Percutaneous Cryoablation for the Treatment of Primary and Metastatic Lung Tumors: Identification of Risk Factors for Recurrence and Major Complications

Safety and Effectiveness of Track Cauterization for Lung Cryoablation

PURPOSE

To evaluate the safety and effectiveness of track cauterization for lung cryoablation through comparison of postprocedural adverse event (AE) rates.

MATERIALS AND METHODS

Fifty-nine patients who underwent 164 percutaneous lung cryoablation procedures between 2013 and 2018 were included in this retrospective study. The study cohort was subdivided by whether track cauterization was conducted or not at the end of the procedure. The study cohort was also subdivided by the number of probes (1-2 probes vs 3-4 probes). Postablation AE rates were assessed by immediate and delayed (at 1 month or later) AEs, pneumothorax, hemothorax, pleural effusion, and whether intervention was required. Univariate and multivariate logistic regression analyses were used to compare differences in AE rates.

RESULTS

Patients who underwent procedures with track cautery were 2.6 times less likely to exhibit pleural effusion (P = .017). Patients who underwent procedures conducted with a higher number of probes were 3.8 times more likely to receive interventions (P < .001), 1.6 times more likely to experience pneumothorax (P = .037), and 2.1 times more likely to experience pleural effusion (P = .003). History of lung surgery, increased number of probes, size of the probe, and absence of track cautery were noted to be significant predictors of AEs and need for interventions (all P < .05).

CONCLUSIONS

Track cauterization in lung cryoablation was proven to reduce pleural effusion, but no difference in pneumothorax or delayed AEs was noted. The use of fewer probes was associated with a lower rate of AEs.

Image-Guided Transbronchial Pulmonary Cryoablation with a Flexible Cryoprobe in Swine: Performance and Radiology-Pathology Correlation

PURPOSE

To evaluate the performance of a prototype flexible transbronchial cryoprobe compared with that of percutaneous transthoracic cryoablation and to define cone-beam computed tomography (CT) imaging and pathology cryolesion features in an in vivo swine model.

MATERIALS AND METHODS

Transbronchial cryoablation was performed with a prototype flexible cryoprobe (3 central and 3 peripheral lung ablations in 3 swine) and compared with transthoracic cryoablation performed with a commercially available rigid cryoprobe (2 peripheral lung ablations in 1 swine). Procedural time and cryoablation success rates for endobronchial navigation and cryoneedle deployment were measured. Intraoperative cone-beam CT imaging features of cryolesions were characterized and correlated with gross pathology and hematoxylin and eosin-stained sections of the explanted cryolesions.

RESULTS

The flexible cryoprobe was successfully navigated and delivered to each target through a steerable guiding sheath (6/6). At 4 minutes after ablation, 5 of 6 transbronchial and 2 of 2 transthoracic cryolesions were visible on cone-beam CT. The volumes on cone-beam CT images were 55.5 cm3 (SE ± 8.0) for central transbronchial ablations (n = 2), 72.5 cm3 (SE ± 8.1) for peripheral transbronchial ablations (n = 3), and 79.5 cm3 (SE ±11.6) for peripheral transthoracic ablations (n = 2). Pneumothorax developed in 1 animal after transbronchial ablation and during ablation in the transthoracic cryoablation. Images of cryoablation zones on cone-beam CT correlated well with the matched gross pathology and histopathology sections of the cryolesions.

CONCLUSIONS

Transbronchial cryoablation with a flexible cryoprobe, delivered through a steerable guiding sheath, is feasible. Transbronchial cryoablation zones are imageable with cone-beam CT, with gross pathology and histopathology similar to those of transthoracic cryoablation.

Investigation of Lung Cancer Cell Response to Cryoablation and Adjunctive Gemcitabine-Based Cryo-Chemotherapy Using the A549 Cell Line

