResultsThe study included 45 HCC lesions treated with TACE and showed complete response in the first follow-up CT performed 4–6 weeks after the procedure; 23 cases showed incomplete lipiodol retention pattern and 22 with complete lipiodol retention pattern which was carefully assessed on non-contrast CT images done 4 to 6 weeks after treatment. Follow-up CT was then performed every 3 months for at least 12 months or until local progression occurred. On the follow-up CT studies, 20 out of the 45 lesions showed persistent complete response (i.e., no local progression), while 25 of them showed local progression. Among the 25 cases with disease progression upon correlation with their lipiodol retention pattern, it was found that local progression occurred in 31.8% of tumors showed CR with complete lipiodol retention, as opposed to 78.2% of tumors showed CR with incomplete lipiodol retention with significant statistical difference and p value 0.010.ConclusionsLipiodol retention pattern of HCC after TACE can predict the potential tumor local outcome. Lesions with incomplete lipiodol retention are at a higher risk of local tumor progression and therefore should probably observed and can be retreated; on the other hand, tumors with complete lipiodol retention have a much lower risk of local disease tumor progression.

Prospective Margin Estimates Predict Local Tumor Progression Following Microwave Ablation of Small Renal Masses.

To evaluate the relationship between prospectively generated ablative margin estimates and local tumor progression (LTP) among patients undergoing microwave ablation (MWA) of small renal masses (SRMs). Between 2017 and 2020, patients who underwent MWA for SRM were retrospectively identified. During each procedure, segmented kidney and tumor shapes were coregistered with intraprocedural helical CT images obtained after microwave antenna placement. Predicted ablation zone shape and size were then overlaid onto the resultant model, and a model-to-model distance algorithm was employed to calculate multiple ablative margin estimates. LTP was modeled as a function of each margin estimate by hazard regression. Models were evaluated using hazard ratios and Akaike information criterion. Receiver operating characteristic curve area under the curve was also estimated using Harrell's and Uno's C indices (HI and UI, respectively). One hundred and twenty-eight patients were evaluated (median age 72.1years). Mean tumor diameter was 2.4 ± 0.9cm. LTP was observed in nine (7%) patients. Analysis showed that decreased estimated margin size as measured by first quartile (Q1; 25th percentile), maximum, and average ablative margin metrics was significantly associated with risk of LTP. For every one millimeter increase in Q1, maximum, and mean ablative margin, the hazard of LTP increased 67% (HR: 1.67; 95% CI = 1.25-2.20, UI = 0.93, HI = 0.77), 32% (HR: 1.32; 95% CI 1.09-1.60; UI = 0.93; HI = 0.76), and 48% (HR: 1.48; 95% CI 1.18-1.85; UI = 0.83; HI = 0.75), respectively. Prospectively generated ablative margin estimates can be used to predict the risk of local tumor progression following microwave ablation of small renal masses. LEVEL OF EVIDENCE 3: Retrospective cohort study.

Fusion imaging versus ultrasound-guided percutaneous thermal ablation of liver cancer: a meta-analysis.

Ultrasound-guided percutaneous thermal ablation has become an alternative treatment for small hepatocellular carcinoma (HCC). Recent evidence suggests that fusion imaging (FI) may improve the feasibility and efficacy of thermal ablation for HCC, while the clinical evidence remains limited. To compare FI versus ultrasound-guided thermal ablation for HCC. Relevant cohort or randomized controlled trials were found by searching Medline, Web of Science, Cochrane Library, and Embase. The pooling of results was performed using a random-effects model incorporating heterogeneity. In this meta-analysis, 15 studies involving 1472 patients (1831 tumors) for FI-guided ablation and 1380 patients (1864 tumors) for ultrasound-guided ablation were included. Pooled results showed that compared to conventional HCC ablation guided by ultrasound, the FI-guided procedure showed a similar technique efficacy rate (risk ratio [RR] = 1.01, 95% confidence interval [CI] = 1.00-1.02, P = 0.25; I2 = 30%). However, FI-guided tumor ablation was associated with a lower incidence of overall complications (RR = 0.70, 95% CI = 0.50-0.97, P = 0.03; I2 = 0%). Moreover, patients receiving FI-guided tumor ablation had a lower risk of local tumor progression during follow-up than those with ultrasound-guided ablation (RR = 0.61, 95% CI = 0.47-0.78, P < 0.001; I2 = 13%). Subgroup analysis according to FI strategy, imaging techniques in controls, and tumor diameter showed consistent results (p for subgroup difference all >0.05). FI-guided thermal ablation may be more effective and safer than ultrasound-guided ablation for patients with HCC.

