Lung cancer ablation: complications

Robotic-assisted bronchoscopy-advancing lung cancer management

The incidental discovery of early-stage, multifocal lung cancer is transforming the medical landscape. Diagnosing and treating such lesions are often troublesome due to their small size, subsolid consistency, and multifocal nature. This has led to the development of electromagnetic navigation bronchoscopy, which enhanced the ease of navigation and improved localization accuracy during diagnostic procedures. Moreover, it opens the door for intricate transbronchial therapeutic procedures thanks to the superior navigational precision. To further automate navigation and increase maneuverability, robotic-assisted bronchoscopy was developed in recent years, where the robotic arms allow a high level of control and stability of the bronchoscope. Recent evidence has shown that the maneuverability, steadiness, and localization accuracy offered by robotic-assisted bronchoscopy systems with the navigation system allow operators to navigate narrower airways and perform complex interventions with great precision. This review illustrates the development, advantages, and applications of various robotic bronchoscopy systems with the latest evidence. We explore the promising future of robotic-assisted bronchoscopy, where such procedures are anticipated to play an essential role in the multidisciplinary management pathway.

Expert consensus on cancer treatment-related lung injury

Background

Although advancements in cancer therapies have substantially improved the survival of cancer patients, these treatments may also result in acute or chronic lung injury. Cancer treatment-related lung injury (CTLI) presents with a diverse array of clinical manifestations and can involve multiple sites. Due to the lack of specific diagnostic protocols, CTLI can deteriorate rapidly and may be life-threatening if not promptly addressed. Unfortunately, there is no universally accepted consensus document on the diagnosis and management of CTLI.

Methods

A multidisciplinary panel comprising experts from respiratory and critical care medicine, oncology, radiation oncology, thoracic surgery, radiology, pathology, infectious diseases, pharmacy, and rehabilitation medicine participated in this consensus development. Through a systematic literature review and detailed panel discussions, the team formulated nine key recommendations.

Results

This consensus document addresses the concept, epidemiology, pathogenesis, risk factors, diagnostic approach, evaluation workflow, management strategies, differential diagnosis, type-specific management and clinical staging of CTLI. Emphasis is placed on raising awareness among clinicians and therapeutic practices through comprehensive guidelines.

Conclusions

The consensus provides a detailed diagnostic protocol for CTLI and introduces a structured management framework based on grading, typing, and staging. It highlights the critical role of multidisciplinary team (MDT) collaboration and emphasizes the need for individualized, whole-process patient care strategies to optimize clinical outcomes.

Complications related to radiofrequency ablation of lung tumors: CT findings and review

Radiofrequency ablation is a treatment option for primary and secondary lung tumors, particularly in non-surgical patients. Although it is considered a safe and effective procedure, various complications can occur. Most of these adverse events are self-limiting and can be treated conservatively; however, some may be severe and require intervention. Radiologists play a pivotal role in the diagnosis and follow-up of these conditions, aiding in their early identification and management in clinical practice. They must be familiar with the expected and unexpected imaging post-procedure features. This article reviews the main complications of radiofrequency ablation of lung tumors and their associated CT findings.

Safety and efficacy of a novel transbronchial radiofrequency ablation system for lung tumours: One year follow-up from the first multi-centre large-scale clinical trial (BRONC-RFII)

BACKGROUND AND OBJECTIVE

Radiofrequency ablation (RFA) is an emerging treatment of lung cancer, yet it is accompanied by certain safety concerns and operational limitations. This first multi-centre, large-scale clinical trial aimed to investigate the technical performance, efficacy and safety of an innovative transbronchial RFA system for lung tumours.

METHODS

The study enrolled patients with malignant lung tumours who underwent transbronchial RFA using an automatic saline microperfusion system between January 2021 and December 2021 across 16 medical centres. The primary endpoint was the complete ablation rate. The performance and safety of the technique, along with the 1-year survival rates, were evaluated.

RESULTS

This study included 126 patients (age range: 23-85 years) with 130 lung tumours (mean size: 18.77 × 14.15 mm) who had undergone 153 transbronchial RFA sessions, with a technique success rate of 99.35% and an average ablation zone size of 32.47 mm. At the 12-month follow-up, the complete ablation rate and intrapulmonary progression-free survival rates were 90.48% and 88.89%, respectively. The results of patients with ground-glass nodules (GGNs) were superior to those of the patients with solid nodules (12-month complete ablation rates: solid vs. pure GGN vs. mixed GGN: 82.14% vs. 100% vs. 96.08%, p = 0.007). No device defects were reported. Complications such as pneumothorax, haemoptysis, pleural effusion, pulmonary infection and pleural pain were observed in 3.97%, 6.35%, 8.73%, 11.11% and 10.32% of patients, respectively. Two subjects died during the follow-up period.

CONCLUSION

Transbronchial RFA utilizing an automatic saline microperfusion system is a viable, safe and efficacious approach for the treatment for lung tumours, particularly for patients with GGNs.

Effectiveness of Track Cauterization in Reduction of Adverse Events for Lung Microwave Ablation

PURPOSE

To evaluate the effectiveness of track cautery for lung microwave ablation (MWA) to reduce postprocedural adverse events (AE).

MATERIALS AND METHODS

Patients who underwent percutaneous lung MWA between 2012 and 2021 were divided into 2 cohorts: patients in whom track cautery was conducted during antenna removal and patients in whom the antenna was simply removed. Patient demographics, treatment history, tumor characteristics, and ablation details were collected. Postprocedural AEs including immediate, enlarging, and delayed pneumothorax (PTX), pleural effusion, and reinterventions were recorded. Univariate and multivariate logistic regression models were used to identify factors associated with AEs.

RESULTS

This study included 365 lung MWA sessions for 190 patients. Of the 165 patients in the cautery cohort, 78 (47%) had immediate PTX, 16 (10%) had enlarging PTX, 2 (1%) had delayed PTX, and 15 (9%) needed interventions. Of the 200 patients in the noncautery cohort, 85 (43%) had immediate PTX, 45 (23%) had enlarging PTX, 16 (8%) had delayed PTX, and 37 (19%) needed interventions. The cautery cohort had significantly reduced rates of enlarging PTX (odds ratio [OR], 0.67; 95% CI, 0.34-1.33; P = .002), delayed PTX (OR, 0.15; 95% CI, 0.03-0.89; P = .037), and pleural effusion (OR, 0.38; 95% CI, 0.15-0.99; P = .049). The presence of emphysema, large tumor size, and left lower lobe location were shown to be significant predictors of AEs and the need for interventions (P < .05).

CONCLUSIONS

Track cauterization is associated with reduction of post-MWA enlarging PTX, delayed PTX, and pleural effusion. Presence of emphysema, lack of track cautery, large tumor size, and tumors in the left lower lobe were shown to be predictors of postprocedural AEs.