Due to the rising annual incidence of lung cancer (LC), new treatment strategies are needed. While various options exist, many, if not all, remain suboptimal. Several studies have shown cryoablation to be a promising approach. Yet, a lack of basic information pertaining to LC response to freezing and requirement for percutaneous access has limited clinical use. In this study, we investigated the A549 lung carcinoma cell line response to freezing. The data show that a single 5 min freeze to -15 °C did not affect cell viability, whereas -20 °C and -25 °C result in a significant reduction in viability 1 day post freeze to <10%. These populations, however, were able to recover in culture. Application of a repeat (double) freeze resulted in complete cell death at -25 °C. Studies investigating the impact of adjunctive gemcitabine (75 nM) pretreatment in combination with freezing were then conducted. Exposure to gemcitabine alone resulted in minimal cell death. The combination of gemcitabine pretreatment and a -20 °C single freeze as well as combination treatment with a -15 °C repeat freeze both resulted in complete cell death. This suggests that gemcitabine pretreatment may be synergistically effective when combined with freezing. Studies into the modes of cell death associated with the increased cell death revealed the increased involvement of necroptosis in combination treatment. In summary, these results suggest that repeat freezing to -20 °C to -25 °C results in a high degree of LC destruction. Further, the data suggest that the combination of gemcitabine pretreatment and freezing resulted in a shift of the minimum lethal temperature for LC from -25 °C to -15 °C. These findings, in combination with previous reports, suggest that cryoablation alone or in combination with chemotherapy may provide an improved path for the treatment of LC.

Large apical lung cancer treated with CT-guided percutaneous cryoablation

Percutaneous lung ablation is increasingly used in the treatment of lung malignancies with good outcomes, but recurrence is commonly reported in ablation of lesions size larger than 3 cm. We report a 50-year-old female with a 9 cm nonsmall cell lung cancer involving the right upper lobe and apical chest wall causing severe neuropathic shoulder pain and significantly disturbing her daily activities. CT-guided percutaneous cryoablation was performed using a 4-phase protocol with complete eradication of the tumor. Follow-up imaging showed no evidence of recurrence 6 months after the procedure. The neuropathic pain was significantly improved after the procedure, and she was pain-free until her death due to metastatic disease elsewhere. To our knowledge, this is the first case of successful cryoablation for an exceptionally large lesion.

Measured Steps: Navigating the Path of Oligoprogressive Lung Cancer with Targeted and Immunotherapies

PURPOSE OF REVIEW

This review discusses the definitions, treatment modalities, management, future directions, and ongoing clinical trials of oligoprogressive disease in oncogene-driven and non-oncogene-driven NSCLC.

RECENT FINDINGS

During the last decades, diagnostic and treatment modalities for oligometastatic NSCLC have advanced significantly, leading to improved survival. Additionally, our understanding of the tumor biology of oligoprogressive disease has expanded. However, despite the efforts of organizations, such as EORTC, ESTRO, and ASTRO proposing definitions for oligometastatic and oligoprogressive disease, heterogeneity in definitions persists in (ongoing) trials. Recognizing the significance of subclassification within oligoprogressive disease in NSCLC and the varying risks associated with subsequent metastatic spread, there is a call for tailored management strategies. A consensus on standardized criteria for the definition of oligoprogressive disease is urgently needed and will not only facilitate meaningful comparisons between studies but also pave the way for the development of personalized treatment plans that take into account the heterogeneous nature of oligoprogressive disease.

Combination of Local Ablative Techniques with Radiotherapy for Primary and Recurrent Lung Cancer: A Systematic Review

In patients with early-stage or recurrent NSCLC who are unable to tolerate surgery, a benefit could derive only from a systemic therapy or another few forms of local therapy. A systematic review was performed to evaluate the feasibility and the effectiveness of radiotherapy combined with local ablative therapies in the treatment of primary and recurrent lung cancer in terms of toxicity profile and local control rate. Six studies featuring a total of 115 patients who met eligibility criteria and 119 lesions were included. Three studies evaluated lung cancer patients with a medically inoperable condition treated with image-guided local ablative therapies followed by radiotherapy: their local control rate (LC) ranged from 75% to 91.7% with only 15 patients (19.4%) reporting local recurrence after combined modality treatment. The other three studies provided a salvage option for patients with locally recurrent NSCLC after RT: the median follow-up period varied from 8.3 to 69.3 months with an LC rate ranging from 50% to 100%. The most common complications were radiation pneumonitis (9.5%) and pneumothorax (29.8%). The proposed intervention appears to be promising in terms of toxicity profile and local control rate. Further prospective studies are need to better delineate combining LTA-RT treatment benefits in this setting.

Special Considerations and Techniques of Interventions in Lung Transplant Recipients

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

Pulmonary Cryoablation Outcomes in Octogenarians and Nonagenarians with Primary Lung Cancer

PURPOSE

To characterize the effectiveness, safety, and length of stay (LOS) associated with pulmonary cryoablation for management of primary lung malignancies in patients aged ≥80 years.