Suppression of Local Tumor Progression in Perivascular Hepatocellular Carcinoma by Combination Therapy with Radiofrequency Ablation and Percutaneous Ethanol Injection: A Propensity Score Matching Analysis

Background and Aims: Radiofrequency ablation (RFA) has replaced percutaneous ethanol injection (PEI) as the treatment of choice for hepatocellular carcinoma (HCC); however, control of local tumor progression (LTP) remains a challenge in perivascular HCC. The aim of this study was to determine whether PEI added to RFA can reduce the LTP rate in perivascular HCC patients. Methods: We retrospectively analyzed 167 patients, with 197 newly diagnosed HCC nodules with peritumoral vessels, who underwent either RFA plus PEI or RFA monotherapy as the first-line treatment between June 2001 and April 2015. Ethanol was injected inside the tumor close to the peritumoral vessels in the combination therapy group. Patients were matched 1:1 according to their propensity scores to reduce selection bias; cumulative LTP was then analyzed using log-rank tests and Cox proportional hazard regression analyses. Results: The two matched groups comprised 62 tumors each. The overall median follow-up period was 34 months (range, 1–140 months). In the RFA plus PEI group, the cumulative LTP rates were 5.7%, 15.5%, and 20.4% at 1, 3, and 5 years, respectively; in the RFA monotherapy group, the rates were 13.2%, 32.0%, and 40.2%, respectively. The rates were significantly lower in the RFA plus PEI group (p = 0.032). Cox proportional hazard regression analysis showed that PEI combination treatment was significantly associated with a reduced risk of local HCC recurrence (hazard ratio, 0.44; 95% confidence interval, 0.19–0.93; p = 0.031). Discussion/Conclusion: The risk of LTP after RFA for perivascular HCC can be significantly reduced by injecting ethanol close to the peritumoral vessels.

Assessing ablation margins of FDG-avid liver tumors during PET/CT-guided thermal ablation procedures: a retrospective study

To retrospectively assess liver tumor ablation margins using intraprocedural PET/CT images from FDG PET/CT-guided microwave or cryoablation procedures and to correlate minimum margin measurements with local progression outcomes. Fifty-six patients (ages 36 to 85, median 62; 32 females) with 77 FDG-avid liver tumors underwent 60 FDG PET/CT guided, percutaneous microwave, or cryoablation procedures. Single breath-hold PET/CT images were used for intraprocedural assessment of the tumor ablation margin: liver tumors remained visible on PET immediately following ablation; microwave ablation zones were visible using contrast-enhanced CT; cryoablation zones (ice balls) were visible using unenhanced CT. Two readers retrospectively determined ablation margin assessability and measured the minimum ablation margin on intraprocedural PET/CT (n = 77) and postprocedural MRI (n = 56). Local tumor progression was assessed on all available follow-up imaging (1-49 months, mean 15). Local tumor progression was correlated with PET/CT minimum margin measurements using clustered survival models for 61 tumors. Minimum ablation margins were more often assessable using intraprocedural PET/CT (≥ 73/77 tumors, 95%) than postprocedural MRI (≤ 35/56 tumors, 63%). In 61 tumors with PET/CT-assessable margins (excluding tumors with overlapping ablations after PET/CT), there was a 6-fold increased risk of local tumor progression [hazard ratio (HR) 6.05; P = 0.004] for minimum ablation margins < 5 mm. Breath-hold PET/CT scans, during PET/CT-guided microwave or cryoablation procedures for FDG-avid liver tumors, enable reliable intraprocedural assessment of the entire tumor ablation margin; a minimum PET/CT ablation margin threshold of 5 mm correlates well with local tumor progression outcomes.

Risk factors for local tumor progression after RFA of pulmonary metastases: a matched case-control study.

