Microwave ablation treatment for medically inoperable stage I non-small cell lung cancers: long-term results

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL RELEVANCE STATEMENT

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

KEY POINTS

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

Dynamic Changes in the Immune Microenvironment in Tumor-Draining Lymph Nodes of a Lewis Lung Cancer Mouse Model After Microwave Ablation

Purpose

Microwave ablation (MWA) is a minimally invasive technique for treating lung cancer. It can induce immune response; however, its effect on the immune microenvironment in tumor-draining lymph nodes (TdLN) is not well understood. This study aims to identify changes in the immune microenvironment in TdLN following MWA in a Lewis lung cancer (LLC) mouse model.

Methods

LLC mouse model was established and followed by MWA. TdLN were collected at various time points, including pre-MWA and days 1, 2, 4, and 8 post-MWA. Flow cytometry was used to determine the frequencies of CD4+ T cells, CD8+ T cells, regulatory T (Treg) cells, natural killer (NK) cells, dendritic cells (DCs) and other immune cells in the TdLN. Certain cytokines were also detected.

Results

Compared with pre-MWA, the frequency of CD4+ T cells significantly increased from day 1 to day 8 post-MWA. The frequency of CD8+ T cells decreased significantly on days 2 and 4, but no significant changes occurred on days 1 and 8. Significant decreases in the frequencies of Treg cells and Klrg1+ Treg cells were observed from day 1 to day 4. On days 4 and 8, there was a significant increase in the frequency of NK cells. The frequency of resident cDC2 significantly increased on day 4, whereas CD11b+ migratory cDCs increased on day 1. Additionally, on day 4, a notable rise was observed in the frequency of NK cells secreting IFN-γ, while on day 8, there was a significant increase in the frequency of CD8+ T cells secreting both IFN-γ and TNF-α.

Conclusion

MWA of lung cancer can alter the immune microenvironment in the TdLN, triggering immune responses. These changes are particularly evident and intricate within the initial 4 days post-MWA. Treatment combined with MWA within a certain period may significantly enhance anti-tumor immunity.

Clinical outcomes of percutaneous microwave ablation for pulmonary oligometastases from hepatocellular carcinoma: a retrospective, multicenter study

BACKGROUND

Pulmonary oligometastases are common in hepatocellular carcinoma (HCC), however, the existing therapeutic options have several limitations. This study aimed to assess the safety and efficacy of microwave ablation (MWA) in the treatment of HCC-originating pulmonary oligometastases.

METHODS

A total of 83 patients, comprising 73 males and 10 females with a median age of 57 years, who had pulmonary oligometastases from HCC, underwent MWA treatment at four different medical institutions. Inclusion criteria for patients involved having primary HCC under control and having less than three oligometastases with a maximum diameter of ≤ 5 cm in the unilateral lung or less than five oligometastases with a maximum diameter of ≤ 3 cm in the bilateral lung. A total of 147 tumors were treated with MWA over 116 sessions. The primary endpoints assessed included technical success, treatment efficacy, and local progression rate, while secondary endpoints encompassed complications, clinical outcomes, overall survival (OS), local progression-free survival (LPFS), and prognostic factors.

RESULTS

The technical success rate for MWA was 100% (116/116 sessions), and the treatment efficacy rate was 82.3% (121/147 tumors). Six months after MWA, the local progression rate was 23.1% (18/147 tumors). Complications were observed in 10.3% (major) and 47.4% (minor) of the 116 sessions, with no cases of ablation-related deaths. The median follow-up period was 21.6 months (range: 5.7-87.8 months). Median OS was 22.0 months, and the 1-, 2-, and 3-year OS rates were 82.6%, 44.5%, and 25.2%, respectively. Median LPFS was 8.5 months. Multivariate Cox regression analysis identified α-fetoprotein (AFP) levels during initial diagnosis and the number of oligometastases as potential independent prognostic factors for OS (p = 0.017 and 0.045, respectively).

CONCLUSION

Percutaneous MWA is a safe and effective treatment modality for pulmonary oligometastases originating from HCC.