MATERIALS AND METHODS

A retrospective single-center database was compiled of all consecutive patients aged ≥80 years who underwent percutaneous computed tomography-guided cryoablation using modified triple-freeze protocol (1-3 ablation probes) for Stage IA-IIB primary lung malignancies between March 2017 and March 2020 (n = 19; 53% women; mean age, 85 years ± 3.5; range, 80-94 years). Follow-up imaging was assessed for local recurrence. Adverse events and LOS were recorded from chart review. Kaplan-Meier analysis was performed to assess both overall and local recurrence-free survival.

RESULTS

Mean patient follow-up period was 21.6 months ± 10.8, and mean imaging follow-up period was 19.2 months ± 9.6. Overall survival at 3 years was 94% (95% CI, 81%-100%). Local recurrence-free survival was 100% throughout the imaging follow-up period. Intraprocedural pneumothorax occurred in 37% (7 of 19) of patients; pneumothorax risk was significantly associated with increased tumor distance from pleura (odds ratio, 1.2; P = .018). Sixty-three percent (12 of 19) of patients were discharged on the day of the procedure, with a mean LOS of 7.7 hours ± 1.6, whereas 37% of patients required overnight observation (2 of 19) or admission (5 of 19), with a mean LOS of 48.1 hours ± 19.4. Overall LOS for all patients was 22.6 hours ± 22.9.

CONCLUSIONS

Percutaneous cryoablation of primary pulmonary malignancies can be performed in select octogenarians and nonagenarians with high 3-year overall and recurrence-free survival. Despite nonnegligible risk of pneumothorax, most patients are discharged on the day of the procedure.

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.

CT-based radiomics models may predict the early efficacy of microwave ablation in malignant lung tumors

PURPOSE

To establish and validate radiomics models for predicting the early efficacy (less than 3 months) of microwave ablation (MWA) in malignant lung tumors.

METHODS

The study enrolled 130 malignant lung tumor patients (72 in the training cohort, 32 in the testing cohort, and 26 in the validation cohort) treated with MWA. Post-operation CT images were analyzed. To evaluate the therapeutic effect of ablation, three models were constructed by least absolute shrinkage and selection operator and logistic regression: the tumoral radiomics (T-RO), peritumoral radiomics (P-RO), and tumoral-peritumoral radiomics (TP-RO) models. Univariate and multivariate analyses were performed to identify clinical variables and radiomics features associated with early efficacy, which were incorporated into the combined radiomics (C-RO) model. The performance of the C-RO model was evaluated by the area under the receiver operating characteristic (ROC) curve (AUC), calibration curve, and decision curve analysis (DCA). The C-RO model was used to derive the best cutoff value of ROC and to distinguish the high-risk group (Nomo-score of C-RO model below than cutoff value) from the low-risk group (Nomo-score of C-RO model higher than cutoff value) for survival analysis of patients.

RESULTS

Four radiomics features were selected from the region of interest of tumoral and peritumoral CT images, which showed good performance for evaluating prognosis and early efficacy in three cohorts. The C-RO model had the highest AUC value in all models, and the C-RO model was better than the P-RO model (AUC in training, 0.896 vs. 0.740; p = 0.036). The DCA confirmed the clinical benefit of the C-RO model. Survival analysis revealed that in the C-RO model, the low-risk group defined by best cutoff value had significantly better progression-free survival than the high-risk group (p<0.05).

CONCLUSIONS

CT-based radiomics models in malignant lung tumor patients after MWA could be useful for individualized risk classification and treatment.

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.

CT-Guided Percutaneous Cryoablation for Lung Metastasis of Colorectal Cancer: A Case Series

PURPOSE

This study aimed to evaluate the efficacy of computed tomography (CT) guided percutaneous cryoablation (CA) for the management of lung metastases in patients with metastatic colorectal cancer (mCRC).

METHODS

Retrospective analysis was performed on 38 mCRC patients with lung metastases, who underwent CT-guided percutaneous CA at our center from May 1, 2020 to November 1, 2021. The technical success rate, 1-year local control (LC) rate, recurrence-free survival (RFS) and treatment-related complications were analyzed.

