Invasive pulmonary aspergillosis secondary to microwave ablation: a multicenter retrospective study

Purpose: Invasive pulmonary aspergillosis (IPA) is a life-threatening complication of microwave ablation (MWA) during the treatment of primary or metastatic lung tumors. The purpose of this study was to investigate the clinical, radiological and demographic characteristics and treatment responses of patients with IPA after MWA.

Materials and methods: From January 2011 to January 2016, all patients who were treated by MWA of their lung tumors from six health institutions were enrolled in this study. Patients with IPA secondary to MWA were identified and retrospectively evaluated for predisposing factors, clinical treatment, and outcome.

Results: The incidence of IPA secondary to lung MWA was 1.44% (23/1596). Of the 23 patients who developed IPA, six died as a consequence, resulting in a high mortality rate of 26.1%. Using computed tomography (CT), pulmonary cavitation was the most common finding and occurred in 87.0% (20/23) of the patients. Sudden massive hemoptysis was responsible for one-third of the deaths (2/6). Most patients (22/23) received voriconazole as an initial treatment, and six patients with huge cavities underwent intracavitary lavage. Finally, 17 patients (73.9%) achieved treatment success.

Conclusions: Lung MWA may be an additional host risk factor for IPA, particularly in elderly patients with underlying diseases and in patients who have recently undergone chemotherapy. Early and accurate diagnosis of IPA after MWA is critical for patient prognosis. Voriconazole should be given as the first-line treatment as early as possible. Bronchial artery embolization or intracavitary lavage may be required in some patients.     

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.     

Management strategy for nerve damage during radiofrequency ablation of thyroid nodules

Objective: The aim of this study was to introduce a management strategy for nerve damage occurring during radiofrequency ablation (RFA).

Methods: From January 2016 to October 2017, 17 patients who experienced the symptoms of nerve damage during RFA were enrolled in this study. If damage to nerves was suspected during RFA, ablation was stopped immediately, and a cold solution of 5% dextrose was injected directly into the space where the nerves were located until symptoms improved. Patients were followed up after the procedure until symptoms had resolved. The clinical data of patients who received a cold dextrose solution injection for nerve damage were compared with those who did not receive such an injection.

Results: Of 17 patients who experienced nerve damage, 12 received an injection of cold dextrose solution shortly after the emergence of symptoms. While resolution of symptoms was seen in all 17 patients, the mean time to recovery was significantly faster in the 12 patients who received treatment with an injection of cold dextrose solution than in those patients who did not receive such a treatment (p value = .041).

Conclusions: In the event of thermal damage to adjacent nerve structures during RFA, the direct injection of a cold dextrose solution is a simple and effective treatment that can result in rapid symptom resolution.     

Microwave ablation of hyperplastic parathyroid glands is a treatment option for end-stage renal disease patients ineligible for surgical resection

Background: Secondary hyperparathyroidism (SHPT) is a frequently encountered problem in patients with end-stage renal disease (ESRD). Some patients with severe SHPT could not be managed by medical treatment and are ineligible for surgical resection.

Purpose: Our objective was to evaluate the efficacy, safety of microwave ablation (MWA) on these patients.

Materials and Methods: Between 1 April 2015 and 28 February 2017, 35 patients (M/F 19/16, age 49.8?±?12.9?years) were enrolled. All patients were treated with MWA. Levels of intact parathyroid hormone (iPTH) and of serum calcium and phosphorus were compared pre- and post-ablation. Repeated-measures ANOVA was used to compare treatment outcomes pre- and post-ablation.

Results: Complete ablation was achieved in all 63 glands in the 35 patients with SHPT. The mean follow-up time was 15.9?±?2.2?months. The maximum gland diameter was 6–31?mm (mean, 14.9?±?5.5?mm). The trends of the changes in iPTH and calcium levels showed a curve: the level of iPTH and calcium at 6?months post-ablation were lower than those pre-ablation (both p?<?.0001); after then iPTH remained relatively stable and the end of follow up, with no rebound (p?<?.0001), while instead of calcium at the end of follow up was not significantly lower than pre-ablation (p?=?.462). The trend in the change in phosphate levels showed a straight line; the level of phosphate at 6?months post-ablation and at the end of follow up both were significantly lower than pre-MWA (p?<?.001). There was no major complication.

