Radiofrequency versus microwave ablation for treatment of the lung tumours: LUMIRA (lung microwave radiofrequency) randomized trial

Special Considerations and Techniques of Interventions in Lung Transplant Recipients

Lung transplant remains an important treatment option for patients with end-stage lung diseases providing improvement in survival rates and quality of life. Specialized considerations should be applied with interventions of lung transplant recipients as they host specific anatomic variations and high risk towards certain complications. In this article, we highlight the role of interventional radiology for lung transplant recipients along with discussion of interventional techniques. Specific emphasis is placed on describing and explaining the techniques pertained to the points of anastomosis, diagnosis and treatment of malignancies, and management of complications in lung transplant recipients.

Robotic versus freehand CT-guided radiofrequency ablation of pulmonary metastases: a comparative cohort study

PURPOSE

Radiofrequency ablation (RFA) is a curative treatment option for small lung metastases, which conventionally involves multiple freehand manipulations until the treating electrode is satisfactorily positioned. Stereotactic and robotic guidance has been gaining popularity for liver ablation, although has not been established in lung ablation. The purpose of this study is to determine the feasibility, safety, and accuracy of robotic RFA for pulmonary metastases, and compare procedures with a conventional freehand cohort.

METHODS

A single center study with prospective robotic cohort, and retrospective freehand cohort. RFA was performed under general anesthesia using high frequency jet ventilation and CT guidance. Main outcomes were (i) feasibility/technical success (ii) safety using Common Terminology Criteria for Adverse Events (iii) targeting accuracy (iv) number of needle manipulations for satisfactory ablation. Robotic and freehand cohorts were compared using Mann-Whitney U tests for continuous variables, and Fisher's exact for categorical variables.

RESULTS

Thirty-nine patients (mean age 65 ± 13 years, 20 men) underwent ablation of 44 pulmonary metastases at single specialist cancer center between July 2019 and August 2022. 20 consecutive participants underwent robotic ablation, and 20 consecutive patients underwent freehand ablation. All 20/20 (100%) robotic procedures were technically successful, and none were converted to freehand procedures. There were 6/20 (30%) adverse events in the robotic cohort, and 15/20 (75%) in the freehand cohort (P = 0.01). Robotic placement was highly accurate with 6 mm tip-to-target distance (range 0-14 mm) despite out-of-plane approaches, with fewer manipulations than freehand placement (median 0 vs. 4.5 manipulations, P < 0.001 and 7/22, 32% vs. 22/22, 100%, P < 0.001).

CONCLUSIONS

Robotic radiofrequency ablation of pulmonary metastases with general anesthesia and high frequency jet ventilation is feasible and safe. Targeting accuracy is high, and fewer needle/electrode manipulations are required to achieve a satisfactory position for ablation than freehand placement, with early indications of reduced complications.

Primary and Metastatic Lung Cancer: Rationale, Indications, and Outcomes of Thermal Ablation

The widespread use of imaging as well as the efforts conducted through screening campaigns has dramatically increased the early detection rate of lung cancer. Historically, the management of lung cancer has heavily relied on surgery. However, the increased proportion of patients with comorbidities has given significance to less invasive therapeutic options like minimally invasive surgery and image-guided thermal ablation, which could precisely target the tumor without requiring general anesthesia or a thoracotomy. Thermal ablation is considered low-risk for lung tumors smaller than 3 cm that are located in peripheral lung and do not involve major blood vessels or airways. The rationale for ablative therapies relies on the fact that focused delivery of energy induces cell death and pathologic necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid and uterine lesions. In the lung, and specifically in the setting of metastatic disease, the 3 main indications for lung ablation are to serve as (1) curative intent, (2) as a strategy to achieve a chemo-holiday in oligometastatic disease, and (3) in oligoprogressive disease. Following these premises, the current paper aims to review the rationale, indications, and outcomes of thermal ablation as a form of local therapy in the treatment of primary and metastatic lung disease.

Ablative Techniques for Sarcoma Metastatic Disease: Current Role and Clinical Applications

Sarcomas are heterogenous mesenchymal neoplasms with more than 80 different histologic subtypes. Lung followed by liver and bone are the most common sites of sarcoma metastatic disease. Ablative techniques have been recently added as an additional alternative curative or palliative therapeutic tool in sarcoma metastatic disease. When compared to surgery, ablative techniques are less invasive therapies which can be performed even in non-surgical candidates and are related to decreased recovery time as well as preservation of the treated organ’s long-term function. Literature data upon ablative techniques for sarcoma metastatic disease are quite heterogeneous and variable regarding the size and the number of the treated lesions and the different histologic subtypes of the original soft tissue or bone sarcoma. The present study focuses upon the current role of minimal invasive thermal ablative techniques for the management of metastatic sarcoma disease. The purpose of this review is to present the current minimally invasive ablative techniques in the treatment of metastatic soft tissue and bone sarcoma, including local control and survival rates.

Percutaneous image-guided thermal ablation of lung cancer: What is the evidence?

Thermal ablation techniques have now been used for more than twenty years in the treatment of primary lung tumours, predominantly non-small cell lung cancer (NSCLC). Although primarily used for the treatment of early-stage disease in non-surgical patients, thermal ablation is now also being used in selected patients with oligometastatic and oligoprogressive disease. This review discusses the techniques available for thermal ablation, the evidence for use of thermal ablation in primary lung tumours in early- and advanced-stage disease and compares thermal ablation to alternative treatment strategies.

Microwave ablation induces abscopal effect via enhanced systemic antitumor immunity in colorectal cancer

Background

Thermal ablation is the primary procedure for the local treatment of lung metastases. It is known that radiotherapy and cryoablation can stimulate an abscopal effect, while the occurrence of abscopal effect induced by microwave ablation is less; the cellular and molecular mechanisms involved in the abscopal effect after microwave ablation should be further elucidated.

Methods

CT26 tumor-bearing Balb/c mice were treated with microwave ablation with several combinations of ablation power and time duration. The growth of primary or abscopal tumors and the survival of mice were both monitored; moreover, immune profiles in abscopal tumors, spleens, and lymph nodes were examined by flow cytometry.

Results

Microwave ablation suppressed tumor growth in both primary and abscopal tumors. Both local and systemic T-cell responses were induced by microwave ablation. Furthermore, the mice exhibiting significant abscopal effect after microwave ablation markedly elevated Th1 cell proportion both in the abscopal tumors and spleens.

Conclusions

Microwave ablation at 3 w-3 min not only suppressed tumor growth in the primary tumors but also stimulated an abscopal effect in the CT26-bearing mice via the improvement of systemic and intratumoral antitumor immunity.

Image-Guided Percutaneous and Transarterial Therapies for Primary and Metastatic Lung Cancer

Lung cancer is the leading cause of cancer mortality in the world. A significant proportion of patients with lung cancer are not candidates for surgery and must resort to other treatment alternatives. Rapid technological advancements in fields like interventional radiology have paved the way for valid treatment modalities like image-guided percutaneous and transarterial therapies for treatment of both primary and metastatic lung cancer. The rationale of ablative therapies relies on the fact that focused delivery of energy induces tumor destruction and pathological necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid, or uterine lesions. In the lung, the 3 main indications for lung ablation include local curative intent, a strategy to achieve a chemoholiday in oligometastatic disease, and recently, oligoprogressive disease. Transarterial therapies include a set of catheter-based treatments that involve delivering embolic and/or chemotherapeutic agents directed into the target tumor via the supplying arteries. This article provides a comprehensive review of the various techniques available and discusses their applications and associated complications in primary and metastatic lung cancer.

