Pathomorphologic evaluation of pulmonary radiofrequency ablation: proof of cell death is characterized by DNA fragmentation and apoptotic bodies

Synchronous Computed Tomography-Guided Percutaneous Transthoracic Needle Biopsy and Microwave Ablation for Highly Suspicious Malignant Pulmonary Ground-Glass Nodules

INTRODUCTION

There is no consensus regarding the most appropriate management of suspected malignant pulmonary ground-glass nodules (GGNs).

OBJECTIVE

We aimed to explore the feasibility and safety of synchronous computed tomography-guided percutaneous transthoracic needle biopsy (PTNB) and microwave ablation (MWA) for patients highly suspicious of having malignant GGNs.

METHODS

We retrospectively reviewed medical records between July 2020 and April 2023 from our medical center. Eligible patients synchronously underwent PTNB and MWA (either MWA immediately after PTNB [PTNB-first group] or PTNB immediately after MWA [MWA-first group]) at the the physician's discretion. We analyzed the rate of definitive diagnosis and technical success, the length of hospital stay, the postoperative efficacy, and periprocedural complications.

RESULTS

Of 65 patients who were enrolled, the rate of definitive diagnosis was 86.2%, which did not differ when stratified by the tumor size, the consolidation-to-tumor ratio, or the sequence of the two procedures (all p > 0.05). The diagnostic rate of malignancy was 83.1%. After the median follow-up duration of 18.5 months, the local control rate was 98.2% and the rate of completed ablation was 48.2%. The rate of perioperative minor and major complications was 44.6% and 6.2%, respectively. The most common adverse events included pain, cough, and mild hemorrhage. Mild hemorrhage took place significantly less frequently in the MWA-first group than in the PTNB-first group (16.7% vs. 45.5%, p < 0.05).

CONCLUSION

Synchronous PTNB and MWA are feasible and well tolerated for patients highly suspicious of having malignant GGNs, providing an alternative option for patients who are ineligible for surgical resection.

Percutaneous core-needle biopsy before and immediately after coaxial microwave ablation in solid non-small cell lung cancer: the comparison of genomic testing from specimens

PURPOSE

To compare the genomic testing based on specimens obtained from percutaneous core-needle biopsy (CNB) before and immediately after coaxial microwave ablation (MWA) in solid non-small cell lung cancer (NSCLC), and to investigate the diagnostic performance of CNB immediately after coaxial MWA in solid NSCLC.

METHODS

Coaxial MWA and CNB were performed for NSCLC patients, with a power of 30 or 40 watts (W) in MWA between the pre- and post-ablation CNB, followed by continuous ablation after the second CNB on demand. The paired specimens derived from the same patient were compared for pathological diagnosis and genomic testing. DNA/RNA extracted from the paired specimens were also compared.

RESULTS

A total of 33 NSCLC patients with solid lesions were included. There were two patients (6.1%) without atypical cells and three patients (9.1%) who had the technical failure of genomic testing in post-ablation CNB. The concordance rate of pathological diagnosis between the twice CNB was 93.9% (kappa = 0.852), while that of genomic testing was 90.9% (kappa = 0.891). For the comparisons of DNA/RNA extracted from pre- and post-ablation CNB in 30 patients, no significant difference was found when the MWA between twice CNB has a power of 30 or 40 W and ablation time within five minutes (P = 0.174).

CONCLUSIONS

If the pre-ablation CNB presented with a high risk of pneumothorax or hemorrhage, the post-ablation CNB could be performed to achieve accurate pathological diagnosis and genomic testing and the maximum effect of ablation, which might allow for the diagnosis of genomic testing in 90.9% of solid NSCLC.

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.

Thermal ablation for primary and metastatic lung tumors: Single-center analysis of peri-procedural and intermediate-term clinical outcomes

PURPOSE

To evaluate the peri-procedural and intermediate-term clinical outcomes of thermal ablation of primary and metastatic lung cancer through analysis of a 5-year institutional experience.

METHODS

In this retrospective, IRB-approved study, 55 consecutive lung ablation interventions (33 cryoablation and 22 microwave ablations) performed at an academic medical center from 2017 to 2022 were evaluated. Cryoablation was performed utilizing multiple 14-guage probes using a triple freeze/thaw protocol. Microwave ablation required a single 14-guage probe, set to 60-80 watts for 5-10 min. Lung disease distribution was 58.2 % bilateral with largest lesion size of 5.5 cm. Periprocedural outcomes including technical success and complications as well as long-term outcomes including radiographic response, objective response ratio (ORR), disease control rate (DCR), progression free survival (PFS), overall survival (OS), and functional status were elucidated.

RESULTS

Technical success rate was 100 %. The most common complication was pneumothorax which occurred in 36 (65.5 %) patients, with 27 (49.1 %) requiring chest tube placement. At 6 months, 52 (98.2 %) of the patients demonstrated a complete response and 1 patient exhibited a partial response, yielding an ORR and a DCR of 100 %. The PFS was 26 ± 19 months, and the OS was 90.9 %, 83.6 %, and 74.5 % at 1, 3, and 5 years, respectively. Additionally, 92.7 % (51) of patients maintained or improved their functional status (ECOG) at 6 months.

