Safety and efficacy of microwave ablation versus argon-helium cryoablation for the treatment of primary high-risk pulmonary nodules: a propensity score-matched study

Introduction

Lung cancer ranks as the most frequently diagnosed malignancy globally and remains the primary cause of cancer-associated mortality (1). With the widespread adoption of low-dose computed tomography​ (CT) scanning, an increasing number of pulmonary nodules are detected (2-4). Surgical resection remains the gold standard for patients with high-risk pulmonary nodules. However, for those with compromised cardiopulmonary function or clear surgical contraindications due to underlying conditions, effective alternative treatments are urgently needed. Moreover, with advances in surgical techniques and improved detection methods, an increasing number of patients who have previously undergone surgical resection for early-stage lung cancer or pulmonary nodules may develop multiple new pulmonary nodules during follow-up. In such cases, extensive reoperation may not be feasible due to the need to preserve lung function. For these patients, alternative local therapies are critical (5).

Tumor thermal ablation is a precise, minimally invasive technique that leverages thermal biological effects to cause irreversible damage or necrosis directly to tumor cells within one or multiple focal lesions in a specific organ (6). As a modality of local thermal ablation, microwave ablation (MWA) offers advantages including minimal invasiveness, rapid recovery, and high repeatability, and has increasingly become a safe and effective minimally invasive alternative to surgical resection (7-10). Previous studies reported a local control rate ranging approximately from 70% to 90% in early-stage lung cancers treated with MWA (11-14).

Cryoablation (CA), a local interventional therapy that induces tissue damage through low-temperature exposure and triggers anti-tumor immune responses, similarly demonstrates advantages such as minimal invasiveness, precision, and low postoperative complication rates. The safety advantages are especially pronounced for nodules located near high-risk structures, such as large vessels, the heart, and pleura (15,16). In the treatment of pulmonary nodules, CA is gradually establishing evidence, showing local control rates similar to MWA (17,18).

Although MWA and CA demonstrate promising clinical potential for treating pulmonary nodules, direct comparative studies between these two techniques in high-risk primary pulmonary nodules remain lacking. Therefore, this study aims to compare the safety and efficacy of MWA versus CA in patients with primary high-risk pulmonary nodules. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1673/rc).

Methods

The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Hangzhou, China) (No. 2025-2243-01) and individual consent for this retrospective analysis was waived.

Patient selection

The present study was a retrospective analysis of patients with primary high-risk nodules who had undergone MWA or CA at Sir Run Run Shaw Hospital (Hangzhou) between January 2019 and December 2023. Patients with high-risk pulmonary nodules who were ineligible for or declined surgical resection, and subsequently underwent MWA or CA, were included in the analysis. A primary pulmonary nodule was defined as high-risk if meeting any of the following criteria: (I) nodules detected for at least 3 months, with a diameter greater than 8 mm; (II) imaging demonstrates an increase in nodule volume and/or the emergence or progression of solid components. Malignant features, including but not limited to spiculation, lobulation, or vacuole sign, were concurrently observed; (III) following multidisciplinary team (MDT) evaluation synthesizing imaging (CT/PET-CT) features, molecular biomarkers, and clinical risk factors, the nodules are determined to be suspicious for malignancy, including but not limited to: spiculation on thin-section CT, SUVmax >2.5 on PET-CT, elevated serum carcinoembryonic antigen (CEA) levels, and ≥20 pack-year smoking history.

Exclusion criteria were as follows: (I) other advanced or end-stage malignancies, including stage IV disease, life expectancy <12 months, or requiring systemic antitumor therapy; (II) prior malignancy with lung nodules assessed as metastases by an MDT based on clinico-radiologic features; (III) lost to follow-up. For patients with primary high-risk pulmonary nodules, a history of malignancy was defined as having undergone curative treatment for any prior malignant tumor with sustained no evidence of disease status for over 3 years. Patient demographic and clinical data were collected through a consecutive, nonselective process.

