Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology

Lung Needle Biopsy and Lung Ablation: Indications, Patient Management, and Postprocedure Imaging Findings

The clinical role and use of percutaneous transthoracic needle biopsy (TTNB) and ablation of lung tumors are evolving. Here we discuss important considerations for referring providers, including current and emerging indications supported by guidelines, critical aspects of pre and postprocedure patient management, and expected postprocedure imaging findings.

Computed tomography-guided microwave ablation for right middle lobe pulmonary nodules: a retrospective, single-center, case-control study

PURPOSE

This retrospective, single-center, case-control study evaluated the safety and efficacy of Computed tomography (CT)-guided microwave ablation (MWA) for pulmonary nodules located in the right middle lobe (RML), a challenging location associated with a high frequency of complications.

METHODS

Between May 2020 and April 2022, 71 patients with 71 RML pulmonary nodules underwent 71 MWA sessions. To comparison, 142 patients with 142 pulmonary nodules in non-RML were selected using propensity score matching. The technical success, technique efficacy, complications, and associated factors were analyzed. The duration of the procedure and post-ablation hospital stay were also recorded.

RESULTS

Technical success was achieved in 100% of all patients. There were no significant differences in technique efficacy rates between the RML and non-RML groups (97.2% vs. 95.1%, p = 0.721). However, both major (47.9% vs. 19.7%, p < 0.001) and minor (26.8% vs. 11.3%, p = 0.004) pneumothorax were more common in the RML group than non-RML group. MWA for RML pulmonary nodules was identified as an independent risk factor for pneumothorax (p < 0.001). The duration of procedures (51.7 min vs. 35.3 min, p < 0.001) and post-ablation hospital stays (4.7 days vs. 2.8 days, p < 0.001) were longer in the RML group than non-RML group.

CONCLUSIONS

CT-guided MWA for RML pulmonary nodules showed comparable efficacy compared with other lobes, but posed a higher risk of pneumothorax complications, necessitating longer MWA procedure times and extended hospital stays.

Cryoablation triggers type I interferon-dependent antitumor immunity and potentiates immunotherapy efficacy in lung cancer

BACKGROUND

Cryoablation is a minimally invasive option for patients with medically inoperable non-small cell lung cancer (NSCLC) and can trigger abscopal immune-regulatory effects. However, it remains unclear how cryoablation affects the host-level immune response in NSCLC. In this study, we investigated the local and systemic immunological effects of cryoablation and the potential of combining cryoablation with programmed cell death protein 1 (PD-1) blockade to boost immunotherapy efficacy in NSCLC.

METHODS

We first investigated systemic immunological effects induced by cryoablation in patients with early-stage NSCLC. Subsequently, we explored cryoablation-induced antitumor immunity and the underlying biological mechanisms using KP (Kras G12D/+, Tp53 -/-) mutant lung cancer cell allograft mouse models. Moreover, the synergistic efficacy of cryoablation and PD-1 blockade was explored in both mouse models and patients with unresectable NSCLC.

RESULTS

We found that cryoablation significantly increased circulating CD8+ T cell subpopulations and proinflammatory cytokines in patients with early-stage NSCLC. In lung cancer cell allograft mouse models, we demonstrated that cryoablation resulted in abscopal growth inhibition of contralateral, non-ablated tumors. Integrated analysis of bulk, single-cell RNA and T cell receptor (TCR) sequencing data revealed that cryoablation reprogrammed the intratumoral immune microenvironment and increased CD8+ T cell infiltration with higher effector signature, interferon (IFN) response, and cytolytic activity. Mechanistically, cryoablation promoted antitumor effect through the STING-dependent type I IFN signaling pathway, and type I IFN signaling blockade attenuated this antitumor effect. We also found that the combination of PD-1 blockade with cryoablation further inhibited tumor growth compared with either treatment alone in an allograft mouse model. Moreover, the combination therapy induced notable tumor suppression and CD8+ T cell infiltration in patients with unresectable NSCLC.

CONCLUSIONS

Our results provide mechanistic insights into how cryoablation triggers the antitumor immune effect in lung cancer, thereby potentiating programmed cell death ligand 1 (PD-L1)/PD-1 blockade efficacy in the clinical treatment of NSCLC.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE STATEMENT

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

KEY POINTS

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

Microwave Ablation for Inoperable Stage I Non-Small Cell Lung Cancer in Patients Aged ≥70 Years: A Prospective, Single-Center Study

PURPOSE

To evaluate the safety and survival outcomes of computed tomography-guided microwave ablation (MWA) for medically inoperable Stage I non-small cell lung cancer (NSCLC) in patients aged ≥70 years.

MATERIALS AND METHODS

This study was a prospective, single-arm, single-center clinical trial. The MWA clinical trial enrolled patients aged ≥70 years with medically inoperable Stage I NSCLC from January 2021 to October 2021. All patients received biopsy and MWA synchronously with the coaxial technique. The primary endpoints were 1-year overall survival (OS) and progression-free survival (PFS). The secondary endpoint was adverse events.

RESULTS

A total of 103 patients were enrolled. Ninety-seven patients were eligible and analyzed. The median age was 75 years (range, 70-91 years). The median diameter of tumors was 16 mm (range, 6-33 mm). Adenocarcinoma (87.6%) was the most common histologic finding. With a median follow-up of 16.0 months, the 1-year OS and PFS rates were 99.0% and 93.7%, respectively. There were no procedure-related deaths in any patient within 30 days after MWA. Most of the adverse events were minor.

CONCLUSION

MWA is an effective and safe treatment for patients aged ≥70 years with medically inoperable Stage I NSCLC.