Efficacy and safety of microwave ablation and its synergistic potential in the treatment of early-stage non-small cell lung cancer

Lung cancer remains the primary cause of cancer-related mortality globally. In the case of early-stage non-small cell lung cancer (NSCLC), surgical resection, such as lobectomy and sub-lobectomy, continues to be the established standard treatment. However, for patients with insufficient cardiopulmonary function and multiple comorbidities who are unable to undergo surgical resection, nonoperative local therapies, including radiotherapy and thermal ablation, are preferred. In recent years, microwave ablation (MWA) has gained popularity for treating early-stage NSCLC due to its high heating efficiency, good tissue conductance, and heat conduction capabilities. This review provides a comprehensive summary of the current efficacy and safety data regarding MWA for early-stage NSCLC and discusses the potential benefits of combining MWA with other therapies.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk prediction of intraoperative pain in percutaneous microwave ablation of lung tumors under CT guidance

OBJECTIVES

To evaluate the effect of intraoperative pain in microwave ablation of lung tumors (MWALT) on local efficacy and establish the pain risk prediction model.

METHODS

It was a retrospectively study. Consecutive patients with MWALT from September 2017 to December 2020 were divided into mild and severe pain groups. Local efficacy was evaluated by comparing technical success, technical effectiveness, and local progression-free survival (LPFS) in two groups. All cases were randomly allocated into training and validation cohorts at a ratio of 7:3. A nomogram model was established using predictors identified by logistics regression in training dataset. The calibration curves, C-statistic, and decision curve analysis (DCA) were used to evaluate the accuracy, ability, and clinical value of the nomogram.

RESULTS

A total of 263 patients (mild pain group: n = 126; severe pain group: n = 137) were included in the study. Technical success rate and technical effectiveness rate were 100% and 99.2% in the mild pain group and 98.5% and 97.8% in the severe pain group. LPFS rates at 12 and 24 months were 97.6% and 87.6% in the mild pain group and 91.9% and 79.3% in the severe pain group (p = 0.034; HR: 1.90). The nomogram was established based on three predictors: depth of nodule, puncture depth, and multi-antenna. The prediction ability and accuracy were verified by C-statistic and calibration curve. DCA curve suggested the proposed prediction model was clinically useful.

CONCLUSIONS

Severe intraoperative pain in MWALT reduced the local efficacy. An established prediction model could accurately predict severe pain and assist physicians in choosing a suitable anesthesia type.

CLINICAL RELEVANCE STATEMENT

This study firstly provides a prediction model for the risk of severe intraoperative pain in MWALT. Physicians can choose a suitable anesthesia type based on pain risk, in order to improve patients' tolerance as well as local efficacy of MWALT.

KEY POINTS

• The severe intraoperative pain in MWALT reduced the local efficacy. • Predictors of severe intraoperative pain in MWALT were the depth of nodule, puncture depth, and multi-antenna. • The prediction model established in this study can accurately predict the risk of severe pain in MWALT and assist physicians in choosing a suitable anesthesia type.

Changes in the pulmonary function of CT-guided microwave ablation for patients with malignant lung tumors

PURPOSE

To investigate the changes in pulmonary function after computed tomography (CT)-guided microwave ablation (MWA) in patients with a malignant lung tumor.

MATERIALS AND METHODS

From June 2020 to January 2022, 133 patients with a malignant lung tumor who underwent CT-guided percutaneous MWA were included in the study. Pulmonary function tests (PFTs) were performed before (the baseline) and 1 month after the MWA. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1%, maximum mid-expiratory flow (MMEF), and diffusion capacity of the lung for carbon monoxide (DLCO-SB) at 1 month post MWA were compared with that at the baseline. The time of procedure and post-procedure length of hospital stay were also recorded.