Conclusions: In this series, MWA was used successfully to treat SHPT patients who are ineligible for surgical resection.     

Safety and technical feasibility of percutaneous ablation for lymph node metastases of hepatocellular carcinoma

Purpose: This study aimed to assess the safety and technical feasibility of percutaneous ablation therapy for lymph node (LN) metastases of hepatocellular carcinoma (HCC).

Material and Methods: A total of 31 consecutive HCC patients with LN metastases who were treated with ablation were included in this retrospective study. Percutaneous ablation was performed under local anesthesia and computed tomography–guidance. The primary endpoint was technique success; secondary endpoints were overall survival (OS), progression-free survival (PFS), and local progression-free survival (LPFS). Survival curves were constructed using Kaplan-Meier method.

Results: The median diameter of metastatic LNs was 30?mm (range, 10–77?mm). The 1-, 3-, and 5-year OS rates were 74.6%, 50.3%, and 50.3%, respectively. The 1-, 3-, and 5-year PFS rates were 24.7%, 0%, and not available for calculation (NA), respectively. The 1-, 3-, and 5-year LPFS rates were 78.7%, 69.9%, and 69.9%, respectively. The technique success and technical effectiveness rates were 100% and 64.5%, respectively. The technical effectiveness rates were 65.4% (17/26) and 60% (3/5) in abdominal LN metastases and distant LN metastases, respectively. Only one patient (1/31, 3.2%) had major complications (massive pleural effusion and severe pneumonia) related to ablation. Minor complications related to ablation included mild abdominal pain (10/31, 32.3%) and self-limiting hematoma (2/31, 6.5%). No ablation-related death occurred.

Conclusion: Percutaneous ablation appears to be a safe and feasible method for treatment of metastatic LNs in patients with HCC.     

A novel software platform for volumetric assessment of ablation completeness

Purpose: To retrospectively evaluate the accuracy of a novel software platform for assessing completeness of percutaneous thermal ablations.

Materials & methods: Ninety hepatocellular carcinomas (HCCs) in 50 patients receiving percutaneous ultrasound-guided microwave ablation (MWA) that resulted in apparent technical success at 24-h post-ablation computed tomography (CT) and with ≥1-year imaging follow-up were randomly selected from a 320 HCC ablation database (2010–2016). Using a novel volumetric registration software, pre-ablation CT volumes of the HCCs without and with the addition of a 5?mm safety margin, and corresponding post-ablation necrosis volumes were segmented, co-registered and overlapped. These were compared to visual side-by-side inspection of axial images.

Results: At 1-year follow-up, CT showed absence of local tumor progression (LTP) in 69/90 (76.7%) cases and LTP in 21/90 (23.3%). For HCCs classified by the software as “incomplete tumor treatments”, LTP developed in 13/17 (76.5%) and all 13 (100%) of these LTPs occurred exactly where residual non-ablated tumor was identified by retrospective software analysis. HCCs classified as “complete ablation with <100% 5?mm ablative margins” had LTP in 8/49 (16.3%), while none of 24 HCCs with “complete ablation including 100% 5?mm ablative margins” had LTP. Differences in LTP between both partially ablated HCCs vs completely ablated HCCs, and ablated HCCs with <100% vs with 100% 5?mm margins were statistically significant (p?<?.0001 and p?=?.036, respectively). Thus, 13/21 (61.9%) incomplete tumor treatments could have been detected immediately, were the software available at the time of ablation.

Conclusions: A novel software platform for volumetric assessment of ablation completeness may increase the detection of incompletely ablated tumors, thereby holding the potential to avoid subsequent recurrences.     

The local efficacy and influencing factors of ultrasound-guided percutaneous microwave ablation in colorectal liver metastases: a review of a 4-year experience at a single center

Purpose: To investigate the clinical effectiveness and safety of ultrasound (US)-guided percutaneous microwave ablation (MWA) for colorectal liver metastasis (CRLM) and evaluate the influencing factors of local efficacy.