Safety and Efficacy Outcomes From a Single-Center Study of Image-Guided Percutaneous Microwave Ablation for Primary and Metastatic Lung Malignancy

Introduction

Image-guided percutaneous microwave ablation (MWA) is becoming a more common treatment option for patients with primary and metastatic lung malignancies. Nevertheless, there is limited literature on the safety and efficacy of MWA compared with standard-of-care therapy, including surgical resection and radiation. This study will report the long-term outcomes after MWA for pulmonary malignancies and investigate the factors related to efficacy, including lesion size, location, and ablation power.

Methods

Retrospective single-center study analyzing 93 patients who underwent percutaneous MWA for primary or metastatic lung malignancies. Outcomes included immediate technical success, local tumor recurrence, overall survival, disease-specific survival, and complications.

Results

At a single institution, 190 lesions (81 primary and 109 metastatic) were treated in 93 patients. Immediate technical success was achieved in all cases. Freedom from local recurrence was 87.6%, 75.3%, and 69.2% and overall survival was 87.7%, 76.2%, and 74.3% at 1 year, 2 years, and 3 years, respectively. Disease-specific survival was 92.6%, 81.8%, and 81.8%. The most common complication was pneumothorax, which occurred in 54.7% (104 of 190) of procedures, with 35.2% (67 of 190) requiring a chest tube. No life-threatening complications occurred.

Conclusions

Percutaneous MWA seems safe and effective for treatment of primary and metastatic lung malignancies and should be considered for patients with limited metastatic burden and lesions less than 3 cm in size.

Prediction of Ablation Volume in Percutaneous Lung Microwave Ablation: A Single Centre Retrospective Study

BACKGROUND

Percutaneous Microwave Ablation (MWA) of lung malignancies is a procedure with many technical challenges, among them the risk of residual disease. Recently, dedicated software able to predict the volume of the ablated area was introduced. Cone-beam computed tomography (CBCT) is the imaging guidance of choice for pulmonary ablation in our institution. The volumetric prediction software (VPS) has been installed and used in combination with CBCT to check the correct position of the device. Our study aimed to compare the results of MWA of pulmonary tumours performed using CBCT with and without VPS.

METHODS

We retrospectively reviewed 1-month follow-up enhanced contrast-enhanced computed tomography (CECT) scans of 10 patients who underwent ablation with the assistance of VPS (group 1) and of 10 patients who were treated without the assistance of VPS (group 2). All patients were treated for curative purposes, the maximum axial diameter of lesions ranged between 5 and 22 mm in group 1 and between 5 and 25 mm in group 2. We compared the presence of residual disease between the two groups.

RESULTS

In group 1 residual disease was seen in only 1 patient (10%) in which VPS had ensured complete coverage of the tumour. In group 2 residual disease was found in 3 patients (30%).

CONCLUSIONS

Using this software during MWA of lung malignancies could improve the efficacy of the treatment compared to the conventional only CBCT guidance.

Toward Improved Outcomes for Patients With Lung Cancer Globally: The Essential Role of Radiology and Nuclear Medicine

PURPOSE

Key to achieving better population-based outcomes for patients with lung cancer is the improvement of medical imaging and nuclear medicine infrastructure globally. This paper aims to outline why and spark relevant health systems strengthening.

METHODS

The paper synthesizes the global lung cancer landscape, imaging referral guidelines (including resource-stratified ones), the reliance of TNM staging upon imaging, relevant multinational health technology assessments, and precisely how treatment selection and in turn patient outcomes hinge upon imaging findings. The final discussion presents data on current global gaps in both diagnostics (including imaging) and therapies and how, informed by such data, improved population-based outcomes are tangible through strategic planning.

RESULTS

Imaging findings are central to appropriate lung cancer patient management and can variably lead to life-prolonging interventions and/or to life-enhancing palliative measures. Early-stage lung cancer can be treated with curative intent but, unfortunately, most patients with lung cancer still present at advanced stages and many patients lack access to both diagnostics and therapies. Furthermore, half of lung cancer cases occur in low- and middle-income countries. The role of medical imaging and nuclear medicine in lung cancer management, as outlined herein, may help inform strategic planning.

CONCLUSION

Lung cancer is the number one cancer killer worldwide. The essential role that medical imaging and nuclear medicine play in early diagnosis and disease staging cannot be overstated, pivotal in selecting the many patients for whom measurably improved outcomes are attainable. Prevention synergized with patient-centered, compassionate, high-quality lung cancer management provision mandate that strategic population-based planning, including universal health coverage strategies, should extend well beyond the scope of disease prevention to include both curative and noncurative treatment options for the millions afflicted with lung cancer.

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.

Microwave ablation treatment for medically inoperable stage I non-small cell lung cancers: long-term results

OBJECTIVES

In the present study, we aim to show the results of microwave ablation (MWA) for medically inoperable stage I non-small cell lung cancers (NSCLCs) with long-term follow-up.

METHODS

From Feb 2011 to Mar 2016, patients with histologically proven clinical stage I NSCLC were treated with CT-guided MWA and retrospectively analyzed. The primary end point was overall survival (OS). Secondary end points included disease-free survival (DFS), cancer-specific survival (CSS), and complications.

RESULTS

A total of 105 patients with 105 lesions underwent MWA. The mean age was 70.7 years (range: 40-86 years), and the mean diameter of all lesions was 2.40 cm (range: 0.9-4.0 cm). Adenocarcinoma was the most common histological type (77, 73.3%), followed by squamous cell carcinomas (21, 20%) and undefined NSCLC (7, 6.7%). With a median follow-up of 54.8 months, the median DFS was 36.0 months, and 1-, 3-, and 5-year DFS rates were 89.5%, 49.4%, and 42.7%, respectively. The median CSS and OS were 89.8 and 64.2 months, respectively. The OS rate was 99% at 1 year, 75.6% at 3 years, and 54.1% at 5 years, while the CSS rates were 99%, 78.9%, and 60.9%, respectively. Patients with stage IB lesions had significant shorter DFS (22.3 months vs. undefined, HR: 11.5, 95%CI: 5.85-22.40) and OS (37.3 vs. 89.8 months, HR: 8.64, 95% CI: 4.49-16.60) than IA disease.

CONCLUSION

MWA is a safe, effective, and potentially curative therapy for medically inoperable stage I NSCLC patients.

KEY POINTS

• In this multicenter retrospective study which included 105 patients, we found the median overall survival (OS) was 64.2 months. The OS rate was 99% at 1 year, 75.6% at 3 years, and 54.1% at 5 years. • Procedures were technically successful and well tolerated in all patients. Most MWA complications were mild or moderate.

Management of Long-Term Sores and Ulcers of Breast Cancer Survivors With Chinese Herbal Medicines: A Case Report

BACKGROUND

The treatment of long-term sores and ulcers of breast cancer metastatic recurrence is a serious challenge with successful cases rarely being documented. Herein we reported a successful case using the internal vitality supporting method of Chinese herbal medicine (CHM).