Innovative Techniques for Image-guided Percutaneous Puncture: Navigating Complex Cases for Successful Outcomes

This article emphasizes image-guided puncture, a common technique used by interventional radiologists. It focuses on ultrasound, fluoroscopy, computed tomography, and computed tomography fluoroscopy-guided procedures. While techniques vary, successful outcomes without complications still heavily rely on operators' skill and judgment. Operators need knowledge of needle characteristics and expert needle manipulation. Continual skill refinement through daily practice is essential, aiming maximum results with minimal invasiveness. This article examines challenging cases of percutaneous needle biopsy, biliary intervention, radiofrequency ablation, and percutaneous abscess drainage while referencing previous review articles and discusses how to succeed in these cases by employing various techniques and approaches in various image-guided procedures. This article aimed to provide interventional radiologists with a comprehensive and practical guide for enhancing their image-guided puncture techniques, ultimately leading to successful outcomes.

Patient-Specific Prediction of Immediate Phase Lung Microwave Ablation Zone Size

PURPOSE

To investigate the effect of patient and tumor-specific characteristics on the size of immediate phase lung microwave ablation (MWA) zone and establish a prediction model.

MATERIALS AND METHODS

This institutional review board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant cohort included 164 lesions from 99 patients who underwent computed tomography (CT)-guided lung MWA, and the 2-dimensional elliptical ground-glass opacity ablation zone was measured. Duration, maximum temperature, tumor depth, presence of emphysema, history of ipsilateral lung ablation, surgery, and radiotherapy were recorded. K-fold cross validation with k = 5 and Least Absolute Shrinkage and Selection Operator were used to build prediction models for the major and minor axes and area of the ablation zone.

RESULTS

The median of immediate phase ablation duration was 2 minutes (interquartile range, 1.5-4.25 minutes) with 65 W of power for all ablations. The mean major and minor axes and area of ablation zone were 3.1 cm (SD ± 0.6), 2.0 cm (SD ± 0.5), and 5.1 cm2 (SD ± 2.1), respectively. The major and minor axes and area of immediate phase ablation zone dimensions were significantly associated with duration (P < .001, P < .001, and P < .001, respectively), maximum temperature (P < .001, P < .001, and P < .001, respectively), tumor depth (P = .387, P < .001, and P < .001, respectively), history of ipsilateral lung ablation (P = .008, P = .286, and P = .076, respectively), and lung radiotherapy (P = .001, P = .042, and P = .015, respectively). The prediction model showed R2 values for major and minor axes and area of the ablation zone to be 0.50, 0.45, and 0.53, respectively.

CONCLUSIONS

Duration of ablation, maximum temperature, tumor depth, history of ipsilateral lung ablation, surgery, and radiotherapy were significantly associated with the ablation zone dimensions and size and can be used to build the prediction model to approximate the immediate phase lung MWA zone.

Risk factors for lung parenchyma hemorrhage and hemoptysis during computed tomography-guided microwave ablation in patients with stage I non-small cell lung cancer: A bicentric retrospective study

OBJECTIVES

This study aimed to identify the risk factors for lung parenchyma hemorrhage and hemoptysis during computed tomography-guided microwave ablation (MWA) in patients with stage I non-small cell lung cancer (NSCLC).

METHODS

A total of 417 patients from two medical centers were included, of whom 353 were from center 1 and 64 were from center 2. The risk factors for lung parenchyma hemorrhage and hemoptysis were selected by univariable and multivariable logistic analyses in the center 1 dataset. The selected risk factors were validated in the center 2 dataset.

RESULTS

The risk factors for lung parenchyma hemorrhage during MWA were focal blood supplies (odds ratio [OR], 2.602; 95% confidence interval [CI], 1.609-4.210; p < 0.001), near vessels larger than 2 mm (OR, 4.145; 95% CI, 1.963-8.755; p < 0.001), and traversing vessels in the track of ablation (OR, 2.961; 95% CI, 1.492-5.874; p = 0.002). The risk factors for hemoptysis were lung parenchyma hemorrhage (OR, 34.165; 95% CI, 12.255-95.247; p < 0.001), needle track traversing the lung parenchyma by >25 mm (OR, 4.494; 95% CI, 1.833-11.018; p = 0.001), and traversing vessels in the track of ablation (OR, 5.402; 95% CI, 2.269-12.865; p < 0.001).

CONCLUSIONS

Focal blood supplies, near vessels larger than 2 mm, and traversing vessels in the track of ablation were independent risk factors for lung parenchyma hemorrhage during MWA. Lung parenchyma hemorrhage, needle track traversing the lung parenchyma by >25 mm, and traversing vessels in the track of ablation were independent risk factors for hemoptysis during MWA.

Technical Feasibility and Safety of Image-Guided Biphasic Monopolar Pulsed Electric Field Ablation of Metastatic and Primary Malignancies

PURPOSE

To assess the technical feasibility and safety of image-guided percutaneous biphasic monopolar pulsed electric field (PEF) ablation of primary and metastatic tumors.

MATERIALS AND METHODS

With institutional review board (IRB) approval and Health Insurance Portability and Accountability Act (HIPAA) compliance, this retrospective, single-institution study cohort of 17 patients (mean age, 53.5 years; range, 20-94 years) with overall progressive disease underwent 26 PEF ablation procedures for 30 metastatic (90%) and primary (10%) target lesions in the thorax (n = 20), abdomen (n = 7), and head and neck (n = 3). Concurrent systemic therapy was used in 14 of the 17 patients (82%). Follow-up imaging was scheduled for 1, 3, and 6 months after PEF ablation, and target and off-target lesion sizes were recorded. The overall response was assessed by the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria with imaging immediately before PEF serving as baseline. Adverse events (AEs) were determined by the Society of Interventional Radiology (SIR) classification.

RESULTS

PEF ablation procedures were well tolerated and technically feasible for all 17 patients. The mean initial sizes of the target and off-target tumors were 2.6 cm (standard deviation [SD] ± 1.5; range, 0.4-6.9 cm) and 2.2 cm (SD ± 1.1; range, 1.0-5.2 cm), respectively. Overall, 15 of the 30 (50%) target lesions and 12 of the 24 (50%) off-target lesions were unchanged or decreased in size at the patient's last follow-up. Eight patients had overall stable disease (47%) at the last follow-up. Of the 26 AEs, there were 9 mild (35%) and 1 moderate (4%) AE.

CONCLUSIONS

All PEF procedures were technically feasible with 1 moderate AE and stable disease for 47% of patients with a median follow-up period of 3 months.

Radiofrequency Ablation in Patients with Interstitial Lung Disease and Lung Neoplasm: A Retrospective Multicenter Study

PURPOSE

To retrospectively investigate the safety and effectiveness of percutaneous radiofrequency (RF) ablation by analyzing results in patients with lung neoplasm accompanied by interstitial lung disease (ILD) on computed tomography (CT) in a multicenter study.