CONCLUSION

Percutaneous thermal ablation techniques are evolving and promising treatments for both primary and metastatic lung tumors. Our 5-year institutional experience demonstrated their safety and efficacy with preservation of functional performance.

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.

Synchronous microwave ablation followed by core-needle biopsy via a coaxial cannula for highly suspected malignant lung ground-glass opacities: A single-center, single-arm retrospective study

Background

This study aimed to retrospectively explore the safety and feasibility of computed tomography (CT)‐guided synchronous microwave ablation (MWA) followed by core‐needle biopsy (CNB) via a coaxial cannula for highly suspected malignant lung ground‐glass opacities (GGOs).

Methods

The clinical data of 66 patients (66 GGOs) treated with CT‐guided synchronous MWA followed by CNB via a coaxial cannula from January 2019 to January 2021 were included in this study. The technical success rate, curative effect, and complications were evaluated.

Results

Technical success rates were 100%. The pneumothorax rate was 36.4% (24/66). 72.7% (48/66) patients had the bronchopulmonary hemorrhage, 81.3% of hemorrhage was attributable to CNB. 24.2% (16/66) patients had varying degrees of pleural effusion. The pathological results were adenocarcinomas (n = 44), atypical adenomatous hyperplasia (n = 2), chronic inflammation (n = 3) and indeterminate pathological diagnosis (n = 17) with a 69.7% (46/66) positive diagnosis rate. The therapeutic response rate was 100.0% (66/66).

Conclusions

Synchronous MWA followed by CNB via a coaxial cannula has a satisfactory ablation effectiveness and an acceptable biopsy positive rate, which is an alternative treatment for highly suspected malignant GGOs.

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.

Lung microwave ablation - an in vivo swine tumor model experiment to evaluate ablation zones

PURPOSE

To evaluate microwave ablation (MWA) algorithms, comparing pulsed and continuous mode in an in vivo lung tumor mimic model.

MATERIALS AND METHODS

A total of 43 lung tumor-mimic models of 1, 2 or 3 cm were created in 11 pigs through an intra-pulmonary injection of contrast-enriched minced muscle. Tumors were ablated under fluoroscopic and 3D-CBCT-guidance using a single microwave antenna. Continuous (CM) and pulsed mode (PM) were used. According to tumor size, 3 different algorithms for both continuous and pulsed mode were used. The ablation zones were measured using post-procedural 3D-CBCT and on pathologic specimens.

RESULTS

Two radiologists measured the ablation zones on CBCT and they significantly correlated with macroscopic and microscopic pathological findings: r = 0.75 and 0.74 respectively (p < 0.0001) (inter-observer correlation r = 0.9). For 1, 2 and 3 cm tumors mimics lesions (TMLs), mean maximal and transverse ablation diameters were 3.6 [Formula: see text] 0.3 × 2.2 [Formula: see text] 0.3 cm; 4.1 [Formula: see text] 0.5 × 2.6 [Formula: see text] 0.3 cm and 4.8 [Formula: see text] 0.3 × 3.2 [Formula: see text] 0.3 cm respectively using CM; And, 3.0 [Formula: see text] 0.2 × 2.1 [Formula: see text] 0.2 cm; 4.0 [Formula: see text] 0.4 × 2.7 [Formula: see text] 0.4 cm and 4.6 [Formula: see text] 0.4 × 3.2 [Formula: see text] 0.4 cm respectively for PM, without any significant difference except for 1 cm TMLs treated by PM ablation which were significantly smaller (p = 0.009) The sphericity index was 1.6, 1.6, 1.5 and 1.4, 1.5, 1.4 at 1, 2 and 3 cm for CM and PM respectively, p = 0.07, 0.14 and 0.13 for 1, 2 and 3 cm tumors mimics.

CONCLUSION

Microwave ablation for 1-3 cm lung tumors were successfully realized but with a moderate reproducibility rate, using either CM or PM. Immediate post ablation CBCT can accurately evaluate ablation zones.

Pathologic Diagnosis and Genetic Analysis of Sequential Biopsy Following Coaxial Low-Power Microwave Thermal Coagulation For Pulmonary Ground-Glass Opacity Nodules

PURPOSE

To evaluate the feasibility, safety, and diagnostic performance of sequential core-needle biopsy (CNB) technique following coaxial low-power microwave thermal coagulation (MTC) for ground-glass opacity (GGO) nodules.

MATERIALS AND METHODS

From December 2017 to July 2019, a total of 32 GGOs (with diameter of 12 ± 4 mm) in 31 patients received two times of CNBs, both prior to and immediately after MTC at a power of 20 watts. The frequency and type of complications associated with CNBs were examined. The pathologic diagnosis and genetic analysis were performed for specimens obtained from the two types of biopsy.

RESULTS

The technical success rates of pre- and post-MTC CNBs were 94% and 100%, respectively. The complication rate was significantly lower with post-MTC CNB as compared to pre-MTC CNB (42% versus 97%, p < 0.001). Larger amount of specimens could be obtained by post-MTC CNB. The pathological diagnosis rate of post-MTC CNB was significantly higher than that of pre-MTC CNB (100% versus 75%, p = 0.008), whereas the success rates of genetic analysis were comparable between the two groups (100% versus 84%, p = 0.063). Regular ablation could be further performed after post-MTC CNB to achieve local tumor control.