Methods: From January 2013 to January 2017, 137 CRLM patients accepting US-guided percutaneous MWA were included. The 2450-MHz microwave ablation system and a cooled-shaft antenna were used. All patients were regularly followed up for at least 6?months. Technical success, complete ablation, local tumor progression (LTP), complications and side effects were assessed. Logistic regression analysis was used to identify the independent prognostic factors for LTP.

Results: In total, 411 lesions (mean diameter 15.4?±?7.2?mm, range 5–67?mm) were treated. Complete ablation was achieved in 99.27% (408/411) of lesions and 97.81% (134/137) of patients. LTP occurred in 5.35% (22/411) of lesions and 16.06% (22/137) of patients. LTP was more likely to occur in lesions larger than 3?cm in diameter (OR: 14.71; p?<?.001; 95% CI: 3.7 3–57.92), near a large vascular structure (OR: 7.04; p?<?.001; 95% CI: 2.41–20.60), near the diaphragm (OR: 4.02; p?=?.049; 95% CI: 1.05–16.11) and in patients with no response to chemotherapy before MWA (OR: 3.25; p?=?.032; 95% CI: 1.14–15.30). MWA was well tolerated, with a major complication rate of 3.65%, a minor complication rate of 8.03% and a mortality rate of 0%. Fever and pain were the most common side effects after MWA.

Conclusions: US-guided percutaneous MWA of CRLM is a safe and effective method that is expected to become a routine treatment for local tumor control of CRLM.     

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.     

Comparison of efficacy and complications between radiofrequency ablation and repeat surgery in the treatment of locally recurrent thyroid cancers: a single-center propensity score matching study

Purpose: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers.

Materials and methods: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n?=?96) or repeat surgery (n?=?125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1–10?years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications—voice changes, hypocalcemia, and immediate procedural complications—were compared between the groups. In addition, pretreatment serum thyroglobulin (T_g) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy.

Results: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p?=?.2). There were no significant differences in mean serum T_g levels and their mean decrease after treatment between the groups (p?=?.891 and p?=?.963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p?=?.316, p?=?.084, respectively). Hypocalcemia occurred only in the repeat surgery group (n?=?18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n?=?7; surgery, n?=?27; p?<?.001).

Conclusion: RFA may be an effective and safe alternative to repeat surgery in the treatment of a small number of locally recurrent thyroid cancers.     

Increasing radiofrequency ablation volumes with the use of internally cooled electrodes and injected hydrochloric acid in ex vivo bovine livers

Purpose: We used an impedance-controlled generator with an internally cooled electrode to perform radiofrequency ablation (RFA) in ex vivo bovine livers, with a single injection of either 38.5% sodium chloride (NaCl) or 10% hydrochloric acid (HCl), to determine the relative effects of these two solutions on tissue impedance, temperature and ablation volume.

Materials and methods: We performed 10 ablations each with injections of NaCl (NaCl-RFA), HCl (HCl-RFA) or nothing (RFA-alone), with a power setting of 200 W for 15?minutes. We recorded tissue impedance before and after injection. We logged temperatures obtained from thermocouple probes positioned 5, 10, 15 and 20?mm from the internally cooled RF electrode. After ablation, we measured ablation zone longitudinal and transverse diameters, and we calculated a spherical ratio (SR) for each ablation.

Results: Mean post-injection impedance of 30.3 (standard deviation [SD] 2.5) ohms for HCl was significantly lower than that of 55.4 (SD 3.5) ohms for NaCl (p?<?.001). Mean maximum temperatures recorded at each respective distance from the RFA electrode were all highest for HCl-RFA and lowest for RFA-alone (p?<?.001). Mean longitudinal and transverse diameters after HCl-RFA (5.50 [SD 0.25] cm and 5.28 [SD 0.22] cm, respectively) were significantly larger than those after NaCl-RFA (4.24 [SD 0.35] cm and 3.55 [SD 0.43] cm, respectively) and after RFA-alone (3.60 [SD 0.10] cm and 2.70 [SD 0.13] cm, respectively) (p?<?.001). Mean SR after HCl-RFA (0.93, SD 0.02) was significantly higher than mean SR after NaCl-RFA (0.76, SD 0.06) and RFA-alone (0.72, SD 0.04) (p?<?.001).