MATERIALS AND METHODS

Patients with lung neoplasm accompanied by ILD who underwent RF ablation between April 2002 and October 2017 at 7 institutions were investigated. Technical success rate and local tumor progression (LTP) of ablated tumors were evaluated. Adverse events including acute exacerbation of ILD were also evaluated. Univariate analyses were performed to identify factors associated with acute exacerbation.

RESULTS

Forty-nine patients with 64 lung neoplasms (mean diameter, 23 mm; range, 4-58 mm) treated in 66 sessions were included. Usual interstitial pneumonia (UIP) pattern on CT was identified in 23 patients (47%). All patients underwent successful RF ablation. Acute exacerbations were seen in 5 sessions (8%, 7% with UIP pattern and 8% without) in 5 patients, all occurring on or after 8 days (median, 12 days; range, 8-30 days). Three of those 5 patients died of acute exacerbation. Treatment resulted in mortality after 5% of sessions, representing 6% of patients. Pleural effusion and fever (temperature ≥ 38°C) after RF ablation were identified by univariate analysis (P = .001 and P = .02, respectively) as significant risk factors for acute exacerbation. The cumulative LTP rate was 43% at 1 year.

CONCLUSIONS

RF ablation appears feasible for patients with lung neoplasm complicated by ILD. Acute exacerbation occurred in 8% of patients with symptoms occurring more than 8 days after ablation and was associated with a 45% mortality rate.

Advances in Image-Guided Ablation Therapies for Solid Tumors

Image-guided solid tumor ablation methods have significantly advanced in their capability to target primary and metastatic tumors. These techniques involve noninvasive or percutaneous insertion of applicators to induce thermal, electrochemical, or mechanical stress on malignant tissue to cause tissue destruction and apoptosis of the tumor margins. Ablation offers substantially lower risks compared to traditional methods. Benefits include shorter recovery periods, reduced bleeding, and greater preservation of organ parenchyma compared to surgical intervention. Due to the reduced morbidity and mortality, image-guided tumor ablation offers new opportunities for treatment in cancer patients who are not candidates for resection. Currently, image-guided ablation techniques are utilized for treating primary and metastatic tumors in various organs with both curative and palliative intent, including the liver, pancreas, kidneys, thyroid, parathyroid, prostate, lung, breast, bone, and soft tissue. The invention of new equipment and techniques is expanding the criteria of eligible patients for therapy, as now larger and more high-risk tumors near critical structures can be ablated. This article provides an overview of the different imaging modalities, noninvasive, and percutaneous ablation techniques available and discusses their applications and associated complications across various organs.

Pathophysiology and Management of Chest Wall Pain after Surgical and Non-Surgical Local Therapies for Lung Cancer

Chest wall pain syndromes can emerge following local therapies for lung cancer and can adversely affect patients' quality-of-life. This can occur after lung surgery, radiation therapy, or percutaneous image-guided thermal ablation. This review describes the multifactorial pathophysiology of chest wall pain syndromes that develop following surgical and non-surgical local therapies for lung cancer and summarizes evidence-based management strategies for inflammatory, neuropathic, myofascial, and osseous pain. It discusses a step-wise approach to treating chest wall pain that begins with non-opioid oral analgesics and includes additional pharmacologic treatments as clinically indicated, such as anticonvulsants, serotonin and norepinephrine reuptake inhibitors, tricyclic antidepressants, and various topical treatments. For myofascial pain, physical medicine techniques, such as acupuncture, trigger point injections, deep tissue massage, and intercostal myofascial release can also offer pain relief. For severe or refractory cases, opioid analgesics, intercostal nerve blocks, or intercostal nerve ablations may be indicated. Fortunately, palliation of treatment-related chest wall pain syndromes can be managed by most clinical providers, regardless of the type of local therapy utilized for a patient's lung cancer treatment. In cases where a patient's pain fails to respond to initial medical management, clinicians can consider referring to a pain specialist who can tailor a more specific pharmacologic approach or perform a procedural intervention to relieve pain.

Safety and feasibility of transbronchial microwave ablation for subpleural lung nodules

BACKGROUND

Transbronchial microwave ablation in treating lung nodules is gaining popularity. However, microwave ablation in subpleural lung nodules raised concerns about pleural-based complications due to the proximity between the pleura and the ablation zone.

METHODS

Patients who underwent transbronchial microwave ablation between March 2019 and November 2022 were included in this analysis. The lung nodules were categorized into the subpleural group-less than 5 mm distance to the nearest pleural surface; the deep nodule group-larger or equal to 5 mm distance to the nearest pleural surface. A review of the safety profile of subpleural lung nodule ablation was conducted.

RESULTS

Eighty-two lung nodules (n = 82) from 77 patients were treated. The mean nodule size was 14.2 ± 5.50 mm. The technical success rate was 100%. The mean procedural time was 133 min. No statistically significant differences were detected in the complication rate and the length of stay between the subpleural and deep nodule groups. Complications occured in 21 nodules (25.6%). No minor pneumothorax was reported. Total five cases of pneumothorax required drainage were observed (6.06% in subpleural nodules [n = 2] vs. 6.12% in deep nodules [n = 3], p = 0.991). Total seven cases of pleuritic chest pain were observed (12.1% in subpleural nodules [n = 4] vs. 6.12% in deep nodules [n = 3], p = 0.340).

CONCLUSIONS

This single-center retrospective analysis found no significant difference in the safety outcomes between subpleural and nonsubpleural lung nodule ablation. The overall rate of complications was low in the cohort. This demonstrated that transbronchial microwave was feasible and safe for most lung nodules.

Experimental validation of the accuracy of robotic-assisted radioactive seed implantation for tumor treatment

An experimental validation of a robotic system for radioactive iodine-125 seed implantation (RISI) in tumor treatment was conducted using customized phantom models and animal models simulating liver and lung lesions. The robotic system, consisting of planning, navigation, and implantation modules, was employed to implant dummy radioactive seeds into the models. Fiducial markers were used for target localization. In phantom experiments across 40 cases, the mean errors between planned and actual seed positions were 0.98 ± 1.05 mm, 1.14 ± 0.62 mm, and 0.90 ± 1.05 mm in the x, y, and z directions, respectively. The x, y, and z directions correspond to the left-right, anterior-posterior, and superior-inferior anatomical planes. Silicone phantoms exhibiting significantly smaller x-axis errors compared to liver and lung phantoms (p < 0.05). Template assistance significantly reduced errors in all axes (p < 0.05). No significant dosimetric deviations were observed in parameters such as D90, V100, and V150 between plans and post-implant doses (p > 0.05). In animal experiments across 23 liver and lung cases, the mean implantation errors were 1.28 ± 0.77 mm, 1.66 ± 0.69 mm, and 1.86 ± 0.93 mm in the x, y, and z directions, slightly higher than in phantoms (p < 0.05), with no significant differences between liver and lung models. The dosimetric results closely matched planned values, confirming the accuracy of the robotic system for RISI, offering new possibilities in clinical tumor treatment.