Curative treatment of oligometastatic pulmonary disease aims at eradication of all metastases. Radiofrequency ablation (RFA) has been shown to be an efficient method and the frequency of local tumor progression (LTP) should be minimized. The objective of this study was to determine the morphological and treatment-related risk factors for LTP after RFA of pulmonary metastases. All patients treated with RFA for pulmonary metastases from 2002 to 2014 were reviewed. All LTPs from 2011 to 2014 were individually matched on the basis of tumor size, number, and histology. In total, 48 LTPs and 112 controls were blindly analyzed for morphological factors including vicinity of bronchus and vessels as well as treatment-related factors such as the size of the ablation zone and ablation margins. In the simple regression analysis, the significant predictive variables were ≤ 5-mm distance to a large bronchus (OR = 4.94; p = 0.0095) or large vessel (OR = 7.09; p < 0.001), minimal ablation margin (≤ 5 mm (OR = 42.67; p < 0.001), and a central-peripheral ablation offset/ablation zone size > 0.36 (OR = 13.83; p = 0.013). In the multiple regression model, only a minimal ablation margin ≤ 5 mm remained a significant risk factor for LTP. Only the minimal ablation margin remains significant in the multiple regression analysis; the other factors are presumably surrogates of an insufficient ablation margin. Improvement of lung RFA outcomes can probably be obtained by immediate post RFA evaluation of ablation margins to ensure a minimal ablation margin of at least 5 mm. • A distance < 5 mm to a bronchus or vessel of over 3 mm diameter is associated with insufficient ablation margin and thus risk factors for local tumor progression after pulmonary radiofrequency ablation. • A minimal ablation margin of > 5 mm after pulmonary RFA is associated with significantly less local tumor progression and should be looked for at the end of treatment session before needle removal in order to decrease local tumor progression. • Tumor location, pleural contact, occurrence of intra-alveolar hemorrhage, pulmonary atelectasis, and pneumothorax are not associated with an increased risk of local tumor progression.

Ultrasound fusion imaging technologies for guidance in ablation therapy for liver cancer.

With advances in imaging technology, images from ultrasound (US) and computed tomography (CT) or magnetic resonance imaging (MRI) can be displayed simultaneously and in real time, according to the angle of the transducer. CT/MR-US fusion imaging improves the visualization of inconspicuous hepatocellular carcinoma (HCC) and helps us to understand the three-dimensional relationship between the liver vasculature and HCC. US fusion imaging guidance facilitates improvement in the treatment response for HCC with poor conspicuity, and the rates of technical success of ablation and local tumor progression for inconspicuous HCC range from 94.4 to 100% and 0 to 8.3%, respectively. Moreover, the development of image fusion has made it possible to compare and overlay pre- and post-ablation US images. This US-US fusion imaging allows side-by-side comparison of the ablative margin, while US-US overlay fusion can visualize the ablative margin because the tumor image is projected onto the ablative hyperechoic zone. Thus, US-US overlay fusion guidance is highly effective for safety margin achievement in local ablation therapy for HCC, providing a lower risk of local tumor progression. This manuscript reviews the current status of ultrasound fusion imaging for percutaneous ablation therapy of HCC.

Multiparametric magnetic resonance-guided and monitored microwave ablation in liver cancer.

The objective of our study was to prospectively evaluate the feasibility, effectiveness, and safety of 1.0T open multiparametric magnetic resonance (MR)-guided and monitored microwave ablation (MWA) of liver cancer. Fifty-six liver lesions (12 - initial hepatocellular carcinoma, 34 - recurrent hepatocellular carcinoma, and 10 - metastatic liver cancers) in 45 patients were treated with MWA ablation using MR guidance and monitoring. The mean diameter of the liver lesions was 1.7 ± 0.9 cm (range, 0.5-4.6 cm). The 56 liver lesions were divided into 3 groups according to diameter: the <1.0 cm group (17 lesions), the 1.0-2.0 cm group (19 lesions), and the >2.0 cm group (20 lesions). Technical success, technical effectiveness, local tumor progression, procedure duration, and complications were assessed. Primary technical effectiveness was assessed 3 months after the MWA, while local tumor progression was assessed more than 3 months after the MWA. The follow-up time for assessment of treatment response ranged from 12 to 30 months (median, 23 months). The technical success rate was 100%. Primary technical effectiveness was achieved in 52/56 (92.8%) lesions. Local tumor progression was detected in three tumors after initial technical effectiveness. The median duration of the intervention per tumor was 66 min (range, 40-156 min). There were no significant differences between lesion groups in the technical success rate, primary technical effectiveness rate, or local tumor progression rate. There were no major complications following the ablation therapy. 1.0T open multiparametric MR-guided and MR-monitored MWA for liver cancer is safe and feasible and decreases the risk of local tumor progression; it also provides good primary technique effectiveness rates and is especially suitable when ultrasound and CT facilitated treatments are inappropriate.