CONCLUSION

Sequential biopsy following coaxial low-power MTC can reduce the risk of complications and provide high-quality specimens for pulmonary GGOs. Combining this technique with standard ablation allows for simultaneous diagnosis and treatment within a single procedure.

Advances in study of the sequence of lung tumor biopsy and thermal ablation

Percutaneous thermal ablation is an important treatment for lung cancer and is widely used in hospitals. Puncture biopsy is generally required for pathological diagnosis before or after thermal ablation. Pathological diagnosis provides both evidence of benign and malignant lesions for ablation therapy and is of important significance for the next step in disease management. Furthermore, the sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and incidence of surgery‐related complications. Ultimately, it may affect the patient's benefit from local treatment. This article reviews the research progress of traditional asynchronous biopsy followed by ablation, the emerging methods of synchronous biopsy followed by ablation, and synchronous ablation followed by biopsy in the last decade.

Key points

The sequence of ablation and biopsy affects the accuracy of pathological diagnosis, the complete ablation rate of thermal ablation, and the incidence of surgical‐related complications.

This article reviewed the recent 10 years' literature on the surgical sequence of biopsy and ablation for lung tumors, the advantages, disadvantages and indications of different orders were analyzed.

The blood cells in NSCLC and the changes after RFA

Lung cancer has attracted a lot of attention because of its high morbidity and mortality. The emergence of RFA provides a new treatment for unresectable NSCLC patients. In addition to killing in situ lung tumors, RFA also provides new immuno-activated antigens, for the treatment of lung cancer. It changes the tumor microenvironment and activates the entire immune system of patients. The peripheral blood cell count is easy to achieve and the blood cells are important in tumor immunity, which changes after RFA. On the one hand, the changes in blood cells identify the immune changes of NSCLC; on the other hand, it provides support and suspicion for the treatment of RFA.

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.

Pathologic Diagnosis and Genetic Analysis of a Lung Tumor Needle Biopsy Specimen Obtained Immediately After Radiofrequency Ablation

PURPOSE

To evaluate the possibility of pathologic diagnosis and genetic analysis of percutaneous core-needle biopsy (CNB) lung tumor specimens obtained immediately after radiofrequency ablation (RFA).

MATERIALS AND METHODS

Patients who underwent CNB of lung tumors immediately after RFA from May 2013 to May 2016 were analyzed. There were 19 patients (8 men and 11 women; median age, 69 years; range, 52-88 years) and 19 lung tumors measuring 0.5-2.6 cm (median, 1.6 cm). Thirteen tumors were solid, and 6 were predominantly ground-glass opacity (GGO) on computed tomography. All specimens were pathologically examined using hematoxylin and eosin (H&E) staining and additional immunostaining, as necessary. The specimens were analyzed for EGFR and KRAS genetic mutations. The safety and technical success rate of the procedure and the possibility of pathologic diagnosis and genetic mutation analysis were evaluated.

RESULTS

Major and minor complication rates were 11% (2/19) and 53% (10/19), respectively. Tumor cells were successfully obtained in 16 cases (84%, 16/19), and technical success rate was significantly lower for GGO-dominant tumors (50%, 3/6) compared with solid lesions (100%, 13/13, p = 0.02). Pathologic diagnosis was possible in 79% (15/19) of cases based on H&E staining alone (n = 12) and with additional immunostaining (n = 3). Although atypical cells were obtained, pathologic diagnosis could not be achieved in 1 case (5%, 1/19). Both EGFR and KRAS mutations could be analyzed in 74% (14/19) of the specimens.

CONCLUSION

Pathologic diagnosis and genetic analysis could be performed even for lung tumor specimens obtained immediately after RFA.

A Comparative Study of Ablation Boundary Sharpness After Percutaneous Radiofrequency, Cryo-, Microwave, and Irreversible Electroporation Ablation in Normal Swine Liver and Kidneys

PURPOSE

To compare ablation boundary sharpness after percutaneous radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA) and irreversible electroporation (IRE) ablation in normal swine liver and kidney.

MATERIALS AND METHODS

Percutaneous CT-guided RFA (n = 5), CA (n = 5), MWA (n = 5) and IRE (n = 5) were performed in the liver and kidney of four Yorkshire pigs. Parameters were chosen to produce ablations 2-3 cm in diameter with a single ablation probe. Contrast-enhanced CT imaging was performed 24 h after ablation, and animals were killed. Treated organs were removed and processed for histologic analysis with hematoxylin and eosin, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Three readers independently analyzed CT, H&E and TUNEL stained images of the ablation boundary to delineate regions of (1) viable cells, (2) complete necrosis or (3) mixture of viable and necrotic cells which was defined as the transition zone (TZ). The width of TZ was compared across the techniques and organs.

RESULTS

Ablations appeared as non-contrast-enhancing regions on CT with sharp transition to enhancing normal tissue. On TUNEL stained slides, the mean width (μm) of the TZ after MWA was 319 ± 157 in liver and 267 ± 95 in kidney, which was significantly lower than RFA (811 ± 477 and 938 ± 429); CA (452 ± 222 and 700 ± 563); and IRE (1319 ± 682 and 1570 ± 962) (all p < 0.01). No significant differences were observed between the organs.

