Pleural puncture that excludes the ablation zone decreases the risk of pneumothorax after percutaneous microwave ablation in porcine lung

Risk assessment of pneumothorax in colorectal lung metastases treated by percutaneous thermal ablation: a multicenter retrospective cohort study

PURPOSE

To evaluate the risk of pneumothorax in the percutaneous image-guided thermal ablation (IGTA) treatment of colorectal lung metastases (CRLM).

METHODS

Data regarding patients with CRLM treated with IGTA from five medical institutions in China from 2016 to 2023 were reviewed retrospectively. Pneumothorax and non-pneumothorax were compared using the Student's t -test, χ 2 test and Fisher's exact test. Univariate logistic regression analysis was conducted to identify potential risk factors, followed by multivariate logistic regression analysis to evaluate the predictors of pneumothorax. Interactions between variables were examined and used for model construction. Receiver operating characteristic curves and nomograms were generated to assess the performance of the model.

RESULTS

A total of 254 patients with 376 CRLM underwent 299 ablation sessions. The incidence of pneumothorax was 45.5%. The adjusted multivariate logistic regression model, incorporating interaction terms, revealed that tumour number [odds ratio (OR)=8.34 (95% CI: 1.37-50.64)], puncture depth [OR=0.53 (95% CI: 0.31-0.91)], pre-procedure radiotherapy [OR=3.66 (95% CI: 1.17-11.40)], peribronchial tumour [OR=2.32 (95% CI: 1.04-5.15)], and emphysema [OR=56.83 (95% CI: 8.42-383.57)] were significant predictive factors of pneumothorax (all P <0.05). The generated nomogram model demonstrated a significant prediction performance, with an area under the receiver operating characteristic curve of 0.800 (95% CI: 0.751-0.850).

CONCLUSIONS

Pre-procedure radiotherapy, tumour number, peribronchial tumour, and emphysema were identified as risk factors for pneumothorax in the treatment of CRLM using percutaneous IGTA. Puncture depth was found to be a protective factor against pneumothorax.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

KEY POINTS

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

Stereotactic body radiation therapy and thermal ablation for treatment of NSCLC: A systematic literature review and meta-analysis

RATIONALE

Stereotactic body radiation therapy (SBRT) is the standard of care for inoperable early stage non-small cell lung cancer (NSCLC). Use of image guided thermal ablation (IGTA; including microwave ablation [MWA] and radiofrequency ablation [RFA]) has increased in NSCLC, however there are no studies comparing all three.

OBJECTIVE

To compare the efficacy of IGTA (including MWA and RFA) and SBRT for the treatment of NSCLC.

METHODS

Published literature databases were systematically searched for studies assessing MWA, RFA, or SBRT. Local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were assessed with single-arm pooled analyses and meta-regressions in NSCLC patients and a stage IA subgroup. Study quality was assessed with a modified methodological index for non-randomized studies (MINORS) tool.

RESULTS

Forty IGTA study-arms (2,691 patients) and 215 SBRT study-arms (54,789 patients) were identified. LTP was lowest after SBRT at one and two years in single-arm pooled analyses (4% and 9% vs. 11% and 18%) and at one year in meta-regressions when compared to IGTA (OR = 0.2, 95%CI = 0.07-0.63). MWA patients had the highest DFS of all treatments in single-arm pooled analyses. In meta-regressions at two and three-years, DFS was significantly lower for RFA compared to MWA (OR = 0.26, 95%CI = 0.12-0.58; OR = 0.33, 95%CI = 0.16-0.66, respectively). OS was similar across modalities, timepoints, and analyses. Older age, male patients, larger tumors, retrospective studies, and non-Asian study region were also predictors of worse clinical outcomes. In high-quality studies (MINORS score ≥ 7), MWA patients had better clinical outcomes than the overall analysis. Stage IA MWA patients had lower LTP, higher OS, and generally lower DFS, compared to the main analysis of all NSCLC patients.

CONCLUSIONS

NSCLC patients had comparable outcomes after SBRT and MWA, which were better than those with RFA.

Risk Factors for Operation Complications of High Dose Rate 3-Dimensional Interstitial Brachytherapy for Lung Cancer

BACKGROUND

The risk factors for operation complications of high-dose-rate dimensional (3D) interstitial brachytherapy for lung malignant tumors are still unclear. We aimed to provide a reliable reference for the preoperative safety assessment of interstitial brachytherapy.