Conclusion: Monopolar, impedance-controlled RFA, with an internally cooled electrode and a single 10% HCl injection may allow larger tumors to be treated, potentially resulting in improved patient outcomes.     

Ultrasound-guided percutaneous microwave ablation versus surgical resection for recurrent intrahepatic cholangiocarcinoma: intermediate-term results

Objective: The aims of this study were to compare the clinical outcomes between ultrasound-guided percutaneous microwave ablation (US-PMWA) and surgical resection (SR) in patients with recurrent intrahepatic cholangiocarcinoma (ICC) and to identify the prognostic factors associated with the two treatment methods.

Methods: This retrospective study was institutional review board approved. A total of 121 patients (102 men and 19 women) with 136 ICCs after hepatectomy from April 2011 to January 2017 were reviewed. Fifty-six patients underwent US-PMWA and 65 patients underwent SR. Survival, recurrence and liver function were compared between the two groups. Effect of changes in key parameters [i.e., overall survival (OS) and recurrence-free survival (RFS)] was statistically analyzed with the log-rank test. Univariate and multivariate analysis were performed on clinicopathological variables to identify factors affecting long-term outcome.

Results: The OS and RFS after MWA were comparable to that of SR (p?=?.405, and p?=?.589, respectively). Estimated 5-year OS rates were 23.7% after MWA and 21.8% after SR; for RFS, estimated 3-year RFS rates were 33.1% after MWA and 30.6% after SR. Major complication rates in SR group were higher than that in MWA (p?<?.001) (SR, 13.8% vs. MWA, 5.3%). Multivariate analysis showed tumor number (p?=?.012), ALBI grade (p?=?.007), and metastasis (p?=?.016), may become OS rate predictors.

Conclusions: US-PMWA had comparable oncologic outcomes with SR and could be a safe and effective treatment for recurrent ICC after hepatectomy.     

Precoagulation with microwave ablation for hepatic parenchymal transection during liver partial resection

Purpose: To evaluate the feasibility of precoagulation with microwave ablation (MWA) for hepatic parenchymal transection during liver partial resection.

Methods: A total of 66 eligible patients were enrolled in this double-blind, randomized, controlled study. Patients were randomized to receive either the traditional clamp-crushing method (Control group) or the MWA precoagulation method (MWA group) for hepatic parenchymal transection during liver partial resection. The operative time, hepatic portal occlusion time, intraoperative blood loss and transfusion, postoperative complications and recovery outcomes were compared.

Results: Compared to the Control group, the MWA group had significantly less intraoperative blood loss. Fewer red blood cell transfusions were observed in the MWA group but without statistical significance. The MWA group showed significantly higher serum alanine aminotransferase and aspartate aminotransferase levels at day 1 postoperatively, but no differences between the MWA and Control groups were found at days 3 and 7. There were no significant differences in terms of operative time, hepatic portal occlusion time, postoperative total bilirubin levels, human albumin solution consumption or length of hospital stay. Postoperative complications such as impaired renal function, pyrexia, admission to ICU, abscess, biliary leakage, intrahepatic and distant tumor recurrence and in-hospital mortality were comparable between the two groups.

Conclusion: Precoagulation with MWA reduced intraoperative blood loss with similar postoperative complications, providing a safe, effective, novel alternative for hepatic parenchymal transection during liver partial resection. Additional results from larger series are recommended to confirm these findings.     

US-guided microwave ablation for secondary hyperparathyroidism in patients after renal transplantation: a pilot study

Objective: To assess the safety and efficacy of ultrasound-guided microwave ablation (MWA) in the treatment of patients who develop secondary hyperparathyroidism (SHPT) after renal transplantation (RT).

Methods: In total, nine patients, each with symptomatic SHPT caused by RT and at least one enlarged parathyroid gland, underwent MWA via hydrodissection. Intact parathyroid hormone (i-PTH), serum calcium, serum phosphorus, creatinine and blood urea nitrogen concentrations, before and after MWA, were assessed and compared.

