Unraveling the binding mechanisms of transglutaminase and substrate subjected to microwaves: Molecular docking and molecular dynamic simulations

Previous studies showed that transglutaminase (TGase) and microwaves acted synergistically to improve the functional properties of proteins. The mechanism behind this has yet to be elucidated. In this study, the phenomenon of microwaves enhancing TGase activity was experimentally validated. Molecular docking and molecular dynamics simulations revealed that moderate microwaves (105 and 108 V/m) increased the structural flexibility of TGase and promoted the orientation of the side chain carboxylate anion group on Asp255, driving the reaction forward. Also, TGase underwent partial transformation from α-helix to turns or coils at 105 and 108 V/m, exposing more residues in the active site and facilitating the binding of the substrate (CBZ-Gln-Gly) to TGase. However, 109 V/m microwaves completely destroyed the TGase structure, inactivating the enzyme. This study provides insights into the molecular mechanisms underlying the interactions between TGase and substrate subjected to microwaves, promoting the future applications of TGase and microwaves in food processing.

Microwave-enhanced thermal removal of organochlorine pesticide (chlordecone) from contaminated soils

Soil contamination with chlordecone, an organochlorine pesticide, is causing serious health problems, affecting crop production and local livestock valorization in the French West Indies. In-situ chemical reduction (ISCR) processes for soil remediation have shown promise but need improvement in terms of time, cost and effective treatment, particularly for andosol soil types. Our study shows that a 10-min microwave treatment significantly reduces chlordecone concentrations (50-90%) in contaminated andosol and nitisol soils. Dry andosol soils show the highest removal yields and reach a higher final temperature (350 °C). Microwave treatment is in all cases more effective or at least as effective as 60 min of conventional heating at a target temperature of 200 °C. The thermal response of andosol and nitisol to microwave exposure is different, as the former is likely to undergo thermal runaway, reaching high temperatures in a short time, resulting in highly efficient thermal removal of chlordecone. These results encourage further scale-up, particularly for the treatment of andosol soils due to their strong microwave response.

The relationship between ablation range and ablation energy in papillary thyroid microcarcinoma: a comparison between microwave ablation and laser ablation

OBJECTIVES

To study the relationship between the ablation range and applied energy of laser ablation (LA) and microwave ablation (MWA) in papillary thyroid microcarcinoma (PTMC).

METHODS

A total of 201 PTMC patients were treated with LA (n = 102) or MWA (n = 99) with single-applicator fixed ablation. The ablation range was determined by contrast-enhanced ultrasound. The ratios of ablation volume, longitudinal diameter, and orthogonal diameter to ablation energy (RAV/E, RAL/E, RAO/E) were analyzed and compared between MWA and LA. The effects of PTMC characteristics and Hashimoto's thyroiditis (HT) on ablation efficiency were evaluated by linear regression.

RESULTS

The RAV/E was 0.72 (0.65-0.84) mm3/J for MWA and 0.48 (0.39-0.54) mm3/J for LA. HT was significantly correlated with RAV/E of LA (coefficient =  - 0.367, p < 0.0001). RAL/E did not differ significantly between MWA and LA (MWA 0.026 mm/J, LA 0.025 mm/J; p = 0.957). However, MWA had a greater RAO/E than LA (MWA 0.014 mm/J, LA 0.012 mm/J; p < 0.0001). The plateau values of MWA and LA on the ablation orthogonal diameter were 10.7 mm and 8.69 mm, respectively.

CONCLUSIONS

MWA showed a higher RAV/E than LA. More intuitively, MWA had a better ablation performance than LA on the orthogonal axis rather than the longitudinal axis. Theoretically, MWA and LA could achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin. HT had a negative effect on LA but not on MWA.

CLINICAL RELEVANCE STATEMENT

This study establishes strong connections between ablation energy and ablation range in papillary thyroid microcarcinoma (PTMC) in vivo, possibly contributing to the supplementation of the PTMC Ablation Consensus or Guidelines and providing a scientific basis for choosing clinical ablation parameters in PTMC.

KEY POINTS

• Both microwave ablation (MWA) and laser ablation (LA) have excellent performance on the ablation longitudinal axis (easily exceeding 10 mm) for papillary thyroid microcarcinoma (PTMC). • MWA performed much better than LA on the ablation orthogonal axis. • MWA and LA are expected to achieve complete ablation of ≤ 6.70 mm and ≤ 4.69 mm PTMC separately by single-applicator fixed ablation considering a unilateral 2-mm safe margin.

Measurement accuracy of a microwave doppler sensor beneath the mattress as a continuous respiratory rate monitor: a method comparison study

PURPOSE

Non-contact continuous respiratory rate monitoring is preferred for early detection of patient deterioration. However, this technique is under development; a gold standard respiratory monitor has not been established. Therefore, this prospective observational method comparison study aimed to compare the measurement accuracy of a non-contact continuous respiratory rate monitor, a microwave Doppler sensor positioned beneath the mattress, with that of other monitors.

METHODS

The respiratory rate of intensive care unit patients was simultaneously measured using a microwave Doppler sensor, capnography, thoracic impedance pneumography, and a piezoelectric sensor beneath the mattress. Bias and 95% limits of agreement between the respiratory rate measured using capnography (standard reference) and that measured using the other three methods were calculated using Bland-Altman analysis for repeated measures. Clarke error grid (CEG) analysis evaluated the sensor's ability to assist in correct clinical decision-making.

RESULTS

Eighteen participants were included, and 2,307 data points were analyzed. The bias values (95% limits of agreement) of the microwave Doppler sensor, thoracic impedance pneumography, and piezoelectric sensor were 0.2 (- 4.8 to 5.2), 1.5 (- 4.4 to 7.4), and 0.4 (- 4.0 to 4.8) breaths per minute, respectively. Clinical decisions evaluated using CEG analyses were correct 98.1% of the time for the microwave Doppler sensor, which was similar to the performance of the other devices.

CONCLUSION

The microwave Doppler sensor had a small bias but relatively low precision, similar to other devices. In CEG analyses, the risk of each monitor leading to inadequate clinical decision-making was low.

TRIAL REGISTRATION NUMBER

UMIN000038900, February 1, 2020.

Novel and Advanced Ultrasound Techniques for Thyroid Thermal Ablation

Thyroid radiofrequency ablation and microwave ablation are widely adopted minimally invasive treatments for diverse thyroid conditions worldwide. Fundamental skills such as the trans-isthmic approach and the moving shot technique are crucial for performing thyroid ablation, and advanced techniques, including hydrodissection and vascular ablation, improve safety and efficacy and reduce complications. Given the learning curve associated with ultrasound-guided therapeutic procedures, operators need training and experience. While training models exist, limited attention has been given to ultrasound maneuvers in ablation needle manipulation. This article introduces two essential maneuvers, the zigzag moving technique and the alienate maneuver, while also reviewing the latest ultrasound techniques in thyroid ablation, contributing valuable insights into this evolving field.

Safety and local efficacy of computed tomography-guided microwave ablation for treating early-stage non-small cell lung cancer adjacent to bronchovascular bundles

OBJECTIVES

To retrospectively evaluate the safety and efficacy of computed tomography (CT)-guided percutaneous microwave ablation in treating early-stage non-small cell lung cancer (NSCLC) adjacent to bronchovascular bundles.

METHODS

Two hundred and thirty-one patients with early-stage NSCLC who underwent CT-guided microwave ablation of the tumor were included for analysis. Among these, 66 lesions were located adjacent to the bronchovascular bundle. Achievement of the specific ablation range (defined as the ablation zone encompassing the tumor and the adjacent vessel) was assessed after ablation. Complications and tumor progression after treatment were examined and compared between the bronchovascular bundle and non-bronchovascular bundle groups.

RESULTS

A total of 231 patients were included. Overall, 1-, 2-, and 3-year local progression-free survival (LPFS) was 77.4%, 70.5%, and 63.8%, respectively. Bronchovascular bundle proximity, pure-solid tumor, tumor size, and ablation margin < 5 mm were independent risk factors for local progression in multivariate analysis. In the bronchovascular bundle group, the 1-, 2- and 3-year LPFS rates were 63.0%, 50.7%, and 43.4%, respectively; vessel proximity and specific ablation range failure were independent risk factors for local progression. Overall survival in the entire cohort was 93.0% at 1 year, 76.1% at 2 years, and 55.0% at 3 years. The incidence of postoperative complications did not significantly differ between the two groups (p > 0.05). The most common complication was pneumothorax. Severe hemoptysis did not occur.

CONCLUSION

Tumor location near the bronchovascular bundles was a significant risk factor for local progression after microwave ablation. Achieving a specific ablation range may increase LPFS for these lesions.

CLINICAL RELEVANCE STATEMENT

Achieving the specific ablation range may improve local efficacy for early-stage non-small cell lung cancer located adjacent to the bronchovascular bundle.

KEY POINTS

• Local efficacy of percutaneous microwave ablation in treating early-stage non-small cell lung cancer was affected by bronchovascular bundle proximity. • Achieving the specific ablation range may improve local efficacy for lesions located adjacent to the bronchovascular bundle.

Safety and efficacy of CT-guided percutaneous microwave ablation for stage I non-small cell lung cancer in patients with comorbid idiopathic pulmonary fibrosis

OBJECTIVES

To evaluate the safety and efficacy of microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) in patients with idiopathic pulmonary fibrosis (IPF).

MATERIALS AND METHODS

A retrospective single-center cohort study was conducted in patients with clinical stage I NSCLC who underwent CT-guided MWA from Nov 2016 to Oct 2021. The patients were divided into the IPF group and the non-IPF group. The primary endpoints were 90-day adverse events and hospital length of stay (HLOS). The secondary endpoints included overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 107 patients (27 with IPF and 80 without IPF) were finally included for analysis. No procedure-related acute exacerbation of IPF or death occurred post-MWA. The rates of adverse events were similar between the groups (48.6% vs. 47.7%; p = 0.998). The incidence of grade 3 adverse events in the IPF group was higher than that in the non-IPF group without a significant difference (13.5% vs. 4.6%; p = 0.123). Median HLOS was 5 days in both groups without a significant difference (p = 0.078). The 1-year and 3-year OS were 85.2%/51.6% in the IPF group, and 97.5%/86.4% in the non-IPF group. The survival of patients with IPF was significantly poorer than the survival of patients without IPF (p < 0.001). There was no significant difference for PFS (p = 0.271).