CASE SUMMARY

A 59-year-old female Chinese patient, 10 years after breast cancer surgery, developed metastatic lesions in the lung. Thereafter she received radiofrequency ablation and adjuvant treatments for 1 year with severe sequelae, a right unhealed sore and ulcer. She became frustrated and depressive. And subsequently sought exclusive treatment under the guidance of a Traditional Chinese Medicine (TCM) physician. The patient's condition was categorized as a Qi (or vitality) deficiency-related sore and ulcer. In the next six months, the patient still follows a traditional Chinese medicine therapeutic regimen based on the internal vitality supporting method of Chinese herbs.

CONCLUSION

The sore and ulcer from the surgical wound were healed. Up to now, the tumor markers have remained stable. TCM personalized survivorship treatment and psychosocial support can help patients improve their quality of life after acute treatment and in the long-term for cancer survivors.

Efficacy of Lung-Tuned Monopole Antenna for Microwave Ablation: Analytical Solution and Validation in a Ventilator-Controlled ex Vivo Porcine Lung Model

The goal of this study was to optimize a lung-tuned monopole antenna to deliver microwave energy at 2.45 GHz into a novel ventilator-controlled ex vivo lung model. An analytic and parametric approach was utilized to create an optimized monopole antenna that was impedance-matched to aerated lung tissue. This lung-tuned antenna was then fabricated using a copper 0.085" semi-rigid copper coaxial cable. For validation, the lung-tuned antenna was inserted centrally into lobes of a ex vivo porcine lung that was fully inflated to physiologically appropriate volumes. Microwave ablations were then created at 50 and 100 W for 1 minute and 5 minutes. Reflected power, cross sectional ablation sizes and spherical shape of the lung-tuned antenna were compared against a liver-tuned antenna in the ventilator-controlled ex vivo lung tissue. The study showed that the lung-tuned antennas delivered energy significantly more efficiently, with less reflected power, compared to the conventionally-used liver-tuned antennas at 50 W at 1 minute (11.8±3.0 vs 16.3±3.1 W; p value=0.03) and 5 minutes (16.2±2.8 vs 19.4±2.9 W; p value=0.04), although this was only true using 100 W at the 1 minute time point (29.0±3.5 vs 38.0±5.3 W; p value=0.02). While overall ablation zone sizes were comparable between the two types of antenna, the lung-tuned antenna did create a significantly more spherical ablation zone compared to the liver-tuned antenna at the 1 minute, 50 W setting (aspect ratio: 0.43±0.07 vs 0.38±0.04; p value=0.04). In both antenna groups, there was a significant rise in the ablation zone aspect ratio between 1 and 5 minutes, indicating that higher power and time settings can increase the spherical shape of ablation zones when using tuned antennas. Adapting this combined analytic and parametric approach to antenna design can be implemented in adaptive tissue-tuning for real-time microwave ablation optimization in lung tissue.

Local progression after computed tomography-guided microwave ablation in non-small cell lung cancer patients: prediction using a nomogram model

OBJECTIVES

To develop an effective nomogram model for predicting the local progression after computed tomography-guided microwave ablation (MWA) in non-small cell lung cancer (NSCLC) patients.

METHODS

NSCLC patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (4:1). The predictors of local progression identified by univariable and multivariable analyses in the training cohort were used to develop a nomogram model. The C-statistic was used to evaluate the predictive accuracy in both the training and validation cohorts.

RESULTS

A total of 304 patients (training cohort: n = 250; validation cohort: n = 54) were included in this study. The predictors selected into the nomogram for local progression included the tumor subtypes (odds ratio [OR], 2.494; 95% confidence interval [CI], 1.415-4.396, p = 0.002), vessels ≥3 mm in direct contact with tumor (OR, 2.750; 95% CI, 1.263-5.988; p = 0.011), tumor diameter (OR, 2.252; 95% CI, 1.034-4.903; p = 0.041) and location (OR, 2.442; 95% CI, 1.201-4.965; p = 0.014). The C-statistic showed good predictive performance in both cohorts, with a C-statistic of 0.777 (95% CI, 0.707-0.848) internally and 0.712 (95% CI, 0.570-0.855) externally (training cohort and validation cohort, respectively). The optimal cutoff value for the risk of local progression was 0.39.

CONCLUSIONS

Tumor subtypes, vessels ≥3 mm in direct contact with the tumor, tumor diameter and location were predictors of local progression after MWA in NSCLC patients. The nomogram model could effectively predict the risk of local progression after MWA. Patients showing a high risk (>0.39) on the nomogram should be monitored for local progression.

Computed Tomography-Guided Percutaneous Microwave Ablation for Renal Cell Carcinoma: Impact of Tumor Size on the Progression Survival Rates

The aim of the present study was to evaluate the safety and efficacy of computed tomography (CT)-guided percutaneous microwave ablation (MWA) of renal cell carcinoma (RCC) along with identifying prognostic factors affecting the progression survival rate. Institutional database retrospective research identified 69 patients with a biopsy proven solitary T1a (82.6%) or TIb (17.4%) RCC who have underwent percutaneous CT-guided MWA. Kaplan–Meier survival estimates for events were graphed and Cox regression analysis was conducted. Mean patient age was 70.4 ± 11.5 years. Mean size of the lesions was 3 ± 1.3 cm. Mean follow up time was 35.6 months (SD = 21.1). The mean progression free survival time from last ablation was 84.2 months. For T1a tumors, the cumulative progression free survival rate for 1, 6, 12 and 36 months were 100% (SE = 0%), 91.2% (SE = 3.7%), 91.2% (SE = 3.7%) and 87.5% (SE = 4.4%); the recurrence free survival rate for T1a RCC was 94.9%. For T1b tumors, the cumulative progression free survival rate for 1, 6, 12 and 36 months were 100% (SE = 0%), 63.6% (SE = 14.5%), 63.6% (SE = 14.5%) and 63.6% (SE = 14.5%). Grade 1 complications were recorded in 5 (7.2%) patients. Significantly greater hazard for progression was found in cases with a tumor size > 4 cm (HR = 9.09, p = 0.048). No statistically important difference regarding tumor progression was recorded between T1a tumors with a diameter ≤3 cm and >3 cm. In summary, the results of the present study show that CT guided percutaneous MWA is an effective technique for treatment of T1a renal cell carcinomas, irrespective of tumor size. T1b tumors were associated with higher progression rates.

Imaging following thermal ablation of early lung cancers: expected post-treatment findings and tumour recurrence

Thermal ablation is a minimally invasive technique that is growing in acceptance and popularity in the management of early lung cancers. Although curative resection remains the optimal treatment strategy for stage I pulmonary malignancies, percutaneous ablative treatments may also be considered for selected patients. These techniques can additionally be used in the treatment of oligometastatic disease. Thermal ablation of early lung tumours can be achieved using several different techniques. For example, microwave ablation (MWA) and radiofrequency ablation (RFA) utilise extreme heat, whereas cryoablation uses extremely cold temperatures to cause necrosis and ultimately cell death. Typically, post-ablation imaging studies are performed within the first 1-3 months with subsequent imaging performed at regular intervals to ensure treatment response and to evaluate for signs of recurrent disease. Surveillance imaging is usually undertaken with computed tomography (CT) and integrated positron-emission tomography (PET)/CT. Typical imaging findings are usually seen on CT and PET/CT following thermal ablation of lung tumours, and it is vital that radiologists are familiar with these appearances. In addition, radiologists should be aware of the imaging findings that indicate local recurrence following ablation. The objective of this review is to provide an overview of the expected post-treatment findings on CT and PET/CT following thermal ablation of early primary lung malignancies, as well as describing the imaging appearances of local recurrence.