RESULTS

The CA procedure was successfully performed in all patients, with a technical success rate of 100%. The 1-year LC rate was 94.7% (36/38), while 16 patients experienced new distant lung metastases during the follow-up period. The median RFS was 20 months (95% CI: 13.0-27.0). The median RFS of patients with and without extrapulmonary metastasis was 15 and 23 months, respectively. Complications were reported in 18 (47.4%) patients following the CA procedure. Pneumothorax was discovered in 15 (39.5%) patients, and five of these patients (13.2%) required chest tube intubation. Two patients (5.3%) presented with hemoptysis during the CA procedure. One patient developed subcutaneous emphysema as detected in the post-procedure follow-up imaging. All patients tolerated the peri-procedural pain well under local anesthesia, and the mean visual analog scale (VAS) score was 2.8.

CONCLUSION

Lung CA is a safe and well-tolerated treatment with a satisfactory local control rate for patients with lung metastases derived from mCRC.

Image-guided percutaneous ablation for lung malignancies

Image-guided percutaneous lung ablation has proven to be an alternative and effective strategy in the treatment of lung cancer and other lung malignancies. Radiofrequency ablation, microwave ablation, and cryoablation are widely used ablation modalities in clinical practice that can be performed along or combined with other treatment modalities. In this context, this article will review the application of different ablation strategies in lung malignancies.

Computed Tomography Evaluation of In Vivo Pulmonary Cryoablation Zone Sizes

PURPOSE

To evaluate ablation zone sizes in patients undergoing pulmonary tumor cryoablation with 14-gauge cryoablation probes.

MATERIALS AND METHODS

A single-center retrospective analysis of all consecutive patients who underwent cryoablation of pulmonary tumors with 1 or more 14-gauge probes (August 2017 to June 2020) was performed. Intraprocedural and 1-2-month postprocedural chest computed tomography (CT) scans were evaluated to characterize pulmonary lesions, ice balls, and ablation zones. Single-probe 14-gauge ablation zone volumes were compared with manufacturer reference isotherms and single- and 2-probe ablation zones from a prior investigation of 17-gauge probes. Overall survival and local recurrence-free survival were calculated to 3 years.

RESULTS

Forty-seven pulmonary malignancies in 42 patients (women, 50%; mean age, 75.2 years ± 11.5) underwent cryoablation with 1 (n = 35), 2 (n = 10), or 3 (n = 2) cryoablation probes. One- to 2-month follow-up CT images were available for 30 of the 42 patients. The mean cryoablation zone volumes at 1-2 months when 1 (n = 21), 2 (n = 8), and 3 (n = 1) probes were used were 5.0 cm³ ± 2.3, 37.5 cm³ ± 20.5, and 28.4 cm³, respectively. The mean single-probe follow-up ablation zone volume was larger than that previously reported for 17-gauge probes (3.0 cm³ ± 0.3) (P < .001) but smaller than manufacturer-reported isotherms (11.6 cm³ for -40 °C isotherm) and the 2-probe ablation zone volume with 17-gauge devices (12.9 cm³ ± 2.4) (for all, P < 001). The 3-year overall survival and local recurrence-free survival were 69% (95% confidence interval [CI], 53%-89%) and 87% (95% CI, 74%-100%), respectively.

CONCLUSIONS

Fourteen-gauge probes generate larger ablation volumes than those generated by 17-gauge probes. Manufacturer-reported isotherms are significantly larger than actual cryoablation zones. Cryoablation can attain low rates of local recurrence.

The Latest on Lung Ablation

Lung cancer is the second most common cancer in both men and women. Despite smoking cessation efforts and advances in lung cancer detection and treatment, long-term survival remains low. For early-stage primary lung carcinoma, surgical resection offers the best chance of long-term survival; however, only about one-third of patients are surgical candidates. For nonsurgical candidates, minimally invasive percutaneous thermal ablation therapies have become recognized as safe and effective treatment alternatives, including radiofrequency ablation, microwave ablation, and cryoablation. Lung ablation is also an acceptable treatment for limited oligometastatic and oligorecurrent diseases. This article discusses the technologies and techniques available for tumor ablation of thoracic malignancies, as well as new treatments on the horizon.

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.