Radiofrequency ablation for hepatocellular carcinoma: Clinical value of ultrasound-ultrasound overlay fusion for optimal ablation and local controllability.

To retrospectively investigate the potential benefit of ultrasound-ultrasound (US-US) overlay fusion guidance for local controllability of radiofrequency ablation (RFA) in the treatment of hepatocellular carcinoma (HCC). Patients (n = 101) with 121 HCCs (mean ± SD, 1.8 ± 0.7cm) who underwent RFA guided by US-US overlay fusion were included in the retrospective study. By overlaying pre/postoperative US, the tumor image could be projected onto the ablative hyperechoic zone. The ablative margin could thereby be evaluated three-dimensionally during the RFA procedure. As a control group, all 325 patients with 453 HCCs who underwent conventional RFA during the same study period were selected. The total number of RF needle insertions per tumor for ablation was significantly more in the US overlay fusion group (mean 1.9 vs. 1.2; P < 0.01). The technical success rates of ablation after a single session were 100% (101/101) and 96.6% (314/325) for the US overlay fusion group and the control group, respectively. For early assessment of RFA response, 5-mm safety margins were achieved in 89.3% (108/121) and 47.0% (213/453) of nodules in the US overlay fusion group and the control group, respectively (P < 0.01). During the follow-up period (median 19months), the 2-year local tumor progression rates were 0.8% (1/121) and 6.0% (27/453) in the US overlay fusion group and the control group, respectively (P = 0.022, log-rank test). US-US overlay fusion guidance can be highly effective for safety margin achievement in RFA for HCC, providing a lower risk of local tumor progression.

Predictive factors of treatment outcomes after percutaneous ablation of hepatocellular carcinoma in the caudate lobe: a retrospective study

BackgroundHepatocellular carcinomas (HCC) arising in the caudate lobe is rare and the treatment is difficult. The aim of this study is to summarize the experience of ultrasound-guided percutaneous ablation therapy for HCC located in the caudate lobe and to investigate the predictive factors of the treatment outcomes.MethodsFrom August 2006 to June 2017, 73 patients (63 males and 10 females; mean age, 54.9 ± 11.6 years; age range, 25–79 years) with 73 caudate lobe HCCs (mean size, 2.6 ± 1.1 cm; size range, 1.0–5.0 cm) were treated with percutaneous ablation, including 33 patients with radiofrequency ablation (RFA), 23 patients with ethanol ablation (EA), and 17 patients with combination of RFA and EA. The treatment outcome and survival after ablation for caudate lobe HCC were assessed and the predictive factors were calculated by univariate and multivariate analyses.ResultsA total of 72 patients achieved complete ablation after the first or second session of ablation. The treatment effectiveness was 98.6% (72/73). During the follow-up, 16 tumors developed local tumor progression (LTP) and a total of 61 patients (61/73, 83.6%) were detected distant recurrence (DR). According to univariate and multivariate analyses, tumor size > 2 cm (hazard ratio[HR] = 3.667; 95% confidence interval[CI], 1.043–12.889; P = 0.043) was a significant prognostic factor of LTP after ablation for HCC in the caudate lobe, while tumor number (HR = 2.245; 95%CI, 1.168–4.317; P = 0.015) was a significant prognostic factor of DR. The mean overall survival time after ablation was 28.7 ± 2.8 months, without independent predictive factors detected. Four patients (4/73, 5.5%) were detected treatment-related major complications, without independent predictive factor detected.ConclusionUltrasound-guided percutaneous ablation is a feasible treatment for a selected case with HCC in the caudate lobe. Tumor size > 2 cm increases the risk of LTP and intrahepatic tumor number is associated with DR after ablation.