Imaging of the thorax after percutaneous thermal ablation of lung malignancies

Image-guided thermal ablation is a minimally invasive treatment option for patients with early stage non-small cell lung cancer or metastatic disease to the lungs. Percutaneous ablation treats malignant tumours in situ, which precludes histopathological evaluation of the ablated tumours. Imaging studies are used as surrogates to assess technical and clinical success. Although it is not universally accepted, a common protocol for surveillance imaging includes contrast-enhanced computed tomography (CT) at 1, 3, 6, 9, 12, 18, 24 months, and yearly thereafter. Integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography (PET)/CT imaging is recommended at 3 and 12 months and when recurrent disease is suspected. There is a complex evolution of the ablation zone on CT and PET imaging studies. The zone of ablation, initially larger than the ablated tumour, undergoes gradual involution. In the process, it may cavitate and resemble a lung abscess. Different contrast-enhancement and radionuclide uptake patterns in and around the ablation zone may indicate a wide range of diagnostic possibilities from a normal physiological response to local progression. Ultimately, the zone of ablation may be replaced by a variety of findings including linear bands of density, pleural thickening, or residual necrotic tumour. Diagnostic and interventional radiologists interpreting post-ablation imaging studies must have a clear understanding of the ablation process and imaging findings on surveillance studies. Accurate and timely recognition of complications and/or local recurrence is necessary to guide further therapy. The purpose of this article is to review imaging protocols and salient imaging findings after thermal ablation of lung malignancies.

Finite Element Analysis of the Microwave Ablation Method for Enhanced Lung Cancer Treatment

Simple Summary

Microwave ablation is a promising modality for treating cancerous tumor cells in patients with localized lung cancer who are non-surgical candidates. Microwave ablation requires the control of the elevation of temperature, ensuring the destruction of cancer cells without damaging healthy tissue. Despite the unquestionable benefits, such as enlarged ablation zones and reduced procedure times, the respiratory movement of the lungs may affect the development and evolution of the necrotic tissue. Apart from the experimental methods, computer modeling has proven to be a powerful approach to improving the ablative treatment’s performance. This study aims to provide a step forward in patient safety by delivering optimal conditions necessary for microwave ablation to be as effective as possible for curing lung cancer with minimized invasiveness and collateral damage. The primary goal is to transfer the treatment plan based on simulation outputs into a reliable and safe microwave ablation procedure.

Abstract

Knowledge of the frequency dependence of the dielectric properties of the lung tissues and temperature profiles are essential characteristics associated with the effective performance of microwave ablation. In microwave ablation, the electromagnetic wave propagates into the biological tissue, resulting in energy absorption and providing the destruction of cancer cells without damaging the healthy tissue. As a consequence of the respiratory movement of the lungs, however, the accurate prediction of the microwave ablation zone has become an exceptionally demanding task. For that purpose, numerical modeling remains a primordial tool for carrying out a parametric study, evaluating the importance of the inherent phenomena, and leading to better optimization of the medical procedure. This paper reports on simulation studies on the effect of the breathing process on power dissipation, temperature distribution, the fraction of damage, and the specific absorption rate during microwave ablation. The simulation results obtained from the relative permittivity and conductivity for inflated and deflated lungs are compared with those obtained regardless of respiration. It is shown that differences in the dielectric properties of inflated and deflated lungs significantly affect the time evolution of the temperature and its maximum value, the time, the fraction of damage, and the specific absorption rate. The fraction of damage determined from the degree of tissue injury reveals that the microwave ablation zone is significantly larger under dynamic physical parameters. At the end of expiration, the ablation lesion area is more concentrated around the tip and slot of the antenna, and the backward heating effect is smaller. The diffuse increase in temperature should reach a certain level to destroy cancer cells without damaging the surrounding tissue. The obtained results can be used as a guideline for determining the optimal conditions to improve the overall success of microwave ablation.

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.

Survival prediction for non-small cell lung cancer patients treated with CT-guided microwave ablation: development of a prognostic nomogram

OBJECTIVES

To explore the outcomes of CT-guided percutaneous microwave ablation (MWA) in non-small cell lung cancer (NSCLC) patients, and then develop an effective nomogram to predict the survival.

METHODS

NSCLC patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (3:1). The primary outcome measurement was overall survival (OS), whose predictors were identified by univariate and multivariate analyses in the training cohort. Then, a predictive nomogram was developed to predict the OS, with the predictive accuracy evaluated by C-statistic and receiver operating characteristic in both the training and validation cohorts.

RESULTS

A total of 234 patients (training cohort: n = 176; validation cohort: n = 58) and 271 tumors with a median OS of 17.0 ± 12.2 months were included. The predictors selected into the nomogram included tumor diameter (hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.37-3.30; p < 0.001), extrapulmonary metastases (HR, 1.77; 95% CI, 1.06-2.95; p = 0.030), tumor stage (HR, 1.38; 95% CI, 1.07-1.79; p = 0.013), tumor type (HR, 2.00; 95% CI, 1.48-2.72; p < 0.001) and post-MWA TKIs (HR, 0.55; 95% CI, 0.34-0.89; p < 0.001), based on the results of univariate and multivariate analyses. The C-statistic showed good predictive performance, with a C-statistic of 0.838 (95% CI, 0.779-0.897) internally and 0.808 (95% CI, 0.695-0.920) externally (training cohort and validation cohort, respectively).

CONCLUSIONS

The nomogram was effective in predicting the OS in NSCLC patients treated with MWA, and could be applied to identify patients who may benefit most from MWA and be helpful for clinical decision making.

Clinical efficacy of systemic chemotherapy combined with radiofrequency ablation and microwave ablation for lung cancer: a comparative study

OBJECTIVE

Local thermal ablation, a minimally invasive technique, has been widely used in clinical treatment of lung cancer. This study aimed to discuss the clinical efficacy of systemic chemotherapy combined with radiofrequency ablation (RFA) versus systemic chemotherapy combined with microwave ablation (MWA) in treating lung cancer.

METHODS

A retrospective analysis involving 124 lung cancer patients, who received RFA (n = 68) and MWA (n = 56) combined with systemic chemotherapy in Cangzhou People's Hospital from August 2017 to December 2019, was conducted. Before comparative analysis for therapeutic efficacy, the two groups of patients were matched with propensity score matching method at a ratio of 1:1. Indicators including progression-free survival (PFS), overall survival (OS), short-term efficacy, tumor marker level, local tumor control rate, and postoperative complications were comparatively analyzed.