Results: Complete ablation was achieved in all patients for a total of 14 ablated parathyroid glands. The mean follow-up time was 17.2?±?1.7?months post-operation. The mean maximum diameter of the parathyroid glands was 1.3?±?0.4?cm (range: 0.4–2.0?cm). The ablation power implemented was 30?W and the mean time for each parathyroid gland to achieve complete ablation was 287.5?±?83.4?s. The mean i-PTH, serum calcium and phosphorus concentrations at one day post-MWA (69.6?pg/mL, 2.23?±?0.29?mmol/L, 1.2 2?±?0.48?mmol/L, respectively) were significantly lower than those before MWA (780.0?pg/mL, 2.62?±?0.32?mmol/L, 1.39?±?0.61?mmol/L, respectively; p?<?.01), whereas the creatinine and blood urea nitrogen concentrations before and after MWA did not differ significantly from each other (p?>?.05). No significant differences were found between the biomarker concentrations observed at one day post-MWA and at the follow-ups (p?>?.05). No major operation-related complications occurred.

Conclusion: Ultrasound-guided MWA is a safe and effective technique for destroying parathyroid gland tissue in patients who develop SHPT after RT and its clinical effects are long-lasting.     

Real-time monitoring radiofrequency ablation using tree-based ensemble learning models

Background: Radiofrequency ablation is a minimally-invasive treatment method that aims to destroy undesired tissue by exposing it to alternating current in the 100?kHz–800?kHz frequency range and heating it until it is destroyed via coagulative necrosis. Ablation treatment is gaining momentum especially in cancer research, where the undesired tissue is a malignant tumor. While ablating the tumor with an electrode or catheter is an easy task, real-time monitoring the ablation process is a must in order to maintain the reliability of the treatment. Common methods for this monitoring task have proven to be accurate, however, they are all time-consuming or require expensive equipment, which makes the clinical ablation process more cumbersome and expensive due to the time-dependent nature of the clinical procedure.

Methods: A machine learning (ML) approach is presented that aims to reduce the monitoring time while keeping the accuracy of the conventional methods. Two different hardware setups are used to perform the ablation and collect impedance data at the same time and different ML algorithms are tested to predict the ablation depth in 3 dimensions, based on the collected data.

Results: Both the random forest and adaptive boosting (adaboost) models had over 98% R² on the data collected with the embedded system-based hardware instrumentation setup, outperforming Neural Network-based models.

Conclusions: It is shown that an optimal pair of hardware setup and ML algorithm (Adaboost) is able to control the ablation by estimating the lesion depth within a test average of 0.3mm while keeping the estimation time within 10ms on a ×86–64 workstation.     

Heat shock protein expression and autophagy after incomplete thermal ablation and their correlation

Objective: To establish a model of incomplete ablation in nude mice with hepatocellular carcinoma (HCC) and to evaluate heat shock protein (HSP) expression and autophagy and their correlation.

Materials and methods: In the first stage, 12 nude mice with HCC were randomly divided into two groups (n?=?6). A sham puncture operation was performed for one group, and palliative laser ablation was performed for the other group. All mice were sacrificed after 18?h, and HSP expression, autophagy, and apoptosis were assessed. In the second stage, 16 nude mice with HCC were randomly divided into two groups (n?=?8). One group was given an HSP90 inhibitor before the operation, and the other group was given dimethyl sulfoxide (DMSO) as a control. HSP expression, autophagy and apoptosis were assessed for the two groups after palliative laser ablation.

Results: In the incomplete ablation model, using nude mice with HCC, HSP90, HSP70, and HSP27 expression was up-regulated, Akt and mTOR phosphorylation was enhanced, autophagy was decreased, and apoptosis was increased. After administration of the HSP90 inhibitor, HSP90, P-Akt, and P-mTOR expression was decreased, autophagy was increased, and apoptosis was further increased.

Conclusion: Autophagy was decreased in the incomplete ablation model and might be inversely correlated with HSP expression. It is suggested that the HSP90/Akt/mTOR pathway is involved in signal transmission between autophagy and HSPs.     