RESULTS

The mean VC, FVC, FEV1, FEV1%, MMEF, and DLCO-SB at the baseline and 1 month post MWA were 3.23 ± 0.75 and 3.22 ± 0.77 (P = 0.926), 3.20 ± 0.75 and 3.21 ± 0.77 (P = 0.702), 2.35 ± 0.70 and 2.35 ± 0.71 (P = 0.992), 91.97 ± 23.14 and 91.87 ± 23.16 (P = 0.837), 1.83 ± 0.93 and 1.81 ± 0.95 (P = 0.476), and 6.38 ± 1.67 and 6.32 ± 1.62 (P = 0.389), respectively. There was no significant difference in the PFT results before and 1 month post MWA. The mean time of procedure and post-MWA length of hospital stay were 33 min and 2.5 days, respectively.

CONCLUSIONS

MWA is a lung parenchyma-sparing local treatment, and pulmonary function at 1 month post MWA was not statistically different from the baseline, indicating that MWA may not affect pulmonary function.

Potential biomarkers for predicting immune response and outcomes in lung cancer patients undergoing thermal ablation

Thermal ablation is a promising alternative treatment for lung cancer. It disintegrates cancer cells and releases antigens, followed by the remodeling of local tumor immune microenvironment and the activation of anti-tumor immune responses, enhancing the overall effectiveness of the treatment. Biomarkers can offer insights into the patient's immune response and outcomes, such as local tumor control, recurrence, overall survival, and progression-free survival. Identifying and validating such biomarkers can significantly impact clinical decision-making, leading to personalized treatment strategies and improved patient outcomes. This review provides a comprehensive overview of the current state of research on potential biomarkers for predicting immune response and outcomes in lung cancer patients undergoing thermal ablation, including their potential role in lung cancer management, and the challenges and future directions.

Synchronous percutaneous core-needle biopsy and microwave ablation for stage I non-small cell lung cancer in patients with Idiopathic pulmonary fibrosis: initial experience

PURPOSE

This study aimed to retrospectively evaluate the safety and feasibility of computed tomography (CT)-guided synchronous percutaneous core-needle biopsy (CNB) and microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

From January 2019 to January 2023, nineteen stage I NSCLC patients with IPF underwent CT-guided synchronous percutaneous CNB and MWA in this study. The technical success rate, complications, local tumor progression (LTP) and overall survival (OS) were observed, and the effect of synchronous percutaneous CNB and MWA were evaluated.

RESULTS

The technical success rate of synchronous percutaneous CNB and MWA was 100%. With a median follow-up time of 20.36 months, the median OS was 25 months (95% CI: 21.79, 28.20). The six-, twelve- and eighteen-month OS rates were 94.73%, 89.47% and 57.89%, respectively. The six-, twelve- and eighteen-month LTP rates were 0%, 10.52% and 31.57%, respectively. Major complications including pneumothorax, bronchopleural fistula and pneumonia occurred in 26.32% (5/19) patients. None of the patients died during the procedure.

CONCLUSIONS

According to the results of the current study, CT-guided synchronous percutaneous CNB and MWA appears to be a safe and effective for stage I NSCLC in patients with IPF and providing an alternative therapeutic option for local control of pulmonary malignancy in high-risk patients.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Microwave ablation with a blunt-tip antenna for pulmonary ground-glass nodules: a retrospective, multicenter, case-control study

PURPOSE

A previous small-sample study verified that a blunt-tip antenna reduced hemorrhage during microwave ablation. We conducted this large-sample, multicenter, case-control study to further verify the efficacy and safety of microwave ablation with a blunt-tip antenna for ground-glass nodules.

MATERIALS AND METHODS

Patients with pulmonary ground-glass nodules were treated with either a sharp-tip (Group A) or blunt-tip antenna (Group B). A total of 147 and 150 patients were retrospectively allocated to Groups A and Group B, respectively. Group A patients underwent 151 procedures, and Group B patients underwent 153 procedures. We assessed the technical success, technique efficacy, and complications.

RESULTS

Technical success and overall technique efficacy were achieved in all patients (100%). Major complications of pneumothorax were more commonly observed in Group A than in Group B (19.7% vs. 2.0%, p < 0.001). Minor complications, such as intrapulmonary hemorrhage (2.0% vs. 9.5%, p = 0.005) and hemothorax (0.0% vs. 2.7%, p = 0.049), occurred less frequently in Group B compared to Group A.