CONCLUSION

MWA was feasible in the treatment of stage I NSCLC in patients with IPF. IPF had an adverse effect on the survival of stage I NSCLC treated with MWA.

CLINICAL RELEVANCE STATEMENT

CT-guided microwave ablation is a well-tolerated and effective potential alternative treatment for stage I non-small cell lung cancer in patients with idiopathic pulmonary fibrosis.

KEY POINTS

• Microwave ablation for stage I non-small cell lung cancer was well-tolerated without procedure-related acute exacerbation of idiopathic pulmonary fibrosis and death in patients with idiopathic pulmonary fibrosis. • No differences were observed in the incidence of adverse events between patients with idiopathic pulmonary fibrosis and those without idiopathic pulmonary fibrosis after microwave ablation (48.6% vs. 47.7%; p = 0.998). • The 1-year and 3-year overall survival rates (85.2%/51.6%) in the idiopathic pulmonary fibrosis group were worse than those in the non- idiopathic pulmonary fibrosis group (97.5%/86.4%) (p < 0.001).

Safety and efficacy of microwave ablation for symptomatic benign thyroid nodules in children

OBJECTIVE

To evaluate the efficacy and safety of microwave ablation (MWA) for the treatment of symptomatic benign thyroid nodules in children.

METHODS

A retrospective study of MWA for the treatment of 34 symptomatic benign thyroid nodules in 25 children was conducted. Volume reduction ratio (VRR), technique efficacy, symptom score, cosmetic score, and thyroid function were used to evaluate the efficacy of the technique. The associated complications and side effects were recorded.

RESULTS

The participants were followed for at least 6 months (median 12 months, range 6-48 months). After MWA treatment, the volumes of the targeted nodules decreased gradually (median volume 5.86 mL before MWA and 0.34 mL at the final follow-up assessment), the VRR achieved was up to 85.03% at the final follow-up assessment, and the technical efficacy at this time was 91.2%. The subjective and objective nodule-related symptoms were also ameliorated. The circulating hormone concentrations reflecting thyroid function remained within their normal ranges in all the participants after one month of follow-up. The procedure had no major complications.

CONCLUSIONS

MWA seems to be an effective and safe technique for the treatment of symptomatic benign thyroid nodules in pediatric patients.

CLINICAL RELEVANCE STATEMENT

Microwave ablation is a safe and effective method to treat symptomatic benign thyroid nodules in pediatric patients. This treatment may be selected if the patient or parents are not suitable or refuse to undergo surgery.

KEY POINTS

• Microwave ablation is effective in reducing the volume of benign thyroid nodules and ameliorating nodule-related symptoms in pediatric patients. • Microwave ablation is a safe method in children, with low complications. • Microwave ablation does not affect the circulating thyroid hormone concentrations of children.

Thermal ablation with configurable shapes: a comprehensive, automated model for bespoke tumor treatment

BACKGROUND

Malignant tumors routinely present with irregular shapes and complex configurations. The lack of customization to individual tumor shapes and standardization of procedures limits the success and application of thermal ablation.

METHODS

We introduced an automated treatment model consisting of (i) trajectory and ablation profile planning, (ii) ablation probe insertion, (iii) dynamic energy delivery (including robotically driven control of the energy source power and location over time, according to a treatment plan bespoke to the tumor shape), and (iv) quantitative ablation margin verification. We used a microwave ablation system and a liver phantom (acrylamide polymer with a thermochromic ink) to mimic coagulation and measure the ablation volume. We estimated the ablation width as a function of power and velocity following a probabilistic model. Four representative shapes of liver tumors < 5 cm were selected from two publicly available databases. The ablated specimens were cut along the ablation probe axis and photographed. The shape of the ablated volume was extracted using a color-based segmentation method.

RESULTS

The uncertainty (standard deviation) of the ablation width increased with increasing power by ± 0.03 mm (95% credible interval [0.02, 0.043]) per watt increase in power and by ± 0.85 mm (95% credible interval [0, 2.5]) per mm/s increase in velocity. Continuous ablation along a straight-line trajectory resulted in elongated rotationally symmetric ablation shapes. Simultaneous regulation of the power and/or translation velocity allowed to modulate the ablation width at specific locations.

CONCLUSIONS

This study offers the proof-of-principle of the dynamic energy delivery system using ablation shapes from clinical cases of malignant liver tumors.

RELEVANCE STATEMENT

The proposed automated treatment model could favor the customization and standardization of thermal ablation for complex tumor shapes.

KEY POINTS

• Current thermal ablation systems are limited to ellipsoidal or spherical shapes. • Dynamic energy delivery produces elongated rotationally symmetric ablation shapes with varying widths. • For complex tumor shapes, multiple customized ablation shapes could be combined.

Cone-beam computed tomography image-guided percutaneous microwave ablation for lung nodules in a hybrid operating room: an initial experience

OBJECTIVES

The experience of thermal ablation of lung lesions is limited, especially performing the procedure under localisation by cone-beam CT in the hybrid operation room (HOR). Here, we present the experience of microwave ablation (MWA) of lung nodules in the HOR.

METHODS

We reviewed patients who underwent image-guide percutaneous MWA for lung nodules in the HOR under general anaesthesia between July 2020 and July 2022. The workflow in the HOR including the pre-procedure preparation, anaesthesia consideration, operation methods, and postoperative care was clearly described.

RESULTS

Forty lesions in 33 patients who underwent MWA under general anaesthesia (GA) in the HOR were analysed. Twenty-seven patients had a single pulmonary nodule, and the remaining six patients had multiple nodules. The median procedure time was 41.0 min, and the median ablation time per lesion was 6.75 min. The median global operation room time was 115.0 min. The median total dose area product was 14881 μGym2. The median ablation volume was 111.6 cm3. All patients were discharged from the hospital with a median postoperative stay of 1 day. Four patients had pneumothorax, two patients had pleural effusion during the first month of outpatient follow-up, and one patient reported intercostal neuralgia during the 3-month follow-up.

CONCLUSIONS

Thermal ablation of pulmonary nodules under GA in the HOR can be performed safely and efficiently if we follow the workflow provided. The procedure provides an alternative to managing pulmonary nodules in patients.

CLINICAL RELEVANCE STATEMENT

Thermal ablation of pulmonary nodules under GA in the HOR can be performed safely and efficiently if the provided workflow is followed.

KEY POINTS

• We tested the feasibility of microwave ablation of lung lesions performed in a hybrid operating room. • To this end, we provide a description of microwave ablation of the lung under cone-beam CT localisation. • We describe a workflow by which ablation of the pulmonary nodule can be performed safely under general anaesthesia.

Computed tomography-guided percutaneous microwave ablation for renal cell carcinoma: evaluating the performance of nephrometry scores

OBJECTIVES

The purpose of the current study is to evaluate the performance of RENAL and mRENAL scores, in the prediction of oncological outcomes in patients treated with microwave ablation (MWA) for (T1) renal cell carcinomas (RCC).

METHODS

Institutional database retrospective research identified 76 patients with a biopsy-proven solitary T1a (84%) or T1b (16%) RCC; all patients underwent CT-guided MWA ablation. Tumor complexity was reviewed by calculating RENAL and mRENAL scores.

RESULTS

The majority of the lesions were exophytic (82.9%), with > 7 mm nearness to the collecting system (53.9%), located posteriorly (73.6%), and lower to polar lines (61.8%). Mean RENAL and mRENAL scores were 5.7 (SD = 1.9) and 6.1 (SD = 2.1) respectively. Progression rates were significantly higher with greater tumor size (> 4 cm), with < 4 mm nearness to the collecting system, for tumors crossing a polar line and with the anterior location. None of the above was associated with complications. RENAL and mRENAL scores were significantly higher in patients with incomplete ablation. The ROC analysis showed the significant prognostic ability of both RENAL and mRENAL scores for progression. In both scores, the optimal cut-off point was 6.5. Univariate Cox regression analysis for progression showed a hazard ratio of 7.73 for the RENAL score and 7.48 for the mRENAL score.

CONCLUSION

The results of the present study show that the risk of progression was higher in patients with RENAL and mRENAL score of > 6.5, in T1b tumors, close to the collective system (< 4 mm), crossing polar lines and anterior location.

CLINICAL RELEVANCE STATEMENT

CT-guided percutaneous MWA is a safe and effective technique for the treatment of T1a renal cell carcinomas. Different morphometric parameters of RCC tumors including RENAL and mRENAL score > 6.5, size, proximity to the collecting system, and crossing of polar lines impact the efficacy of MWA and progression survival rates.

KEY POINTS

• The risk of progression is higher in patients with RENAL and mRENAL score > 6.5, in T1b tumors, close to the collective system (< 4 mm), crossing polar lines and anterior location. • The significant prognostic ability of the mRENAL score for progression was higher than the respective of the RENAL score. • Complications were not associated with any of the above factors.

Microwave ablation versus laparoscopic resection for hepatocellular carcinoma in patients with clinically significant portal hypertension: a propensity score-matched study of postoperative liver decompensation

OBJECTIVES

The study of postoperative liver decompensation after microwave ablation (MWA) for hepatocellular carcinoma (HCC) in patients with clinically significant portal hypertension (CSPH) is still lacking. The purpose of the present study was to compare the postoperative liver decompensation after MWA and laparoscopic resection (LR) for HCC in patients with CSPH.

METHODS

The present retrospective study enrolled 222 HCC patients with CSPH who underwent MWA (n = 67) or LR (n = 155). Postoperative liver decompensation, complications, postoperative hospital stays, and overall survival were analyzed. Factors associated with postoperative liver decompensation were identified.