CONCLUSION

Under similar conditions, the width of the TZ at the ablation boundary varies significantly between different ablation techniques.

Diagnostic yield of a biopsy performed immediately after lung radiofrequency ablation

OBJECTIVES

To evaluate the diagnostic performance of lung biopsies performed immediately after radiofrequency ablation (RFA).

METHODS

Twenty consecutive patients were treated with lung RFA. A biopsy was performed immediately after RFA, through the cannula used to insert the RFA probe to avoid hampering the RFA probe placement. Biopsies were analysed for diagnostic of malignancy and tumour morphological characteristics. Recurrence of RFA and procedure-related complications are reported.

RESULTS

Mean tumour size was 17.3 mm (±6.2 mm). Ninety per cent (18/20) of biopsies were able to help diagnose malignancy. Cancer subtype and origin were determined in 70 % (14/20) of tumours, including 12 metastases and two primary lung cancers. During a median follow-up of 24 months, one tumour demonstrated local progression (5 %). The overall survival, lung disease-free survival and progression-free survival rates at 12 months were 100 %, 75 % and 65 %, respectively. Adverse events of the procedure including RFA and biopsy were five pneumothoraces requiring chest tube placement (25 %), seven minor pneumothoraces (35 %) and one subsegmental intrapulmonary haemorrhage (5 %) not requiring any treatment.

CONCLUSIONS

A biopsy performed immediately after lung RFA allowed diagnosis of malignancy in 90 % of cases. This diagnosis is obtained without the need for additional puncture and does not hamper the accuracy of the initial RF probe placement.

KEY POINTS

• Treatment and biopsy are feasible during the same procedure, avoiding multiple punctures. • The best puncture path can be preserved to treat the lung tumour. • Malignancy can be determined on a post-RFA biopsy in 90 % of cases. • Cancer classification can be assessed in 70 % of cases after lung RFA.

Diagnostic Ability of Percutaneous Needle Biopsy Immediately After Radiofrequency Ablation for Malignant Lung Tumors: An Initial Experience

PURPOSE

To evaluate the safety and diagnostic ability of percutaneous needle biopsy performed immediately after lung radiofrequency ablation (RFA).

MATERIALS AND METHODS

From May 2013 to April 2014, percutaneous needle biopsy was performed immediately after RFA for 3 patients (2 men and 1 woman, aged 57-76 years) who had lung tumors measuring 1.3-2.6 cm in diameter. All patients had prior history of malignancy, and all tumors were radiologically diagnosed as malignant. Obtained specimens were pathologically classified using standard hematoxylin and eosin staining.

RESULTS

We completed three planned sessions of RFA followed by percutaneous needle biopsy, all of which obtained tumor tissue that could be pathologically diagnosed. Two tumors were metastatic from renal clear cell carcinoma and rectal adenocarcinoma, respectively; one tumor was primary lung adenocarcinoma. There was no death or major complication related to the procedures. Although pneumothorax occurred in two patients, these resolved without the need for aspiration or chest tube placement. Tumor seeding was not observed, but 21 months after the procedure, one case developed local tumor progression that was treated by additional RFA.

CONCLUSION

Pathologic diagnosis was possible by needle biopsy immediately after RFA for lung tumors. This technique may reduce the risks and efforts of performing biopsy and RFA on separate occasions.

Immune Response After Radiofrequency Ablation and Surgical Resection in Nonsmall Cell Lung Cancer

The objective includes radiofrequency ablation (RFA) of a cancerous nodule results in immunogenic cell death. Tumor antigens are presented and the inflammatory environment may help stimulate adaptive and innate antitumor immunity. The objective of this study was to investigate the immune response following RFA and subsequent surgical resection in early stage non-small cell lung cancer (NSCLC). In methods, a single-session approach of computed tomography-guided tumor biopsy with immediate frozen section (and proof of NSCLC) was performed followed by RFA of the tumor in 4 patients with a solitary pulmonary nodule. Blood samples were collected before RFA and 3 days thereafter. All patients underwent radical surgical resection by video-assisted thoracoscopic lobectomy 8 days following RFA. In results, intense infiltrations of CD4⁺ and CD8⁺ lymphocytes were found along the perimeter of the RFA-treated tumor tissue, whereas the central tumor areas remained devoid of lymphocytes. In the peripheral blood, the frequency of proinflammatory, immunostimulatory IFNγ-secreting, and immunostimulatory BDCA-3⁺/B7-H3^- dendritic cells increased after RFA. Furthermore, a significant increase in T-cell proliferation was detected in T-cell assays after RFA and tumor resection. In this article, a local and systemic immune response subsequent to RFA and complete surgical resection in patients with NSCLC was identified for the first time. Treatment of patients with NSCLC with RFA and surgery leads to an activated and highly T-cell-stimulatory phenotype of dendritic cells, which may promote long-term immunity against NSCLC. The data suggest that the RFA-induced necrotic tumor debris can serve as an in situ antigen source to induce an autologous antitumor immune response.