CONCLUSION

In the treatment of ground-glass nodules, microwave ablation with a blunt-tip antenna had equal efficacy compared to microwave ablation with a sharp-tip antenna but had a decreased number of hemorrhage and hemothorax complications.

Microwave ablation for the treatment of peripheral ground-glass nodule-like lung cancer: Long-term results from a multi-center study

Introduction

Microwave ablation (MWA) is an effective and safe approach for the treatment of ground-glass nodule (GGN)-like lung cancer, but long-term follow-up is warranted. Therefore, this multi-center retrospective study aimed to evaluate the results of MWA for the treatment of peripheral GGN-like lung cancer with a long-term follow-up.

Materials and Methods

From June 2013 to January 2018, a total of 87 patients (47 males and 40 females, mean age 64.6 ± 10.2 years) with 87 peripheral lung cancer lesions showing GGN (mean long axis diameter, 17 ± 5 mm) underwent computed tomography (CT)-guided percutaneous MWA. All GGN-like lung cancers were histologically verified. The primary endpoints were local progression-free survival (LPFS) and overall survival (OS). The secondary endpoints were cancer-specific survival (CSS) and complications.

Results

During a median follow-up of 65 months, both the 3-year and 5-year LPFS rates were 96.6% and 96.6%. The OS rate was 94.3% at 3 years and 84.9% at 5 years, whereas the 3-year and 5-year CSS rates were 100% and 100%, respectively. No periprocedural deaths were observed. Complications were observed in 49 patients (51.6%). Grade 3 or higher complications included pneumothorax, pleural effusion, hemorrhage, and pulmonary infection, which were identified in ten (10.5%), two (2.1%), two (2.1%), and one (1.1%) patient, respectively.

Conclusions

CT-guided percutaneous MWA is an effective, safe, and potentially curative treatment regimen for GGN-like lung cancer.

Stereotactic Body Radiation Therapy Versus Ablation Versus Surgery for Early-Stage Lung Cancer in High-Risk Patients

Current treatment for early-stage lung cancer focuses on surgical intervention as the mainstay of treatment; however, this poses issues in patients that are high-risk or unable to tolerate any operation. In this case, sublobar resection or radiation therapy has been the primary treatment for these subsets of patients. Alternative approaches include stereotactic body radiation therapy (SBRT) and thermal ablation. In this article, we focus on treatment strategies using SBRT, thermal ablation, or surgery as it pertains to high-risk patients with early-stage lung cancer.

Effects of microwave ablation on cysts and cystic neoplasms with tissue-mimicking model: an ex vivo study

BACKGROUND AND PURPOSE

Microwave ablation (MWA) is a promising modality that needs to be further investigated for cystic lesions. The present study aimed to determine the effects of MWA on cysts and cystic neoplasms with a tissue-mimicking model.

METHODS

Twenty New Zealand White rabbits were randomly divided into Group A (cyst mimic models, n = 10, φ = 5 cm) and Group B (cystic neoplasm mimicking models, n = 10, φ = 5 cm). For each group, ex vivo rabbit healthy bladder and VX2-implanted tumor bladder were fixed and embedded in agarose gel to mimic cyst and cystic neoplasm. In the MWA experimental subgroups, microwave antennas guided by computed tomography (CT) were introduced into these models. A system thermometer was placed at the outer edge of the bladder wall to monitor temperature changes. Immediately after MWA, ex vivo rabbit healthy bladders and VX2-implanted tumor bladders were harvested for gross anatomy and prepared for pathological evaluation.

RESULTS

A total of twenty cyst and cystic neoplasm mimicking models were successfully developed. Ninety percent of the MWA procedures were successful, and no peri-procedural complications were encountered. The temperature of the cystic wall increased with duration in both MWA experimental subgroups and an effective ablation temperature (>60 °C) was achieved. Pathological examination of the cyst and cystic neoplasm mimic models revealed degenerative necrosis of the bladder wall mucosal epithelial cells, loss of bladder wall tissue structure and coagulative necrosis of VX2 tumor cells.