RESULTS

After propensity score matching, the postoperative liver decompensation rate was significantly lower in the MWA group than that in the LR group (15.5% versus 32.8%, p = 0.030). The multivariable regression analysis identified that type of treatment (MWA vs. LR, odds ratio [OR] 0.44; 95% confidence interval [CI], 0.21-0.91; p = 0.026) and Child-Pugh B (OR, 2.86; 95% CI, 1.24-6.61; p = 0.014) were independent predictors for postoperative liver decompensation. The rate of complications for patients in the MWA group was significantly lower than that in the LR group (p < 0.001). And MWA showed shorter postoperative hospital stays than LR (3 days vs. 6 days, p < 0.001). Overall survival rate between the two groups was not significantly different (p = 0.163).

CONCLUSION

Compared with laparoscopic resection, microwave ablation has a lower rate of postoperative liver decompensation and might be a better option for HCC patients with CSPH.

CLINICAL RELEVANCE STATEMENT

Microwave ablation exhibited a lower incidence of postoperative liver decompensation in comparison to laparoscopic resection, thereby conferring greater advantages to hepatocellular carcinoma patients with clinically significant portal hypertension.

KEY POINTS

•Postoperative liver decompensation rate after microwave ablation was lower than that of laparoscopic resection for hepatocellular carcinoma in patients with clinically significant portal hypertension. •Microwave ablation showed shorter postoperative hospital stays than laparoscopic resection. •Microwave ablation had fewer complications than laparoscopic resection.

Effectiveness of treating menorrhagia using microwave endometrial ablation at a frequency of 2.45 GHz

BACKGROUND

Microwave endometrial ablation (MEA) is a minimally invasive treatment for menorrhagia. It has been covered by the national insurance in Japan since April 2012, and its demand has been increasing as the importance of women's health has advanced in society.

AIM

To examine the efficacy of MEA as a treatment option for menorrhagia.

METHODS

In this study, we retrospectively analyzed 76 patients who underwent MEA between January 2016 and March 2020 in our department. MEA was performed in the lithotomy position, under general anesthesia, and with transabdominal ultrasound guidance, including the entire endometrial circumference while confirming endometrial coagulation. The Microtaze AFM-712 and the Sounding Applicator CSA-40CBL-1006200C were used for MEA, and the endometrium was ablated using a Microtaze output of 70 W and coagulation energization time of 50 s per cycle. The visual analog scale (VAS) was used to evaluate menorrhagia, menstrual pain, and treatment satisfaction. Additionally, the hemoglobin (Hb) levels before and after MEA and associated complications were investigated.

RESULTS

The average age of the patients was 44.8 ± 4.0 years. While 14 patients had functional menorrhagia, 62 had organic menorrhagia, of whom 14 had endometrial polyps, 40 had uterine fibroids, and 8 had adenomyosis. The VAS score before MEA and 3 and 6 mo after the procedure were 10, 1.3 ± 1.3, and 1.3 ± 1.3, respectively, for menorrhagia and 10, 1.3 ± 1.8, and 1.3 ± 1.8, respectively, for menstrual pain, both showing improvements (P < 0.001). The MEA Hb level significantly improved from 9.2 ± 4.2 g/dL before MEA to 13.4 ± 1.2 g/dL after MEA (P = 0.003). Treatment satisfaction was high, with a VAS score of 9.6 ± 0.7. Endometritis was observed in one patient after surgery and was treated with antibiotics.

CONCLUSION

MEA is a safe and effective treatment for menorrhagia.

Risk of persistent air leaks following percutaneous cryoablation and microwave ablation of peripheral lung tumors

OBJECTIVES

To compare the incidence of persistent air leak (PAL) following cryoablation vs MWA of lung tumors when the ablation zone includes the pleura.

METHODS

This bi-institutional retrospective cohort study evaluated consecutive peripheral lung tumors treated with cryoablation or MWA from 2006 to 2021. PAL was defined as an air leak for more than 24 h after chest tube placement or an enlarging postprocedural pneumothorax requiring chest tube placement. The pleural area included by the ablation zone was quantified on CT using semi-automated segmentation. PAL incidence was compared between ablation modalities and a parsimonious multivariable model was developed to assess the odds of PAL using generalized estimating equations and purposeful selection of predefined covariates. Time-to-local tumor progression (LTP) was compared between ablation modalities using Fine-Gray models, with death as a competing risk.

RESULTS

In total, 260 tumors (mean diameter, 13.1 mm ± 7.4; mean distance to pleura, 3.6 mm ± 5.2) in 116 patients (mean age, 61.1 years ± 15.3; 60 women) and 173 sessions (112 cryoablations, 61 MWA) were included. PAL occurred after 25/173 (15%) sessions. The incidence was significantly lower following cryoablation compared to MWA (10 [9%] vs 15 [25%]; p = .006). The odds of PAL adjusted for the number of treated tumors per session were 67% lower following cryoablation (odds ratio = 0.33 [95% CI, 0.14-0.82]; p = .02) vs MWA. There was no significant difference in time-to-LTP between ablation modalities (p = .36).

CONCLUSIONS

Cryoablation of peripheral lung tumors bears a lower risk of PAL compared to MWA when the ablation zone includes the pleura, without adversely affecting time-to-LTP.

KEY POINTS

• The incidence of persistent air leaks after percutaneous ablation of peripheral lung tumors was lower following cryoablation compared to microwave ablation (9% vs 25%; p = .006). • The mean chest tube dwell time was 54% shorter following cryoablation compared to MWA (p = .04). • Local tumor progression did not differ between lung tumors treated with percutaneous cryoablation compared to microwave ablation (p = .36).

Ultrasound and microwave techniques for assisting ageing on lees of red wines

Ageing on lees is a slow process that carries microbiological and economic risks in the wineries. This study evaluates the possibility of enhancing the extraction of different compounds from the lees, using combined strategies, such as ultrasound (US) or microwaves (MW) and the addition of inactive dry yeasts (IDY), to reduce the lees ageing time. The complete chemical analysis of the wine was done, amino acids, polysaccharides, colour and volatile compounds, together with the sensory analysis. The combined treatments increased the release of total polysaccharides, mannoproteins and total monosaccharides in the wines, and some amino acids like proline. However, wines treated with US and MW, with and without lees, showed a decrease in tannins and colour intensity, and in some volatile compounds like fatty acid esters, acetates and terpenes. The wines treated with IDY and MW were the best valued for their floral and red berry flavours and less astringency.

Violation of molecular structure of intracellular water as a possible cause of carcinogenesis and its suppression by microwave radiation(hypothesis)

The manuscript discusses a possible hypothesis about the transformation of healthy cells into cancer cells as a result of modification of the molecular structure of intracellular water from normal hexagonal to abnormal cubic phase (which may be caused by radiation, chemical, viral, mechanical and microbiological factors) and the possibility of returning to its original state under the influence of microwave radiation. The authors are not aware of any relevant experimental and theoretical support for this hypothesis in other literature.Our hypothesis is based on a completely unexpected experimental fact that we have received. It turned out that the radio spectra of cancer-affected tissues and the cubic phase of water are identical which confirms that these tissues really contain a cubic phase of water. It should be expected that the use of radiation of "therapeutic" frequencies may lead to regression of tumor growth. This assumption is based on another experimental fact confirming the possibility of the transition of the molecular structure of water from the cubic phase to the hexagonal phase (which is contained in healthy tissues) when irradiated with therapeutic frequencies.The conducted experiments demonstrate the real possibilities of structural-phase and spectral mutual transformations of the water medium under the influence of extremely low intensity flows of microwaves at "therapeutic" frequencies of 1000 MHz and 985 MHz or "pathologic" frequencies of 990 MHz and 51 GHz. The aim of this study was to experimentally verify a possible causal relationship between the violation of the molecular structure of intracellular water in healthy tissues and carcinogenesis.

Microwave Therapy for Frostbite Management: A Case Series

Microwave body tightening and contouring is a common and efficient cosmetic medical procedure. The current study presents preliminary data about microwave treatment for body contouring where an innovative and unexpected benefit on frostbites was shown. This is a case series on two patients with frostbite treated with microwave therapy. The participants received the treatment for five sessions at 20-day intervals, including the beginning of the study. In addition to being satisfied with the treatment of their skin imperfections, the patients noticed a remarkable and progressive improvement in frostbite on their limbs. Both patients experienced a significant improvement in skin sensation and appearance and no side effects were observed. Our findings confirmed the safety and efficacy of microwave therapy in treating cellulite and skin laxity but rather a positively effect and a significant improvement in the treatment of frostbite as a secondary intention.

Non-thermal disruption of β-adrenergic receptor-activated Ca2+ signalling and apoptosis in human ES-derived cardiomyocytes by microwave electric fields at 2.4 GHz

The ubiquity of wireless electronic-device connectivity has seen microwaves emerge as one of the fastest growing forms of electromagnetic exposure. A growing evidence-base refutes the claim that wireless technologies pose no risk to human health at current safety levels designed to limit thermal (heating) effects. The potential impact of non-thermal effects of microwave exposure, especially in electrically-excitable tissues (e.g., heart), remains controversial. We exposed human embryonic stem-cell derived cardiomyocytes (CM), under baseline and beta-adrenergic receptor (β-AR)-stimulated conditions, to microwaves at 2.4 GHz, a frequency used extensively in wireless communication (e.g., 4G, Bluetooth™ and WiFi). To control for any effect of sample heating, experiments were done in CM subjected to matched rates of direct heating or CM maintained at 37 °C. Detailed profiling of the temporal and amplitude features of Ca²⁺ signalling in CM under these experimental conditions was reconciled with the extent and spatial clustering of apoptosis. The data show that exposure of CM to 2.4 GHz EMF eliminated the normal Ca²⁺ signalling response to β-AR stimulation and provoked spatially-clustered apoptosis. This is first evidence that non-thermal effects of 2.4 GHz microwaves might have profound effects on human CM function, responsiveness to activation, and survival.