Serum inflammatory factors and circulating immunosuppressive cells are predictive markers for efficacy of radiofrequency ablation in non-small-cell lung cancer

In recent years, percutaneous radiofrequency ablation (RFA) has been developed as a new tool in the treatment of non-small-cell lung cancer (NSCLC) in non-surgical patients. There is growing evidence that RFA-mediated necrosis can modulate host immune responses. Here we analysed serum inflammatory factors as well as immunosuppressive cells in the peripheral blood to discover possible prognostic indicators. Peripheral blood and serum samples were collected before RFA and within 3 months after the treatment in a total of 12 patients. Inflammatory cytokines and growth factors were measured in serum by the Bio-Plex assay. Myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs ) were evaluated in the peripheral blood via flow cytometry. In patients developing local or lymphogenic tumour relapse (n=4), we found an early significant increase in the concentration of tumour necrosis factor (TNF)-α as well as chemokine (C-C motif) ligand (CCL)-2 and CCL-4 compared to patients without relapse (n=4) and healthy donors (n=5). These changes were associated with an elevated activity of circulating MDSC indicated by an increased nitric oxide (NO) production in these cells. Elevated serum levels of TNF-α, CCL-2 and CCL-4 associated with an increased NO production in circulating MDSCs might be an early indicator of the incomplete RFA and subsequently a potential tumour relapse in NSCLC.

Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update

Image-guided tumor ablation has become a well-established hallmark of local cancer therapy. The breadth of options available in this growing field increases the need for standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison among treatments that use different technologies, such as chemical (eg, ethanol or acetic acid) ablation, thermal therapies (eg, radiofrequency, laser, microwave, focused ultrasound, and cryoablation) and newer ablative modalities such as irreversible electroporation. This updated consensus document provides a framework that will facilitate the clearest communication among investigators regarding ablative technologies. An appropriate vehicle is proposed for reporting the various aspects of image-guided ablation therapy including classification of therapies, procedure terms, descriptors of imaging guidance, and terminology for imaging and pathologic findings. Methods are addressed for standardizing reporting of technique, follow-up, complications, and clinical results. As noted in the original document from 2003, adherence to the recommendations will improve the precision of communications in this field, leading to more accurate comparison of technologies and results, and ultimately to improved patient outcomes.

Modern diagnostic and therapeutic interventional radiology in lung cancer

Imaging has an important role in the multidisciplinary management of primary lung cancer. This article reviews the current state-of-the-art imaging modalities used for the evaluation, staging and post-treatment follow-up and surveillance of lung cancers, and image-guided percutaneous techniques for biopsy to confirm the diagnosis and for local therapy in non-surgical candidates.

Ki 67 is an independent predictive biomarker of cancer specific and local recurrence-free survival after lung tumor ablation

BACKGROUND

The objective of this work was to evaluate the feasibility of histopathological analysis of tissue extracted on multitined electrodes and assess whether tissue characteristics can be used as biomarkers of oncologic outcomes after lung tumor radiofrequency (RF) ablation.

METHODS

Treatment-related data regarding RF ablation of lung malignancies at our institution was collected using a Health Insurance Portability and Accountability Act-compliant ablation database. Institutional review board waiver was obtained for this study. Immunohistochemical analysis of tissue extracted from the electrodes after lung tumor RF ablation was performed for proliferation (Ki-67) and apoptosis (caspase-3). Patient, tumor demographics, and ablation parameters were recorded. Local tumor progression-free survival (LPFS), disease-specific survival (DSS), and overall survival (OS) were assessed using Kaplan-Meier methodology. Multivariate analysis determined factors affecting these oncological outcomes.

RESULTS

A total of 47 lung tumors in 42 patients were ablated; 30 specimens were classified as coagulation necrosis (CN) and 17 as Ki-67-positive (+) tumor cells (viable). Tumor sizes were similar in the CN and Ki-67+ groups (P = 0.32). Median LPFS was 10 versus 16 months for Ki-67+ and CN groups, and 1-year LPFS was 34 and 75 %, respectively (P = 0.003). Median OS was 20 and 46 months (P = 0.12), and median DSS was 20 and 68 months (P = 0.01) for the Ki-67 + and CN groups, respectively. Identification of Ki-67+ tumor cells more than tripled the risk of death from cancer [hazard ratio (HR) = 3.65; 95 % confidence interval (95 % CI), 1.34-9.95; P = 0.01] and tripled the risk of local tumor progression (LTP) (HR = 3.01; 95 % CI, 1.39-6.49; P = 0.005).

CONCLUSIONS

Ki-67+ tumor cells on the electrode after pulmonary tumor RF ablation is an independent predictor of LTP, shorter LPFS, and DSS.

Determination of the apoptotic index in osteosarcoma tissue and its relationship with patients prognosis

Background

Nowadays it remains a controversial issue whether a correlation exists between the apoptosis rate of tumor tissue and the prognosis of the patients. We aimed to explore the prognostic significance of apoptosis index of human osteosarcoma tissue.

Methods

The technique of terminal DNA breakpoints in situ 3 - hydroxy end labeling (TUNEL) was used to detect and analysis apoptosis index in 56 osteosarcoma specimens. The relationships between apoptosis index of tumor tissue and long term survival of patients as well as pathologic classification, tumor clinical stages, tumor size and level of serum alkaline phosphatase were analyzed.