PATIENTS AND METHODS

We analyzed the degree and incidence of operational complications in 120 eligible patients with lung carcinoma who underwent computed tomography (CT)-guided HDR interstitial brachytherapy. Univariate and multivariate analyses were used to study the relationships between patient-related factors, tumor-related factors, operation-related factors, and operational complications.

RESULTS

The most frequent complications of CT-guided HDR interstitial brachytherapy were pneumothorax and hemorrhage. In univariate analysis, smoking, emphysema, distance of implanted needles through the normal lung tissue, number of implanted needle adjustments, and distance of the lesion from the pleura were the risk factors for pneumothorax; the tumor size, distance of the tumor from the pleura, number of implanted needle adjustments, and distance of the implanted needle through the normal lung tissue were risk factors for hemorrhage. In multivariate analysis, the depth of the implanted needle through the normal lung tissue and distance of the lesion from the pleura were independent risk factors for pneumothorax. Tumor size, number of implanted needle adjustments, and distance through normal lung tissue were independent risk factors for hemorrhage.

CONCLUSION

This study provides a reference for the clinical treatment of lung cancer by analyzing the risk factors for complications of interstitial brachytherapy.

The efficacy and safety of thermal ablation for patients with lung malignancy: a meta-analysis of 12 studies in China

BACKGROUND

Thermal ablation has been increasingly used in the treatment of lung cancer in recent years. This meta-analysis aims to investigate the therapeutic effect and safety of thermal ablation plus chemotherapy as compared with chemotherapy alone in treating patients with lung malignancy in China based on current evidence.

METHODS

Databases including PubMed, Web of Science, Embase and the Cochrane Library were searched for clinical reports. Additional literature search was also performed by searching the reference list of included studies and latest reviews. Raw data including objective response rate, disease control rate, progression-free survival, overall survival and the incidence of major complication were extracted and pooled.

RESULTS

A total of 12 studies in China including 1282 patients with lung malignancy were included in this meta-analysis. The number of studies that reported data of objective response rate, disease control rate, progression-free survival, overall survival and major complication was 8, 7, 7, 6 and 7, respectively. The combination therapy of thermal ablation plus chemotherapy showed a significantly better efficacy in improving objective response rate (odds ratio = 2.73; P < 0.001) and disease control rate (odds ratio = 2.43; P < 0.001) as compared with chemotherapy alone. Thermal ablation was also a significant protective factor for progression-free survival (hazard ratio = 0.43; P < 0.001) and overall survival (hazard ratio = 0.49; P < 0.001). Besides, thermal ablation did not increase the risk of major complication (odds ratio = 0.75; P = 0.252).

CONCLUSION

The present meta-analysis based on these studies in China suggested that thermal ablation is a promising technique to provide better disease response and survival outcomes for patients with lung malignancy. Thermal ablation is worth further promotion in treating lung malignancy and application in clinical practice.

Therapeutic Bronchoscopy for Lung Nodules: Where Are We Now?

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

Comparison of Percutaneous Image-Guided Microwave and Cryoablation for Sarcoma Lung Metastases: 10-Year Experience