Value of CEUS combined with feeding artery ablation in the microwave ablation of large solid benign thyroid nodules

OBJECTIVES

To investigate the value of contrast-enhanced ultrasound (CEUS) combined with feeding artery ablation in the microwave ablation (MWA) of large solid benign thyroid nodules (LSBTNs) with a diameter ≥ 4 cm.

METHODS

We retrospectively analyzed 122 patients with LSBTN ≥ 4 cm in diameter treated with MWA. During evaluations before and after MWA, 53 patients who underwent conventional ultrasound examination were classified as the routine group, and 69 patients who underwent CEUS combined with feeding artery ablation were classified as the union group. The differences in ablation energy required per milliliter (AERPM), complication rate, regrowth rate, and volume reduction rate (VRR) were compared between the two groups.

RESULTS

The AERPM of the union group was significantly less than that of the routine group (956.3 ± 38.5 J/mL vs. 1025.9 ± 121.5 J/mL, p < 0.001). The complication rate of the routine group was significantly higher than that of the union group (13.2% vs. 2.9%, p = 0.031). The regrowth rate of the routine group (22.6%, 12/53) was significantly higher than that of the union group (7.2%, 5/69) (p = 0.015). At the 1st, 3rd, 6th, 12th, 18th, and 24th month after ablation, the mean VRRs of the routine group were significantly less than those of the union group, with p values of < 0.001, < 0.001, 0.002, 0.007, 0.013, and < 0.001, respectively.

CONCLUSIONS

The application of CEUS combined with feeding artery ablation in the MWA of LSBTNs is helpful to reduce the regrowth rate, improve the ablation efficiency, and reduce bleeding.

KEY POINTS

• CEUS combined with feeding artery ablation in MWA of LSBTNs is helpful to reduce regrowth rate. • CEUS combined with feeding artery ablation can help improve ablation efficiency than conventional ultrasound in LSBTNs. • CEUS combined with feeding artery ablation helps reduce the incidence of bleeding during MWA.

Microwave ablation versus surgical resection for subcapsular hepatocellular carcinoma: a propensity score-matched study of long-term therapeutic outcomes

OBJECTIVES

The therapeutic efficacy of microwave ablation (MWA) for subcapsular hepatocellular carcinoma (HCC) has not been well characterized. We aimed to compare the long-term outcomes of MWA and surgical resection (SR) in patients with subcapsular HCC.

METHODS

This retrospective study comprised 321 patients with subcapsular HCC meeting the Milan criteria who received MWA (n = 99) or SR (n = 222). Local tumor progression (LTP), overall survival (OS), and disease-free survival (DFS) were analyzed using propensity score matching (PSM) to compare the therapeutic efficacy.

RESULTS

In the total cohort, there were no significant differences in 5-year LTP rates (14.0% vs. 8.9%, p = 0.12), OS rates (70.7% vs. 73.2%, p = 0.63), and DFS rates (38.3% vs. 41.2%, p = 0.22) between the MWA and SR groups. After PSM, the cumulative LTP rates at 1, 3, and 5 years were 9.7%, 14.0%, and 16.4% in the MWA group (n = 84) and 7.2%, 8.6%, and 10.6% in the SR group (n = 84), respectively, with no significant difference (p = 0.31). Neither corresponding OS rates (96.4%, 84.8%, and 73.0% vs. 95.2%, 85.5%, and 72.1%, p = 0.89) nor DFS rates (76.0%, 52.6%, and 38.1% vs. 76.2%, 44.7%, and 32.3%, p = 0.43) were significantly different between the MWA and SR groups. Whereas MWA obtained fewer complications for both cohorts (both p < 0.05).

CONCLUSION

MWA showed comparable long-term therapeutic outcomes to SR, and it might be an alternative curative option for subcapsular HCC within the Milan criteria.

KEY POINTS

• Microwave ablation showed comparable local tumor progression, overall survival, and disease-free survival to surgical resection for subcapsular hepatocellular carcinoma meeting the Milan criteria. • Microwave ablation obtained fewer complications and shorter postoperative hospital stay.

A comparison study of microwave ablation vs. histotripsy for focal liver treatments in a swine model

OBJECTIVE

To compare the acute and chronic safety and treatment effects of non-invasive hepatic histotripsy vs. percutaneous microwave (MW) ablation in a healthy porcine model.

METHODS

This was a dual-arm study in which each animal (n = 14) received either a single hepatic microwave (n = 6) or histotripsy (n = 6 single treatment; n = 2 double treatment) under ultrasound guidance. The goal was to create 2.5-3.0 cm short-axis treatments in similar locations across modalities. Animals were survived for 1 month with contrast-enhanced CT imaging on days 0, 2, 7, 14, and 28. On day 28, necropsy and histopathology were performed.

RESULTS

All procedures were well-tolerated. MW ablation zones were longer and more oblong, but equivalent in the short axes to histotripsy zones on immediate post-procedure CT (p < 0.001 and p = 0.45, respectively). Overall, MW volumes were larger (21.4 cm³ vs. 13.4 cm³; p = 0.001) and histotripsy treatment zones were more spherical (p = 0.007). Histotripsy zones were close to the prescribed size (p < 0.001). Over the study period, histotripsy treatment zones decreased in volume while microwave ablation zones slightly increased (-83% vs. +17%, p = 0.001). There were several imaging-only findings: Branch portal vein thrombus with both histotripsy (7/8) and MW (6/6), hematoma in 2/6 MW only, and a gallbladder injury in 1/6 MW animals. The ablation zones demonstrated complete cellular destruction for both modalities.

CONCLUSION

Histotripsy was associated with more spherical treatments, fewer biliary complications, and greater treatment zone involution. Hepatic MW and histotripsy treatment in a normal porcine model appear at least equally effective for creating treatment zones with a similar safety profile.

KEY POINTS

• Microwave ablation and histotripsy for liver treatment in a healthy porcine model yield equivalent procedural tolerance and cellular destruction. • Histotripsy was associated with more spherical treatments, fewer biliary complications, and greater treatment zone involution over the 28-day follow-up period. • These findings confirm the safety and efficacy of hepatic histotripsy and support the pursuit of clinical trials to further evaluate the translatability of these results.

Microwave ablation without subsequent lumpectomy versus breast-conserving surgery for early breast cancer: a propensity score matching study

PURPOSE

To compare the efficacy of ultrasound-guided percutaneous microwave ablation (MWA) without subsequent lumpectomy and breast-conserving surgery (BCS) in patients with early breast cancer (BC).

MATERIALS AND METHODS

This retrospective cohort study enrolled 106 patients with early BC (T_0/1/2 N_0/1 M₀) treated by MWA (n = 21) or BCS (n = 85) from October 2014 to December 2020. Propensity score matching (PSM) was performed to balance the baseline characteristics between MWA and BCS groups. The tumor progression, overall survival (OS), disease-specific survival (DSS), complications, and cosmetic results were compared.

RESULTS

After PSM, there were 21 patients with balanced baseline characteristics in each group. After a median follow-up of 43 months (range, 15-89 months), there was no significant difference in tumor progression (10% vs 2%, p = 0.18), OS (96% vs 99%, p = 0.36), DSS (100% vs 99%, p > 0.99), and complications (0% vs 19%, p = 0.58). The operation time of MWA was shorter (60 min vs 101 min, p < 0.001) than that of BCS. For the management of metastatic lymph nodes, five (5/21, 24%) patients with six metastatic nodes underwent ablation in the MWA group and three patients (3/21, 14%) with six metastatic nodes underwent axillary lymph node dissection in the BCS group. All the patients in the MWA group reported excellent cosmetic results, but 29% of BCS patients expressed dissatisfaction with breast asymmetry (10%) and scar formation (19%) (p < 0.001).

CONCLUSION

This pilot study indicated that in selected early BC patients, microwave ablation without subsequent lumpectomy had comparable tumor control effect with breast-conserving surgery and better cosmetic results at an intermediate follow-up.HighlightsMWA without subsequent lumpectomy has a comparable interim survival effect and better cosmetic results as BCS in the treatment of selected early breast cancer.MWA has the potential to be a viable and promising therapeutic option for breast cancer patients reluctant or intolerant to surgery with the advantage of minimal invasion.

Effectiveness of microwave endometrial ablation combined with hysteroscopic transcervical resection in treating submucous uterine myomas

BACKGROUND

Hypermenorrhea is characterized by excessive menstrual bleeding that causes severe anemia and interferes with everyday life. This condition can restrict women’s social activities and decrease their quality of life. Microwave endometrial ablation (MEA) using a 2.45-GHz energy source is a minimally invasive alternative to conventional hysterectomy for treating hypermenorrhea that is resistant to conservative treatment, triggered by systemic disease or medications, or caused by uterine myomas and fibrosis. The popularity of MEA has increased worldwide. Although MEA can safely and effectively treat submucous myomas, some patients may still experience recurrent hypermenorrhea postoperatively and may require additional treatment.

AIM

To investigate the efficacy of MEA combined with transcervical resection (TCR).

METHODS

Participants underwent cervical and endometrial evaluations. Magnetic resonance imaging and hysteroscopy were performed to evaluate the size and location of the myomas. TCR was performed before MEA using a hystero-resectoscope. MEA was performed using transabdominal ultrasound. The variables included operation time, number of ablation cycles, length of hospital stay, and visual analog scale cores for hypermenorrhea, dysmenorrhea, and treatment satisfaction at 3 and 6 mo postoperatively. The postoperative incidence of amenorrhea, changes in hemoglobin concentrations, and MEA-related complications were evaluated.

RESULTS

A total of 34 women underwent a combination of MEA and TCR during the study period. Two patients were excluded from the study as their histopathological tests identified uterine malignancies (uterine sarcoma and endometrial cancer). The 32 eligible women (6 nulliparous, 26 multiparous) had a mean age of 45.2 ± 4.3 years (range: 36–52 years). Patients reported very severe hypermenorrhea (10/10 points on the visual analog scale) before the procedure. However, after the procedure, the hypermenorrhea scores decreased to 1.2 ± 1.3 and 0.9 ± 1.3 at 3 and 6 mo, respectively (P < 0.001). The mean follow-up duration was 33.8 ± 16.8 mo. Although 10 women (31.3%) developed amenorrhea during this period, none experienced a recurrence of hypermenorrhea. No surgical complications were observed.