Pre-ablation assessment

All patients were comprehensively informed about the advantages and disadvantages of MWA and CA prior to the procedure. This included detailed explanations of the technical principles, anticipated therapeutic outcomes, procedure-related complications, estimated differences in operative duration and postoperative recovery processes, and the associated cost structures. The final decision regarding the ablation modality was made by the patient and/or their authorized representative, who subsequently provided written informed consent.

Routine preoperative laboratory tests, including complete blood count, platelet count, prothrombin time, and international normalized ratio (INR), were obtained. Patients taking anticoagulant or antiplatelet medications were instructed to discontinue these agents 2–7 days prior to the ablation procedure. All patients fasted for at least 12 hours prior to the procedure.

Ablation technique

All lung MWA and CA procedures were performed by two experienced (>5 years) interventional radiologists under CT guidance. General anesthesia was administered through a combination of intravenous and inhalational agents. Continuous monitoring of cardiac activity and vital parameters was maintained throughout each procedure. Upon completion, a follow-up CT scan was performed to detect any immediate complications, and patients were subsequently transferred to an inpatient unit for observation.

The MWA treatments were carried out using a KY-2000 system (Kangyou Medical Co., Ltd., Jintan, China), operating at a frequency of 2,450±50 MHz, with a continuous wave output adjustable between 0 and 100 watts. The microwave antenna used had an effective length ranging from 100 to 180 mm and an outer diameter of 14–20 G, featuring a 1.5 cm active tip. A water circulation cooling mechanism was employed to regulate the antenna’s surface temperature during ablation. Energy was typically delivered at 30–50 W, aiming to achieve an ablation margin of approximately 0.5 cm around the lesion. If a single application did not produce complete ablation, an additional overlapping ablation cycle was performed until full coverage of the target was confirmed.

CA was performed using VisualICE™ system with IceRod1.5 cryoprobes (Boston Scientific, Marlborough, MA, USA), under CT guidance to ensure the targeted nodule was encompassed by an adequate margin. The number and positioning of the probes were selected to maintain an inter-probe distance of 15–20 mm and to keep all probes within 10 mm of the tumor boundary, while avoiding disruption of surrounding anatomical structures. The ablation protocol consisted of three freeze-thaw cycles. The protocol included a first freeze of 3 minutes, a thaw period of 3 minutes, a second freeze lasting 8 minutes, followed by a 5-minute thaw, and a final 8-minute freeze before active thawing. The ablation zone was assessed with non-contrast CT imaging at 3–5-minute intervals during the procedure to confirm ice coverage with at least a 5 mm circumferential margin beyond the tumor.

Pathology

Intraoperative concurrent biopsy was performed for high-risk pulmonary nodules; however, a definitive pathological diagnosis was not obtained in some cases. The reasons included: (I) lesion proximity to critical structures (e.g., airways, major vessels, or cardiac structures), where percutaneous biopsy posed significant risks; (II) lesions often being smaller than 1 cm or lacking a solid component, resulting in higher false-negative rates for percutaneous biopsy; (III) explicit patient refusal of biopsy after thorough counseling.

Follow-up and outcome measurements

After ablation, patients underwent outpatient follow-up with CT imaging scheduled at 1, 3, and 6 months, and then at six-month intervals thereafter. The primary endpoints assessed in this study included technical success, clinical efficacy, safety profile, disease-free survival (DFS), and overall survival (OS). Technical success for an individual tumor was determined based on post-procedural CT imaging showing a region of ground-glass opacity fully covering the lesion with a minimum 5-mm ablation margin surrounding the tumor at the end of the ablation. Local tumor progression was identified by the presence of irregular focal enhancement exceeding 15 Hounsfield units (HU) compared to the baseline appearance of the non-enhanced ablation zone on follow-up imaging (19,20). DFS was defined as the time interval from the initial ablation procedure to the occurrence of local tumor progression. OS was measured from the initiation of treatment until death or the last follow-up, which was conducted on November 24, 2024. Safety assessment was based on the incidence of procedure-related complications, and all adverse events (AEs) were classified according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0 (21). Comparison of postoperative pain experiences in patients undergoing MWA and CA. Pain score was self-assessed by patients using a visual analog scale (VAS), with scores ranging from 0 (indicating no pain) to 10 (representing the most severe pain imaginable). Baseline pain scores were recorded upon emergence from anesthesia, with subsequent assessments at 2- to 4-hour intervals during the first 24 postoperative hours, particularly during activity. The peak pain score within 24 hours was utilized for analysis. For patients with pain scores ≥4, nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., celecoxib, parecoxib sodium) or weak opioids (e.g., codeine tablets) were administered, followed by efficacy reassessment 30 minutes post-intravenous administration or 1 hour post-oral administration.