Enhancing precision in lung tumor ablation through innovations in CT-guided technique and angle control

BACKGROUND

This retrospective study aimed to evaluate the precision and safety outcomes of image-guided lung percutaneous thermal ablation (LPTA) methods, focusing on radiofrequency ablation (RFA) and microwave ablation (MWA). The study utilized an innovative angle reference guide to facilitate these techniques in the treatment of lung tumors.

METHODS

This study included individuals undergoing LPTA with the assistance of laser angle guide assembly (LAGA) at our hospital between April 2011 and March 2021. We analyzed patient demographics, tumor characteristics, procedure details, and complications. Logistic regressions were employed to assess risk factors associated with complications.

RESULTS

A total of 202 patients underwent ablation for 375 lung tumors across 275 sessions involving 495 ablations. Most procedures used RFA, especially in the right upper lobe, and the majority of ablations were performed in the prone position (49.7%). Target lesions were at a median depth of 39.3 mm from the pleura surface, and remarkably, 91.9% required only a single puncture. Complications occurred in 31.0% of ablations, with pneumothorax being the most prevalent (18.3%), followed by pain (12.5%), sweating (6.5%), fever (5.0%), cough (4.8%), hemothorax (1.6%), hemoptysis (1.2%), pleural effusion (2.0%), skin burn (0.6%), and air emboli (0.2%). The median procedure time was 21 min. Notably, smoking/chronic obstructive pulmonary disease emerged as a significant risk factor for complications.

CONCLUSION

The LAGA-assisted LPTA enhanced safety by improving accuracy and reducing risks. Overall, this investigation contributes to the ongoing efforts to refine and improve the clinical application of these thermal ablation techniques in the treatment of lung tumors.

Absence of Arrhythmogenicity with Biphasic Pulsed Electric Fields Delivered to Porcine Airways

Pulsed electric field (PEF) technologies treat many types of tissue. Many systems mandate synchronization to the cardiac cycle to avoid the induction of cardiac arrhythmias. Significant differences between PEF systems make the assessment of cardiac safety from one technology to another challenging. A growing body of evidence suggests that shorter duration biphasic pulses obviate the need for cardiac synchronization, even when delivered in a monopolar fashion. This study theoretically evaluates the risk profile of different PEF parameters. It then tests a monopolar, biphasic, microsecond-scale PEF technology for arrhythmogenic potential. PEF applications of increasing likelihood to induce an arrhythmia were delivered. The energy was delivered throughout the cardiac cycle, including both single and multiple packets, and then with concentrated delivery on the t-wave. There were no sustained changes to the electrocardiogram waveform or to the cardiac rhythm, despite delivering energy during the most vulnerable phase of the cardiac cycle, and delivery of multiple packets of PEF energy across the cardiac cycle. Only isolated premature-atrial contractions (PAC) were observed. This study provides evidence that certain varieties of biphasic, monopolar PEF delivery do not require synchronized energy delivery to prevent harmful arrhythmias.

Treatment strategies for malignant pulmonary nodule: beyond lobectomy. Point-counterpoint

PURPOSE OF REVIEW

Technological advancement in low-dose computed tomography resulted in an increased incidental discovery of early-stage lung cancer and multifocal ground glass opacity. The demand for parenchyma-preserving treatment strategies is greater now than ever. Pulmonary ablative therapy is a groundbreaking technique to offer local ablative treatment in a lung-sparing manner. It has become a promising technique in lung cancer management with its diverse applicability. In this article, we will review the current development of ablative therapy in lung and look into the future of this innovative technique.

RECENT FINDINGS

Current literature suggests that ablative therapy offers comparable local disease control to other local therapies and stereotactic body radiation therapy (SBRT), with a low risk of complications. In particular, bronchoscopic microwave ablation (BMWA) has considerably fewer pleural-based complications due to the avoidance of pleural puncture. BMWA can be considered in the multidisciplinary treatment pathway as it allows re-ablation and allows SBRT after BMWA.

SUMMARY

With the benefits which ablative therapy offers and its ability to incorporate into the multidisciplinary management pathway, we foresee ablative therapy, especially BMWA gaining significance in lung cancer treatment. Future directions on developing novel automated navigation platforms and the latest form of ablative energy would further enhance clinical outcomes for our patients.

Device safety assessment of bronchoscopic microwave ablation of normal swine peripheral lung using robotic-assisted bronchoscopy

INTRODUCTION

The aim of this study was to assess the safety of bronchoscopic microwave ablation (MWA) of peripheral lung parenchyma using the NEUWAVE™ FLEX Microwave Ablation System, and robotic-assisted bronchoscopy (RAB) using the MONARCH™ Platform in a swine model.

METHODS

Computed tomography (CT)-guided RAB MWA was performed in the peripheral lung parenchyma of 17 Yorkshire swine (40-50 kg) and procedural adverse events (AEs) documented. The acute group (day 0, n = 5) received 4 MWAs at 100 W for 1, 3, 5, and 10 min in 4 different lung lobes. Subacute and chronic groups (days 3 and 30, n = 6 each) received one MWA (100 W, 10 min) per animal.

RESULTS

The study was completed without major procedural complications. No postprocedural AEs including death, pneumothorax, bronchopleural fistula, hemothorax, or pleural effusions were observed. No gross or histological findings suggestive of thromboembolism were found in any organ. One 3-Day and one 30-Day swine exhibited coughing that required no medication (minor AEs), and one 30-Day animal required antibiotic medication (major AE) for a suspected lower respiratory tract infection that subsided after two weeks. CT-based volumetric estimates of ablation zones in the acute group increased in an ablation time-dependent (1-10 min) manner, whereas macroscopy-based estimates showed an increasing trend in ablation zone size.

CONCLUSION

The NEUWAVE FLEX and MONARCH devices were safely used to perform single or multiple RAB MWAs. The preclinical procedural safety profile of RAB MWA supports clinical research of both devices to investigate efficacy in select patients with oligometastatic disease or primary NSCLC.

Clinical practice guidelines on image-guided thermal ablation of primary and metastatic lung tumors (2022 edition)

The main contents of the Clinical Practice Guidelines on Image-Guided Thermal Ablation (IGTA) of Primary and Metastatic Lung Tumors (2022 Edition) include the following: epidemiology of primary and metastatic lung tumors; the concepts of the IGTA and common technical features; procedures, indications, contraindications, outcomes evaluation, and related complications of IGTA on primary and metastatic lung tumors; and limitations and future development.

Therapeutic Bronchoscopy for Lung Nodules: Where Are We Now?