CONCLUSION

Reducing the size of uterine myomas by combining MEA and TCR can safely and effectively treat hypermenorrhea in patients with submucous myomas.

Synthesis of new Spiropyrazole derivatives under microwaves irradiation and docking study for inhibition the microbes and COVID-19

Synthesis of a new series of spiropyrazole derivatives using microwaves irradiation with high yield in minutes was achieved through a cycloaddition reaction of nitrile imines and arylidenes of 5-bromo-indan-1-one. The structure of the new spiropyrazoles was assured based on their available spectral analyses and the comparison of the extracted data with the literature reports. Molecular docking simulations of all new synthesized spiropyrazole derivatives into leucyl-tRNA synthetase editing domain of Candida albicans (Pdb: 2WFC) indicated that about seven spiropyrazole derivatives can fit deeply in the active site via the formation of stable complexes. In addition, the docking study was utilized to tested the ability of these spiropyrazoles to inhibit COVID-19 through the interaction with COVID-19 main protease (Pdb: 6LU7). The results were surprising which revealed high docking score ranging from -7.764 to -5.9464 kcal/mol. Moreover, the nitrogen atom of pyrazole, Br atom and the C=O group of indanone are essential parts in the binding mode of almost the active derivatives. The results of the docking study are a glimmer of hope to complete the study on these compounds and examine them in the laboratory to ensure their effectiveness as antimicrobials and antiviral, especially Covid-19. Moreover, pharmacokinetics and physicochemical properties were studied.

Influence of water saturation and soil properties on the removal of organic pollutants using microwave heating

Properties of fluids and media, such as soil moisture, may play a significant role in the absorption of microwave and heat distribution during the remediation of soil contaminated with volatile and semi-volatile compounds. Previous studies have been performed on soil samples placed inside a microwave oven cavity in a reactor far from the waveguide outlet or directly inside the metal waveguides. These conditions are far from in situ applications where the unsaturated soil is directly exposed to microwaves through the antenna slots. The objective of this study was therefore to understand better how soil temperature and pollutant recovery change during microwave and conduction heating and how soil properties, liquid type, and saturation influence that. We developed a unique experimental setup that consists of a splittable soil column inserted inside the cavity of a modified domestic microwave oven (power 1000 W and frequency 2.45 GHz) so that the soil surface is in direct contact with the radiated microwaves. Experiments with electrical resistance heating using the same column but with a modified design were conducted for comparison. We used three types of soils spanning fine, medium, and coarse sands, and two semi-volatile pollutants (xylene and diesel fuel). The pollutants and water of different volumes (12% and 25%) were mixed with soils to make the artificially contaminated soils. Temperature values were measured at different points along the sand-packed column using fiber-based optical thermocouples. We evaluated treatment efficiency in space (soil analysis) and time (outlet phase decantation). The experimental results show that microwave heating technology is optimal for water saturation of around 12%, which gives the best compromise between the overall dielectric properties and allows rapid and efficient heating. The temperature increases fast at the beginning of the microwave heating and stabilizes because of the latent heat of the water and pollutant vaporization and then increases again but slowly for dry soil conditions. A maximum temperature of 170 °C was achieved after 140 min of microwave heating. The type of soil and pollution can drastically affect remediation efficiency through mechanical mechanisms (because of a pressure increase) in addition to physical mechanisms (evaporation) for pollutant removal. The removal efficiencies, using the outlet fluids decantation, were 67%, 73%, and 75% for fine, medium, and coarse sand, respectively, for the applied heating time. We found that microwave heating works better in coarser sand where classical conduction heating usually failed. Comparing the two types of heating (microwave and conductive heating) under the same conditions highlights that the use of microwaves makes it possible to reach very high temperatures in a shorter time than with thermal conduction heating.

Computer model of a spectrum analyzer for a virtual laboratory: development and introduction to the educational process

The worldwide COVID-19 pandemic has changed the development plans of every country. Instead, governments had to constantly deal with ever-emerging issues in healthcare, education, economics and industry. As a result, there has been an accelerated introduction of digitalization in these spheres. Thus, an increasing number of people have started using electronic services that have improved their digital literacy. This feature has had a positive impact on society and helped to create new interaction tools between populations and governments, students and institutions, customers and companies. The article aims to analyze how studying radio electronics can be improved by involving new tools and how they can be applied in distance learning. This work presents the results of the development and application of a virtual radio signal simulation in the educational process in the form of a laboratory practicum. Working on this approach required specific research in the field; the foreign experience was observed and studied. The review allowed us to find out how digitalization and the application of digital tools affect the behaviour, cognition, and overall performance of students during the pandemic. The authors conducted a questionnaire among students to evaluate the features of the virtual laboratory work and their effect on the educational process. The results analyzed are given in the article. They showed that students highly appreciate the introduction of such tools in learning. Moreover, like the entire laboratory, the proposed model can be used in the educational process offline and with distance learning. Finally, the article describes the experience and results of the software package's development and integration for the spectrum analyzer's computer model and virtual laboratory work using the MS VS environment in C ++. The results of the conducted work demonstrate the versatility of the proposed approach, its positive impact on the educational process, high potential in the other spheres.

Why electrohypersensitivity and related symptoms are caused by non-ionizing man-made electromagnetic fields: An overview and medical assessment

Much of the controversy over the cause of electrohypersensitivity (EHS) lies in the absence of recognized clinical and biological criteria for a widely accepted diagnosis. However, there are presently sufficient data for EHS to be acknowledged as a distinctly well-defined and objectively characterized neurologic pathological disorder. Because we have shown that 1) EHS is frequently associated with multiple chemical sensitivity (MCS) in EHS patients, and 2) that both individualized disorders share a common pathophysiological mechanism for symptom occurrence; it appears that EHS and MCS can be identified as a unique neurologic syndrome, regardless their causal origin. In this overview we distinguish the etiology of EHS itself from the environmental causes that trigger pathophysiological changes and clinical symptoms after EHS has occurred. Contrary to present scientifically unfounded claims, we indubitably refute the hypothesis of a nocebo effect to explain the genesis of EHS and its presentation. We as well refute the erroneous concept that EHS could be reduced to a vague and unproven "functional impairment". To the contrary, we show here there are objective pathophysiological changes and health effects induced by electromagnetic field (EMF) exposure in EHS patients and most of all in healthy subjects, meaning that excessive non-thermal anthropogenic EMFs are strongly noxious for health. In this overview and medical assessment we focus on the effects of extremely low frequencies, wireless communications radiofrequencies and microwaves EMF. We discuss how to better define and characterize EHS. Taken into consideration the WHO proposed causality criteria, we show that EHS is in fact causally associated with increased exposure to man-made EMF, and in some cases to marketed environmental chemicals. We therefore appeal to all governments and international health institutions, particularly the WHO, to urgently consider the growing EHS-associated pandemic plague, and to acknowledge EHS as a mainly new real EMF causally-related pathology.

Potential use of microwave technology in dermatology

BACKGROUND

Microwaves are used in medicine for diagnostics, and treatment of cancer. Recently, novel microwave devices (Swift^®, Emblation Ltd, UK and miraDry^®, Miramar Labs Inc., CA) have been cleared by the FDA and Health Canada for various dermatological conditions.

OBJECTIVE AND METHODS

To review the dermatological use of microwave-based treatments (plantar warts, corns, actinic keratosis, dermatophytosis, axillary hyperhidrosis, osmidrosis, and hidradenitis suppurativa). Clinical trials, case reports, or in vitro studies for each condition are summarized.

RESULTS AND CONCLUSION

Microwaves are a promising alternative therapy for cutaneous warts, actinic keratosis, axillary hyperhidrosis, and osmidrosis, with favorable safety profiles. However, patients with hidradenitis suppurativa have had negative clinical outcomes. Limited treatment of corns showed good pain reduction but did not resolve hyperkeratosis. A preliminary in vitro study indicated that microwave treatment inhibits the growth of T. rubrum. We present the first case of toenail onychomycosis successfully treated with microwaves. Despite the advancements in the use of microwaves, the mechanism of action in non-ablative treatment is not well understood; further research is needed. More high-quality randomized clinical trials with larger groups and long follow-up periods are also required to evaluate the clinical benefits and possible adverse effects of microwaves in treating dermatological conditions.

Response to "Non-thermal microwave effects: Conceptual and methodological problems"

The objective of this response letter is to expose the reader of Food Chemistry to the most recent advances and discussions about non-thermal effects of microwaves on microorganisms and enzymes. Although these effects showed to be too subtle for any practical use in food processing, experimental and molecular dynamics studies bring evidences that electric fields at low frequencies or with high intensity can have non-thermal effects, such as activity changes in enzymes during ohmic processing or electroporation of cells in pulsed electric field processing. This brief review broadens the scope of this controversial topic to show that innovative experiments and simulations are collaborating with the advance of emerging electro technologies in food processing. .

Microwave irradiation assisted intensive and quick delignification of lignocellulosic biomass, and confirmation by spectral, morphological and crystallinity characterization

The purpose of this work was to use a microwave-assisted technique to improve and accelerate lignin removal from rice straw biomass. Using a Box-Behnken experimental design, the effect of four critical process parameters, viz. microwave power (480-800 W), irradiation time (4-12 min), bleaching solution concentration (0.4-3.0 %), and bleaching time (1-5 h) on the delignification (%) was investigated, and the process was optimised using response surface methodology. The experimental data best fitted a quadratic model with an R² of 0.9964. The optimized value of process parameters (in aforementioned sequence) was found to be 671 W, 8.66 min, 2.67 %, and 1 h respectively, for the best delignification of 93.51 percent.The absence of lignin peaks (1516 and 1739 cm^-1) was corroborated by deconstructed morphological structure and higher crystallinity in the optimised delignified sample (53.7 %).