Statistical analysis

For continuous variables, data were presented as mean ± standard deviation (SD) when following a normal distribution, or as median with interquartile range (IQR) for non-normally distributed data. Categorical data were summarized as counts and percentages, with 95% confidence intervals for proportions estimated using the Wilson score method. Group comparisons for continuous variables were performed using either the t-test or the Wilcoxon rank-sum test, depending on distributional assumptions, while categorical variables were analyzed using the chi-square test. To balance the potential confounding variables at baseline, a propensity score matching (PSM) method was used to match the patients’ gender, age, and Charlson Comorbidity Index (CCI) using the nearest neighbor matching method with caliper width of 0.05 at the ratio 1:2. Matching success was determined by a standardized mean difference <0.2 on variables following the match. DFS was evaluated by using the Kaplan-Meier method. Local control rates at 1, 2, and 3 years were also estimated from the Kaplan-Meier survival curves at both the patient and lesion levels. All statistical analyses were conducted using software (RStudio version 1.1.414, RStudio, Boston, MA, USA). An alpha level of 0.05 was chosen to indicate statistical significance. All reported P values are two-sided.

Results

Baseline characteristics before and after PSM

A total of 31 patients with 35 primary high-risk pulmonary nodules treated by CA and 108 patients with 127 nodules treated by MWA were included. After PSM, a total of 95 patients were ultimately enrolled, with 29 patients with 33 nodules in the CA group and 66 patients with 81 nodules in the MWA group. The patient selection flowchart is presented in Figure 1. The median patient age was 62 years (range, 31–87 years), with 58/139 (41.73%) were males. The median tumor dimensions were 7.55 mm (6.11, 10.75 mm) at short axial and 10.65 mm (7.53, 14.15 mm) at long. Most of them (150/162, 92.59%) were peripherally located. Thirty-five nodules underwent simultaneous biopsy. In the CA group (9 cases), 4 were diagnosed as adenocarcinoma, 2 were squamous cell carcinoma, and 3 were pulmonary tissue. In the MWA group (26 cases), 11 were adenocarcinoma, 4 were squamous cell carcinoma, 1 was considered non-small cell carcinoma, 1 was neuroendocrine tumor and 9 were pulmonary tissue. A summary of baseline variables of our study cohort is in Tables 1,2.

Figure 1 Flowchart of the study. CA, cryoablation; MWA, microwave ablation.