Three-dimensional contrast-enhanced ultrasound fusion imaging predicts local tumor progression by evaluating ablative margin of radiofrequency ablation for hepatocellular carcinoma: a preliminary report

Purpose: To investigate the feasibility of three-dimensional contrast-enhanced ultrasound (3DCEUS) fusion in evaluating ablative margin (AM) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) and compare with those of computed tomography (CT) fusion.Patients and methods: In total, 55 patients (47 men, 8 women; mean age, 56.0 ± 10.6 years) with 55 HCCs were included. Pre- and post-RFA 3DCEUS images were fused to assess AM immediately after RFA. The AM measured on fusion imaging was categorized into two groups: (A) AM <5 mm, and (B) AM ≥5 mm. The agreement of AM evaluation was compared between 3DCEUS and CT fusion. The influence of AMs evaluated by 3DCEUS fusion on the risk of local tumor progression (LTP) was assessed.Results: For 3DCEUS fusion, registration success rate was 96.4% (53/55). AM evaluation resulted in 28 tumors in group A and 25 tumors in group B. For CT fusion, AM evaluation resulted in 31 tumors with AM <5 mm and 23 tumors with AM ≥5 mm. AM was successful evaluated by both technique in 53 (96.4%) tumors. The agreement between 3DCEUS and CT fusion was excellent (kappa coefficient = 0.924, p < .001). LTP was identified in 5 tumors (9.4%, 5/53). LTPs all occurred in the area where unachieved 5 mm AM was evaluated by 3DCEUS fusion. Cumulative rate of LTP was significantly higher in group A than in group B (28% versus 0%; p = .033, log-rank test).Conclusions: 3DCEUS fusion enables AM evaluation for HCC immediately after RFA with comparable accuracy to CT fusion. AM <5 mm evaluated by 3DCEUS fusion has high predictive value for LTP.

Local tumor progression after ultrasound-guided percutaneous microwave ablation of stage T1a renal cell carcinoma: risk factors analysis of 171 tumors

Purpose: To retrospectively review long-term oncologic outcomes after ultrasound (US)-guided percutaneous microwave ablation (MWA) of T1a renal cell carcinoma (RCC) and to identify the incidence and risk factors that predict local tumor progression (LTP) after MWA of RCC.Materials and methods: The present study was approved by the institutional review board. A total of 162 patients with 171 RCC nodules (mean size, 2.6 ± 0.8 cm; range, 0.6–4.0 cm) were treated by MWA between April 2006 and January 2017. The influence of eight factors (age; sex; longest tumor diameter; tumor number, location and pathology type; ablation power and time) affecting the risk of LTP was assessed. Univariate Kaplan–Meier and Cox proportional hazard models were used for statistical analysis.Results: LTP occurred in five patients (5 tumors) after US-guided percutaneous MWA of stage T1a RCC. The overall occurrence of LTP was 2.9% per tumor and 3.0% per patient with a median follow-up of 45.5 months. Among the 162 patients, there were no instances of LTP-related deaths; however, 20 patients died of other diseases. All patients with LTP survived through follow-up. The survival rate of LTP-free patients at 1, 3 and 5 years were 98.7%, 89.5% and 82.1%, respectively (p = .38). Univariate and multivariate analysis identified tumor location to be the only independent predictor of LTP.Conclusions: US-guided percutaneous MWA for T1a RCC achieved a relatively low LTP incidence rate. Tumors adjacent to the renal pelvis or bowel increased the potential of LTP occurrence.

First follow-up radiographic response is one of the predictors of local tumor progression and radiation necrosis after stereotactic radiosurgery for brain metastases.