The effect of long-term radiofrequency exposure on cognition in human observational studies: A protocol for a systematic review

BACKGROUND

The long term effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) for frequencies from 100 kHz to 300 GHz on cognitive performance are best assessed using observational studies. In recent years, the use of mobile (cell) phones has been the main source of RF EMF exposure to the brain, although other sources of exposure may be significant. Cognitive function includes various mental and psychological abilities, which can be measured in a range of domains, such as learning, memory, reasoning, problem solving, decision making and attention. Although effects on cognitive function may be most evident later in life, in the experimental setting acute and immediate effects can only be studied. Observational studies are needed when effects are observed after months or years following short or long-term exposure. The importance of the effects of exposure on children has also been recently identified.

OBJECTIVES

To assess the long-term effects of RF EMF local and whole-body exposure compared to no or a lower level of exposure on indicators of cognition, including complex attention, executive function, learning and memory, perceptual motor ability and social cognition, but excluding cognitive effects caused by neurodegenerative diseases or neurodevelopmental disorders, and to assess if there is evidence of a dose response relationship.

STUDY ELIGIBILITY AND CRITERIA

We will include observational studies that have evaluated cognitive effects of RF energy including a comparator group with a different level of exposure. Studies must report at least one validated measure of cognitive function, including global or domain specific measures, or cognitive impairment, with a minimum follow-up of 6 months. Cohort or case-control studies published in the peer review literature in any language are eligible. We will exclude cross-sectional studies and any that only report brain structure or biomarkers.

STUDY APPRAISAL AND SYNTHESIS METHOD

We will conduct searches of PubMed, Embase, PsycINFO and the EMF-Portal. At least two authors will independently screen the titles/abstracts of all records, with any conflicts resolved by a third reviewer. Full-text screening will also be conducted independently by two authors with conflicts resolved by consensus. Data will be extracted from the studies included, such as identifiers and characteristics of the study design, exposure and comparator groups, participants, outcomes assessed and results. Risk of bias will be assessed with the Office of Health Assessment and Translation (OHAT) tool. We will conduct a meta-analysis of similar studies with a random effects model in STATA or similar software, if two or more studies are available for a given exposure-outcome combination. Confidence in the body evidence will be judged using GRADE methods as adapted by OHAT for reviews of environmental exposures.

CT-monitored minimal ablative margin control in single-session microwave ablation of liver tumors: an effective strategy for local tumor control

OBJECTIVES

To investigate the usefulness of minimal ablative margin (MAM) control by intra-procedural contrast-enhanced CT (CECT) in microwave ablation (MWA) of liver tumors.

METHODS

A total of 334 consecutive liver tumors (240 hepatocellular carcinomas [HCCs] and 94 colorectal liver metastases [CRLMs]) in 172 patients treated with percutaneous MWA were retrospectively included. MAM of each tumor was assessed after expected ablation completion using intra-procedural CECT, allowing within-session additional ablation to any potentially insufficient margin. On immediate post-MWA MRI, complete ablation coverage of tumor and final MAM status were determined. The cumulative local tumor progression (LTP) rate was estimated by using the Kaplan-Meier method. To identify predictors of LTP, Cox regression analysis with a shared frailty model was performed.

RESULTS

Intra-procedural CECT findings prompted additional ablation in 18.9% (63/334) of tumors. Final complete ablation coverage of tumor and sufficient MAM were determined by MRI to be achieved in 99.4% (332/334) and 77.5% (259/334), and their estimated 6-month, 1-year, and 2-year LTP rates were 3.2%, 7.5%, and 12.9%; and 1.0%, 2.1%, and 6.9%, respectively. Insufficient MAM on post-MWA MRI, perivascular tumor location, and tumor size (cm) were independent risk factors for LTP (hazard ratio = 14.4, 6.0, and 1.1, p < 0.001, p = 0.003, and p = 0.011, respectively), while subcapsular location and histology (HCC vs CRLM) were not.

CONCLUSIONS

In MWA of liver tumors, intra-procedural CECT monitoring of minimal ablative margin facilitates identification of potentially suboptimal margins and guides immediate additional intra-session ablation to maximize rates of margin-sufficient ablations, the latter being a highly predictive marker for excellent long-term local tumor control.

KEY POINTS

• In MWA of liver tumors, intra-procedural CECT can identify potentially suboptimal minimal ablative margin, leading to immediate additional ablation in a single treatment session. • Achieving a finally sufficient ablative margin through the MWA with intra-procedural CECT monitoring of minimal ablative margin results in excellent local tumor control.

Multi-institutional analysis of outcomes for thermosphere microwave ablation treatment of colorectal liver metastases: the SMAC study

OBJECTIVES

Oligometastatic colorectal cancer benefits of locoregional treatments but data concerning microwave ablation (MWA) are limited and interactions with systemic therapy are still debated. The aim of this study is to evaluate safety and effectiveness of Thermosphere™ MWA (T-MWA) of colorectal liver metastases (CLM) and factors affecting local tumor progression-free survival (LTPFS).

METHODS

In this multi-institutional retrospective study (January 2015-September 2019), patients who underwent T-MWA for CLM were enrolled. Complications according to SIR classification were collected, primary efficacy and LTP were calculated. Analyzed variables included CLM size at diagnosis and at ablation, CLM number, ablation margins, intra-segment progression, chemotherapy before ablation (CBA), variations in size (ΔS_DIA-ABL), and velocity of size variation (V_DIA-ABL) between CLM diagnosis and ablation. Uni/multivariate analyses were performed using mixed effects Cox model to account for the hierarchical structure of data, patient/lesions.

RESULTS

One hundred thirty-two patients with 213 CLM were evaluated. Complications were reported in 6/150 procedures (4%); no biliary complications occurred. Primary efficacy was achieved in 204/213 CLM (95.7%). LTP occurred in 58/204 CLM (28.4%). Six-, twelve-, and eighteen-month LTPFS were 88.2%, 75.8%, and 69.9%, respectively. At multivariate analysis, CLM size at ablation (p = 0.00045), CLM number (p = 0.046), ablation margin < 5 mm (p = 0.0035), and intra-segment progression (p < 0.0001) were statistically significant for LTPFS. ΔS_DIA-ABL (p = 0.63) and V_DIA-ABL (p = 0.38) did not affect LTPFS. Ablation margins in the chemo-naïve group were larger than those in the CBA group (p < 0.0001).

CONCLUSION

T-MWA is a safe and effective technology with adequate LTPFS rates. Intra-segment progression is significantly linked to LTPFS. CBA does not affect LTPFS. Anticipating ablation before chemotherapy may take the advantages of adequate tumor size with correct ablation margin planning.

KEY POINTS

• Thermosphere™-Microwave ablation is a safe and effective treatment for colorectal liver metastases with no registered biliary complications in more than 200 ablations. • Metastases size at time of ablation, intra-segment progression, and minimal ablation margin < 5 mm were found statistically significant for local tumor progression-free survival. • Chemotherapy before ablation modifies kinetics growth of the lesions but deteriorates ablation margins and does not significantly impact local tumor progression-free survival.

Aggregation-induced emission luminogens for highly effective microwave dynamic therapy

Aggregation-induced emission luminogens (AIEgens) exhibit efficient cytotoxic reactive oxygen species (ROS) generation capability and unique light-up features in the aggregated state, which have been well explored in image-guided photodynamic therapy (PDT). However, the limited penetration depth of light in tissue severely hinders AIEgens as a candidate for primary or adjunctive therapy for clinical applications. Coincidentally, microwaves (MWs) show a distinct advantage for deeper penetration depth in tissues than light. Herein, for the first time, we report AIEgen-mediated microwave dynamic therapy (MWDT) for cancer treatment. We found that two AIEgens (TPEPy-I and TPEPy-PF6) served as a new type of microwave (MW) sensitizers to produce ROS, including singlet oxygen (1O2), resulting in efficient destructions of cancer cells. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and live/dead assays reveal that the two AIEgens when activated by MW irradiation can effectively kill cancer cells with average IC-50 values of 2.73 and 3.22 μM, respectively. Overall, the ability of the two AIEgens to be activated by MW not only overcomes the limitations of conventional PDT, but also helps to improve existing MW ablation therapy by reducing the MW dose required to achieve the same therapeutic outcome, thus reducing the occurrence of side-effects of MW radiation.

The effect of exposure to radiofrequency fields on cancer risk in the general and working population: A protocol for a systematic review of human observational studies

BACKGROUND

The World Health Organization (WHO) has an ongoing project to assess potential health effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in the general and working population. Here we present the protocol for a systematic review of the scientific literature on cancer hazards from exposure to RF-EMF in humans, commissioned by the WHO as part of that project.

OBJECTIVE

To assess the quality and strength of the evidence provided by human observational studies for a causal association between exposure to RF-EMF and risk of neoplastic diseases.

ELIGIBILITY CRITERIA

We will include cohort and case-control studies investigating neoplasia risks in relation to three types of exposure to RF-EMF: near-field, head-localized, exposure from wireless phone use (SR-A); far-field, whole body, environmental exposure from fixed-site transmitters (SR-B); near/far-field occupational exposures from use of handheld transceivers or RF-emitting equipment in the workplace (SR-C). While no restriction on tumour type will be applied, we will focus on selected neoplasms of the central nervous system (brain, meninges, pituitary gland, acoustic nerve) and salivary gland tumours (SR-A); brain tumours and leukaemias (SR-B, SR-C).

INFORMATION SOURCES

Eligible studies will be identified through Medline, Embase, and EMF-Portal.

RISK-OF-BIAS ASSESSMENT

We will use a tailored version of the OHAT's tool to evaluate the study's internal validity.

DATA SYNTHESIS

We will consider separately studies on different tumours, neoplasm-specific risks from different exposure sources, and a given exposure-outcome pair in adults and children. When a quantitative synthesis of findings can be envisaged, the main aims of the meta-analysis will be to assess the strength of association and the shape of the exposure-response relationship; to quantify the degree of heterogeneity across studies; and explore the sources of inconsistency (if any). When a meta-analysis is judged inappropriate, we will perform a narrative synthesis, complemented by a structured tabulation of results and appropriate visual displays.

