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.     

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.     

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.     

The impact of technical parameters on ablation volume during MR-guided focused ultrasound of desmoid tumors

Purpose: Desmoid tumors are benign, locally aggressive soft tissue tumors derived from fibroblasts. Magnetic resonance-guided focused ultrasound (MRgFUS) is a safe and effective treatment for desmoid tumors. The purpose of this study was to retrospectively review the MRgFUS treatments of desmoid tumors at our institution to determine which technical treatment parameters contributed most significantly to the accumulation of thermal dose.

Materials and methods: The study protocol was approved by the local IRB. We retrospectively reviewed data from MRgFUS treatments performed in histologically-confirmed desmoid tumors, over a period of 18?months. Sonication parameter means were compared with ANOVA. Mixed effects and linear regression models were used to evaluate the relative contribution of different parameters to thermal dose volume.

Results: Nine-hundred thirty-six sonications were reviewed in 13 treatments. Accumulated dose per sonication was greatest for elongated sonications (0.96?cc?±?0.90) compared to short (0.88?±?0.93?cc) and nominal (0.55?±?0.70?cc) sonications, p?<?.001. 65.2% of short sonications resulted in high percentage ablations, compared to 46.0% of nominal and 35.1% of elongated sonications. Standardized beta coefficients (anticipated increased volume in cc per unit) for power, duration, energy and average temperature were 0.006, 0.057, 0.00035 and 0.03, p?<?.001. Regarding dose efficacy, dose area contributed the greatest to this variability – 50.7% (45.5–54.8%), followed by distance – 16.6% (12.9–20.0%).

Conclusions: A variety of sonication parameters significantly contributed to thermal ablation volume following MRgFUS of desmoid tumors, in reproducible patterns. This work can serve as the basis for future models working toward improved planning for MRgFUS treatments.     

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.     

Comparison of microwave ablation and radiofrequency ablation for hepatocellular carcinoma: a systematic review and meta-analysis

Background: Microwave ablation (MWA) has several advantages over radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC). We aimed to compare the efficacy and safety of MWA with those of RFA for HCC from the perspectives of percutaneous and laparoscopic approaches.

Methods: PubMed/MEDLINE, Embase, the Cochrane library, and China Biology Medicine databases were searched. Studies comparing the efficacy and safety of MWA with those of RFA in patients with HCC were considered eligible. Complete ablation (CA), local recurrence (LR), disease-free survival (DFS), overall survival (OS), and the major complication rate were compared between MWA and RFA.

Results: Four randomized controlled trials and 10 cohort studies were included. For percutaneous ablation, no significant difference was found between MWA and RFA regarding CA, LR, DFS, OS, and the major complication rate. A subgroup analysis of tumors measuring ≥3?cm revealed no difference in CA and LR for percutaneous ablation. For laparoscopic ablation, a significantly lower LR rate and a non-significant trend toward a higher major complication rate were observed for the MWA group (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.16–4.02, p?=?.01 for LR; OR 0.21, 95% CI 0.04–1.03, p?=?.05 for major complication rate). CA, DFS, and OS were similar between the two groups.

Conclusions: Percutaneous (P)-MWA had similar therapeutic effects compared with P-RFA for HCC. Patients undergoing laparoscopic MWA had a lower LR rate; however, their major complication rate appeared to be higher. The superiority of MWA over RFA remains unclear and needs to be confirmed by high-quality evidence.     

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.     

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.     

Efficacy and safety of high-intensity focused ultrasound ablation for hepatocellular carcinoma by changing the acoustic environment: microbubble contrast agent (SonoVue) and transcatheter arterial chemoembolization

Objective: To compare efficacy and safety of microbubble contrast agent (SonoVue) and transcatheter arterial chemoembolization (TACE) in combination with high-intensity focused ultrasound (HIFU) for treatment of patients with hepatocellular carcinoma (HCC).

Methods: According to our inclusion criteria, we retrospectively reviewed 52 patients with HCCs, and divided them into SonoVue group and TACE group. Tumors were examined by enhanced magnetic resonance imaging. Change of lesions, alpha-fetoprotein values, hepatic and renal function were measured pre- and postoperatively. Then, adverse events were observed and clinical follow-up was performed.

Results: Clinical efficacy and the majority of treatment parameters were similar, except for time and energy required for the first massive grey-scale changes in SonoVue group, which were significantly lower than those in TACE group (p?<?.05). For adverse events, only rate of fever (3.85%) in SonoVue group was significantly lower than that in TACE group (50.00%, p?<?.05). The ‘diagnosis and treatment cycle’ in SonoVue group (11.5?±?2.9) was remarkably shorter than TACE group (22.7?±?6.3, p?<?.05). Energy efficiency factor was positively correlated with distance from the deepest layer of lesion to the hepatic capsule or to the abdominal wall in SonoVue group, while that was negatively correlated with iodized oil deposition in TACE group.

Conclusion: Using microbubble (SonoVue) in HIFU procedure has a similar therapeutic effect compared with TACE, and does not increase the risk of treatment. It might present a new strategy in clinical treatment, especially for patients with a smaller diameter of HCC.     

Reasons for different therapeutic effects of high-intensity focused ultrasound ablation on excised uterine fibroids with different signal intensities on T2-weighted MRI: a study of histopathological characteristics

Objective: The objective of this study was to explore the correlations between the therapeutic effect of high intensity focused ultrasound (HIFU) and histopathological characteristics of excised uterine fibroids with different signal intensities as visualized on T2-weighted magnetic resonance imaging (MRI).