Local progression (LP) and radiation necrosis (RN) occur in >20% of cases following stereotactic radiosurgery (SRS) for brain metastases (BM). Expected outcomes following SRS for BM include tumor control/shrinkage, local progression and radiation necrosis. 1427 patients with 4283 BM lesions were treated using SRS at Cleveland Clinic from 2000 to 2012. Clinical, imaging and radiosurgery data were collected from the database. Local tumor progression and RN were the primary end points and correlated with patient and tumor‐related variables. 5.7% of lesions developed radiographic RN and 3.6% showed local progression at 6 months. Absence of new extracranial metastasis (P < 0.001), response to SRS at first follow‐up scan (local progression versus stable size (P < 0.001), partial resolution versus complete resolution at first follow up [P = 0.009]), prior SRS to the same lesion (P < 0.001), IDL% (≤55; P < 0.001), maximum tumor diameter (>0.9 cm; P < 0.001) and MD/PD gradient index (≤1.8, P < 0.001) were independent predictors of high risk of local tumor progression. Absence of systemic metastases (P = 0.029), good neurological function at 1st follow‐up (P ≤ 0.001), no prior SRS to other lesion (P = 0.024), low conformity index (≤1.9) (P = 0.009), large maximum target diameter (>0.9 cm) (P = 0.003) and response to SRS (tumor progression vs. stable size following SRS [P < 0.001]) were independent predictors of high risk of radiographic RN. Complete tumor response at first follow‐up, maximum tumor diameter <0.9 cm, tumor volume <2.4 cc and no prior SRS to the index lesion are good prognostic factors with reduced risk of LP following SRS. Complete tumor response to SRS, poor neurological function at first follow‐up, prior SRS to other lesions and high conformity index are favorable factors for not developing RN. Stable or partial response at first follow‐up after SRS have same impact on local progression and RN compared to those with complete resolution or progression.

Three-Dimensional Measurement of Hepatocellular Carcinoma Ablation Zones and Margins for Predicting Local Tumor Progression

PurposeTo propose a postprocessing technique that measures tumor surface with insufficient ablative margins (≤ 5 mm) on magnetic resonance (MR) imaging to predict local tumor progression (LTP) following radiofrequency (RF) ablation. Materials and MethodsA diagnostic method is proposed based on measurement of tumor surface with a margin ≤ 5 mm on MR imaging. The postprocessing technique includes fully automatic registration of pre- and post–RF ablation MR imaging, a semiautomatic segmentation of pre–RF ablation tumor and post–RF ablation volume, and a subsequent calculation of the three-dimensional exposed tumor surface area. The ability to use this surface margin ≤ 5 mm to predict local recurrence at 2 years was then tested on 16 patients with cirrhosis who were treated by RF ablation with a margin ≤ 5 mm in 2012: eight with LTP matched according to tumor size and number and α-fetoprotein level versus eight without local recurrence. ResultsThe error of estimated tumor surface with a margin ≤ 5 mm was less than 12%. Results of a log-rank test showed that patients with a tumor surface area > 425 mm2 had a 2-year LTP rate of 77.5%, compared with 25% for patients with a tumor surface area ≤ 425 mm2 (P = .018). ConclusionsThis proof-of-concept study proposes an accurate and reliable postprocessing technique to estimate tumor surface with insufficient ablative margins, and underscores the potential usefulness of tumor surface with a margin ≤ 5 mm to stratify patients with HCC treated by RF ablation according to their risk of LTP.

Percutaneous thermal ablation for primary hepatocellular carcinoma: A systematic review and meta-analysis.

Percutaneous thermal ablation using radiofrequency ablation (RFA) and microwave ablation (MWA) are both widely available curative treatments for hepatocellular carcinoma. Despite significant advances, it remains unclear which modality results in better outcomes. This meta-analysis of randomized controlled trials (RCT) and observational studies was undertaken to compare the techniques in terms of effectiveness and safety. Electronic reference databases (Medline, EMBASE and Cochrane Central) were searched between January 1980 and May 2014 for human studies comparing RFA and MWA. The primary outcome was the risk of local tumor progression (LTP). Secondary outcomes were complete ablation (CA), overall survival, and major adverse events (AE). The ORs were combined across studies using the random-effects model. Ten studies (two prospective and eight retrospective) were included, and the overall LTP rate was 13.6% (176/1298). There was no difference in LTP rates between RFA and MWA [OR (95% CI): 1.01(0.67-1.50), P = 0.9]. The CA rate, 1- and 3-year overall survival and major AE were similar between the two modalities (P > 0.05 for all). In subgroup analysis, there was no difference in LTP rates according to study quality, but LTP rates were lower with MWA for treatment of larger tumors [1.88(1.10-3.23), P = 0.02]. There was no significant publication bias or inter-study heterogeneity (I(2) < 50% and P > 0.1) observed in any of the measured outcomes. Overall, both RFA and MWA are equally effective and safe, but MWA may be more effective compared to RFA in preventing LTP when treating larger tumors. Well-designed, larger, multicentre RCTs are required to confirm these findings.