Results

Our studies showed the cases with high apoptosis index had significantly longer survival time. Apoptosis index in osteosarcoma tissue was correlated with tumor size and level of serum alkaline phosphatase but not with pathologic classifications and clinical stages of tumor.

Conclusion

Our results demonstrated that apoptosis index of osteosarcoma tissue combined with serum alkaline phosphatase could used as valid indicators to predicate the malignant level and prognosis of osteosarcoma cases, which would contribute to enhance efficacy of clinical treatments for osteosarcoma.

Pulmonary aspergilloma in a cavity formed after percutaneous radiofrequency ablation

We report two cases of pulmonary aspergilloma (PA) in a cavity formed after percutaneous radiofrequency ablation (PRFA), a rare complication that has only been described once in the literature. The first patient was a 59-year-old white woman treated for a secondary lung nodule of an advanced hepatocellular carcinoma. One month after PRFA, a consolidation of a cavity was noticed with an "air crescent sign," and aspergilloma serology was highly positive. A bisegmentectomy was performed due to the proximity of the lesion to mediastinal vessels and the absence of significant regression after antifungal treatment. Histological examination confirmed the diagnosis of PA. The second patient was a 61-year-old white man followed-up for a non-small-cell lung cancer. A cavitation with thick margins in the ablation zone was noticed 6 months after PRFA. A biopsy was performed, and aspergilloma was diagnosed. Medical treatment with itraconazole was administered for 13 months, and there was significant regression.

Factors influencing local tumor control in patients with neoplastic pulmonary nodules treated with microwave ablation: a risk-factor analysis

OBJECTIVE

This study was performed to evaluate risk factors predictive of local tumor control after microwave ablation of primary and secondary lung malignancies up to 3 cm in maximal diameter.

MATERIALS AND METHODS

The single-antenna microwave ablation treatment of 91 index tumors in 57 patients was studied retrospectively. Time to local tumor progression was monitored on CT scans over the follow-up period. Estimation of overall time to local tumor progression was performed with the Cox regression model. Factors hypothesized to correlate with ablation response included tumor diameter, tumor shape (round or oval versus irregular), clear versus ill-defined tumor margin, adjacency to the pleura, adjacency to bronchi, presence of vessels at least 3 mm in diameter a maximum of 5 mm from the index tumor, energy applied to the index tumor, and the occurrence of cavernous formations after ablation. A logistic regression model was used to correlate the data.

RESULTS

Thirty of 91 (33.0%) index tumors, found in 21 of 57 (36.8%) patients, underwent local progression. The mean time to local tumor progression was 8.3 ± 5.5 months (range 2.1-25.2 months), and the estimated median time to local tumor progression was 22.6 ± 12.4 months. The risk factors that correlated significantly with local tumor progression were a maximal diameter greater than 15.5 mm (p < 0.01), irregular shape of the index tumor (p < 0.01), pleural contact (p = 0.02), and less than 26.7 J/mm(3) applied to the index tumor (p < 0.001). After regression analysis, shape of the index tumor (p = 0.03) and energy deployed per unit volume of the index tumor (p = 0.001) were found to be independent risk factors. Conversely, tumor margin definition (p = 0.06) and proximity of cavernous formations (p = 0.19), juxtatumoral vessels (p = 0.08), and bronchi (p = 0.89) did not affect tumor progression after ablation.

CONCLUSION

The independent predictive factors for local tumor progression in primary and secondary lung neoplasms up to 3 cm in diameter observed in this study were irregular shape of the index tumor and energy application of less than 26.7 J/mm(3) to the index tumor.

Immunologic response to tumor ablation with irreversible electroporation

Background

Irreversible electroporation (IRE) is a promising technique for the focal treatment of pathologic tissues, which involves placing minimally invasive electrodes within the targeted region. However, the knowledge about the therapeutic efficacy and immune reactions in response to IRE remains in its infancy.

Methods

In this work, to detect whether tumor ablation with IRE could trigger the immunologic response, we developed an osteosarcoma rat model and applied IRE directly to ablate the tumor. In the experiment, 118 SD rats were randomized into 4 groups: the control, sham operation, surgical resection, and IRE groups. Another 28 rats without tumor cell implantation served as the normal non-tumor-bearing group. We analyzed the changes in T lymphocyte subsets, sIL-2R and IL-10 levels in the peripheral blood one day before operation, as well as at 1, 3, 7,14 and 21 days after the operation. Moreover, splenocytes were assayed for IFN-γ and IL-4 production using intracellular cytokine staining one day before the operation, as well as at 7 and 21 days after operation.

Results

We found that direct IRE completely ablated the tumor cells. A significant increase in peripheral lymphocytes, especially CD3⁺ and CD4⁺ cells, as well as an increased ratio of CD4⁺/CD8⁺ were detectable 7 days after operation in both the IRE and surgical resection groups. Compared with the surgical resection group, the IRE group exhibited a stronger cellular immune response. The sIL-2R level of the peripheral blood in the IRE group decreased with time and was significantly different from that in the surgical resection group. Moreover, ablation with IRE significantly increased the percentage of IFN-γ-positive splenocytes.