CONCLUSION

Our data indicate that MWA could cause thermal damage to the tissue structure of cyst and cystic neoplasm, and it is an effective technique for treating cystic diseases.HIGHLIGHTSex vivo rabbit healthy bladder and VX2-implanted tumor bladder were fixed and embedded in agarose gel to mimic cyst and cystic neoplasm.The temperature of the cystic wall increased with MWA duration and an effective ablation temperature (> 60 °C) was achieved.MWA could cause thermal damage to the tissue structure of the cyst and cystic neoplasm and it is effective in treating cystic diseases, as assessed by histopathology.

The safety and feasibility of three-dimensional visualization planning system for CT-guided microwave ablation of stage I NSCLC (diameter ≤2.5 cm): A pilot study

Background

Microwave ablation (MWA) of lung tumors is a technique that is dependent on the ablationist's level of expertise. The selection of the optimum puncture path and determination of appropriate ablative parameters is the key to the success and safe of the procedure. The objective of this study was to describe the clinical use of a novel three-dimensional visualization ablation planning system (3D-VAPS) for aided MWA of stage I non-small cell lung cancer (NSCLC).

Methods

This was a single-arm, single-center, retrospective study. From May 2020 to July 2022, 113 consented patients with stage I NSCLC received MWA treatment in 120 MWA sessions. The 3D-VAPS was used to determine that: (1) the overlap between the gross tumor region and simulated ablation; (2) the proper posture and appropriate puncture site on the surface of the body; (3) the puncture path; and (4) presetting preliminarily ablative parameters. Patients were monitored with contrast-enhanced CT scans at 1, 3, and 6 months, as well as every 6 months following that. The primary endpoints were technical success and a complete ablation rate. Local progression-free survival (LPFS), overall survival (OS), and comorbidities were secondary study objectives.

Results

The mean diameter of tumors was 1.9 ± 0.4 cm (range 0.9-2.5 cm). The mean duration was 5.34 ± 1.28 min (range 3.0-10.0 min). The mean power output was 42.58 ± 4.23 (range 30.0-50.0W). The median follow-up time was 19.0 months (6.0-26.0 months). The technical success rate was 100%. Three-month after the procedure, the complete ablation rate was 97.35%. 6, 9, 12, and 24 months LPFS rates were 100%, 98.23%, 98.23%, and 96.46%, respectively. One-year and 2-year OS rates were 100% and 100%. There were no patients who died both during the procedure and after the MWA of 30 days. The complications after MWA included pneumothorax (38.33%), pleural effusion (26.67%), intrapulmonary hemorrhage (31.67%), and pulmonary infection (2.50%).

Conclusions

This research describes and confirms that 3D-VAPS is a feasibility and safe method for MWA of stage I NSCLC treatment. 3D-VAPS may be helpful to optimize the puncture path, assess reasonable ablative parameters, and minimize complications.

Clinical efficacy of thermal ablation for the treatment of pulmonary carcinoid tumor: a propensity-matched analysis

OBJECTIVE

To investigate the clinical efficacy of thermal ablation in the treatment of pulmonary carcinoid (PC) tumor.

METHODS

Data of patients with inoperable PC diagnosed from 2000 to 2019 were obtained from the SEER database and analyzed according to different therapeutic modality: thermal ablation vs non-ablation. Propensity score matching (PSM) was used to reduce intergroup differences. Kaplan-Meier curves and the log-rank test were used to compare intergroup differences of overall survival (OS) and lung cancer-specific survival (LCSS). Cox proportional risk models were used to reveal prognostic factors.

RESULTS

After PSM, the thermal ablation group had better OS (p < .001) and LCSS (p < .001) than the non-ablation group. Subgroup analysis stratified by age, sex, histologic type and lymph node status subgroups showed similar survival profile. In the subgroup analysis stratified by tumor size, the thermal ablation group showed better OS and LCSS than those of the non-ablation group for tumors ≤3.0 cm, not statistically significant for tumors >3.0 cm. Subgroup analysis by M stage showed that thermal ablation was superior to non-ablation in OS and LCSS for patients with M0 stage, but no significant difference was found in subgroups with distant metastatic disease. Multivariate analysis showed that thermal ablation was an independent prognostic factor for OS (HR: 0.34, 95% CI: 0.25-0.46, p < .001) and LCSS (HR: 0.23, 95%CI: 0.12-0.43, p < .001).