EVIDENCE ASSESSMENT

Confidence in evidence will be assessed in line with the GRADE approach.

FUNDING

This project is supported by the World Health Organization. Co-financing was provided by the New Zealand Ministry of Health; the Istituto Superiore di Sanità in its capacity as a WHO Collaborating Centre for Radiation and Health; ARPANSA as a WHO Collaborating Centre for Radiation Protection.

REGISTRATION

PROSPERO CRD42021236798.

Hydrogen-rich syngas production from biomass in a steam microwave-induced plasma gasification reactor

Substitution of fossil fuels by sustainable practices must be rapidly implemented to mitigate the impacts of climate change. The conversion of biomass into combustible gas is investigated in a microwave-induced plasma reactor using pure steam as the plasma working gas for the first time. The optimum results are achieved at the highest forward microwave power of 6 kW with biomass carbon conversion efficiency over 98% and complete biomass energy recovery in syngas. Unreacted steam is simply condensed out, leading to the production of a syngas with low inert dilution and high calorific value in the range 10.5-12 MJ/Nm³. The syngas produced is rich in hydrogen, exceeding 60% by volume. The proposed process could aid in the transition to a carbon neutral economy as it has the potential to efficiently convert biomass to syngas that can be used for the sustainable generation of fuels, chemicals and energy.

Microwave ablation of colorectal liver metastases: Impact of a 10-mm safety margin on local recurrence in a tertiary care hospital

Microwave ablation (MWA) for colorectal liver metastasis (CLM) has been traditionally considered inferior to surgery due to the higher rate of local recurrence. The study investigated whether a safety margin of 10 mm can improve local control in patients undergoing surgical MWA. Surgical MWA was used to treat 53 lesions in 22 patients with CLM at our Institution from June 2012 to June 2017. The patients’ mean age was 64.5 years, and the median size of the lesion was 16.5 mm (9–34 mm). MWA was associated with liver resection in 16 patients (72.7%). The median follow-up was 32.4 months. Univariate and multivariate analyses were performed to identify factors associated with tumor recurrence. Median ablation area was 36.6 mm² (30–50 mm²). The complication rate was 22.7%. No local recurrence was observed during follow-up. Disease-free survival was 20 months (4.8–55.2 months). Univariate analysis revealed that the number of liver metastases and node-positive primary tumors were associated with tumor recurrence. Multivariate analysis revealed that node-positive primary tumor was the only factor significantly associated with tumor recurrence (p = 0.049; odds ratio, 12; 95% confidence interval, 1–143). When performed with a 10-mm safety margin, surgical MWA can lead to acceptable oncological outcomes with low morbidity. Therefore, it represents a good option in selected patients with CLM.

Thermal ablation in the treatment of intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

OBJECTIVE

To summarize the efficacy and safety of thermal ablation for the treatment of intrahepatic cholangiocarcinoma (ICC).

METHODS

MEDLINE, EMBASE, Cochran Library, and Web of Science databases were searched for studies reporting outcomes in patients with ICC treated with thermal ablation. Meta-analyses of cumulative overall survival (OS) and recurrence-free survival (RFS), Kaplan-Meier survival rates according to time to local tumor progression (TTLTP), technical efficacy, and incidence of complications were analyzed. Pooled hazard ratios of common variables were calculated to explore factors associated with OS.

RESULTS

Twenty observational studies comprising 917 patients were reviewed (primary ICC [n = 502]; post-surgical recurrent ICC [n = 355]; information not available [n = 60]). The pooled proportion of technical efficacy was 91.9% (95% CI, 87.3-94.9%). The pooled 1-, 3-, and 5-year OS rates were 82.4% (95% CI, 75.1-88.9%), 42.1% (95% CI, 36.0-48.4%), and 28.5% (95% CI, 21.2-36.2%). Primary tumors showed higher 3-year OS rates than recurrent ones, with borderline significance (p = 0.072). The pooled 1- and 3-year RFS rates were 40.0% (95% CI, 33.6-46.4%) and 19.2% (95% CI, 8.4-32.7%). The pooled 1-, 3-, and 5-year TTLTP rates were 79.3% (95% CI, 65.1-90.9%), 59.5% (95% CI, 49.1-69.4%), and 58.2% (95% CI, 44.9-70.9%). The pooled incidence of major complications was 5.7% (95% CI, 4.1-7.8%). Tumor size (> 3 cm), multiple tumors, and age (> 65 years) were factors associated with shorter OS.

CONCLUSION

Thermal ablation is a successful alternative with a good safety profile, especially for a single ICC smaller than 3 cm.

KEY POINTS

• The pooled 1-, 3-, and 5-year OS rates following thermal ablation for the treatment of intrahepatic cholangiocarcinoma were 82.4%, 42.1%, and 28.5%. • The pooled incidence of major complications was 5.7%. • A tumor size > 3 cm (HR: 2.12, p = 0.006), multiple tumors (HR: 1.67, p = 0.004), and age > 65 years (HR: 1.67, p = 0.006) were factors associated with shorter OS.

Transurethral Microwave Thermotherapy for Benign Prostatic Hyperplasia: An Updated Cochrane Review

PURPOSE

To assess the effects of transurethral microwave thermotherapy (TUMT) for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

We performed a comprehensive search using multiple databases up to May 2021, with no language or publication status restrictions. We included parallel-group randomized controlled trials of participants with BPH who underwent TUMT. We used standard Cochrane methods, including a GRADE assessment of the certainty of the evidence (CoE).

RESULTS

In this update of a previous Cochrane review, we included 16 trials with 1,919 participants. TUMT probably results in little to no difference in urologic symptom scores at short-term follow-up compared to transurethral resection of the prostate (TURP). There is likely to be little to no difference in the quality of life. TUMT likely results in fewer major adverse events. TUMT, however, probably results in a large increase in the need for retreatment. There may be little to no difference in erectile function between these interventions. However, TUMT may result in fewer cases of ejaculatory dysfunction compared to TURP. The overall CoE was moderate to low.

CONCLUSIONS

TUMT provides a similar reduction in urinary symptoms compared to TURP, with fewer major adverse events and fewer cases of ejaculatory dysfunction at short-term follow-up. However, TUMT probably results in a large increase in retreatment rates. Study limitations and imprecision reduced the confidence we can place in these results.

Percutaneous management of bone metastases: State of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty/vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600 Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900 MHz-2450 MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65 °C-85 °C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

A multicenter 10-year oncologic outcome of ultrasound-guided percutaneous microwave ablation of clinical T1 renal cell carcinoma: will it stand the test of time?

OBJECTIVES

We updated the experience on percutaneous microwave ablation for renal cell carcinoma with five-center data and long-term follow-up.

METHODS

This retrospective study reviewed the T1N0M0 renal cell carcinoma patients who underwent microwave ablation between April 2006 and December 2019. Clinicopathological and procedural data were collected. Technical effectiveness and complications were assessed, and the Kaplan-Meier method was used for cancer-specific survival, disease-free survival, overall survival, and local neoplastic process analyses.

RESULTS

A total of 323 consecutive patients (mean age, 62.9 years ± 14.0) with 371 biopsy-proved tumors (mean diameter, 2.9 cm ± 1.2) were enrolled, and 42.6% of the tumors were located adjacent to collecting system/bowel and technical effectiveness was achieved in 360 (97.0%) tumors. For 275 cT1a patients, during median follow-up time of 66.0 months (IQR, 58.4-73.6), 10-year local neoplastic processes, cancer-specific survival, disease-free survival, and overall survival rates were 1.9%, 87.4%, 71.8, and 67.5%, respectively. For 48 cT1b patients, during the median follow-up time of 30.4 months (IQR, 17.7-44.8), 5-year local tumor progression, cancer-specific survival, disease-free survival, and overall survival rates were 11.3%, 91.4%, 69.1, and 89.2%, respectively. Major complications showed no differences between cT1a (3.5%) and cT1b (6.9%) patients (p = 0.28). A clinical risk stratification system was developed based on multivariable model to predict DFS and CSS with c-indexes of 0.78 (95% CI: 0.71-0.85) and 0.77 (95% CI: 0.65-0.90), respectively.

CONCLUSIONS

With matured follow-up at five institutions, ultrasound-guided percutaneous microwave ablation is a reliable treatment option for cT1a renal cell carcinoma even in dangerous location and appears to be promising for cT1b tumors.

KEY POINTS

• To our knowledge, this is the first multicenter cohort of long-term oncologic outcomes with percutaneous MWA of cT1 RCC. • The predicting model we developed is accurate to predict the long-term DFS and CSS, which can help to provide a better MWA prognostication over routinely available clinical information. • The available evidence shows that microwave ablation of clinical stage T1 RCC is safe and reliable with promising long-term oncologic outcomes, especially for cT1a RCC with excellent 10-year results.

Percutaneous thermal ablation of lung metastases from thyroid carcinomas. A retrospective multicenter study of 107 nodules. On behalf of the TUTHYREF network

PURPOSE

To determine efficacy and safety of thermal ablation (TA) for the local treatment of lung metastases of thyroid cancer.

METHODS

We retrospectively studied 47 patients from 10 centers treated by TA (radiofrequency, microwaves, and cryoablation) over 10 years. The endpoints were overall survival (OS), local efficacy, complications (CTCAE classification), and factors associated with survival. OS curves after first TA were built using the Kaplan-Meier method and compared with the log-rank test.

RESULTS

A total of 107 lung metastases during 75 sessions were treated by radiofrequency (n = 56), microwaves (n = 9), and cryoablation (n = 10). Median follow-up time after TA was 5.2 years (0.2-13.3). OS was 93% at 2 years (95% confidence interval (CI): 86-94) and 79% at 3 years (95% CI: 66-91). On univariate and multivariate analysis with a Cox model, histology was the only significant factor for OS. OS at 3 years was 94% for follicular, oncocytic, or papillary follicular variant carcinomas, compared to 59% for papillary, medullary, insular or anaplastic carcinomas (P = 0.0001). The local control rate was 98.1% at 1 year and 94.8% at 2, 3, 4, and 5 years. Morbidity was low with no major complications (grade 4 and 5 CTCAE) and no complications in 29 of 75 sessions (38.7%).