Oligoprogression in Non-Small Cell Lung Cancer

Simple Summary

Several retrospective studies present evidence of oligoprogressive disease (OPD) in patients with non-small cell lung cancer (NSCLC) with driver mutations such as EGFR. The strategy of local ablative therapy (LAT) with radiotherapy, followed by the continuation of the same anticancer drug therapy beyond progression disease, is recommended in the current NCCN guideline. Although evidence of the use of this strategy in the treatment of the driver mutation-negative NSCLC is missing, LAT with radiotherapy for OPD after combination therapy of immune checkpoint inhibitor with cytotoxic chemotherapy is expected. Tumors outside of the radiation field may further respond to the immune checkpoint inhibitors due to an abscopal effect. In the future, to achieve long-term survival in advanced NSCLC, it will be important to validate this treatment strategy via prospective comparative studies and to actively implement it in clinical practice.

Abstract

We reviewed the literature on oligoprogressive disease (OPD) and local ablative therapy (LAT) in patients with advanced non-small cell lung cancer (NSCLC). The frequency of OPD varies depending on its definition and is estimated to be between 15–47%. The implications of the strategy of continuing the same anticancer agents beyond progressive disease after LAT with radiation therapy for OPD are based on the concept of progression in which only a small number of lesions, not more than about four, proliferate after chemotherapy. In the case of OPD harboring driver mutations such as EGFR, prospective studies are underway. However, evidence from retrospective studies support this strategy, which is currently recommended in some guidelines. The prognosis in OPD cases during the administration of an immune checkpoint inhibitor (ICI) is relatively promising. Additionally, LAT with radiation for OPD after the first-line treatment of ICI with cytotoxic chemotherapy may overcome the resistance to the combination drug therapy due to an abscopal effect. To achieve long-term survival in advanced-stage NSCLC, it is important to verify the optimal method and timing of the therapy through prospective comparative studies as well as patient selection based on patient characteristics and biomarker levels.

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

Imaging of the thorax after percutaneous thermal ablation of lung malignancies

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

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

PURPOSE

To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung.

MATERIALS AND METHODS

A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 63 studies, including existing systematic reviews and meta-analysis, retrospective cohort studies, and single-arm trials were identified. The expert writing group developed and agreed on 7 recommendations on the use of image-guided thermal ablation in the lung.

CONCLUSION

SIR considers image-guided thermal ablation to be an acceptable treatment option for patients with inoperable Stage I NSCLC, those with recurrent NSCLC, as well as patients with metastatic lung disease.

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

Background: Hemoptysis is common following percutaneous image-guided cryoablation of pulmonary tumors. Objective: To evaluate the effect of a final active thaw on the incidence, grade, and onset of hemoptysis following 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 2017 to 2020. The final thaw of a triple-freeze protocol was active (electrical, helium-free) in 27/60 sessions (45%, active group) and passive in 33/60 sessions (55%, passive group). Incidence, onset, and management of hemoptysis were recorded using prospectively collected data. Hemoptysis, pneumothorax, and hemothorax within 30 days post ablation were graded per Common Terminology Criteria for Adverse Events version 5.0 (CTCAE). Volume of immediate post-treatment changes on CT was quantified using semi-automated 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 logrank testing. Results: Hemoptysis occurred following 26/60 (43%) sessions and was self-limited (Grade 1) in 22/26 (85%). The incidence of hemoptysis was lower in the active than passive group (64% vs 19%, respectively; p=.002). The odds of hemoptysis adjusted for immediate post-treatment changes were 92% lower in the active group (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 following the final freeze reduces the incidence and grade of hemoptysis and delays the onset of hemoptysis following percutaneous cryoablation of pulmonary tumors without adversely affecting other procedural complications and local tumor control. Clinical Impact: Active thaw following 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.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Is There a Role for Percutaneous Ablation for Early Stage Lung Cancer? What Is the Evidence?

PURPOSE OF REVIEW

For patients with early stage non-small-cell lung cancer (NSCLC), thermal ablation (TA) has become in the least two decades an option of treatment used worldwide for patients with comorbidities who are not surgical candidates. Here, we review data published with different TA techniques: radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation. This paper reviews also the comparison that has been made between TA and stereotactic radiotherapy (SBRT).

RECENT FINDINGS

A majority of retrospective studies, the absence of comparative studies, and the variety of techniques make difficult to get evident data. Nevertheless, these stand-alone techniques have demonstrated local efficacy for tumors less than 3 cm and good tolerance on fragile patients. Many recent reviews and database analyses show that outcomes after TA (mainly RFA and MWA) are comparable to SBRT in terms of survival rates. For patients who are unfit for surgery, TA has demonstrated interesting results for safety, benefits in overall survival, and acceptable local control.