Cryoablation and immunity in non-small cell lung cancer: a new era of cryo-immunotherapy

Despite remarkable advances in tumor response and patient survival in the past decade, systemic immunotherapies for lung cancer result in an objective response in only around half of patients treated. On the basis of this limitation, combination strategies are being investigated to improve response rates. Cryoablation has been proposed as one such technique to induce immunogenic cell death and synergize with systemic immunotherapies, including immune checkpoint inhibitors. Cryoablation has been traditionally delivered percutaneously with imaging guidance although recent technological advances allow for bronchoscopic delivery. Herein, we review the pre-clinical and clinical evidence for the use of cryoablation in non-small cell lung cancer and potential induction of anti-tumor immunity. We highlight ongoing studies involving this approach and propose areas of future investigation.

Factors Associated with Hospital Length of Stay and Adverse Events following Percutaneous Ablation of Lung Tumors

PURPOSE

To explore the association between risk factors established in the surgical literature and hospital length of stay (HLOS), adverse events, and hospital readmission within 30 days after percutaneous image-guided thermal ablation of lung tumors.

MATERIALS AND METHODS

This bi-institutional retrospective cohort study included 131 consecutive adult patients (67 men [51%]; median age, 65 years) with 180 primary or metastatic lung tumors treated in 131 sessions (74 cryoablation and 57 microwave ablation) from 2006 to 2019. Age-adjusted Charlson Comorbidity Index, sex, performance status, smoking status, chronic obstructive pulmonary disease (COPD), primary lung cancer versus pulmonary metastases, number of tumors treated per session, maximum axial tumor diameter, ablation modality, number of pleural punctures, anesthesia type, pulmonary artery-to-aorta ratio, lung densitometry, sarcopenia, and adipopenia were evaluated. Associations between risk factors and outcomes were assessed using univariable and multivariable generalized linear models.

RESULTS

In univariable analysis, HLOS was associated with current smoking (incidence rate ratio [IRR], 4.54 [1.23-16.8]; P = .02), COPD (IRR, 3.56 [1.40-9.04]; P = .01), cryoablations with ≥3 pleural punctures (IRR, 3.13 [1.07-9.14]; P = .04), general anesthesia (IRR, 10.8 [4.18-27.8]; P < .001), and sarcopenia (IRR, 2.66 [1.10-6.44]; P = .03). After multivariable adjustment, COPD (IRR, 3.56 [1.57-8.11]; P = .003) and general anesthesia (IRR, 12.1 [4.39-33.5]; P < .001) were the only risk factors associated with longer HLOS. No associations were observed between risk factors and adverse events in multivariable analysis. Tumors treated per session were associated with risk of hospital readmission (P = .03).

CONCLUSIONS

Identified preprocedural risk factors from the surgical literature may aid in risk stratification for HLOS after percutaneous ablation of lung tumors, but were not associated with adverse events.

Safety and Effectiveness of Percutaneous Image-Guided Thermal Ablation of Juxtacardiac Lung Tumors

PURPOSE

To evaluate the safety and effectiveness of percutaneous image-guided thermal ablation (IGTA) for juxtacardiac lung tumors.

MATERIALS AND METHODS

This bi-institutional retrospective cohort study included 23 consecutive patients (13 [57%] male; mean age, 55 years ± 18) with 30 juxtacardiac lung tumors located ≤10 mm from the pericardium treated in 28 IGTA sessions (25 sessions of cryoablation and 3 sessions of microwave ablation) between April 2008 and August 2022. The primary outcome was any adverse cardiac event within 90 days after ablation. Secondary outcomes included noncardiac adverse events, local tumor progression-free survival (LT-PFS), and the cumulative incidence of local tumor progression with death as a competing risk. Two tumors treated without curative intent or follow-up imaging were considered in the safety analysis but not in the progression analysis.

RESULTS

The median imaging follow-up duration was 22 months (interquartile range [IQR], 10-53 months). Primary technical success was achieved in 25 (89%) ablations. No adverse cardiac events attributable to IGTA occurred. One patient experienced a phrenic nerve injury. The median LT-PFS duration was 59 months (IQR, 32-73 months). At 1, 3, and 5 years, LT-PFS was 90% (95% CI, 78%-100%), 74% (CI, 53%-100%), and 45% (CI, 20%-97%), respectively, and the cumulative incidence of local tumor progression was 4.3% (CI, 0.29%-19%), 11% (CI, 1.6%-30%), and 26% (CI, 3.3%-58%), respectively.

CONCLUSIONS

IGTA is safe and effective for lung tumors located ≤10 mm from the pericardium. No adverse cardiac events were not observed within 90 days after ablation.

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.

Up-to-date evidence on image-guided thermal ablation for metastatic lung tumors: a review

The aim of this review was to summarize the latest evidence on image-guided thermal ablation therapies for lung metastases. PubMed was used to search for relevant articles that reported the oncological outcomes of thermal ablation for metastatic lung tumors, and those published in 2010 or later were selected for review. Ablative therapies were applied for lung metastases from various types of primary tumors, but most commonly colorectal ones. Radiofrequency ablation (RFA) was the most evaluated technique, followed by microwave ablation (MWA). The local control rates of ablative therapies were generally favorable, approximately 80–90% in many studies. Representative studies demonstrated promising overall survival rates of approximately 50% or higher 5 years after ablation for lung metastases from colorectal cancer or mixed types of primary tumors. Nevertheless, the survival outcomes varied depending on the type of primary tumor and background factors of patients such as other metastases and comorbidities. Several studies had aimed to compare the outcomes of various ablative therapies such as RFA, MWA, and cryoablation; however, conclusive data are not yet available to determine the most appropriate ablation modality for lung metastases. Further data accumulation is needed, especially for long-term outcomes and comparisons with other therapies.

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

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