Lobar resection has been the established standard of care for peripheral early-stage non-small cell lung cancer (NSCLC). Over the last few years, surgical lung sparing approach (sublobar resection [SLR]) has been compared with lobar resection in T1N0 NSCLC. Three nonsurgical options are available in those patients who have a prohibitive surgical risk, and those who refuse surgery: stereotactic body radiotherapy (SBRT), percutaneous ablation, and bronchoscopic ablation. Local ablation involves placement of a probe into a tumor, and subsequent application of either heat or cold energy, pulsing electrical fields, or placement of radioactive source under an image guidance to create a zone of cell death that encompasses the targeted lesion and an ablation margin. Despite being in their infancy, the bronchoscopic ablative techniques are undergoing rapid research, as they extrapolate a significant knowledge-base from the percutaneous techniques that have been in the radiologist's armamentarium since 2000. Here, we discuss selected endoscopic and percutaneous thermal and non-thermal therapies with the focus on their efficacy and safety.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

Optimization of pleural multisite anesthetic technique during CT-guide microwave ablation of peripheral lung malignancy for improving treatment tolerance

OBJECTIVE

To assess the effect and safety of subpleural multisite anesthesia based on the area of thermal radiation during CT-guided lung malignancy microwave ablation (MWA) on the incidence of moderate or severe pain and the analgesic drug usage.

MATERIALS AND METHODS

Consecutive patients with lung malignancies were retrospectively evaluated between January 2016 and December 2019. Patients undergoing CT-guided lung malignancy MWA were either given in the method of (a) standard subpleural puncture point anesthesia between January 2016 and June 2018 and (b) subpleural multisite anesthesia based on the area of thermal radiation between July 2018 and December 2019. The relationship between local anesthesia mode and moderate or severe pain, and pain medications usage was assessed by using multivariable logistic regression models.

RESULTS

A total of 243 consecutive patients were included in the study. Moderate or severe pain occurred in 84 of 124 (67.7%) patients with subpleural puncture point anesthesia and in 20 of 119 (16.8%) patients with subpleural anesthesia in the area of thermal radiation (p=.001). The intravenous pain medication was required in 56 of 124 (45.2%) patients with subpleural puncture point anesthesia and in 9 of 119 (7.6%) patients with subpleural multisite anesthesia based on the area of thermal radiation (p=.001). Local anesthesia methods (p = 0.001), pleura-to-lesion distance (p=.02) and tumor size (p=.015) were independent risk factors for developing moderate or severe pain. There were no differences in adverse events and local tumor progression rate.

CONCLUSIONS

Subpleural multisite anesthesia based on the area of thermal radiation for peripheral lung malignancy MWA can result in lower intraprocedural pain compared with the subpleural puncture point anesthesia. Thus, a subpleural multisite anesthesia technique may be most helpful when performing MWA of peripheral malignancy in patients who are not sedated with general or intravenous anesthesia.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

MR-Guided Microwave Ablation for Lung Malignant Tumor: A Single Center Prospective Study

Objectives

To prospectively investigate the feasibility and efficacy of MRI-guided MWA for lung malignant tumor in our single center.

Materials and Methods

22 patients [mean age, 56.86 ± 13.05(23–73)years] with 23 malignant lung tumors were enrolled in the study. 21 patients had a single lesion and 1 patient had 2 lesions in the ipsilateral lung. The average maximum diameter of the lesion was 1.26 ± 0.65 (0.50-2.58)cm. Percutaneous MWA was guided by 1.5T MRI scanner using a MR-compatible microwave antenna to the target the lung lesions and ablation area was monitored intraoperatively by using a shielded MR-compatible microwave device and then follow-up.

Results

All patients were successfully treated under MR-guided MWA for lung tumors. Average operation time was 72.21 ± 24.99 (36–158) mins. T2WI signal intensity of the lesion gradually decreased over the course of MWA. The center of the ablated zones showed a short T1 and short T2 signals with the ring-like of long T1 and long T2 signals surrounded after immediately evaluation. No serious complications occurred. The average follow-up period was 12.89 ± 4.33 (2.0-19.6) months. Local recurrence occurred in one patient, representing a technical efficacy of 95.5% (21/22).

Conclusion

Magnetic resonance-guided microwave ablation for lung malignant tumor was feasible and demonstrated unique advantages in efficacy evaluation.

Update on Image-Guided Thermal Lung Ablation: Society Guidelines, Therapeutic Alternatives, and Postablation Imaging Findings

Percutaneous image-guided thermal ablation (IGTA) has been endorsed by multiple societies as a safe and effective lung-preserving treatment for primary lung cancer and metastases involving the lung and chest wall. This article reviews the role of IGTA in the care continuum of patients with thoracic neoplasms and discusses strategies to identify the optimal local therapy considering patient and tumor characteristics. The advantages and disadvantages of percutaneous thermal ablation compared to surgical resection and stereotactic body radiotherapy are summarized. Principles of radiofrequency ablation, microwave ablation, and cryoablation, as well as the emerging use of transbronchial thermal ablation, are described. Specific considerations are presented regarding the role of thermal ablation for early-stage non-small cell lung cancer (NSCLC), multifocal primary NSCLC, pulmonary metastases, salvage of recurrent NSCLC after surgery or radiation, and pain palliation for tumors involving the chest wall. Recent changes to professional society guidelines regarding the role of thermal ablation in the lung, including for treatment of oligometastatic disease, are highlighted. Finally, recommendations are provided for imaging follow-up after thermal ablation of lung tumors, accompanied by examples of expected postoperative findings and patterns of disease recurrence.

Percutaneous Image-Guided Ablation of Lung Tumors

Tumors of the lung, including primary cancer and metastases, are notoriously common and difficult to treat. Although surgical resection of lung lesions is often indicated, many conditions disqualify patients from being surgical candidates. Percutaneous image-guided lung ablation is a relatively new set of techniques that offers a promising treatment option for a variety of lung tumors. Although there have been no clinical trials to definitively compare its efficacy to those of traditional treatments, lung ablation is widely practiced and generally accepted to be safe and effective. Especially encouraging results have recently emerged for cryoablation, one of the newer ablative techniques. This article reviews the indications, techniques, contraindications, and complications of percutaneous image-guided ablation of lung tumors with special attention to cryoablation and its recent developments in protocol optimization.

Transbronchial lung parenchyma cryoablation with a novel flexible cryoprobe in an in vivo porcine model

PURPOSE

The purpose of this study was to evaluate the feasibility and safety of transbronchial cryoablation with a novel flexible cryoprobe using nitrogen as the refrigerant in an in vivo porcine model of lung parenchyma.

MATERIALS AND METHODS

A novel flexible cryoprobe using nitrogen as the refrigerant was used for transbronchial cryoablation of lung parenchyma in six normal female pigs. The cryoprobe was delivered to the distal bronchus in the bilateral porcine lungs via the bronchoscopic working channel under virtual bronchoscopy guidance. The position was confirmed with real-time computed tomography (CT). The whole procedure included two freeze-thaw cycles (15 min and 2 min, respectively). CT images were obtained during cryoablation and at 24 h, one week, two weeks and four weeks after the treatment to assess the effectiveness and safety of the procedure. Ablation zone tissue samples were obtained at 24 h and four weeks after the cryoablation for further histopathological analysis.