Treatment efficacy

The technical success rates were both 100%. Most patients (110/139, 79.14%) underwent ablation with a single applicator or needle, while 19.42% (27/139) required two, and only 2 patients (1.44%) required three. Within a median follow-up period of 25 months, disease progression occurred in 12 nodules, with progression rates of 11.43% (4/35) in the CA group and 6.30% (8/127) in the MWA group. After PSM, the rates remained with no statistical difference (12.12% vs. 7.41%, P=0.472). Figures 2,3 are examples of CA and MWA, respectively. According to Kaplan-Meier analysis, no significant difference was found in DFS between the two groups at the patient-level and lesion-level before and after PSM (Figure 4). On lesion level, the 1-year, 2-year, and 3-year local control rates for the CA group and the MWA group were 96.88% (95% CI: 91.03–100%), 85.70% (95% CI: 70.99–100%) and 77.91% (95% CI: 59.75–100%) vs. 100% (95% CI: 100–100%), 99.10% (95% CI: 97.36–100%), and 91.44% (95% CI: 85.01–98.37%), respectively before PSM. After PSM, the rates were 96.67% (95% CI: 90.45–100%), 84.58% (95% CI: 68.94–100%) and 76.13% (95% CI: 56.92–100%) vs. 100% (95% CI: 100–100%), 100% (95% CI: 100–100%) and 88.88% (95% CI: 80.10–98.63%) respectively. On patient-level, the 1-year, 2-year, and 3-year local control rates for the CA group and the MWA group were 96.43% (95% CI: 89.79–100%), 83.28% (95% CI: 66.58–100%), and 74.03% (95% CI: 53.67–100%) vs. 97.97% (95% CI: 95.22–100%), 94.47% (95% CI: 89.84–99.34%), and 82.67% (95% CI: 73.93–92.45%), respectively before PSM. After PSM, the local control rate was 96.15% (95% CI: 89.04–100%), 81.73% (95% CI: 63.82–100%) and 71.51% (95% CI: 49.88–100%) vs. 96.74% (95% CI: 92.41–100%), 93.08% (95% CI: 86.73–99.89%) and 75.36% (95% CI: 63.30–89.72%) respectively. All the patients were alive at the last follow-up.

Figure 2 A 66-year-old male patient with squamous cell carcinoma treated with cryoablation. (A) Preoperative chest CT showed a solid nodule in the right upper lobe with an eccentric cavity, suggestive of high risk. (B) CT-guided coaxial biopsy using an 18 G × 15 cm needle yielded two ~1 cm tissue samples. Immunohistochemistry of the pathological specimen showed CK7(−), TTF-1(−), Napsin A(−), CK5/6(+), P40(+), and BRG1(+), confirming squamous cell carcinoma. (C) Cryoablation was performed with one 17 G cryoprobe and three freeze-thaw cycles. Post-procedure CT showed minimal bleeding and a trace pneumothorax. (D) Follow-up at 2 years post-ablation showed no recurrence or progression, with only a linear fibrotic proliferative focus noted. CT, computed tomography.

Figure 3 A 59-year-old female patient diagnosed with a pulmonary nodule 5 years ago and has undergone routine follow-up every 6 months. (A) Preoperative chest CT revealed a mixed ground-glass nodule in the right middle lobe, measuring 9.4 mm in the longest diameter, with a rounded lower margin and irregular shape, showing a slow increase in size over the past 2 years. (B) The patient subsequently underwent microwave ablation of the right lung nodule, using a power setting of 35 watts for 5 minutes. (C) Postoperative imaging showed a small pneumothorax in the right chest. (D) Nine months after the procedure, a follow-up CT demonstrated a linear fibrotic proliferative focus at the ablation site, with no signs of recurrence or progression. CT, computed tomography.

Figure 4 Kaplan-Meier analysis of local disease-free survival in the (A) lesions and (B) patients from the entire cohort; lesion-level (C) and patient-level (D) local disease-free profile in the propensity score-matched cohort.

Complications, pain score and length of stay

The complication rates were comparable between the two groups: CA, 25/31 (80.65%; 95% CI: 63.72–90.81%) vs. MWA 68/108 (62.96%; 95% CI: 53.56–71.48%) (P=0.104) before PSM. The rates were 23/29 (79.31%; 95% CI: 61.61–90.15%) vs. 48/66 (72.73%; 95% CI: 60.96–82.00%) after PSM. The most common complications were pneumothorax (50.36%), and pleural effusion (30.22%). No ablation-related deaths occurred. There was no statistically significant difference in the complication rates between the two groups (P>0.05), as shown in Table 3. One case of severe complication occurred in the MWA group, in which the patient developed pulmonary embolism (PE). The patient, a 67-year-old woman with low preoperative venous thromboembolism risk, developed hypoxia (SpO₂ 91%), tachycardia, and chest tightness on postoperative day 2 after MWA of a left pulmonary nodule. D-dimer was markedly elevated (>20 µg/mL), and CT pulmonary angiography confirmed bilateral PE. She received oxygen therapy and anticoagulation with low-molecular-weight heparin. Her condition improved with treatment, and she was discharged in stable condition.