Radiofrequency ablation of liver cancers adjacent to the gallbladder without gallbladder isolation under contrast-enhanced ultrasound monitoring: a preliminary study

Purpose: The purpose of this study was to investigate the feasibility, safety and efficacy of intra-procedural contrast-enhanced ultrasound (CEUS) monitoring of the radiofrequency ablation (RFA) of liver cancers adjacent to gallbladder (GB) without GB isolation.

Materials and methods: From May 2016 to July 2017, patients with liver cancers adjacent to GB (≤10?mm) who intended to undergo ultrasound-guided RFA without GB isolation in our hospital were prospectively enrolled. During the RFA procedures, CEUS was employed to evaluate the therapeutic response and the perfusion of the intact GB wall. The outcomes of GB and liver cancers were followed up and recorded.

Results: 23 patients (18 male, 5 female) with 23 liver cancers (mean 18?mm, range 8–34?mm) adjacent to GB were enrolled. There were 12 tumors that abutted the GB while 11 tumors located within 10?mm of the GB. After the RFA procedures, intra-procedural CEUS evaluation demonstrated the perfusion of the GB wall was intact in all 23 patients and technical success rate of RFA was 100% (23/23). According to the contrast-enhanced CT/MR one month after RFA, the technical efficacy rate was 100% (23/23). During the follow-up period (range: 12–23?months, median: 17?months), no local tumor progression occurred and no major complications arised. Overall survival at 1-year was 100%. Thickening of GB wall was detected in 11 patients. The thickness of GB wall returned to the pre-ablation level in five patients.

Conclusion: CEUS-monitored RFA of liver cancers adjacent to GB without GB isolation was feasible, safe and effective.     

Radiofrequency ablation combined with percutaneous ethanol injection for hepatocellular carcinoma: a systematic review and meta-analysis

Background: Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) are important treatments for patients with hepatocellular carcinoma (HCC) who are not eligible for resection and liver transplantation. Therefore, it is important to establish comparisons between RFA, PEI and the two therapies in combination.

Aims: To evaluate the clinical efficacy and safety of combined RFA-PEI versus monotherapy with either RFA or PEI for HCC to provide references for clinical practice and further research.

Methods: We searched all eligible studies published before September 2015 in the Cochrane Library, PubMed, Embase, Web of Science and Chinese databases, such as CBM, CNKI, VIP and WanFang and also retrieved papers from other sources. All relevant controlled trials were collected. Meta-analyses were performed using RevMan version 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark).

Results: Thirteen trials with 1621 patients were identified. Compared with PEI, RFA was associated with significant improvement in overall survival (OS) rate at 1, 2, 3 and 4 years, cancer-free survival (CFS) rate at 1, 2 and 3 years and complete tumour necrosis. RFA was associated with a significant reduction in the local recurrence rate at 1, 2 and 3 years. However, RFA was also associated with a higher total risk of complications. Compared with RFA alone, combined RFA-PEI was associated with a significant improvement in the OS rate at 1.5, 2 and 3 years and a significant reduction in the local recurrence rate. However, combined RFA-PEI was also associated with a higher risk of fever.

Conclusion: The combination of RFA and PEI appears to be the optimal treatment strategy when considering combined RFA-PEI or either RFA or PEI alone. Combined RFA-PEI significantly improves OS and reduces the risk of local recurrence without increasing major complications. Further large-scale studies are needed to assess economic outcomes and quality of life.     

Ultrasound-guided percutaneous laser ablation is safe and effective in the treatment of small renal tumors in patients at increased bleeding risk

Purpose: The aim of this retrospective study was to assess the safety and effectiveness of laser ablation (LA) in patients with small renal cell carcinomas (RCC) and increased risk of bleeding.

Material and methods: From 2013 to 2017, nine patients (six males, three females, aged 68.5?±?12.2 years) at high risk of bleeding underwent ultrasonography-guided LA for an RCC. Patients were considered at increased risk of bleeding because of impairment of coagulation parameters, concomitant antiplatelet therapy, or at-risk location of the tumor (one, five, and three patients, respectively). RCC diameter ranged from 11 to 23?mm. According to tumor size, two or three laser fibers were introduced through 21-gauge needles and 1800 J per fiber were delivered in 6?min with a fixed power of 5 W. Major and minor complications, technical success, and primary and secondary technical effectiveness and tumor recurrence were recorded.