Background: Outcomes between percutaneous microwave (MWA) and cryoablation of sarcoma lung metastases have not been compared to our knowledge. Objective: To compare technical success, complications, local tumor control, and overall survival (OS) following MWA versus cryoablation of sarcoma lung metastases. Methods: This retrospective cohort study included 27 patients (16 women, 11 men; median age 64 years; Eastern Cooperative Oncology Group performance score 0-2) who underwent 39 percutaneous CT-guided ablation sessions (21 MWA, 18 cryoablation; 1-4 sessions per patient) to treat 65 sarcoma lung metastases (median 1 tumor per patient, range 1-12; median tumor diameter 11 mm, range 5-33 mm; 25% non-peripheral) from 2009 to 2021. We compared complications by ablation modality using generalized-estimating equations. We evaluated ablation modality, tumor size, and location (peripheral vs non-peripheral) in relation to local tumor progression using proportional Cox hazard models with death as competing risk. We estimated OS using the Kaplan-Meier method. Results: Primary technical success was 97% for both modalities. Median follow-up was 23 months (range: 1-102 months; interquartile range: 12, 44 months). A total of 7/61 (12%) tumors progressed. Estimated 1-year and 2-year local control rates were, for tumors >1 cm, 97% and 95% following MWA versus 99% and 98% following cryoablation, and for tumors ≤1 cm, 74% and 62% following MWA versus 86% and 79% following cryoablation. Tumor size ≤1 cm was associated with decreased cumulative incidence of local progression (p =.048); ablation modality and tumor location were not associated with progression (p =.86; p =.54). Complications (CTCAE grade ≤3) occurred in 17/39 sessions (44%), prompting chest tube placement in nine (23%). No complications with grade ≥4 occurred. OS at 1-, 2-, and 3-years was 100%, 89%, and 82%, respectively. Conclusion: High primary technical success, local control, and OS support MWA and cryoablation for treating sarcoma lung metastases. Ablation modality and tumor location did not affect local progression. Treatment failure was low, especially for small tumors. No life-threatening complications occurred. Clinical Impact: Percutaneous MWA and cryoablation are both suited for treatment of sarcoma lung metastases, especially for tumors ≤1 cm, whether peripheral or non-peripheral. Complications, if they occur, are not life-threatening.

Risk prediction of pneumothorax in lung malignancy patients treated with percutaneous microwave ablation: development of nomogram model

OBJECTIVES

To develop effective nomograms for predicting pneumothorax and delayed pneumothorax after microwave ablation (MWA) in lung malignancy (LM) patients.

METHODS

LM patients treated with MWA were randomly allocated to a training or validation cohort at a ratio of 7:3. The predictors of pneumothorax identified by univariate and multivariate analyses in the training cohort were used to develop a predictive nomogram. The C-statistic was used to evaluate predictive accuracy in both cohorts. A second nomogram for predicting delayed pneumothorax was developed and validated using identical methods.

RESULTS

A total of 552 patients (training cohort: n = 402; validation cohort: n = 150) were included; of these patients, 27.9% (154/552) developed pneumothorax, with immediate and delayed pneumothorax occurring in 18.8% (104/552) and 9.1% (50/552), respectively. The predictors selected for the nomogram of pneumothorax were emphysema (hazard ratio [HR], 6.543; p < .001), history of lung ablation (HR, 7.841; p= .025), number of pleural punctures (HR, 1.416; p < .050), ablation zone encompassing pleura (HR, 10.225; p < .001) and pulmonary fissure traversed by needle (HR, 10.776; p < .001). The C-statistics showed good predictive performance in the training and validation cohorts (0.792 and 0.832, respectively). Another nomogram for delayed pneumothorax was developed based on emphysema (HR, 2.952; p= .005), ablation zone encompassing pleura (HR, 4.915; p < .001) and pulmonary fissure traversed by needle (HR, 4.348; p = .015). The C-statistics showed good predictive performance in the training cohort, and it had efficacy for prediction in the validation cohort (0.719 and 0.689, respectively).

CONCLUSIONS

The nomograms could effectively predict the risk of pneumothorax and delayed pneumothorax after MWA.

Outcomes Following Percutaneous Microwave and Cryoablation of Lung Metastases from Adenoid Cystic Carcinoma of the Head and Neck: A Bi-Institutional Retrospective Cohort Study

OBECTIVE

The aim of this study was to report outcomes following percutaneous microwave and cryoablation of lung metastases from adenoid cystic carcinoma (ACC) of the head and neck.

MATERIAL AND METHODS

This bi-institutional retrospective cohort study included 10 patients (6 females, median age 59 years [range 28-81]) who underwent 32 percutaneous ablation sessions (21 cryoablation, 11 microwave) of 60 lung metastases (median 3.5 tumors per patient [range 1-16]) from 2007 to 2019. Median tumor diameter was 16 mm [range 7-40], significantly larger for cryoablation (22 mm, p = 0.002). A median of two tumors were treated per session [range 1-7]. Technical success, local control, complications, and overall survival were assessed.