The pain scores of the CA group were significantly lower than those of the MWA group before [CA: 1.00 (0.00, 1.00) vs. MWA: 2.00 (1.00, 4.00), P<0.001] and after PSM [CA: 1.00 (0.00, 1.00) vs. MWA: 2.00 (1.00, 4.00), P=0.002]. The median hospital stay was 5.00 (3.50, 5.00) days in the CA group and 4.00 (3.00, 5.25) days in the MWA group with no significant difference (P=0.471) before PSM and remained non-significant difference after PSM [CA: 5.00 (4.00, 5.00) vs. 5.00 (4.00, 6.00) days, P=0.931].

Discussion

The main findings of this study are as follows: both MWA and CA achieved a 100% technical success rate. No statistically significant difference was observed in DFS between the two groups, suggesting comparable efficacy in local disease control. Additionally, there was no significant difference in the overall incidence of postoperative complications between the two treatment modalities, although the CA group demonstrated significantly lower pain scores compared to the MWA group.

MWA offers several advantages, including high efficiency, rapid heating, creation of a larger ablation zone, and reduced energy attenuation by surrounding tissues, making it particularly suitable for treating pulmonary lesions. Previous studies have reported a local recurrence rate of around 10% and local control rates of approximately 85% in early-stage lung cancer, findings that are consistent with the outcomes of our study. Minor discrepancies may be attributed to differences in lesion size, location, and histological types (12,14,22,23). CA, on the other hand, is a relatively newer ablation modality that relies on the Joule-Thomson effect to induce cell death through extreme hypothermia. Subsequent rewarming further enhances the cytotoxic effect by causing cell membrane rupture and promoting vascular thrombosis (24). Our observed local disease progression rate for CA (4/35, 11.43%) aligned with previously reported data (23,25,26). Prior comparative studies similarly showed no significant differences in efficacy between MWA and CA (27,28). Our study further emphasizes that a similar finding is observed between MWA and CA in the treatment of high-risk pulmonary nodules.

The overall incidence of complications did not differ significantly between the groups, with pneumothorax and pleural effusion being the most frequent. These findings align with prior studies (23,29-31). A total of 4 patients (12.90%) in the CA group and 12 patients (11.11%) in the MWA group underwent closed thoracic drainage, comparable to an earlier report (22). Although pneumothorax occurred with a relatively high incidence, mild cases were effectively managed with conservative measures, while moderate to severe cases achieved successful resolution through closed thoracic drainage. No cases of respiratory failure or ablation-related deaths occurred in either group. Hemoptysis was slightly more frequent in CA, potentially related to its freeze-thaw cycles (32), but events were generally minor and self-limited. Notably, one case of PE occurred in the MWA group but not in the CA group, likely related to MWA’s thermal effects. MWA induces high-frequency oscillation of polar molecules, causing tumor necrosis and vascular endothelial injury, which can activate coagulation cascades. Lesions near pulmonary arteries may increase PE risk. Therefore, preoperative venous thromboembolism risk assessment (e.g., Caprini model), mechanical measures (e.g., intermittent pneumatic compression), and early ambulation are recommended with pharmacologic prophylaxis (low-molecular-weight heparin) added when necessary. For patients with acute hypoxemia or chest pain and markedly elevated D-dimer (>20 µg/mL), prompt CT pulmonary angiography is essential to rule out PE.

Several studies have reported that CA is less painful compared with other techniques, likely due to the local anesthetic effect of extreme cold and vasoconstriction, which minimizes edema and the release of pain-inducing substances (15,33,34). This advantage may be particularly relevant in frail or high-risk patients. From a real-world perspective, minimizing pain not only improves patient comfort and recovery but may also enhance treatment adherence in older or comorbid populations. Furthermore, although CA is not currently reimbursed, its demonstrated safety and efficacy may inform future healthcare policy.