Image-guided percutaneous ablation for the treatment of lung malignancies: current state of the art

Image-guided percutaneous lung ablation has proven to be a valid treatment alternative in patients with early-stage non-small cell lung carcinoma or oligometastatic lung disease. Available ablative modalities include radiofrequency ablation, microwave ablation, and cryoablation. Currently, there are no sufficiently representative studies to determine significant differences between the results of these techniques. However, a common feature among them is their excellent tolerance with very few complications. For optimal treatment, radiologists must carefully select the patients to be treated, perform a refined ablative technique, and have a detailed knowledge of the radiological features following lung ablation. Although no randomized studies comparing image-guided percutaneous lung ablation with surgery or stereotactic radiation therapy are available, the current literature demonstrates equivalent survival rates. This review will discuss image-guided percutaneous lung ablation features, including available modalities, approved indications, possible complications, published results, and future applications.

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.

Co-ablation versus cryoablation for the treatment of stage III-IV non-small cell lung cancer: A prospective, noninferiority, randomized, controlled trial (RCT)

Background

This study compared a co‐ablation (CA) system, which is a novel ablation device, with an argon‐helium cryoablation (AHC) system. We aimed to compare the efficacy and safety of CA and AHC for the treatment of stage III–IV non‐small cell lung cancer (NSCLC).

Methods

We conducted a multicenter randomized controlled trial (RCT) to determine whether CA was noninferior to AHC. The primary efficacy endpoints were the iceball coverage rate (ICR) and the disease control rate (DCR) one month after treatment. Noninferiority was declared if the lower limit of two‐sided 95% confidence interval (CI) was less than 10%. The ICR and DCR were identified by logistic regression. Treatment safety was assessed.

Results

A total of 81 patients underwent randomization (41 assigned to the CA and 40 assigned to the AHC groups)and transthoracic ablation. The ICRs in the CA and AHC groups were 99.24% ± 2.18% and 98.66% ± 3.79%, respectively. Central lesions were associated with an increased risk of an incomplete ICR. The DCRs in the CA and AHC groups were 97.6% and 95%, respectively. A smaller lesion area in the CA group was significantly correlated with a better DCR. The rate of complications was 29.26% in the CA group and 30% in the AHC group. (P = 0.943). There was less probe usage per patient in the CA group.

Conclusions

We determined that CA is noninferior to AHC in terms of efficacy and safety for the treatment of stage III–IV NSCLC. A smaller lesion area in the CA group was significantly correlated with a better DCR.

Key points

CA was noninferior to AHC for stage III–IV NSCLC.

Cryoablation for T1N0M0 non-small cell lung cancer using liquid nitrogen

OBJECTIVES

To evaluate local control and complications of cryoablation for T1N0M0 non-small cell lung cancer using liquid nitrogen.

METHODS

This is a retrospective observational study on 101 patients with T1N0M0 NSCLC who underwent cryoablation between 2013 and 2019. Exclusion criteria included tumors without pathological diagnosis. The study population was divided into 4 groups according to the quartile of maximum tumor diameter. The study outcomes included local control, recurrence-free survival (RFS), treatment complications, and change in pulmonary function. Median follow-up period was 35 months.

RESULTS

Tumor diameter was divided into ≤0.9 cm (n = 21), 1.0-1.2 (n = 29), 1.3-1.7 (n = 24), and ≥1.8 (n = 27). Ten patients experienced local recurrences, which were observed none in both the groups of ≤0.9 cm and 1.0-1.2 cm (0%), one in the group of 1.3-1.7 cm (4%), and the other 9 in the group of ≥1.8 cm (33 %), indicating the local control to be better in smaller tumors (p < 0.001). The 3-year RFS was 86 % in ≤0.9 cm, 97 % in 1.0-1.2 cm, 92 % in 1.3-1.7 cm, and 53 % in≥1.8 cm, indicating the survival to be better in smaller tumors (p < 0.001). No patient had treatment-related mortality. The most frequent complication was pneumothorax, with a rate of 24 %. Forced expiratory volume in 1 s at 6 months after cryoablation was 97 ± 10 % of the pretreatment one.

CONCLUSION

The local control and recurrence-free survival of cryoablation for T1N0M0 NSCLC was satisfactory for tumors <1.8 cm. While main complication was pneumothorax, the decrease of pulmonary function was just 3%.

