CT-guided percutaneous microwave ablation of pulmonary malignant tumors

Cone Beam CT Derived Laser-Guided Percutaneous Lung Ablation: Minimizing Needle-Related Complications Under General Anesthesia with Lung Separation

RATIONALE AND OBJECTIVES

Percutaneous lung tumor ablations are mostly performed in computed tomography (CT) rooms under local anesthesia with conscious sedation. However, maintaining the breath-hold phase during this can be challenging, affecting image quality and increasing complications. With the advent of hybrid operating rooms (HORs), this procedure can be performed with endotracheal tube (ETGA) intubation under general anesthesia with lung separation, ensuring precise imaging in a single-stage setting. Lung separation provides surgical exposure of one lung while ensuring ample gas exchange with the other. This study evaluated tumor ablations performed in an HOR equipped with cone beam CT and laser guidance.

MATERIALS AND METHODS

This retrospective study included patients who underwent lung tumor ablation under general anesthesia with an ETGA in an HOR between July 2020 and May 2023. Anesthesia considerations, perioperative management, and postoperative follow-ups were evaluated.

RESULTS

65 patients (78 tumors) underwent ablation using two types of lung ventilation methods including a single-lumen tube with a blocker (SLT/BL) (n = 15) and double-lumen tube (DLT) (n = 50). Most patients experienced desaturation during the apnea phase of dynamic CT and needling. The average SpO2 value was significantly lower in the DLT group than in the SLT/BL group during the procedure (81.1% versus 88.7%, P = 0.033). Five, three, and two patients developed pneumothorax, subcutaneous emphysema, and pleural effusion, respectively.

CONCLUSION

Percutaneous ablation under general anesthesia with endotracheal intubation and lung separation performed in HORs was feasible and safe. The setup minimized complication risks and maintained a balance between patient safety and successful procedures.

Cone-beam computed tomography image-guided percutaneous microwave ablation for lung nodules in a hybrid operating room: an initial experience

OBJECTIVES

The experience of thermal ablation of lung lesions is limited, especially performing the procedure under localisation by cone-beam CT in the hybrid operation room (HOR). Here, we present the experience of microwave ablation (MWA) of lung nodules in the HOR.

METHODS

We reviewed patients who underwent image-guide percutaneous MWA for lung nodules in the HOR under general anaesthesia between July 2020 and July 2022. The workflow in the HOR including the pre-procedure preparation, anaesthesia consideration, operation methods, and postoperative care was clearly described.

RESULTS

Forty lesions in 33 patients who underwent MWA under general anaesthesia (GA) in the HOR were analysed. Twenty-seven patients had a single pulmonary nodule, and the remaining six patients had multiple nodules. The median procedure time was 41.0 min, and the median ablation time per lesion was 6.75 min. The median global operation room time was 115.0 min. The median total dose area product was 14881 μGym2. The median ablation volume was 111.6 cm3. All patients were discharged from the hospital with a median postoperative stay of 1 day. Four patients had pneumothorax, two patients had pleural effusion during the first month of outpatient follow-up, and one patient reported intercostal neuralgia during the 3-month follow-up.

CONCLUSIONS

Thermal ablation of pulmonary nodules under GA in the HOR can be performed safely and efficiently if we follow the workflow provided. The procedure provides an alternative to managing pulmonary nodules in patients.

CLINICAL RELEVANCE STATEMENT

Thermal ablation of pulmonary nodules under GA in the HOR can be performed safely and efficiently if the provided workflow is followed.

KEY POINTS

• We tested the feasibility of microwave ablation of lung lesions performed in a hybrid operating room. • To this end, we provide a description of microwave ablation of the lung under cone-beam CT localisation. • We describe a workflow by which ablation of the pulmonary nodule can be performed safely under general anaesthesia.

CT-guided microwave ablation of the nonsurgical aspergilloma

Background

Aspergillosis is a fungal infection that can lead to development of an aspergilloma, especially in patients with a history of cavitary lung disease. It is generally managed with antifungal therapy followed by surgical intervention. There are, however, limited options for the nonsurgical patient. Microwave ablation is already an effective, minimally invasive treatment being used in some lung malignancies and may be an alternative and definitive treatment in the inoperable patient.

Methods

Two patients were considered for microwave ablation following their diagnoses of aspergillosis with hemoptysis. We sought to evaluate the efficacy of CT-guided microwave ablation of an aspergilloma in these patients who were not good candidates for surgical intervention.

Results

Two male patients presented with hemoptysis and were found to have an aspergilloma. Case 1 was initially treated with antifungals and did not improve. He proceeded with VATS, and the procedure was aborted intraoperatively secondary to a frozen chest cavity. The patient subsequently elected to undergo CT-guided microwave ablation. He did not experience any immediate complications but was hospitalized for hemoptysis several weeks later. He developed alveolar hemorrhage and ultimately succumbed to PEA arrest.Case 2 was without hemoptysis at follow up and chose to pursue microwave ablation for definitive treatment. Case 2 developed post ablation pneumothorax requiring chest tube placement. Follow-up CT chest imaging was consistent with resolution of the aspergilloma.