RESULTS

All ablation procedures (12/12; 100%) were performed successfully. No major complications occurred during the procedure or the observation period. The ablation zones were clearly depicted on CT with a maximal ablation zone volume at 24 h (21.88 ± 12.61 [SD] cm³) compared to 3.64 ± 2.06 (SD) cm³ and 10.73 ± 3.84 (SD) cm³ at the end of the 1st and 2nd freeze-thaw cycles, respectively (P < 0.001). Histopathological analysis revealed that a coagulative necrotic zone was formed along the target bronchus, with obvious vascular occlusion and hemorrhage 24 h after treatment. The lesions gradually formed fibrosis after four weeks.

CONCLUSION

The novel flexible bronchoscopy-guided cryoablation is a feasible, safe and effective modality in an in vivo porcine model of peripheral normal lung parenchyma, suggesting potential capabilities for the treatment of peripheral lung cancer in humans.

Safety and Feasibility of Cryoablation during Immunotherapy in Patients with Metastatic Soft Tissue Sarcoma

PURPOSE

Patients with metastatic soft tissue sarcoma (STS) undergo a wide array of treatments, including surgery, radiation, chemotherapy, immunotherapy, and ablative therapies, to control their disease. The combination of cryoablation and immunotherapy may lead to an enhanced antitumor immune response via the abscopal effect. It is hypothesized that the combination of cryoablation and immunotherapy in patients with metastatic STS is safe and feasible.

MATERIALS AND METHODS

A single-center retrospective analysis was performed on patients with metastatic STS who underwent cryoablation. Sixteen patients were treated with 27 cryoablation procedures while receiving ipilimumab and nivolumab from April 2017 to July 2020. Response Evaluation Criteria in Solid Tumors, 1.1, were used to determine the outcomes of nontarget tumors. Progression-free survival (PFS) and overall survival (OS) were calculated from the date of the first cryoablation after initiating immunotherapy until progression or death.

RESULTS

Thirty-four tumors were cryoablated, 23 of which were intentionally subtotal. The most common tumor subtype was liposarcoma (n = 4). Thirteen (81%) patients had previously demonstrated disease progression on multiple lines of chemotherapy. All tumors cryoablated with a complete intention demonstrated a complete response. Seven patients had a clinical benefit, including 1 with a complete response, 1 with a partial response, and 5 with stable disease. The median OS was 14.1 months, with a median PFS of 2.3 months (95% confidence interval, 1.8-14.3). Five patients had pneumothoraces after cryoablation, 2 of whom required chest tube placement. Eleven patients experienced adverse events related to immunotherapy, 10 of whom experienced grade 1 or 2.

CONCLUSIONS

Cryoablation in patients with metastatic STS undergoing immunotherapy is feasible and safe.

Lung Thermal Ablation: Comparison between an Augmented Reality Computed Tomography (CT) 3D Navigation System (SIRIO) and Standard CT-Guided Technique

Simple Summary

Lung cancer is the leading cause of cancer mortality worldwide. In recent years, numerous technologies have been used to perform image-guided percutaneous thermal ablation, mainly including radiofrequency ablation, microwave ablation, and cryoablation. These image-guided ablation techniques have emerged as a safe, cost-effective, minimally invasive treatment alternative for patients who do not require surgery. Procedural planning, monitoring, and lesion targeting are generally performed with the help of computed tomography; navigation systems are emerging as valid tool to reduce procedural time and radiation dose administration. In the present paper, we investigate the efficacy of an optical-based navigation system (SIRIO) to perform lung thermal ablation. SIRIO proved to be a reliable and effective tool when performing CT-guided LTA, displaying a significant decrease in the number of required CT scans, procedure time, and radiation doses administered to patients.

Abstract

(1) Background: The aim of this retrospective study is to assess safety and efficacy of lung radiofrequency (RFA) and microwave ablation (MWA) using an augmented reality computed tomography (CT) navigation system (SIRIO) and to compare it with the standard CT-guided technique. (2) Methods: Lung RFA and MWA were performed with an augmented reality CT 3D navigation system (SIRIO) in 52 patients. A comparison was then performed with a group of 49 patients undergoing the standard CT-guided technique. All the procedures were divided into four groups based on the lesion diameter (>2 cm or ≤2 cm), and procedural time, the number of CT scans, radiation dose administered, and complications rate were evaluated. Technical success was defined as the presence of a “ground glass” area completely covering the target lesion at the immediate post-procedural CT. (3) Results: Full technical success was achieved in all treated malignant lesions for all the considered groups. SIRIO-guided lung thermo-ablations (LTA) displayed a significant decrease in the number of CT scans, procedure time, and patients’ radiation exposure (p < 0.001). This also resulted in a dosage reduction in hypnotics and opioids administrated for sedation during LTA. No significant differences were observed between the SIRIO and non-SIRIO group in terms of complications incidence. (4) Conclusions: SIRIO is an efficient tool to perform CT-guided LTA, displaying a significant reduction (p < 0.001) in the number of required CT scans, procedure time, and patients’ radiation exposure.

Management of bronchopleural fistula with endobronchial valve in hybrid operating room following transbronchial microwave ablation

Transbronchial microwave ablation for the treatment of lung nodules is gaining popularity. In the present case, transbronchial microwave ablation to a right middle lobe lesion was performed under electromagnetic navigation bronchoscopy guidance. It was complicated with pneumothorax and persistent air leak despite chest drainage and chemical pleurodesis. A diagnosis of bronchopleural fistula was reached and an endobronchial valve was implanted to the middle lobe segmental bronchus with almost immediate cessation of air leak. Our case demonstrated that endobronchial valve is safe and effective in managing bronchopleural fistula after transbronchial microwave ablation.

Outcomes with multi-disciplinary management of central lung tumors with CT-guided percutaneous high dose rate brachyablation

BACKGROUND

Centrally located lung tumors present treatment challenges given their proximity to mediastinal structures including the central airway, esophagus, major vessels, and heart. Therapeutic options can be limited for medically inoperable patients, particularly if they have received previous thoracic radiotherapy. High dose rate (HDR) brachyablation was developed to improve the therapeutic ratio for patients with central lung tumors. The purpose of this study is to report initial safety and efficacy outcomes with this treatment for central lung malignancies.

METHODS

From September 2015 to August 2019, a total of 25 patients with 37 pulmonary tumors were treated with percutaneous HDR brachyablation. Treatment was delivered by a multi-disciplinary team of interventional radiologists, pulmonologists, and radiation oncologists. Twenty-three patients received a median dose of 21.5 Gy (range 15-27.5) in a single fraction, whereas two patients received median dose of 24.75 Gy (range 24-25.5) over 2-3 fractions. Tumor local control (LC) was evaluated by Response Evaluation Criteria in Solid Tumors v1.1. Treatment-related toxicities were graded by Common Terminology Criteria for Adverse Events v5.0, with adverse events less than 90 days defined as acute, and those occurring later were defined as late. LC, progression-free survival (PFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method.