CONCLUSION

For patients with inoperable PC, thermal ablation might be a potential treatment option, especially in M0-stage with tumor size ≤3 cm.

The Biological Effects of Compound Microwave Exposure with 2.8 GHz and 9.3 GHz on Immune System: Transcriptomic and Proteomic Analysis

It is well-known that microwaves produce both thermal and nonthermal effects. Microwave ablation can produce thermal effects to activate the body's immune system and has been widely used in cancer therapy. However, the nonthermal effects of microwaves on the immune system are still largely unexplored. In the present study, we exposed rats to multifrequency microwaves of 2.8 GHz and 9.3 GHz with an average power density of 10 mW/cm², which are widely used in our daily life, to investigate the biological effects on the immune system and its potential mechanisms. Both single-frequency microwaves and multifrequency microwaves caused obvious pathological alterations in the thymus and spleen at seven days after exposure, while multifrequency microwaves produced more pronounced injuries. Unexpectedly, multifrequency microwave exposure increased the number of both leukocytes and lymphocytes in the peripheral blood and upregulated the proportion of B lymphocytes among the total lymphocytes, indicating activation of the immune response. Our data also showed that the cytokines associated with the proliferation and activation of B lymphocytes, including interleukin (IL)-1α, IL-1β and IL-4, were elevated at six hours after exposure, which might contribute to the increase in B lymphocytes at seven days after exposure. Moreover, multifrequency microwave exposure upregulated the mRNA and protein expression of B cell activation-associated genes in peripheral blood. In addition to immune-associated genes, multifrequency microwaves mainly affected the expression of genes related to DNA duplication, cellular metabolism and signal transduction in the peripheral blood and spleen. In conclusion, multifrequency microwaves with 2.8 GHz and 9.3 GHz caused reversible injuries of the thymus and spleen but activated immune cells in the peripheral blood by upregulating mRNA and protein expression, as well as cytokine release. These results not only uncovered the biological effects of multifrequency microwave on the immune system, but also provide critical clues to explore the potential mechanisms.

Microwave ablation plus camrelizumab monotherapy or combination therapy in non-small cell lung cancer

Purpose

Immunotherapy has become widely applied in non-small cell lung cancer (NSCLC) patients. However, the relatively low response rate of immunotherapy monotherapy restricts its application. Combination therapy improves the response rate and prolongs patient survival; however, adverse events (AEs) associated with immunotherapies increase with combination therapy. Therefore, exploring combination regimens with equal efficacy and fewer AEs is urgently required. The aim of this study was to evaluate the efficacy and safety of microwave ablation (MWA) plus camrelizumab monotherapy or combination therapy in NSCLC.

Materials and methods

Patients with pathologically confirmed, epidermal growth factor receptor/anaplastic lymphoma kinase-wild-type NSCLC were retrospectively enrolled in this study. Patients underwent MWA to the pulmonary lesions first, followed by camrelizumab monotherapy or combination therapy 5–7 days later. Camrelizumab was administered with the dose of 200 mg every 2 to 3 weeks. Treatment was continued until disease progression or intolerable toxicities. The technical success and technique efficacy of ablation, objective response rate (ORR), progression-free survival (PFS), overall survival (OS), complications of ablation, and AEs were recorded.

Results

From January 1, 2019 to December 31, 2021, a total of 77 patients underwent MWA and camrelizumab monotherapy or combination therapy. Technical success was achieved in all patients (100%), and the technique efficacy was 97.4%. The ORR was 29.9%. The PFS and OS were 11.8 months (95% confidence interval, 9.5–14.1) and not reached, respectively. Smoking history and response to camrelizumab were correlated with PFS, and response to camrelizumab was correlated with OS in both the univariate and multivariate analyses. No periprocedural deaths due to ablation were observed. Complications were observed in 33 patients (42.9%). Major complications included pneumothorax (18.2%), pleural effusion (11.7%), pneumonia (5.2%), bronchopleural fistula (2.6%), and hemoptysis (1.3%). Grade 3 or higher AEs of camrelizumab, including reactive capillary endothelial proliferation, fatigue, pneumonia, edema, and fever, were observed in 10.4%, 6.5%, 5.2%, 2.6%, and 2.6% of patients, respectively.