Follow-up after radiological intervention in oncology: ECIO-ESOI evidence and consensus-based recommendations for clinical practice

Interventional radiology plays an important and increasing role in cancer treatment. Follow-up is important to be able to assess treatment success and detect locoregional and distant recurrence and recommendations for follow-up are needed. At ECIO 2018, a joint ECIO-ESOI session was organized to establish follow-up recommendations for oncologic intervention in liver, renal, and lung cancer. Treatments included thermal ablation, TACE, and TARE. In total five topics were evaluated: ablation in colorectal liver metastases (CRLM), TARE in CRLM, TACE and TARE in HCC, ablation in renal cancer, and ablation in lung cancer. Evaluated modalities were FDG-PET-CT, CT, MRI, and (contrast-enhanced) ultrasound. Prior to the session, five experts were selected and performed a systematic review and presented statements, which were voted on in a telephone conference prior to the meeting by all panelists. These statements were presented and discussed at the ECIO-ESOI session at ECIO 2018. This paper presents the recommendations that followed from these initiatives. Based on expert opinions and the available evidence, follow-up schedules were proposed for liver cancer, renal cancer, and lung cancer. FDG-PET-CT, CT, and MRI are the recommended modalities, but one should beware of false-positive signs of residual tumor or recurrence due to inflammation early after the intervention. There is a need for prospective preferably multicenter studies to validate new techniques and new response criteria. This paper presents recommendations that can be used in clinical practice to perform the follow-up of patients with liver, lung, and renal cancer who were treated with interventional locoregional therapies.

Lung Ablation - How I Do It

Interventional oncology and the value of thermal ablation of small tumors is increasingly recognized by the oncological community. Primary lung cancers and lung metastases have been one of the most researched applications of percutaneous ablation and as interventional oncologists gain more experience and confidence, it is becoming a more effective treatment with expanding indications. Importantly, the current literature does not demonstrate major differences in survival between ablation, sublobar resection, and stereotactic body radiation. The advantages of percutaneous ablation over other local therapies like surgery or SBRT are significantly lower morbidity, mortality, and repeatability of treatments. The focus of this essay is to highlight technical and procedural aspects of lung ablation as well as management and follow-up in a practical fashion.

Comparing cryoablation and microwave ablation for the treatment of patients with stage IIIB/IV non-small cell lung cancer

The aim of the present study was to compare the safety and efficacy of cryoablation (CA) and microwave ablation (MWA) as treatments for non-small cell lung cancer (NSCLC). Patients with stage IIIB or IV NSCLC treated with CA (n=45) or MWA (n=56) were enrolled in the present study. The primary endpoint was progression-free survival (PFS); the secondary endpoints included overall survival (OS) time and adverse events (AEs). The median PFS times between the two groups were not significantly different (P=0.36): CA, 10 months [95% confidence interval (CI), 7.5-12.4] vs. MWA, 11 months (95% CI, 9.5-12.4). The OS times between the two groups were also not significantly different (P=0.07): CA, 27.5 months (95% CI, 22.8-31.2 months) vs. MWA, 18 months (95% CI, 12.5-23.5). For larger tumors (>3 cm), patients treated with MWA had significantly longer median PFS (P=0.04; MWA, 10.5 months vs. CA, 7.0 months) and OS times (P=0.04; MWA, 24.5 months vs. CA, 14.5 months) compared patients treated with CA. However, for smaller tumors (≤3 cm), median PFS (P=0.79; MWA, 11.0 months vs. CA, 13.0 months) and OS times (P=0.39; MWA, 30.0 months vs. CA, 26.5 months) between the two groups did not differ significantly. The incidence rates of AEs were similar in the two groups (P>0.05). The number of applicators, tumor size and length of the lung traversed by applicators were associated with a higher risk of pneumothorax and intra-pulmonary hemorrhage in the two groups. Treatment with CA resulted in significantly less intraprocedural pain compared with treatment with MWA (P=0.001). Overall, the present study demonstrated that CA and MWA were comparably safe and effective procedures for the treatment of small tumors. However, treatment with MWA was superior compared with CA for the treatment of large tumors.

Cryoablation of Lung Metastases: Review of Recent Literature and Ablation Technique

This article reviews the current indications for image-guided thermal ablation of pulmonary metastatic disease. It also summarizes data regarding the efficacy and complications of lung cryoablation and present techniques for performing lung cryoablation as informed by the recent literature.

Lung Ablation: Indications and Techniques

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