There are several limitations in this study that should be acknowledged when interpreting the findings. First, complete histopathological confirmation was not available for all patients. Although MDT consensus and imaging characteristics were used to diagnose, the absence of pathological confirmation—the gold standard—introduces the possibility of misclassification and diagnostic uncertainty, which may have influenced the reported outcomes. Second, the sample size of the CA cohort was relatively small compared with the MWA cohort. This imbalance, combined with the single-center and retrospective design, limits the statistical power to detect differences and may restrict the generalizability of the results. Finally, a potential source of selection bias stems from the lack of inclusion of CA in the national medical insurance reimbursement system. Because CA often required higher out-of-pocket costs, patients choosing this modality may represent a distinct socioeconomic or clinical subgroup, further confounding comparisons between the two techniques. Although PSM was applied to mitigate baseline differences, such methods cannot fully eliminate these inherent biases. Larger, multicenter, prospective studies with standardized histological confirmation and more balanced representation of treatment groups are warranted to validate and extend these findings.

Conclusions

In conclusion, the present study demonstrated that both CA and MWA are comparably effective and safe treatment options for patients with high-risk pulmonary nodules. For patients who are not suitable candidates for surgical resection, CA and MWA represent both promising and viable minimally invasive alternatives. Moreover, CA may offer the advantage of reduced procedural pain compared to MWA.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1673/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1673/dss