Conclusion

These findings indicated that IRE could not only locally destroy the tumor but also change the status of cellular immunity in osteosarcoma-bearing rats. This provides experimental evidence for the clinical application of IRE in osteosarcoma treatment.

[Radiofrequency ablation for the treatment of lung neoplasms: a retrospective study of 329 cases]

背景与目的

射频消融（radiofrequency ablation, RFA）是近年来用于无法手术的肺部恶性肿瘤及肺转移瘤治疗的替代方案。本研究旨在评估肺射频消融术的安全性和临床疗效。

方法

本研究回顾性分析1999年10月-2006年7月在第四军医大学唐都医院胸腔外科进行肺部恶性肿瘤射频消融术的患者329例（其中肺部原发肿瘤237例，转移瘤92例），对其进行射频治疗后的并发症、局部进展以及1年、2年和5年总生存期的临床资料进行了研究及评价分析。

结果

行射频手术的患者术后出现的并发症包括：气胸63例（19.1%），咯血14例（死亡1例，4.2%），血胸10例（3.0%），肺炎15例（4.5%）和心包填塞3例（死亡1例，0.9%），术后30天内的死亡率为0.6%，针道肿瘤种植的患者6例（1.8%）。中位无进展时间为21.6个月。1年、2年和5年总生存率分别为68.2%、35.3%和20.1%。共有78例（23.7%）患者出现后期肿瘤局部进展。肺部肿瘤原位局部进展的患者的肿瘤包块直径大多 > 4 cm; 在肿瘤局部进展方面，肿瘤 < 3 cm的患者与直径介于3 cm-4 cm的肿瘤患者相比没有明显差异，这两组患者与直径 > 4 cm的肿瘤患者间存在明显差异。

结论

对于肺部恶性肿瘤来说，射频治疗是一种耐受性良好、疗效可靠安全的治疗方法。

More than just tumor destruction: immunomodulation by thermal ablation of cancer

Over the past decades, thermoablative techniques for the therapy of localized tumors have gained importance in the treatment of patients not eligible for surgical resection. Anecdotal reports have described spontaneous distant tumor regression after thermal ablation, indicating a possible involvement of the immune system, hence an induction of antitumor immunity after thermoinduced therapy. In recent years, a growing body of evidence for modulation of both adaptive and innate immunity, as well as for the induction of danger signals through thermoablation, has emerged. Induced immune responses, however, are mostly weak and not sufficient for the complete eradication of established tumors or durable prevention of disease progression, and combination therapies with immunomodulating drugs are being evaluated with promising results. This article aims to summarize published findings on immune modulation through radiofrequency ablation, cryoablation, microwave ablation therapy, high-intensity focused ultrasound, and laser-induced thermotherapy.

Elevated serum levels of heat shock protein 70 can be detected after radiofrequency ablation

Due to their adjuvant effect and their ability to chaperone tumor-associated peptides, heat shock proteins constitute a potent alarm signal for the immune system and can lead to activation of anti-tumor T-cell immunity. Radiofrequency ablation has been reported to induce heat shock protein expression especially that of heat shock protein 70 in sublethally damaged tumor cells. In this study, we evaluated the release of heat shock protein 70 into the serum of cancer-bearing patients directly after radiofrequency ablation. Sera of 22 patients undergoing radiofrequency ablation for the treatment of primary and secondary malignancies of the liver, kidney, and lung, as well as control sera of 20 patients undergoing diagnostic liver biopsy were analyzed using a manufactured heat shock protein 70 ELISA. A significant increase in serum levels of heat shock protein 70 was detectable in the patient cohort 1 day after radiofrequency ablation. More than a twofold increase was observed in nine out of 22 patients, which tended to correlate with favorable clinical outcome. No patient of the control group revealed a comparable increase. Radiofrequency ablation can lead to a release of heat shock protein 70 into the serum, which is transiently detectable 1 day after treatment. Elevated heat shock protein 70 serum levels may constitute a biomarker for favorable clinical outcome.

[Clinical application and advances in radiofrequency ablation of lung neoplasms]

肺癌是全世界因肿瘤死亡的首位原因。近年来，射频消融作为一种微创治疗方法在原发性和继发性肺部肿瘤治疗中得到越来越多的应用，并取得了较大进展。射频消融术后的疗效评价并不简单，推荐使用CT、MRI和PET综合评价。本文对其原理、基础研究、临床应用、疗效、进展等方面进行综述。

The efficacy of bipolar and multipolar radiofrequency ablation of lung neoplasms - results of an ablate and resect study

OBJECTIVE

Radiofrequency ablation (RFA) has obtained increasing attention as an interventional approach for the local treatment of primary and secondary lung neoplasms. The local effect of the procedure is usually controlled by radiologic means. The objectives of this 'ablate and resect' study were to investigate the efficacy of bipolar and multipolar RFA by histologic evaluation and to compare the two techniques.

METHODS

In a total of 32 subjects with histologically proven non-small-cell lung cancer or pulmonary metastases from an extrathoracic primary tumor, bipolar, or multipolar RFA was performed during open thoracotomy. Curative resection (lobectomy or wedge resection including mediastinal lymph node dissection) was performed subsequently. The extent of cell death and early histologic findings following RFA were determined by histology and immunohistochemistry (nicotinamide adenine dinucleotide (NADH) and monoclonal anti-mitochondrial antibodies MAB 1273).