Results: Just one Grade 1 complication was observed: a small asymptomatic hematoma that spontaneously resolved. Technical success was 100%, 1 month technical efficacy was 88.9% (8/9 patients). One patient with residual tumor was successfully retreated 1 month later, and secondary efficacy rate was 100%. No local tumor recurrence occurred during a median follow-up of 26 months (range 11–49 months).

Conclusions: LA is safe and effective in the treatment of small RCC and might represent a valid option in patients with increased risk of bleeding.     

Activated hepatic stellate cells promote progression of post-heat residual hepatocellular carcinoma from autophagic survival to proliferation

Background: Microscopic residual tumor often occurs after thermal ablation for medium-large hepatocellular carcinoma (HCC), leading to early aggressive recurrence or late relapse during follow-up. The mechanism how microscopic residual HCC cells survive sublethal heat stress and develop rapid outgrowth remains poorly understood.

Methods: HCC cells were exposed to sublethal heat treatment and co-cultured with conditioned media from activated HSCs (HSC-CM). Changes of cell proliferation, parameters of cell autophagy and activation of signaling pathways in heat-treated residual HCC cells were analyzed. An HCC orthotopic model was subjected to partial thermal ablation and antitumor effects of a combined treatment regimen were studied.

Results: HCC cells survived sublethal heat stress via activation of autophagy. HSC-CM enhanced autophagic survival within 24?h and then promoted proliferation of heat-treated residual HCC cells through HGF/c-Met signaling. Inhibition of autophagy or c-Met increased apoptosis of heat-treated residual HCC cells and reversed the protective effect of HSC-CM. HGF modulated biological status in autophagic survival or proliferation of heat-treated residual HCC through HGF/c-Met/ERK signaling and downstream components of ATG5/Beclin1 or cyclinD1. In an animal model, inhibiting autophagy in combination with c-Met inhibitor significantly thwarted tumor progression of residual HCC after incomplete thermal ablation via the suppressed autophagy, the decreased proliferation and the increased apoptosis.

Conclusions: Activated HSCs promote progression of residual HCC cells after sublethal heat treatment from autophagic survival to proliferation via HGF/c-Met signaling. A combined treatment regimen of inhibiting autophagy and c-Met signaling could be used to suppress tumor progression of residual HCC after incomplete thermal ablation.     

Clinical analysis of high-intensity focussed ultrasound ablation for abdominal wall endometriosis: a 4-year experience at a specialty gynecological institution

Objective: To evaluate the long-term clinical effect of high-intensity focussed ultrasound (HIFU) as a non-invasive modality for ablation of abdominal wall endometriosis (AWE) foci.

Methods: All women who were diagnosed with cutaneous endometriosis and underwent HIFU ablation and 4-year follow-up were included. Patient symptoms, imaging performed, HIFU ablation, recurrence, lesion location, size and number were collected and analyzed.

Results: A total of 51 women with 57 painful abdominal wall masses with a median volume of 4.00?cm³ and a mean age of 30.5±2.12 years were treated with HIFU. The main symptoms were a palpable painful abdominal mass (93%), protrusion of the skin (28.1%, 16) or lack of protrusion of the skin (71.9%, 41). Ultrasound was initially performed in 100% (51) of women, whereas 6% (3) required MRI examinations to distinguish the features and range of the masses. Ablation was performed with a median 300?s of sonication time, 40?min treatment time, 150?W of power and 41800?J of total energy to treat lesions that were a median volume of 3.83?cm³. No severe complications occurred, except in one patient with a first-degree skin burn, during the 48-month follow-up period. The pooled recurrence of cutaneous endometriosis occurred in 3.9% (2) of women.

Conclusion: The diagnosis of AWE should be confirmed with imaging of the lesion number, location, size and features before HIFU ablation. HIFU should be the first choice for the treatment of AWE as it is a non-invasive method, with high efficiency and safety and rapid postoperative recovery.