RESULTS

There was no statistical difference in disease control rate and objective response rate (90.6% and 78.1% vs 93.8% and 84.4%) between RFA group and MWA group. The incidence of complications was 12.5% in RFA group and 18.8% in MWA group with no statistically significant difference. In addition, the local tumor control rate in MWA group (90.6%) was significantly higher than that in RFA group (78.1%). Regarding survival, a statistically significant difference was observed in median PFS of RFA and MWA groups (9.2 months vs 10.4 months, p < 0.05), while OS in two groups slightly varied.

CONCLUSION

MWA was superior to RFA over local tumor control rate and PFS and showed great potential in lung cancer ablation treatment.

Heating technology for malignant tumors: a review

The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

Society of Interventional Radiology Quality Improvement Standards on Percutaneous Ablation of Non-Small Cell Lung Cancer and Metastatic Disease to the Lungs

PURPOSE

To provide guidance on quality improvement thresholds for outcomes and complications of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease.

MATERIALS AND METHODS

A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Data were extracted from relevant studies and thresholds were derived from a calculation of 2 standard deviations from the weighted mean of each outcome. A modified Delphi technique was used to achieve consensus agreement on the thresholds.

RESULTS

Data from 29 studies, including systematic reviews and meta-analyses, retrospective cohort studies, and single-arm trials were extracted for calculation of the thresholds. The expert writing group agreed on thresholds for local control, overall survival and adverse events associated with image-guided thermal ablation.

CONCLUSION

SIR recommends utilizing the indicator thresholds to review and assess the efficacy of ongoing quality improvement programs. When performance falls above or below specific thresholds, consideration of a review of policies and procedures to assess for potential causes, and to implement changes in practices, may be warranted.

Continuous versus pulsed microwave ablation in the liver: any difference in intraoperative pain scores?

Background

This study prospectively compared intraoperative pain scores during percutaneous microwave ablation of the liver in patients randomized between continuous and pulsed energy delivery algorithms.

Methods

During a 12-month period, 20 patients who underwent microwave liver ablation were prospectively randomized between 2 different energy delivery modes: “continuous mode” (CM, n=10) and “pulsed mode” (PM, n=10). All ablation sessions were performed using the same microwave ablation platform under computed tomographic guidance and intravenous analgesia. Within 30 min post ablation, all patients completed a questionnaire assigning a numeric pain intensity score from 0 (no pain) to 10.

Results

Mean pain scores were 8.17±1.850 in the CM group and 4.50±1.567 in the PM group, with a statistically significant difference of 3.667±2.807 pain units (P=0.001). The mean procedure time was 53.5±20.90 min in the PM group vs. 58.5±17.44 min in the CM group (P=0.279). The mean size of the lesions was 2.81±0.95 cm in the PM group and 2.81±0.85 cm in the CM group (P=0.984). On a per-lesion basis, technical success was achieved in all evaluable tumors in both groups. No difference was noted in the local tumor control on the 6-month imaging evaluation. No complications were observed in the CM arm, while small perihepatic hemorrhagic fluid collections were reported in the PM group.

Conclusions

Both algorithms for microwave energy delivery have comparable treatment effects in terms of 6-month local tumor control for liver lesions <3 cm in diameter. PM treatments compared to CM appear to induce significantly less pain in patients undergoing percutaneous liver ablation under intravenous analgesia.

Alternatives to Surgery for Early-Stage Non-Small Cell Lung Cancer: Thermal Ablation

Thermal ablation involves the application of heat or cold energy to the lung under image guidance to eradicate tumors. It is indicated for treatment of early-stage non-small cell lung cancer in nonsurgical patients. Ablation technologies have advanced, such that nearly all small tumors can now be treated safely and effectively. Ablation does not cause a lasting decline in pulmonary function tests and may therefore be used to treat multiple synchronous and metachronous lung tumors, a chief advantage over other treatments. Large series with intermediate- and long-term data have been reported showing favorable overall survival, similar to radiation therapy.

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.

Long-Term Outcomes in Percutaneous Radiofrequency Ablation for Histologically Proven Colorectal Lung Metastasis

Introduction

To evaluate the long-term outcome of image-guided radiofrequency ablation (RFA) when treating histologically confirmed colorectal lung metastasis in terms of overall survival (OS), progression-free survival (PFS) and local tumour control (LTC).

Materials and Methods

Retrospective single-centre study. Consecutive RFA treatments of histologically proven lung colorectal metastases between 01/01/2008 and 31/12/14. The primary outcome was patient survival (OS and PFS). Secondary outcomes were local tumour progression (LTP) and complications. Prognostic factors associated with OS/ PFS were determined by univariate and multivariate analyses.

Results

Sixty patients (39 males: 21 females; median age 69 years) and 125 colorectal lung metastases were treated. Eighty percent (n = 48) also underwent lung surgery for lung metastases. Mean metastasis size (cm) was 1.4 ± 0.6 (range 0.3–4.0). Median number of RFA sessions was 1 (1–4). During follow-up (median 45.5 months), 45 patients died (75%). The estimated OS and PFS survival rates at 1, 3, 5, 7, 9 years were 96.7%, 74.7%, 44.1%, 27.5%, 16.3% (median OS, 52 months) and 66.7%, 31.2%, 25.9%, 21.2% and 5.9% (median PFS, 19 months). The LTC rate was 90% with 6 patients developing LTP with 1-, 2-, 3- and 4-year LTP rates of 3.3%, 8.3%, 10.0% and 10.0%. Progression-free interval < 1 year (P = 0.002, HR = 0.375) and total number of pulmonary metastases (≥ 3) treated (P = 0.037, HR = 0.480) were independent negative prognostic factors. Thirty-day mortality rate was 0% with no intra-procedural deaths.

Conclusion

The long-term OS and PFS following RFA for the treatment of histologically confirmed colorectal lung metastases demonstrate comparable oncological durability to surgery.

Electronic supplementary material

The online version of this article (10.1007/s00270-020-02623-1) contains supplementary material, which is available to authorized users.

Synchronous core-needle biopsy and microwave ablation for highly suspicious malignant pulmonary nodule via a coaxial cannula

Aims

This study aimed to evaluate the safety and feasibility of computed tomography (CT)-guided synchronous percutaneous core-needle biopsy and microwave ablation (MWA) for highly suspicious malignant pulmonary nodules.

Materials and Methods

This retrospective study evaluated medical records of 54 consecutive patients (mean age, 65.5 ± 11.2 years) with 62 highly suspicious malignant pulmonary nodules who synchronously underwent percutaneous core-needle biopsy and MWA via a coaxial cannula (Group A) or sequentially underwent these procedures (Group B) from September 2016 to November 2017. All patients were followed up for at least 6 months after MWA. The safety and feasibility of synchronous core-needle biopsy and MWA were analyzed by comparing clinical data, technical success rate, complication, and curative effect per nodule with those of sequential procedures.

Results

Technical success rates were 100% in both groups. The pneumothorax rate was 29.6% (8/27) in Group A and 57.1% (20/35) in Group B, which was statistically different (P = 0.031). In Group A, hemoptysis and pleural effusion rates were 22.2% (6/27), and in Group B, the corresponding rates were 28.6% (10/35) and 20.0% (7/35), respectively. No postprocedural pulmonary artery pseudoaneurysm, bronchopleural fistula, or needle-tract tumor seeding developed in both groups. After 6 months' follow-up, the effective rates (complete + partial response) in both groups were 100%.