RESULTS

Intra-operative bipolar and multipolar RFA is a safe procedure, and there was no bleeding or thermal damage of the lung tissue. Routine histologic staining could not identify tumor cell death. However, immunohistochemistry was able to verify cell death in the ablated tumor tissue. Complete tumor cell necrosis was determined in 12 tumors (37.5%); and scattered vital tumor tissue was detected in 16 tumors (50%). Incomplete ablation with a ratio of >20% vital tumor tissue was found in four tumors (12.5%), particularly surrounding vascular structures within the tumor tissue or in marginal zones of the tumor tissue. The local efficacy of bipolar and multipolar RFA was comparable, and incomplete ablations were found only in adenocarcinoma.

CONCLUSIONS

Bipolar and multipolar RFA in an open thoracotomy setting is a technically feasible and safe procedure. Early immunohistochemical findings after RFA showed complete tumor cell necrosis in 38% of cases. The high rate of viable tumor cells remaining after ablation casts doubt on RFA as a curative concept. This approach should be reserved for palliative indications. Patients fulfilling the criteria for curative resection should not be denied surgery.

Liposomal doxorubicin increases radiofrequency ablation-induced tumor destruction by increasing cellular oxidative and nitrative stress and accelerating apoptotic pathways

PURPOSE

To determine if oxidative and nitrative stress and/or apoptosis contribute to increased coagulation when combining radiofrequency (RF) ablation with liposomal doxorubicin.

MATERIALS AND METHODS

Animal care committee approval was obtained. R3230 mammary adenocarcinomas in Fischer rats were treated with either RF ablation (n = 43), 1 mg of intravenously injected liposomal doxorubicin (n = 26), or combined therapy (n = 30) and were compared with control subjects (n = 11). A subset of animals receiving combination therapy (n = 24) were treated in the presence or absence of N-acetylcysteine (NAC) administered 24 hours and 1 hour before RF ablation. Tumors were analyzed 2 minutes to 72 hours after treatment to determine the temporal range of response by using immunohistochemical staining of the apoptosis marker cleaved caspase-3, phosphorylated gammaH2AX, and HSP70 and of markers of oxidative and nitrative stress (8-hydroxydeoxyguanosine [8-OHdG], 4-hydroxynonenal [4-HNE]-modified proteins, and nitrotyrosine [NT]). Statistical analyses, including t tests and analysis of variance for comparisons where appropriate, were performed.

RESULTS

By 4 hours after RF ablation alone, a 0.48-mm +/- 0.13 (standard deviation) peripheral band with 57.0% +/- 7.3 cleaved caspase-3 positive cells was noted at the ablation margin, whereas a 0.73-mm +/- 0.18 band with 77.7% +/- 6.3 positivity was seen for combination therapy (P < .03 for both comparisons). Combination therapy caused increased and earlier staining for 4-HNE-modified proteins, 8-OHdG, NT, and gammaH2AX with colocalization to cleaved caspase-3 staining. A rim of increased HSP70 was identified peripheral to the area of cleaved caspase-3. Parameters of oxidative and nitrative stress were significantly inhibited by NAC 1 hour following RF ablation, resulting in decreased cleaved caspase-3 positivity (0.28-mm +/- 0.09 band of 25.9% +/- 7.4 positivity vs 0.59-mm +/- 0.11 band of 62.9% +/- 6.0 positivity, P < .001 for both comparisons).

CONCLUSION

Combining RF ablation with liposomal doxorubicin increases cell injury and apoptosis in the zone of increased coagulation by using a mechanism that involves oxidative and nitrative stress that leads to accelerated apoptosis.

Systemic inflammatory response and downmodulation of peripheral CD25+Foxp3+ T-regulatory cells in patients undergoing radiofrequency thermal ablation for lung cancer

Radiofrequency thermal ablation (RFTA) is a local tumor-destructing technique that can potentially modulate the host immune response through mechanisms that are not clearly defined. We assessed whether RFTA could affect multiple systemic inflammatory and immunological parameters, including CD25+Foxp+ cells, in patients with primary or metastatic lung tumors. Three days after RFTA, a moderate and temporary systemic inflammatory response developed, as demonstrated by the increase in peripheral neutrophils and monocytes and in plasma levels of proinflammatory chemokines (MIP-1alpha, MIP-1beta, eotaxin, and interleukin[IL]-8) and acute phase reactants (complement C3 and C4, serum amyloid, alpha1 antichymotrypsin, and C-reactive protein). Moreover, we found a concomitant release of the anti-inflammatory factor IL-10. Thirty days after RFTA, a significant reduction in CD25+Foxp3+ counts with an increase in CD4+ T-cell proliferation and number of interferon-gamma-secreting cells was observed. The reduction in CD25+Foxp3+ cells lasted up to 90 days after treatment. The use of RFTA in lung cancer patients has an immunomodulatory activity: it induces a self-limiting systemic inflammation early and later a reduction of circulating CD25+Foxp3+ Tregs. In addition to tumor ablation, downmodulation of this regulatory subset might be an important mechanism involved in the long-term clinical efficacy of RFTA.