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1673/coif). X.T. is a current employee of Boston Scientific Corporation. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Institutional Review Board of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine (Hangzhou, China) (No. 2025-2243-01) and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Bray F, Laversanne M, Sung H, Ferlay J, Siegel RL, Soerjomataram I, Jemal A. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin 2024;74:229-63. [Crossref] [PubMed]
2. Fan L, Wang Y, Zhou Y, Li Q, Yang W, Wang S, Shan F, Zhang X, Shi J, Chen W, Liu SY. Lung Cancer Screening with Low-Dose CT: Baseline Screening Results in Shanghai. Acad Radiol 2019;26:1283-91. [Crossref] [PubMed]
3. He YT, Zhang YC, Shi GF, Wang Q, Xu Q, Liang D, Du Y, Li DJ, Jin J, Shan BE. Risk factors for pulmonary nodules in north China: A prospective cohort study. Lung Cancer 2018;120:122-9. [Crossref] [PubMed]
4. Yang W, Qian F, Teng J, Wang H, Manegold C, Pilz LR, Voigt W, Zhang Y, Ye J, Chen Q, Han BAME Thoracic Surgery Collaborative Group. Community-based lung cancer screening with low-dose CT in China: Results of the baseline screening. Lung Cancer 2018;117:20-6. [Crossref] [PubMed]
5. Zhou D, Yao T, Huang X, Wu F, Jiang Y, Peng M, Qian B, Liu W, Yu F, Chen C. Real-world comprehensive diagnosis and "Surgery + X" treatment strategy of early-stage synchronous multiple primary lung cancer. Cancer Med 2023;12:12996-3006. [Crossref] [PubMed]
6. Ye X, Fan W, Wang H, Wang J, Wang Z, Gu S, et al. Expert consensus workshop report: Guidelines for thermal ablation of primary and metastatic lung tumors (2018 edition). J Cancer Res Ther 2018;14:730-44. [Crossref] [PubMed]
7. Hu Y, Xue G, Liang X, Li Z, Wang N, Cao P, Wang G, Zhang H, Zheng X, Wang A, Zhao W, Han C, Wei Z, Ye X. Computed tomography-guided microwave ablation for right middle lobe pulmonary nodules: a retrospective, single-center, case-control study. Int J Hyperthermia 2024;41:2307479. [Crossref] [PubMed]
8. Narsule CK, Sridhar P, Nair D, Gupta A, Oommen RG, Ebright MI, Litle VR, Fernando HC. Percutaneous thermal ablation for stage IA non-small cell lung cancer: long-term follow-up. J Thorac Dis 2017;9:4039-45. [Crossref] [PubMed]
9. NCCN. NCCN Guideline (Version 3.2025). Accessed April 12 2025. Available online: https://www.nccn.org/login?ReturnURL=https://www.nccn.org/professionals/physician_gls/pdf/nscl.pdf
10. Zhang J, Xu K, Du K, Han X, Jiao D. Simultaneous percutaneous microwave ablation and biopsy for highly suspected malignant pulmonary nodules: a retrospective cohort study. Quant Imaging Med Surg 2023;13:7214-24. [Crossref] [PubMed]
11. Han X, Yang X, Huang G, Li C, Zhang L, Qiao Y, Wang C, Dong Y, Chen X, Feng Q. Safety and clinical outcomes of computed tomography-guided percutaneous microwave ablation in patients aged 80 years and older with early-stage non-small cell lung cancer: A multicenter retrospective study. Thorac Cancer 2019;10:2236-42. [Crossref] [PubMed]
12. Nance M, Khazi Z, Kaifi J, Avella D, Alnijoumi M, Davis R, Bhat A. Computerized tomography-Guided Microwave Ablation of Patients with Stage I Non-small Cell Lung Cancers: A Single-Institution Retrospective Study. J Clin Imaging Sci 2021;11:7. [Crossref] [PubMed]
13. Yang X, Ye X, Huang G, Han X, Wang J, Li W, Wei Z, Meng M. Repeated percutaneous microwave ablation for local recurrence of inoperable Stage I nonsmall cell lung cancer. J Cancer Res Ther 2017;13:683-8. [Crossref] [PubMed]
14. Zhao H, Steinke K. Long-term outcome following microwave ablation of early-stage non-small cell lung cancer. Journal of Medical Imaging and Radiation Oncology 2020;64:787-93. [Crossref] [PubMed]
15. Colak E, Tatlı S, Shyn PB, Tuncalı K, Silverman SG. CT-guided percutaneous cryoablation of central lung tumors. Diagn Interv Radiol 2014;20:316-22. [Crossref] [PubMed]
16. Murphy MC, Tahir I, Saenger JA, Abrishami Kashani M, Muniappan A, Levesque VM, Shyn PB, Silverman SG, Fintelmann FJ. Safety and Effectiveness of Percutaneous Image-Guided Thermal Ablation of Juxtacardiac Lung Tumors. J Vasc Interv Radiol 2023;34:750-8. [Crossref] [PubMed]