Conclusions

Synchronous core-needle biopsy and MWA via a coaxial cannula is technically safe and feasible in the management of highly suspicious malignant pulmonary nodules, and this procedure has lesser complications and similar effects (both 100% effective treatment) compared with sequential procedures.

Delta-radiomics increases multicentre reproducibility: a phantom study

Texture analysis (TA) can provide quantitative features from medical imaging that can be correlated to clinical endpoints. The challenges relevant to robustness of radiomics features have been analyzed by many researchers, as it seems to be influenced by acquisition and reconstruction protocols. Delta-texture analysis (D-TA), conversely, consist in the analysis of TA feature variations at different acquisition times, usually before and after a therapy. Aim of this study was to investigate the influence of different CT scanners and acquisition parameters in the robustness of TA and D-TA. We scanned a commercial phantom (CIRS model 467, Gammex, Middleton, WI, USA), that is used for the calibration of electron density, two times by varying the disposition of plugs, using three different scanners. After the segmentation, we extracted TA features with LifeX and calculated TA features and D-TA features, defined as the variation of each TA parameters extracted from the same position by varying the plugs with the formula (Y-X)/X. The robustness of TA and D-TA features were then tested with intraclass coefficient correlation (ICC) analysis. The reliability of TA parameters across different scans, with different acquisition parameters and ROI positions has shown poor reliability in 12/37 and moderate reliability in the remaining 25/37, with no parameters showing good reliability. The reliability of D-TA, conversely, showed poor reliability in 10/37 parameters, moderate reliability in 10/37 parameters, and good reliability in 17/37 parameters. The comparison between TA and D-TA ICCs showed a significant difference for the whole group of parameters (p:0.004) and for the subclasses of GLCM parameters (p:0.033), whereas for the other subclasses of matrices (GLRLM, NGLDM, GLZLM, Histogram), the difference was not significant. D-TA features seem to be more robust than TA features. These findings reinforce the potentiality for using D-TA features for early assessment of treatment response and for developing tailored therapies. More work is needed in a clinical setting to confirm the results of the present study.

[Minimally Invasive Therapies for Early Stage Non-small Cell Lung Cancer]

肺癌是目前全球最常见的癌症和癌症死亡的主要原因，其中非小细胞肺癌（non-small-cell lung cancer, NSCLC）约占肺癌总数的85%。随着计算机断层扫描（computed tomography, CT）等影像学筛查手段得到不断普及，肺癌的病理类型从以往以晚期中央型肺鳞癌为主，转变为现在的以早期周围型磨玻璃样结节等为表现的肺腺癌为主。肺癌的早诊早治有着重要意义，而微创介入技术的不断发展完善，使得肺癌治疗有了更多的选择，例如立体定向放射、经皮穿刺消融、支气管介入等。本文将就目前临床常见的这些微创介入治疗的作用原理、优势、不足及展望做一评述。

Radiofrequency Ablation, Where It Stands in Interventional Radiology Today

Radiofrequency ablation (RFA) is one of the first developed minimally invasive definitive cancer therapies. The safety and efficacy of RFA is well documented and has led to its incorporation into multiple international societal guidelines. By expanding on the body of knowledge acquired during the clinical use of RFA, alternative ablative technologies have emerged and are successfully competing for locoregional therapy market share. The adaption of newer ablative technologies is leading to a rapid decline in the utilization of RFA by interventional radiologists despite the lack of proven superiority. In their 2010 article, Hong and Georgiades stated "… RFA is likely to remain the mainstay of ablations for small tumors until sufficient experience emerges for the widespread acceptance for alternative ablative modalities." Within a decade of this publication, has this time arrived?

Lung Ablation: Indications and Techniques

Lung ablation is ever more recognized since its initial report and use almost two decades ago. With technological advancements in thermal modalities, particularly microwave ablation and cryoablation, better identification of the cohort of patients who best benefit from ablation, and understanding the role of imaging after ablation, image-guided thermal ablation for primary and secondary pulmonary malignancies is increasingly recognized and accepted as a cogent form of local therapy.

Percutaneous thermal ablation of primary and secondary lung tumors: Comparison between microwave and radiofrequency ablation

PURPOSE

The purpose of this study was to retrospectively compare microwave (MWA) and radiofrequency (RFA) ablation in the percutaneous treatment of primary and secondary lung tumors.

MATERIAL AND METHODS

A total of 115 patients with a total of 160 lung tumors (primary, n=41; secondary, n=119) were retrospectively included. There were 56 men and 59 women with a mean age of 67.8±12.7 (SD) years (range: 42-89 years) who underwent either MWA (61 patients; 79 tumors) or RFA (54 patients; 81 tumors). The primary study endpoints were local recurrence during follow-up and the incidence of complications during and following thermal ablation. The MWA and RFA groups were compared in terms of treatment efficacy and complication rates.

RESULTS

Demographics were similar in the two groups. Mean tumor diameter was smaller in RFA group (13.1±5.1 [SD] mm; range: 4-27mm) than in MWA group (17.1±8.3 [SD] mm; range: 5-36mm) (P<0.001). Ablation volumes at one month were 24.1±21.7 (SD) cm³ (range: 2-97.8 cm³) in RFA group and 30.2±35.9 (SD) cm³ (range: 1.9-243.8 cm³) in MWA group (P=0.195). During a mean overall follow-up duration of 488±407 (SD) days (range: 30-1508 days), 9/160 tumors (5.6%) developed local recurrence: six (6/79; 7.6%) in the RFA group and three (3/81; 3.7%) in the MWA group (P=0.32). Pneumothoraces were more frequent in the RFA group (32/79; 40.5%) than in the MWA group (20/81; 24.7%) (P=0.049). The mean length of hospital stay was 4.5±3.7 (SD) days (range: 1-25 days) in the RFA group and 4.7±4.6 (SD) days (range: 2-25 days) in the MWA group (P=0.76).

CONCLUSIONS

MWA favorably compares with RFA and can be considered as an effective and safe thermal ablation technique for lung tumors, especially in situations where RFA has limited efficacy.

Is microwave ablation more effective than radiofrequency ablation in achieving local control for primary pulmonary malignancy?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was 'Is microwave ablation (MWA) more effective than radiofrequency ablation (RFA) in achieving local control for primary lung cancer?'. Altogether, 439 papers were found, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Both are thermal ablative techniques, with microwave ablation (MWA) the newer technique and radiofrequency ablation (RFA) with a longer track record. Lack of consensus with regard to definitions of technical success and efficacy and heterogeneity of study inclusions limits studies for both. The only direct comparison study does not demonstrate a difference with either technique in achieving local control. The quality of evidence for MWA is very limited by retrospective nature and heterogeneity in technique, power settings and tumour type. Tumour size and late-stage cancer were shown to be associated with higher rates of local recurrence in 1 MWA study. RFA studies were generally of a higher level of evidence comprising prospective trials, systematic review and meta-analysis. The recurrence rates for MWA and RFA overlapped, and for the included studies ranged between 16% and 44% for MWA and 9% and 58% for RFA. The current evidence, therefore, does not clearly demonstrate a benefit of MWA over RFA in achieving local control in primary lung cancer.

