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).

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.

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.

Magnetic Resonance Imaging for Guidance and Follow-up of Thoracic Needle Biopsies and Thermal Ablations.

Magnetic resonance imaging (MRI) is used for the guidance and follow-up of percutaneous minimally invasive interventions in many body parts. In the thorax, computed tomography (CT) is currently the most used imaging modality for the guidance and follow-up of needle biopsies and thermal ablations. Compared with CT, MRI provides excellent soft tissue contrast, lacks ionizing radiation, and allows functional imaging. The role of MRI is limited in the thorax due to the low hydrogen proton density and many air-tissue interfaces of the lung, as well as respiratory and cardiac motion. Here, we review the current experience of MR-guided thoracic needle biopsies and of MR-guided thermal ablations targeting lesions in the lung, mediastinum, and the chest wall. We provide an overview of MR-compatible biopsy needles and ablation devices. We detail relevant MRI sequences and their relative advantages and disadvantages for procedural guidance, assessment of complications, and long-term follow-up. We compare the advantages and disadvantages of CT and MR for thoracic interventions and identify areas in need of improvement and additional research.

Active Versus Passive Thaw After Percutaneous Cryoablation of Pulmonary Tumors: Effect on Incidence, Grade, and Onset of Hemoptysis.

BACKGROUND. Hemoptysis is common after percutaneous image-guided cryoablation of pulmonary tumors. OBJECTIVE. The purpose of our study was to evaluate the effect of a final active thaw on the incidence, grade, and onset of hemoptysis after percutaneous cryoablation of pulmonary tumors. METHODS. This retrospective cohort study included 60 consecutive CT-guided cryoablation sessions targeting 95 pulmonary tumors in 47 patients from March 2017 to September 2020. The final thaw of a triple-freeze protocol was active (electrical, helium-free) in 27 of 60 sessions (45%, active group) and passive in 33 of 60 sessions (55%, passive group). The incidence, onset, and management of hemoptysis were recorded using prospectively collected data. Hemoptysis, pneumothorax, and hemothorax within 30 days after ablation were graded according to Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The volume of immediate posttreatment changes on CT was quantified using semiautomated segmentation. Outcomes were compared between groups using generalized estimating equation models. A parsimonious multivariable model for hemoptysis incidence was developed using purposeful selection of predefined covariates followed by bootstrap resampling. Local tumor control was compared between groups using the Kaplan-Meier method and log-rank testing. RESULTS. Hemoptysis occurred after 26 of 60 (43%) sessions and was self-limited (CTCAE grade 1) in 22 of 26 (85%) sessions. The incidence of hemoptysis was lower in the active group than in the passive group (19% vs 64%, respectively; p = .002). The odds of hemoptysis adjusted for immediate posttreatment changes were 92% lower in the active group (odds ratio [OR], 0.08 [95% CI, 0.02-0.37]; p = .004). The odds of hemoptysis greater than grade 1 were 79% lower in the active group (OR, 0.21 [95% CI, 0.07-0.64]; p = .006). In the active group, the onset of hemoptysis was significantly delayed (OR, 0.75 [95% CI, 0.61-0.91]; p = .005). Pneumothorax (p = .60), hemothorax (p = .84), and local tumor control (p = .77) did not differ between groups. CONCLUSION. Active thaw after the final freeze reduces the incidence and grade of hemoptysis and delays the onset of hemoptysis after percutaneous cryoablation of pulmonary tumors without adversely affecting other procedural complications and local tumor control. CLINICAL IMPACT. Active thaw after the final freeze improves the safety profile of triple-freeze cryoablation of pulmonary tumors by reducing the incidence and grade of hemoptysis and by delaying the onset of hemoptysis beyond the immediate recovery period.