Percutaneous Lung Thermal Ablation of Non-surgical Clinical N0 Non-small Cell Lung Cancer: Results of Eight Years’ Experience in 87 Patients from Two Centers

To evaluate the survival outcomes of percutaneous thermal ablation (RFA + microwaves) for patients presenting N0 non-small-cell lung cancer (NSCLC) ineligible for surgery. Eighty-seven patients from two comprehensive cancer centers were included. Eighty-two patients were treated with RFA electrodes and five with microwave antenna. Overall survival (OS) and disease-free survival (DFS) were estimated and predictive factors of local tumor progression, OS and DFS identified and compared by univariate and multivariate analyses Median follow-up was 30.5 months (interquartile range 16.7-51) and tumor size was 21 mm (range 10-54 mm). Treatment was incomplete for 14 patients with a local tumor progression of 11.5, 18.3, and 21.1 % at 1, 2, and 3 years, respectively. Two patients presented with neurological (grade III or IV) complications, and one died of respiratory and multivisceral failure as a result of the procedure at 29 days. In univariate analysis, increasing tumor size (P = 0.003) was the only predictive factor related to risk of local tumor progression. 5-year OS and DFS were 58.1 and 27.9 %, respectively. Sex (P = 0.044), pathology (P = 0.032), and tumor size >2 cm (P = 0.046) were prognostic factors for DFS. In multivariate analysis, pathology (P = 0.033) and tumor size >2 cm (P = 0.032) were independent prognostic factors for DFS. Oversized and overlapping ablation of N0 NSCLC was well tolerated, effective, with few local tumor progressions, even over long-term follow-up. Increasing tumor size was the main prognostic factor linked to OS, DFS, and local tumor progression.

Radiofrequency ablation versus partial nephrectomy for the treatment of clinical stage 1 renal masses: a systematic review and meta-analysis

Background Over the past two decades, the clinical presentation of renal masses has evolved, where the rising incidence of small renal masses (SRMs) and concomitant minimal invasive treatments have led to noteworthy changes in paradigm of kidney cancer. This study was to perform a proportional meta-analysis of observational studies on perioperative complications and oncological outcomes of partial nephrectomy (PN) and radiofrequency ablation (RFA). Methods The US National Library of Medicine’s life science database (Medline) and the Web of Science were exhaustly searched before August 1, 2013. Clinical stage 1 SRMs that were treated with PN or RFA were included, and perioperative complications and oncological outcomes of a total of 9 565 patients were analyzed. Results Patients who underwent RFA were significantly older (P &lt;0.001). In the subanalysis of stage T1 tumors, the major complication rate of PN was greater than that of RFA (laparoscopic partial nephrectomy (LPN)/robotic partial nephrectomy (RPN): 7.2%, open partial nephrectomy (OPN): 7.9%, RFA: 3.1%, both P &lt;0.001). Minor complications occurred more frequently after RFA (RFA: 13.8%, LPN/RPN: 7.5%, OPN: 9.5%, both P &lt;0.001). By multivariate analysis, the relative risks for minor complications of RFA, compared with LPN and OPN, were 1.7-fold and 1.5-fold greater (both P &lt;0.01), respectively. Patients treated with RFA had a greater local progression rate than those treated by PN (RFA: 4.6%, LPN/RPN: 1.2%, OPN: 1.9%, both P &lt;0.001). By multivariate analysis, the local tumor progression for RFA versus LPN/RPN and OPN were 4.5-fold and 3.1-fold greater, respectively (both P &lt;0.001). Conclusions The current data illustrate that both PN and RFA are viable strategies for the treatment of SRMs. Compared with PN, RFA showed a greater risk of local tumor progression but a lower major complication rate, which is considered better for poor candidates. PN is with no doubt the golden treatment for SRMs, and LPN has been widely accepted as the first option for nephron-sparing surgery by experienced urologists. RFA may be the best option for select patients with significant comorbidity.