17. Liu S, Liang B, Li Y, Xu J, Qian W, Lin M, Xu M, Niu L. CT-Guided Percutaneous Cryoablation in Patients with Lung Nodules Mainly Composed of Ground-Glass Opacities. J Vasc Interv Radiol 2022;33:942-8. [Crossref] [PubMed]
18. Liu S, Zhu X, Qin Z, Xu J, Zeng J, Chen J, Niu L, Xu M. Computed tomography-guided percutaneous cryoablation for lung ground-glass opacity: A pilot study. J Cancer Res Ther 2019;15:370-4. [Crossref] [PubMed]
19. Ahmed MTechnology Assessment Committee of the Society of Interventional Radiology. Image-guided tumor ablation: standardization of terminology and reporting criteria--a 10-year update: supplement to the consensus document. J Vasc Interv Radiol 2014;25:1706-8. [Crossref] [PubMed]
20. Bojarski JD, Dupuy DE, Mayo-Smith WW. CT imaging findings of pulmonary neoplasms after treatment with radiofrequency ablation: results in 32 tumors. AJR Am J Roentgenol 2005;185:466-71. [Crossref] [PubMed]
21. U.S. Department of Health and Human Services. Common Terminology Criteria for Adverse Events (CTCAE). s v4.0. Accessed April 8 2025. Available online: https://evs.nci.nih.gov/ftp1/CTCAE/CTCAE_4.03/Archive/CTCAE_4.0_2009-05-29_QuickReference_8.5x11.pdf
22. Lee YC, Hong JA, Chou HP, Chang NW, Weng CY, Huang CS, Hsu PK, Guo CY, Liu CA, Wu HT, Shen SH, Chen CK. Risk factors associated with complications and local tumour progression in image-guided triple-freezing cryoablation for lung tumour: a longitudinal study. Int J Hyperthermia 2025;42:2492769. [Crossref] [PubMed]
23. Moore W, Talati R, Bhattacharji P, Bilfinger T. Five-year survival after cryoablation of stage I non-small cell lung cancer in medically inoperable patients. J Vasc Interv Radiol 2015;26:312-9. [Crossref] [PubMed]
24. Erinjeri JP, Clark TW. Cryoablation: mechanism of action and devices. J Vasc Interv Radiol 2010;21:S187-91. [Crossref] [PubMed]
25. Zemlyak A, Moore WH, Bilfinger TV. Comparison of survival after sublobar resections and ablative therapies for stage I non−small cell lung cancer. Journal of the American College of Surgeons 2010;211:68-72. [Crossref] [PubMed]
26. Callstrom MR, Woodrum DA, Nichols FC, Palussiere J, Buy X, Suh RD, et al. Multicenter Study of Metastatic Lung Tumors Targeted by Interventional Cryoablation Evaluation (SOLSTICE). J Thorac Oncol 2020;15:1200-9. [Crossref] [PubMed]
27. Das SK, Huang YY, Li B, Yu XX, Xiao RH, Yang HF. Comparing cryoablation and microwave ablation for the treatment of patients with stage IIIB/IV non-small cell lung cancer. Oncol Lett 2020;19:1031-41. [Crossref] [PubMed]
28. Li HW, Long YJ, Yan GW, Bhetuwal A, Zhuo LH, Yao HC, Zhang J, Zou XX, Hu PX, Yang HF, Du Y. Microwave ablation vs. cryoablation for treatment of primary and metastatic pulmonary malignant tumors. Mol Clin Oncol 2022;16:62. [Crossref] [PubMed]
29. Kennedy SA, Milovanovic L, Dao D, Farrokhyar F, Midia M. Risk factors for pneumothorax complicating radiofrequency ablation for lung malignancy: a systematic review and meta-analysis. J Vasc Interv Radiol 2014;25:1671-81.e1. [Crossref] [PubMed]
30. Mal R, Domini J, Wadhwa V, Makary MS. Thermal ablation for primary and metastatic lung tumors: Single-center analysis of peri-procedural and intermediate-term clinical outcomes. Clin Imaging 2023;98:11-5. [Crossref] [PubMed]
31. Wang N, Xu J, Wang G, Xue G, Li Z, Cao P, Hu Y, Cai H, Wei Z, Ye X. Safety and efficacy of microwave ablation for lung cancer adjacent to the interlobar fissure. Thorac Cancer 2022;13:2557-65. [Crossref] [PubMed]
32. Wrobel MM, Bourgouin PP, Abrishami Kashani M, Leppelmann KS, Vazquez R, Pachamanova DA, Fintelmann FJ. Active Versus Passive Thaw After Percutaneous Cryoablation of Pulmonary Tumors: Effect on Incidence, Grade, and Onset of Hemoptysis. AJR Am J Roentgenol 2021;217:1153-63. [Crossref] [PubMed]
33. Inoue M, Nakatsuka S, Yashiro H, Ito N, Izumi Y, Yamauchi Y, Hashimoto K, Asakura K, Tsukada N, Kawamura M, Nomori H, Kuribayashi S. Percutaneous cryoablation of lung tumors: feasibility and safety. J Vasc Interv Radiol 2012;23:295-302; quiz 305. [Crossref] [PubMed]
34. Allaf ME, Varkarakis IM, Bhayani SB, Inagaki T, Kavoussi LR, Solomon SB. Pain control requirements for percutaneous ablation of renal tumors: cryoablation versus radiofrequency ablation—initial observations. Radiology 2005;237:366-70. [Crossref] [PubMed]