RESULTS

Of 37 treated tumors, 88% were metastatic. Tumor location was central and ultra-central in 24.3% and 54.1%, respectively. Average tumor volume was 11.6 cm³ (SD 12.4, range 0.57-62.8). Median follow-up was 19 months (range 3-48). Two-year LC, PFS, and OS were 96.2%, 29.7%, and 65.5%, respectively. Thirteen of 39 (33.3%) catheter implantation procedures were associated with trace minor pneumothorax requiring no intervention, 1 (2.5%) procedure with minor radiographic pulmonary hemorrhage, and 4 (10.3%) with major pneumothorax requiring chest tube insertions. All procedural complications resolved within 24 h from treatment. Acute grade 1-2 toxicity was identified in 4 patients, whereas none developed late toxicity beyond 90 days of follow-up.

CONCLUSION

Percutaneous HDR brachyablation is a safe and promising treatment option for centrally located primary and metastatic lung tumors. Future comparisons with stereotactic body radiotherapy and other ablative techniques are warranted to expand multi-disciplinary management options.

Artificial pneumothorax improves radiofrequency ablation of pulmonary metastases of hepatocellular carcinoma close to mediastinum

BACKGROUND

To investigate the feasibility, safety and efficacy of percutaneous radiofrequency ablation (RFA) of pulmonary metastases from hepatocellular carcinoma (HCC) contiguous with the mediastinum using the artificial pneumothorax technique.

METHOD

A total of 40 lesions in 32 patients with pulmonary metastases from HCC contiguous with the mediastinum accepted RFA treatment from August 2014 to May 2018 via the artificial pneumothorax technique. After ablation, clinical outcomes were followed up by contrast enhanced CT. Technical success, local tumor progression (LTP), intrapulmonary distant recurrence (IDR), and adverse events were evaluated. Overall survival (OS) and local tumor progression free survival (LTPFS) were recorded for each patient.

RESULTS

The tumor size was 1.4 ± 0.6 cm in diameter. RFA procedures were all successfully performed without intra-ablative complications. Technical success was noted in 100% of the patients. Five cases of LTP and 8 cases of IDR occurred following the secondary RFA for treatment. Slight pain was reported in all patients. No major complications were observed. The 1, 2, and 3-year LTPFS rates were 90.6, 81.2, and 71.8%, and the 1, 2, and 3-year OS rates were 100, 100 and 87.5%, respectively.

CONCLUSION

Artificial pneumothorax adjuvant RFA is a feasible, safe, and efficient method for treatment of pulmonary metastases from HCC contiguous with the mediastinum.

Image-guided percutaneous ablation for the treatment of lung malignancies: current state of the art

Image-guided percutaneous lung ablation has proven to be a valid treatment alternative in patients with early-stage non-small cell lung carcinoma or oligometastatic lung disease. Available ablative modalities include radiofrequency ablation, microwave ablation, and cryoablation. Currently, there are no sufficiently representative studies to determine significant differences between the results of these techniques. However, a common feature among them is their excellent tolerance with very few complications. For optimal treatment, radiologists must carefully select the patients to be treated, perform a refined ablative technique, and have a detailed knowledge of the radiological features following lung ablation. Although no randomized studies comparing image-guided percutaneous lung ablation with surgery or stereotactic radiation therapy are available, the current literature demonstrates equivalent survival rates. This review will discuss image-guided percutaneous lung ablation features, including available modalities, approved indications, possible complications, published results, and future applications.

Transbronchial microwave ablation of lung nodules with electromagnetic navigation bronchoscopy guidance-a novel technique and initial experience with 30 cases

Background

Microwave ablation of lung nodules may provide a faster, larger and more predictable ablation zone than other energy sources, while bronchoscopic transbronchial ablation has theoretical advantage of fewer pleural-based complications than percutaneous approach. Our study aims to determine whether the novel combination of bronchoscopic approach and microwave ablation in management of lung nodules is technically feasible, safe and effective.

Methods

This is a retrospective analysis of a single center experience in electromagnetic navigation bronchoscopy microwave ablation in hybrid operating room. Patients had high surgical risks while lung nodules were either proven malignant or radiologically suspicious. Primary endpoints include technical feasibility and safety.

Results

Total of 30 lung nodules from 25 patients were treated. Mean nodule size was 15.1 mm, and bronchus directly leads to the nodules (bronchus sign positive) in only half of them. Technical success rate was 100%, although some nodules required double ablation for adequate coverage. Mean minimal ablation margin was 5.51 mm. The mean actual ablation zone volume was -21.4% compared to predicted, likely due to significant tissue contraction ranging from 0-43%. There was no significant heat sink effect. Mean hospital stay was 1.73 days, and only 1 patient stayed for more than 3 days. Complications included pain (13.3%), pneumothorax requiring drainage (6.67%), post-ablation reaction (6.67%), pleural effusion (3.33%) and hemoptysis (3.33%). After median follow up of 12 months, none of the nodules had evidence of progression.

Conclusions

Bronchoscopic transbronchial microwave ablation is safe and feasible for treatment of malignant lung nodules. Prospective study on clinical application of this novel technique is warranted.

Risk prediction of pleural effusion in lung malignancy patients treated with CT-guided percutaneous microwave ablation: a nomogram and artificial neural network model

OBJECTIVES

To develop an effective nomogram and artificial neural network (ANN) model for predicting pleural effusion after percutaneous microwave ablation (MWA) in lung malignancy (LM) patients.

METHODS

LM patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (7:3). The predictors of pleural effusion identified by univariable and multivariable analyses in the training cohort were used to develop a nomogram and ANN model. The C-statistic was used to evaluate the predictive accuracy in both the training and validation cohorts.

RESULTS

A total of 496 patients (training cohort: n = 357; validation cohort: n = 139) were enrolled in this study. The predictors selected into the nomogram for pleural effusion included the maximum power (hazard ratio [HR], 1.060; 95% confidence interval [CI], 1.022-1.100, p = 0.002), the number of pleural punctures (HR, 2.280; 95% CI, 1.103-4.722; p = 0.026) and the minimum distance from needle to pleura (HR, 0.840; 95% CI, 0.775-0.899; p < 0.001). The C-statistic showed good predictive performance in both cohorts, with a C-statistic of 0.866 (95% CI, 0.787-0.945) internally and 0.782 (95% CI, 0.644-0.920) externally (training cohort and validation cohort, respectively). The optimal cutoff value for the risk of pleural effusion was 0.16.