RESULTS

Primary technical success was achieved for 55/60 tumors (91.7%). Median follow-up was 40.6 months (clinical) and 32.5 months (imaging, per tumor). Local control at 1, 2, and 3 years was 94.7%, 80.8%, and 76.4%, respectively, and did not differ between ablation modalities. Five of fifteen recurrent tumors underwent repeat ablation, and secondary technical success was achieved in four (80%). Assisted local tumor control at 1, 2, and 3 years was 96.2%, 89.8%, and 84.9%, respectively. Complications occurred following 24/32 sessions (75.0%) and 57.2% Common Terminology Criteria for Adverse Events (CTCAE) lower than grade 3. Of 13 pneumothoraces, 7 required chest tube placements. Hemoptysis occurred after 7/21 cryoablation sessions, and bronchopleural fistula developed more frequently with microwave (p = 0.037). Median length of hospital stay was 1 day [range 0-10], and median overall survival was 81.5 months (IQR 40.4-93.1).

CONCLUSION

Percutaneous computed tomography-guided microwave and cryoablation can treat lung metastases from ACC of the head and neck. Complications are common but manageable, with full recovery expected.

Percutaneous microwave ablation of solitary presumptive pulmonary metastases in two dogs with appendicular osteosarcoma

OBJECTIVE

To describe percutaneous microwave ablation (MWA) of presumptive pulmonary metastases and the outcome of two dogs.

ANIMALS

Two dogs with pulmonary lesions after treatment of spontaneously occurring appendicular osteosarcoma.

STUDY DESIGN

Preliminary prospective clinical study.

METHODS

Two large-breed dogs were referred from tertiary veterinary hospitals 146 and 217 days after limb amputation to pursue MWA as an alternative therapy to metastasectomy. Both dogs had been receiving chemotherapy protocols at their respective referral centers.

RESULTS

A novel percutaneous approach for MWA with ultrasonographic or computed tomographic (CT) guidance was successfully performed. The only complications consisted of pneumothoraxes, requiring treatment in one dog. In the weeks after their procedures, both dogs were reported to do well at home. Dog 1 died and dog 2 was euthanized 82 and 19 days, respectively, after their MWA of confirmed (dog 1) or presumed (dog 2) metastatic disease.

CONCLUSION

Percutaneous MWA of pulmonary nodules was technically feasible in two dogs without major complications.

CLINICAL SIGNIFICANCE

Percutaneous MWA may provide a minimally invasive option for treatment of osteosarcoma pulmonary metastases. Additional studies are required to evaluate the benefits of MWA on survival and confirm histologic cell death within pulmonary neoplastic lesions.

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.

High power microwave ablation of normal swine lung: impact of duration of energy delivery on adverse event and heat sink effects

PURPOSE

The purpose of this study is to assess the impact of duration of energy delivery on adverse events (AEs) and heat sink effects during high power microwave ablation (MWA) of normal swine lung.

MATERIALS AND METHODS

High power (100 W) MWA was performed with short (2 min, 18 ablations) or long (10 min, nine ablations) duration of energy delivery in unilateral lung of swine (n = 10). CT imaging was done prior to sacrifice at 2 or 28 d post-treatment, with additional imaging at 7 and 14 d for the latter cohort. Ablation zones were assessed with CT imaging and histopathology analysis. Differences in AEs and ablation characteristics between groups were compared with Fisher's exact test and Student's t-test, respectively.

RESULTS

There were no significant differences in formation of air-filled needle tract, cavitation, and pneumonia (p > 0.5) between the treatment groups. Intra-procedural pneumothorax requiring chest tube placement occurred in three animals. Substantial (>20%, p = 0.01) intra-procedural ablation zone distortion was observed in both groups. The presence of large airways or blood vessels did not result in heat sink effect within the ablation zones and was not indicative of reduced ablation size. Increased energy delivery yielded larger (8.9 ± 3.1 cm³ vs. 3.4 ± 1.7 cm³, p < 0.001) spherical ablations (sphericity: 0.70 ± 0.10 vs. 0.56 ± 0.13, p = 0.01).

CONCLUSIONS

High power MWA of normal lung with longer duration of energy delivery can create larger spherical ablations, without significant differences in post-procedure AEs when compared with shorter energy delivery time.

Decision Making in Interventional Oncology: Ablative Options in the Lung

Image-guided ablation is safe and effective for the treatment of both primary and metastatic tumors in the lung. This article reviews the three most commonly used ablative options: radiofrequency ablation, microwave ablation, and cryoablation. We describe the advantages of each ablation modality in the lung and how to choose the most appropriate ablation device based on patient and tumor characteristics. The optimal technique for lung ablation is discussed and technical tips for improving clinical outcome are described.