Methods: We collected 47 specimens of uterine fibroids after surgical resection and classified them into four groups according to preoperative T2-weighted MRI hypo-intense, isointense, heterogeneous intense and homogeneous hyper-intense. Then, specimens in each group were irradiated by HIFU with the same parameters and the necrotic tissue volume was calculated. The smooth muscle cell (SMC) count and collagen fiber content were quantitatively measured and compared between different groups. We analyzed the correlation between the necrotic tissue volume and SMC count and the collagen fiber content.

Results: Necrotic tissue volume gradually decreased from the hypo-intense group to the homogeneous hyper-intense group (p?=?.008). The SMC count from the hypo-intense group to the homogeneous hyper-intense group was 215.6?±?59.3, 237.0(89.5), 232.3?±?72.5 and 330.5?±?30.9, respectively; collagen fiber content was 0.65?±?0.07, 0.64?±?0.10, 0.53?±?0.11 and 0.41?±?0.06, respectively. Comparison among the four groups showed that SMC count progressively increased (p?=?.001) but collagen fiber content progressively decreased (p?=?.000) from the hypo-intense group to the homogeneous hyper-intense group. Correlation analysis showed that necrotic tissue volume was negatively correlated with SMC count (R?=??0.488, p=.013) but positively correlated with collagen fiber content (R?=?0.534, p?=?.005).

Conclusions: Differences in histopathological characteristics may be one of the reasons for different therapeutic effects of HIFU ablation on uterine fibroids with different signal intensities on T2-weighted MRI.     

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.     

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.     

Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition

Purpose: Although magnetite nanoparticles (MNPs) are promising agents for hyperthermia therapy, insufficient drug encapsulation efficacies inhibit their application as nanocarriers in the targeted drug delivery systems. In this study, porous magnetite nanoparticles (PMNPs) were synthesized and coated with a thermosensitive polymeric shell to obtain a synergistic effect of hyperthermia and chemotherapy.

Materials and methods: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500?Da (PEG1500) and phase transition temperature of 48?±?2?°C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells.

Results: Heat treatment of DOX-PEG1500-PMNPs containing 235?±?26?mg·g^?1 DOX at 48?°C by waterbath, MRgFUS, and AMF, respectively led to 71?±?4%, 48?±?3%, and 74?±?5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy.

Conclusion: The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.     

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.     

An assessment of the survival impact of multimodal anesthesia/analgesia technique in adults undergoing cytoreductive surgery with hyperthermic intraperitoneal chemotherapy: a propensity score matched analysis

Background: Studies suggest volatile anesthetics and opioids may enhance the malignant potential of cancer cells. The objective of this single institution retrospective study was to evaluate the survival impact of a multimodal opioid-sparing nonvolatile anesthetic technique (MA) in a group of patients who had undergone cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) for appendiceal carcinomatosis.

Methods: Propensity score matching (PSM) and Cox proportional hazard models were used to compare the survivals of patients who received MA (MA group), to those who received volatile-opioid anesthesia (volatile-opioid group).

Results: Of the 373 patients, 110 (29%) were in the MA group and 263 (71%) in the volatile-opioid group. The MA group was older (mean?±?standard deviation (SD): 55?±?11 versus 53?±?10?years, p?=?.035) and had more patients with ASA scores 3 or 4 (90% versus 81%, p?=?.032), and those with high grade tumors (18% versus 12%, p?=?.009). Intraoperative opioid consumption was lower in the MA group (mean morphine equivalents?±?SD: 13?±?10 versus 194?±?789, p?<?.0001). After PSM, 107 patients remained in each group. In the adjusted Cox proportional hazards model after PSM, MA was not associated with improved progression free survival (PFS) (HR 1.45, 95% CI [0.94–2.22], p?=?.093) or overall survival (OS) (HR 1.66, 95% CI [0.86–3.20], p?=?.128), when compared to volatile-opioid anesthesia.

Conclusions: In this retrospective study, a multimodal opioid-sparing nonvolatile anesthetic approach was not associated with improved survival.

Precis’ statement: In this study of patients undergoing major cancer surgery, the use of multimodal anesthetic and analgesic agents, while avoiding volatile anesthetics and minimizing opioid use was not associated with improved survival.     

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.     

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.     

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.     

Real-time optoacoustic temperature determination on cell cultures during heat exposure: a feasibility study

Objective/Purpose: In order to study the effects of hyperthermia and other temperature-related effects on cells and tissues, determining the precise time/temperature course is crucial. Here we present a non-contact optoacoustic technique, which provides temperatures during heating of cultured cells with scalable temporal and spatial resolution.

Methods: A thulium laser (1.94?µm) with a maximum power of 15?W quickly and efficiently heats cells in a culture dish because of low penetration depth (1/e penetration depths of 78?µm) of the radiation in water. A repetitively Q-switched holmium laser (2.1?µm) is used simultaneously to probe temperatures at different locations in the dish by using the photoacoustic effect. Due to thermoelastic expansion of water, pressure waves are emitted and measured with an ultrasonic hydrophone at the side of the dish. The amplitudes of the waves are temperature dependent and can be used to calculate the temperature/time course at any location of probing.

Results: We measured temperatures of up to 55?°C with a heating power of 6?W after 10?s, and subsequent lateral temperature profiles over time. Within this profile, temperature fluctuations were found, likely owing to thermal convection and water circulation. By using cultured retinal pigment epithelial cells, it is shown that the probe laser pulses alone cause no biological damage, while immediate cell damage occurs when heating for 10?s at temperatures exceeding 45?°C.

Conclusions: This method shows great potential not only as a noninvasive, non-contact method to determine temperature/time responses of cells in culture, but also for complex tissue and other materials.