CONCLUSIONS

Maximum power, number of pleural punctures and minimum distance from needle to pleura were predictors of pleural effusion after MWA in LM patients. The nomogram and ANN model could effectively predict the risk of pleural effusion after MWA. Patients showing a high risk (>0.16) on the nomogram should be monitored for pleural effusion.

Efficacy of Tract Embolization After Percutaneous Pulmonary Radiofrequency Ablation

PURPOSE

To evaluate the efficacy of tract embolization technique using gelatin sponge slurry with iodinated contrast medium (GSSI) to reduce the incidence of pneumothorax and chest tube placement after computed tomography-guided lung radiofrequency ablation (RFA).

MATERIALS AND METHODS

In this single-institute retrospective study, we examined all patients with metastatic cancer treated from January 2016 to December 2019 by interventional radiologists with computed tomography-guided lung RFA. Since 2017 in our institution, we have applied a tract embolization technique using GSSI for all RFA. Patients were included into those who underwent lung RFA performed either with GSSI (Group A) or without GSSI (Group B). Univariate and multivariate analyses were performed between the two groups to identify risk factors for pneumothorax and chest tube placement, including patient demographics and lesion characteristics.

RESULTS

This study included 116 patients (54 men, 62 women; mean age, 65 ± 11 years) who underwent RFA. Group A comprised 71 patients and Group B comprised 45 patients. Patients who underwent tract embolization had a significantly lower incidence of pneumothorax (Group A, 34% vs. Group B, 62%; p < 0.001) and chest tube insertion (Group A, 10% vs. Group B, 29%; p < 0.01). No embolic complications occurred. The hospitalization stay was significantly shorter in patients who underwent tract embolization (mean, 1.04 ± 0.2 days; p = 0.02).

CONCLUSION

Tract embolization after percutaneous lung RFA significantly reduced the rate of post-RFA pneumothorax and chest tube placement and was safer than the standard lung RFA technique.

Image guided thermal ablation in lung cancer treatment

Lung ablation has been introduced into lung cancer treatment for about two decades. Currently, 3 main choices of thermal energy for lung ablation are radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation. As a mostly palliative, occasionally curative intent local treatment, the feasibility and safety of lung ablation have been validated in small size lung cancer treatment, especially in lung tumor ≤3 cm. Improved techniques and experience in recent years help render outcomes much better than before for lung cancer patients who are medically inoperable with early stage primary lung cancer, and patients with oligometastasis or local recurrence. For stage IA non-small cell lung cancer (NSCLC) patients underwent RFA, 1- and 2-year overall survival rate were reported as 86.3% and 69.8%. And 1- and 2-year local recurrence rate were reported as 68.9% and 59.8%. Limitations, including heat sink, skin burn, and inconsistent heat conduction, are observed in the first applied ablation technique, RFA. MWA and cryoablation are developed to overcome these limitations and achieve the goal of less morbidity. Generally, imaged guided thermal ablation has a good safety profile, with pneumothorax as the most common morbidity. This article will mainly discuss the current features and application of these ablation techniques in lung cancer treatment.

Radiofrequency Ablation for Stage I Non-Small Cell Lung Cancer: An Updated Review of Literature from the Last Decade

This review summarizes the current findings on radiofrequency ablation (RFA) for stage I non-small cell lung cancer (NSCLC) from relevant literature published in the last decade. While most earlier studies included small populations and had short follow-up periods, more robust data have become available owing to prospective or large cohort studies. The reported overall survival rates after RFA for stage I NSCLC were 83-96%, 40-74%, and 23-61% at 1, 3, and 5 years, respectively, in recent studies. Furthermore, many comparative studies on the outcomes of RFA and stereotactic body radiotherapy have been performed. Most of these studies report no significant difference in survival outcomes between the therapies. Currently, major guidelines define RFA as a reasonable alternative treatment for stage I NSCLC in non-surgical candidates.

Comparing cryoablation and microwave ablation for the treatment of patients with stage IIIB/IV non-small cell lung cancer

The aim of the present study was to compare the safety and efficacy of cryoablation (CA) and microwave ablation (MWA) as treatments for non-small cell lung cancer (NSCLC). Patients with stage IIIB or IV NSCLC treated with CA (n=45) or MWA (n=56) were enrolled in the present study. The primary endpoint was progression-free survival (PFS); the secondary endpoints included overall survival (OS) time and adverse events (AEs). The median PFS times between the two groups were not significantly different (P=0.36): CA, 10 months [95% confidence interval (CI), 7.5-12.4] vs. MWA, 11 months (95% CI, 9.5-12.4). The OS times between the two groups were also not significantly different (P=0.07): CA, 27.5 months (95% CI, 22.8-31.2 months) vs. MWA, 18 months (95% CI, 12.5-23.5). For larger tumors (>3 cm), patients treated with MWA had significantly longer median PFS (P=0.04; MWA, 10.5 months vs. CA, 7.0 months) and OS times (P=0.04; MWA, 24.5 months vs. CA, 14.5 months) compared patients treated with CA. However, for smaller tumors (≤3 cm), median PFS (P=0.79; MWA, 11.0 months vs. CA, 13.0 months) and OS times (P=0.39; MWA, 30.0 months vs. CA, 26.5 months) between the two groups did not differ significantly. The incidence rates of AEs were similar in the two groups (P>0.05). The number of applicators, tumor size and length of the lung traversed by applicators were associated with a higher risk of pneumothorax and intra-pulmonary hemorrhage in the two groups. Treatment with CA resulted in significantly less intraprocedural pain compared with treatment with MWA (P=0.001). Overall, the present study demonstrated that CA and MWA were comparably safe and effective procedures for the treatment of small tumors. However, treatment with MWA was superior compared with CA for the treatment of large tumors.

Microwave Ablation in Primary Lung Malignancies

Lung cancer is the leading cause of cancer-related mortality worldwide. Eighty-five percent of cases correspond to non-small cell lung cancer (NSCLC) and pivotal nonsurgical options for early-stage disease include percutaneous ablation and stereotactic body radiation therapy (SBRT). Microwave Ablation (MWA) is a locoregional treatment option that has many advantages over radiofrequency ablation and has been able to overcome the limitations of this technique in the treatment of early-stage NSCLC. In this review article, we highlight the current evidence supporting the use of MWA in patients with early-stage NSCLC and discuss the technical considerations of the procedure, including optimal patient selection and planning strategies, as well as the potential complications and reported outcomes. Finally, we mention future trends involving ablation in NSCLC, including its role in combination with SBRT in central tumors, management of post-SBRT local recurrence, and its potential as an adjuvant treatment option for patients with resistance to systemic therapy or in combination with checkpoint inhibitors.

Cryoablation of Lung Metastases: Review of Recent Literature and Ablation Technique

This article reviews the current indications for image-guided thermal ablation of pulmonary metastatic disease. It also summarizes data regarding the efficacy and complications of lung cryoablation and present techniques for performing lung cryoablation as informed by the recent literature.