Usefulness of percutaneous microwave ablation for large non-small cell lung cancer: A preliminary report

The role of microwave ablation (MWA) in patients with non-small cell lung cancer (NSCLC) remains ill-defined. This retrospective study evaluated the oncological outcomes of CT-guided MWA in patients with large NSCLC. Kaplan-Meier analysis was used to evaluate overall survival (OS) and cancer-specific survival (CSS). The log-rank test was used to compare survival between patients with an NSCLC size greater or smaller than 4 cm. The likelihood of local tumor progression (LTP) was analyzed using a multivariable regression model. A total of 53 patients with 65 tumors were analyzed. The mean tumor size was 5.0±1.8 cm. At the 1-month CT scan, complete tumor ablation was observed in 44.6% of cases. In 18.5% of cases a redo-MWA session was carried out, while in 4.6%, a third MWA was necessary to obtain complete tumor necrosis. The mean follow-up was 28.1±20.6 months with a median duration of 21.5 months. The 1-year, 2-year, 3-year and 5-year OS rates were 78.2, 48.3, 34.8 and 18.3%, respectively. The median CSS was 25 months (95% CI 15.5–34.5). The 1-year, 2-year, 3-year and 5-year CSS rates were 84.3, 53.7, 42.1 and 30.0%, respectively. OS in patients with tumor size ≥4 cm was significantly lower when compared with those having smaller tumors (P=0.03). LTP was observed in 19 patients (35.8%). Incomplete tumor ablation [odds ratio (OR) 6.57; P<0.05] and tumor size ≥4 cm (OR 0.18; P<0.05) were significant independent predictors of LTP. In conclusion, CT-guided MWA may represent a useful tool in the multimodality treatment of patients with large advanced NSCLC.

Percutaneous needle biopsy of retroperitoneal lesions: technical developments

Percutaneous Needle Biopsy (PNB) is the insertion of a needle into a suspected lesion or an organ with the aim to obtain cells or tissue for diagnosis. It’s a relatively non-invasive procedure and is performed by radiologist under guidance of imaging techniques such as ultrasound (US), computed tomography (CT), fluoroscopy, magnetic resonance imaging (MRI), and positron emission tomography CT (PET-CT). The choice of imaging technique depends on the evaluation of the target lesion and patient compliance. PNB includes two categories: fine-needle aspiration biopsy (FNAB) that is the use of a thin needle (18-25 gauge) to extract cells for cytological evaluation; and core needle biopsy (CNB) that is the use of a larger needle (9-20 gauge) to extract a piece of tissue for histological evaluation. The indications for biopsy are the characterization of nature (benign or malignant) of a lesion, diagnosis and staging of tumor, and biological or immunohistochemical/genetic analisys on tissue. Success of PNB is the procurement of sufficient material to characterize lesions and to guide the patient outcome. Major complications are rare. PNB became a useful technique in diagnosis and study of retroperitoneal lesions, because of a more suitable access to specific intra-abdominal structures, lowering the risk of injury of interposed structures (such as bowel, great vessels). (www.actabiomedica.it)

Magnetic resonance enterography (MRE) and ultrasonography (US) in the study of the small bowel in Crohn's disease: state of the art and review of the literature

Crohn’s disease (CD) is a chronic idiopathic disease and its diagnosis is based on a combination of clinical symptoms, laboratory tests and imaging data. There isn’t a diagnostic gold standard: the ileocolonoscopy with mucosal biopsies represents the standard for luminal disease, while cross-sectional imaging such as Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) can show transmural alterations and extraintestinal manifestations. CD is usually diagnosed in the young age and after baseline diagnosis, the patients have to undergo to variable follow-up depending on remission or active disease. The aim of our review is to compare Magnetic Resonance Enterography (MRE) to Ultrasonography (US) in the follow-up of CD. (www.actabiomedica.it)

Diagnostic value/performance of radiological liver imaging during chemoterapy for gastrointestinal malignancy: a critical review

This article reviews the main toxic effect, complications and relative imaging findings of the liver that may appear during the oncologic follow up among patients affected by gastrointestinal malignancy. Awareness of the causative chemotherapeutic agent and regimens, pathophysiology and relative characteristic imaging findings of hepatic injuries is critical in order to obtain an accurate diagnosis especially when these parenchymal lesions are focal. An accurate synergic radiological diagnosis with Computed Tomography (CT) and Magnetic Resonance (MR) techniques may induce a potential termination of ineffective/toxic chemotherapy during early phases of treatment, changing the therapeutic plan in order to avoid first unnecessary liver biopsy and then invasive treatment as hepatic resection if not required.

Efficacy of radiofrequency ablation and microwave ablation in the treatment of thoracic cancer: A systematic review and meta-analysis

BACKGROUND

Radiofrequency ablation and microwave ablation are frequently prescribed for thoracic cancer. However, few writers have been able to draw on any systematic research into the differences between the two ablation methods.

METHODS

A literature search was carried out using Embase, PUBMED, Web of Science, Cochrane Library, and CNKI databases, with additional searches carried out manually using terms associated with thoracic cancer and thermal ablation. Then we used Google Scholar for a complementary search. Data were extracted from studies of patients that underwent radiofrequency ablation or microwave ablation, and the investigator carried out efficacy evaluation and follow up. The data obtained from the literature were summarized and analyzed using Cochrane Revman software Version 5.3 and SPSS 22.0.

RESULTS

There were seven comparative studies, but no randomized studies identified for data extraction; 246 patients received radiofrequency ablation therapy and 319 controls received microwave ablation. There was no significant difference in the six-month, one-year, two-year, and three-year survival rates, and adverse reactions were found in the two treatments. For patients' long-term survival rate, the two treatments can achieve a similar survival time.

CONCLUSION

In the treatment of thoracic cancer, microwave ablation can achieve the same efficacy as radiofrequency ablation.

1000 consecutive ablation sessions in the era of computer assisted image guidance - Lessons learned

•

Computer assisted targeting techniques are simple to use and improve results in ablative tumour treatments.

•

The indications for ablative soft tissue tumour ablation are increasing.

•

Treatments are superior to resective surgery in terms of complications and hospitalization, oncological non-inferiority remains to be proven.

•

An incomplete ablation can be retreated without negative effects on survival.

•

Jet ventilation is an effective technique to minimize organ displacement during percutaneous or laparoscopic ablation.

Background

Ablation therapies for tumours are becoming more used as ablation modalities evolve and targeting solutions are getting better. There is an increasing body of long-term results challenging resection and proving lower morbidities and costs. The aim of this paper is to share the experiences from a high-volume centre in introducing computer assisted targeting solutions and efficient ablation modalities like microwave generators and irreversible electroporation.

Material and methods

One thousand consecutive treatments in one high-volume centre were evaluated retrospectively from prospectively collected data.

Results

The purpose of this paper is to present the benefits of going into computer assisted targeting techniques and microwave technology; pitfalls and overview of outcomes. The main target organ was the liver and the main indications were ablation of hepatocellular carcinomas and colorectal liver metastases. With the assistance of computer assisted targeting the local recurrence rate within 6 months has dropped from 30 to near 10%. The survival of patients with hepatocellular carcinoma and colorectal liver metastases is not worse if the tumour can be retreated after a local recurrence. Multiple colorectal liver metastases can be treated successfully.