CONCLUSIONS

TA is a useful, safe and effective option for local treatment of lung metastases from thyroid carcinoma. Prolonged OS was obtained, especially for lung metastases from follicular, oncocytic, or papillary follicular variant carcinomas. Achieving disease control with TA delays the need for systemic treatment.

European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 Clinical Practice Guideline for the Use of Minimally Invasive Treatments in Malignant Thyroid Lesions

The growing detection of papillary thyroid microcarcinomas (PTMCs) is paralleled by an increase in surgical procedures. Due to the frequent indolent nature, cost, and risk of surgery, active surveillance (AS) and ultrasound-guided minimally invasive treatments (MITs) are in suitable cases of incidental PTMC proposed as alternatives to thyroidectomy. Surgery and radioiodine are the established treatments for relapsing cervical differentiated thyroid carcinoma (DTC) metastases. But radioiodine refractoriness, risk of surgical complications, adverse influence on quality of life, or declining repeat surgery have led to AS and MIT being considered as alternatives for slow-growing DTC nodal metastases. Also, for distant radioiodine-refractory metastases not amenable to surgery, MIT is proposed as part of a multimodality therapeutic approach. The European Thyroid Association and the Cardiovascular and Interventional Radiological Society of Europe commissioned these guidelines for the appropriate use of MIT. Based on a systematic PubMed search, an evidence-based approach was applied, and both knowledge and practical experience of the panelists were incorporated to develop the manuscript and the specific recommendations. We recommend that when weighing between surgery, radioiodine, AS, or MIT for DTC, a multidisciplinary team including members with expertise in interventional radiology assess the demographic, clinical, histological, and imaging characteristics for appropriate selection of patients eligible for MIT. Consider TA in low-risk PTMC patients who are at surgical risk, have short life expectancy, relevant comorbidities, or are unwilling to undergo surgery or AS. As laser ablation, radiofrequency ablation, and microwave ablation are similarly safe and effective thermal ablation (TA) techniques, the choice should be based on the specific competences and resources of the centers. Use of ethanol ablation and high-intensity focused ultrasound is not recommended for PTMC treatment. Consider MIT as an alternative to surgical neck dissection in patients with radioiodine refractory cervical recurrences who are at surgical risk or decline further surgery. Factors that favor MIT are previous neck dissection, presence of surgical complications, small size metastases, and <4 involved latero-cervical lymph nodes. Consider TA among treatment options in patients with unresectable oligometastatic or oligoprogressive distant metastases to achieve local tumor control or pain palliation. Consider TA, in combination with bone consolidation and external beam radiation therapy, as a treatment option for painful bone metastases not amenable to other established treatments.

Microwave scan and brain biomarkers to rule out intracranial hemorrhage: study protocol of a planned prospective study (MBI01)

Purpose

The aim of this planned study is to evaluate the ability of a cranial microwave scanner in conjunction with nine brain biomarkers (Aβ40, Aβ42, GFAP, H-FABP, S100B, NF-L, NSE, UCH-L1 and IL-10) to detect and rule out traumatic intracranial hemorrhage in an emergency department setting. Traumatic brain injury is a world-wide topic of interest for researchers and clinicians. It affects 2% of the population per annum and presents challenges for physicians as patients’ initial signs and symptoms do not always correlate with the extent of brain injury. The gold standard for diagnosis of intracranial hemorrhage is head computerized tomography (CT) with the drawbacks of high cost and radiation exposure. A fast, secure way of diagnosing without these drawbacks has potential to make care more effective and reduce cost.

Methods

Study will be prospective and enroll adult, consenting patients with head trauma who seek emergency department care. Only patients where the treating physician prescribes a head-CT will be included. The microwave scan and blood sampling will be performed in close temporal proximity to the CT scan. Results will be analyzed with sensitivity, specificity and receiver operator characteristics analysis to provide the best combination of a number of biomarkers and the microwave scan.

Conclusion

This study will explore the diagnostic accuracy of a head microwave scanner in combination with biomarkers in ruling out intracranial hemorrhage in traumatic brain injury patients presenting to the emergency department. Potentially, this combined diagnostic approach could achieve both high sensitivity and high specificity, thereby reducing the need of CT-head scans when managing these patients.

Clinicaltrials.gov identifier: NCT04666766. Registered December 11, 2020.

Fast and easily obtained information about mobilizable metals from sediment samples. Extraction assisted by benzothiophene-based ionic liquids

A fast and easy method for trace metal extraction on sediments was developed in our laboratories. Three new stable S-metylbenzothiophenium salts were employed along with microwaves to modify the BCR protocol to obtain the concentration of metals of the first two fractions in only one step. The optimum conditions were obtained with 0.125 g of sediment irradiated at 250 W for 30 s at 120 °C, in 5 ml of an aqueous mixture of 10 mM of 1,2-dimethylbenzothiophenium tetrafluoroborate and 0.5 M of hydroxylamine chlorhydrate at pH 2. The method validation was carried out employing BCR 701. The extracted metals were determined by ICP OES. A student's paired t-test was applied with the reference method, giving satisfactory results.

Percutaneous management of bone metastases: state of the art

Interventional radiology is playing an increasingly important role in the local treatment of bone metastases; this treatment is usually done with palliative intent, although in selected patients it can be done with curative intent. Two main groups of techniques are available. The first group, centered on bone consolidation, includes osteoplasty / vertebroplasty, in which polymethyl methacrylate (PMMA) is injected to reinforce the bone and relieve pain, and percutaneous osteosynthesis, in which fractures with nondisplaced or minimally bone fragments are fixed in place with screws. The second group centers on tumor ablation. Tumor ablation refers to the destruction of tumor tissue by the instillation of alcohol or by other means. Thermoablation is the preferred technique in musculoskeletal tumors because it allows for greater control of ablation. Thermoablation can be done with radiofrequency, in which the application of a high frequency (450 Hz-600Hz) alternating wave to the tumor-bone interface achieves high temperatures, resulting in coagulative necrosis. Another thermoablation technique uses microwaves, applying electromagnetic waves in an approximate range of 900MHz to 2450MHz through an antenna that is placed directly in the core of the tumor, stimulating the movement of molecules to generate heat and thus resulting in coagulative necrosis. Cryoablation destroys tumor tissue by applying extreme cold. A more recent, noninvasive technique, magnetic resonance-guided focused ultrasound surgery (MRgFUS), focuses an ultrasound beam from a transducer placed on the patient's skin on the target lesion, where the waves' mechanical energy is converted into thermal energy (65°C-85°C). Treatment should be planned by a multidisciplinary team. Treatment can be done with curative or palliative intent. Once the patient is selected, a preprocedural workup should be done to determine the most appropriate technique based on a series of factors. During the procedure, protective measures must be taken and the patient must be closely monitored. After the procedure, patients must be followed up.

Periportal fields cause stronger cooling effects than veins in hepatic microwave ablation: an in vivo porcine study

BACKGROUND

Vascular cooling effects are a well-known source for tumor recurrence in thermal in situ ablation techniques for hepatic malignancies. Microwave ablation (MWA) is an ablation technique to be considered in the treatment of malignant liver tumors. The impact of vascular cooling in MWA is still controversial.

PURPOSE

To evaluate the influence of different intrahepatic vessel types, vessel sizes, and vessel-to-antenna-distances on MWA geometry in vivo.

MATERIAL AND METHODS

Five MWAs (902-928 MHz) were performed with an energy input of 24.0 kJ in three porcine livers in vivo. MWA lesions were cut into 2-mm slices. The minimum and maximum radius of the ablation area was measured for each slice. Distances were measured from ablation center toward all adjacent hepatic vessels with a diameter of ≥1 mm and within a perimeter of 20 mm around the antenna. The respective vascular cooling effect relative to the maximum ablation radius was calculated.

RESULTS

In total, 707 vessels (489 veins, 218 portal fields) were detected; 370 (76%) hepatic veins and 185 (85%) portal fields caused a cooling effect. Portal fields resulted in higher cooling effects (37%) than hepatic veins (26%, P < 0.01). No cooling effect could be observed in close proximity of vessels within the central ablation zone.

CONCLUSION

Hepatic vessels influenced MWA zones and caused a distinct cooling effect. Portal fields resulted in more pronounced cooling effect than hepatic veins. No cooling effect was observed around vessels situated within the central white zone.

Influence of the heating mechanism during the aqueous processing of vine shoots for the obtaining of hemicellulosic oligosaccharides

This work deals with the revalorization of an important winery residue such as the vine shoots by the obtaining of oligosaccharides with potential prebiotic activity. The manufacture of these added-value products was performed by an autohydrolysis treatment assisted with microwaves to make the process less time consuming and more environmentally friendly. The influence of the reaction time (0-40 min) and the temperature (140-200) on the production of oligosaccharides during the microwave-assisted autohydrolysis was evaluated. The highest concentration of oligosaccharides (168.3 g/Kg oven-dried vines shoots) was achieved during the treatment carried out at 180 °C for 20 min. To assess the benefits of the assistance of the autohydrolysis treatment with the microwaves a conventionally heated treatment was performed using conditions (180 °C for 15 min) that provoked similar effects on the solubilisation of the hemicellulosic fraction. This treatment permitted the obtaining of 203.5 g oligosaccharides/Kg oven-dried vines shoots using 61.0% more of the time needed to carry out the microwaves-assisted autohydrolysis. Although the microwave-assisted treatment permitted the manufacture of a lower amount of oligosaccharides, only consumed 28.8% of the energy needed to perform the conventionally heated treatment. The oligosaccharides manufactured by the two treatments were substituted xyloglucans with different polymerization and acetylation degrees, which due to their potential prebiotic activity could be highly appreciated by pharmaceuticals and food industries. Thus, this work demonstrated the environmental sustainability of the microwave-assisted autohydrolysis for the revalorisation of the vine shoots.