Conclusion

MWA combined with camrelizumab monotherapy or combination therapy is effective and safe for the treatment of NSCLC.

Survival benefit of thermal ablation therapy for patients with stage II-III non-small cell lung cancer: A propensity-matched analysis

Background

Thermal ablation (TA) is considered a safe alternative to surgical resection for the treatment of non-small cell lung cancer (NSCLC). While previous studies have shown that TA is beneficial for stage I NSCLC patients, however, few have reported on TA efficacy in patients with stage II-III NSCLC. The current study investigated the impact of TA on the overall survival (OS) and cancer-specific survival (CSS) of patients with stage II-III NSCLC.

Methods

Data on patients with stage II-III NSCLC who did not undergo surgical resection between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM), Kaplan-Meier survival curves, and Cox regression were used for statistical analyses.

Results

A total of 57,959 stage II-III NSCLC patients who did not undergo surgical resection were included in this study, 261 of whom received TA. Overall, TA was associated with a longer OS (p = 0.035) and CSS (p = 0.005) than non-ablation. After 1:3 PSM, 252 patients receiving TA and 732 patients not receiving ablation were enrolled in the matched cohort. The OS (p = 0.047) and CSS (p = 0.029) remained higher in the TA group than in the non-ablation group after PSM. Cox regression analysis showed that age, sex, primary tumor site, pathological type, tumor size, radiotherapy, chemotherapy, and thermal ablation were independently associated with OS and CSS (p <0.05). Subgroup analysis found that the advantages of TA were more pronounced among individuals ≥70 years of age, with tumor size ≤3.0 cm, or who did not receive radiotherapy.

Conclusion

TA could be an effective alternative treatment for stage II-III NSCLC patients unsuitable for surgical resection, particularly those ≥70 years of age, with tumor size ≤3.0 cm, or who have not received radiotherapy.

Synchronous Microwave Ablation Combined With Cisplatin Intratumoral Chemotherapy for Large Non-Small Cell Lung Cancer

Background

Microwave ablation (MWA) and intratumoral chemotherapy (ITC) are useful for treating tumors in animal models; however, their clinical use in patients with large non−small cell lung cancer (NSCLC) remains unknown. This retrospective study aimed to evaluate preliminary outcomes of MWA + ITC for large NSCLC.

Methods

From November 2015 to April 2020, a total of 44 NSCLC patients with a mean lesion diameter of 6.1 ± 1.5 cm were enrolled and underwent synchronous MWA + ITC procedures. The primary endpoint was local progression-free survival (LPFS); secondary endpoints were progression-free survival (PFS), complications, overall survival (OS), and associated prognostic factors.

Results

The median follow-up time was 19.0 months. At the 1-month CT scan, complete tumor ablation was observed in 47.7% of cases. Median LPFS was 12.1 months; 1-, 2-, and 3-year LPFS rates were 51.2%, 27.9%, and 13.6%, respectively. A shorter LPFS was significantly associated with large lesions (HR 1.23, 95% CI 1.02–1.49; p = 0.032). Median PFS was 8.1 months; 1-, 2-, and 3-year PFS rates were 29.5%, 18.2%, and 9.1%, respectively. LPFS was significantly superior to PFS (p = 0.046). Median OS was 18.8 months. The 1-, 2-, 3-, and 5-year OS rates were 65.9%, 43.2%, 26.4%, and 10.0%, respectively. In univariate comparisons, high performance status (PS) score, smoking, and larger lesions were significantly correlated with poor survival. In multivariate analysis, advanced age, higher PS score, higher stage, larger lesion, and prior systematic treatment were independent prognostic factors for shorter OS. Adverse events were well tolerated and all patients recovered after appropriate intervention.

Conclusions

MWA + ITC is a safe and effective new modality of local treatment for large NSCLC and can significantly prolong LPFS.