Discussion

The incorporation of computer assisted targeting technologies for ultrasound-, ct guided- and laparoscopic tumour ablation has been very successful and without a noticeable learning curve. The same is true for switching from radiofrequency energies to microwave generators and irreversible electroporation.

Conclusion

It is well worthwhile upgrading ablation and targeting technologies to achieve excellent and reproducible results and minimizing operator dependency.

Microwave ablation followed by immediate biopsy in the treatment of non-small cell lung cancer

BACKGROUND

To evaluate the efficacy and safety of microwave ablation (MWA) followed by immediate biopsy in the treatment of non-small cell lung cancer (NSCLC) and to clarify whether pathology changes can predict treatment responses and patient survival.

METHODS

Patients with pathologically confirmed NSCLC pre-ablation were treated with MWA, and immediate biopsy was carried out right after ablation in one procedure. Pathology changes were categorized according to the pre- and postablation pathology: Group A, same histology type; Group B, paired histology type with burning degeneration; Group C, no definite histology type; Group D, no definite cancer cells. The internal correlations between pathology changes and baseline characteristics, responses to MWA and survival were evaluated.

RESULTS

A total of 68 patients were enrolled in the study, of which 19, 28, 11 and 10 patients were classified into Group A, Group B, Group C and Group D, respectively. In total, 85.3 and 69.1% patients were diagnosed with malignant tumors and the same pathology type, respectively. No significant difference in clinical-pathologic characteristics or response to MWA between the groups was observed. Upon combining Groups A, B and C, Group D exhibited longer progression-free survival (PFS) (Groups A + B + C versus Group D, 11.7 months, 95% CI 9.6-13.7 versus 26.6 months, 95% CI 19.0-34.2, p = .253) and overall survival (OS) (15.9 months, 95% CI 14.2-17.5, versus 29.8 months, 95% CI, 24.3-35.3, p = .395), although no significant differences were observed. Complications were identified in 63 (92.6%), of which 17 (25.0%) patients had major complications.

CONCLUSIONS

Immediate biopsy post-MWA can distinguish cancer cells or histology types in most cases of NSCLC. However, pathology changes pre- and postablation could not predict the response to MWA and patient survival.

Comparison study of computed tomography-guided radiofrequency and microwave ablation for pulmonary tumors: A retrospective, case-controlled observational study

BACKGROUND

The aim of this study was to compare the safety, efficacy, and prognostic value of radiofrequency ablation (RFA) and microwave ablation (MWA) for lung tumors.

METHODS

Between March 2012 and January 2018, 238 patients with lung cancer were treated with MWA (139, 58.4%) or RFA (99, 41.6%) in our center. Patient and tumor characteristics, complications, complete ablation (CA) rate, and prognosis were compared between the groups. Meta-analysis was used to systematically compare the outcomes of RFA and MWA for the treatment of lung tumors.

RESULTS

Ablation was successfully completed in all patients and no procedure-related death occurred. The total complication rates in the RFA and MWA groups were 24.2% (24/99) and 16.5% (23/139), respectively, and there was no statistically significant difference (P = 0.142). The initial and total CA rates were similar at P > 0.05 (RFA vs. MWA: initial CA, 97.0% vs. 96.4%; total CA, 99.0% vs. 98.6%, respectively). During follow-up, there was no significant difference in median progression-free (RFA vs. MWA: 12.5 months, 95% confidence interval [CI] 5.002-19.998 vs. 9.5 months, 95% CI 6.623-12.377; P = 0.673) or overall survival (RFA vs. MWA: 33 months, 95% CI 27.070-38.930 vs. 30 months, 95% CI, 18.482-41.518; P = 0.410) between the groups. Combined with the results of published comparison studies, meta-analysis further confirmed that the outcomes of these two treatments were similar.

CONCLUSION

Both RFA and MWA are safe and effective treatments with a survival benefit for selected patients with primary and metastatic lung tumors.

Evolution of Stereotactic Ablative Radiotherapy in Lung Cancer and Birmingham's (UK) Experience

Stereotactic ablative radiotherapy (SABR) has taken a pivotal role in early lung cancer management particularly in the medically inoperable patients. Retrospective studies have shown this to be well tolerated with comparable results to surgery and no significant increase in toxicity. Paucity of randomized evidence has dictated initiation of several trials to provide good quality evidence to steer future practice. This review summaries salient developments in lung SABR, comparisons to surgery and other platforms and our local experience at University Hospitals Birmingham, UK of lung SABR since its initiation in June 2013.

Multimodality Treatment of Advanced Non-small Cell Lung Cancer: Where are we with the Evidence?

PURPOSE OF REVIEW

The majority of patients with non-small cell lung cancer (NSCLC) present with advanced disease and overall survival rates are poor. This article outlines the current and outstanding evidence for the use of multimodality treatment in this group of patients, including in combination with an increasing number of treatment options, such as immunotherapy and genotype-targeted small molecule inhibitors.

RECENT FINDINGS

Optimal therapy for surgically resectable stage III disease remains debatable and currently the choice of treatment reflects each individual patient's disease characteristics and the expertise and opinion of the thoracic multi-disciplinary team. Evidence for a distinct oligometastatic state in which improved outcomes can be achieved remains minimal and there is as yet no consensus definition for oligometastatic lung cancer. Whilst there is supporting evidence for the aggressive management of isolated metastases, the use of consolidative therapy for multiple metastases remains unproven.

SUMMARY

Evolution of new RT technologies, improved surgical technique and a plethora of interventional-radiology-guided ablative therapies are widening the choice of available treatment modalities to patients with NSCLC. In the setting of resectable locally advanced disease and the oligometastatic state, there is a growing need for randomised comparison of the available treatment modalities to guide both treatment and patient selection.

Efficacy and safety of radiofrequency ablation for lung cancers: A systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy and safety of radiofrequency ablation(RFA) for patients with lung cancers using meta-analysis.

METHODS AND MATERIALS

A literature search (PubMed, Embase, Web of science and China National Knowledge Infrastructure) was undertaken until August 2017 to identify sufficient studies evaluating the efficacy and safety of RFA. Pooled proportions of estimates were calculated by performing the random effect model, including technical success rate, recurrence rate, local tumor progression rate and complications.

RESULTS

A total of 25 eligible studies were collected, giving a sample size of 1989 patients with 3025 lung tumors. In the present series, the pooled technical success rate was 96%(95%CIs: 93%-100%). Further, we observed pooled recurrence rate of 35%(95%CIs: 12%-59%) following RFA. Additionally, the pooled rate of local tumor progression was 26%(95%CIs: 20%-32%). One hundred and ninety major complications of RFA were reported in 20 studies, giving a pooled proportion of 6% (95%CIs: 3%-8%) for major RFA complications. Pooled rate of minor complications was 27% (95%CIs:14%-41%).

CONCLUSION

In this meta-analysis, RFA was found to be a safe and efficient treatment for the patients with lung cancers. The efficacy and safety of RFA for lung cancer deserve future investigation in further well-designed randomized controlled trials.