Conclusion

Microwave ablation is a safe and effective therapeutic approach in the treatment of lung malignancy with no severe or death related complications. There are almost no absolute contraindications. Microwave ablation may be utilized as a therapeutic option in the treatment of an aspergilloma in the non-surgical patient. This novel application may challenge the current gold standard of surgical intervention.

MRI-guided microwave ablation and albumin-bound paclitaxel for lung tumors: Initial experience

Magnetic resonance-guided microwave ablation (MRI-guided MWA) is a new, minimally invasive ablation method for cancer. This study sought to analyze the clinical value of MRI-guided MWA in non-small cell lung cancer (NSCLC). We compared the precision, efficiency, and clinical efficacy of treatment in patients who underwent MRI-guided MWA or computed tomography (CT)-guided microwave ablation (CT-guided MWA). Propensity score matching was used on the prospective cohort (MRI-MWA group, n = 45) and the retrospective observational cohort (CT-MWA group, n = 305). To evaluate the advantages and efficacy of MRI-guided MWA, data including the accuracy of needle placement, scan duration, ablation time, total operation time, length of hospital stay, progression-free survival (PFS), and overall survival (OS) were collected and compared between the two groups. The mean number of machine scans required to adjust the needle position was 7.62 ± 1.69 (range 4–12) for the MRI-MWA group and 9.64 ± 2.14 (range 5–16) for the CT-MWA group (p < 0.001). The mean time for antenna placement was comparable between the MRI and CT groups (54.41 ± 12.32 min and 53.03 ± 11.29 min, p = 0.607). The microwave ablation time of the two groups was significantly different (7.62 ± 2.65 min and 9.41 ± 2.86 min, p = 0.017), while the overall procedure time was comparable (91.28 ± 16.69 min vs. 93.41 ± 16.03 min, p = 0.568). The overall complication rate in the MRI-MWA group was significantly lower than in the CT-MWA group (12% vs. 51%, p = 0.185). The median time to progression was longer in the MRI-MWA group than in the CT-MWA group (11 months [95% CI 10.24–11.75] vs. 9 months [95% CI 8.00–9.99], p = 0.0003; hazard ratio 0.3690 [95% CI 0.2159–0.6306]). OS was comparable in both groups (MRI group 26.0 months [95% CI 25.022–26.978] vs. CT group 23.0 months [95% CI 18.646–27.354], p = 0.18). This study provides hitherto-undocumented evidence of the clinical effects of MRI-guided MWA on patients with NSCLC and determines the relative safety and efficiency of MRI- and CT-guided MWA.

Technical and safety performance of CT-guided percutaneous microwave ablation for lung tumors: an ablate and resect study

Background

Percutaneous image-guided thermal ablation has an increasing role in the treatment of primary and metastatic lung tumors. Achieving acceptable clinical outcomes requires better tools for pre-procedure prediction of ablation zone size and shape.

Methods

This was a prospective, non-randomized, single-arm, multicenter study conducted by Medtronic (ClinicalTrials.gov ID: NCT02323854). Subjects scheduled for resection of metastatic or primary lung nodules underwent preoperative percutaneous microwave ablation. Ablation zones as measured via CT imaging following ablation immediately and before resection surgically versus predicted ablation zones as prescribed by the investigational system software were compared. This CT scan occurred after the ablation was finished but the antenna still in position. Time (minutes) from antenna placement to removal was 23.7±13.1 (n=14); median: 21.0 (range, 6.0 to 48.0). The definition of the secondary endpoint of complete ablation was 100% non-viable tumor cells based on nicotinamide adenine dinucleotide hydrogen (NADH) staining. Safety endpoints were type, incidence, and severity of adverse events.

Results

Fifteen patients (mean age 58.9 years; 67% male; 33% female) were enrolled in the study, 33.3% (5/15) with previous thoracic surgery, 73% (11/15) with metastasis, and 27% (4/15) with primary lung tumors. All underwent percutaneous microwave ablation followed by surgical resection the same day. Complete ablation was detected in 54.4% (6/11), incomplete ablation in 36.4% (4/11), and delayed necrosis in 9.1% (1/11). There were no device-related adverse events. Ablation zone volume was overestimated in all patients.

Conclusions

Histological complete ablation was observed in 55% of subjects. CT scanning less than an hour after ablation and tissue shrinkage may account for the smaller zone of ablation observed compared to predicted by the investigational system software.

Percutaneous Microwave Coagulation Therapy: A Promising Therapeutic Method for Breaking the Barrier of the Intertumor Heterogeneity

Intertumor heterogeneity is common in various cancers and has been widely accepted as the primary cause of the diversity and variation of the effect of the same treatment on patients with the same type of tumor. Percutaneous microwave coagulation therapy (PMCT) is a minimally invasive and effective approach for destroying tumors by microwave beam under image guidance, which has been applied in lung cancer. However, no previous study has investigated the capability of PMCT solving intertumor heterogeneity. Here, we performed a component analysis of four lung cancer patients' tumor microenvironment (TME) via single-cell RNA sequencing (scRNA-seq) and treated all four cases with PMCT. One patient's TME could be classified into a hot tumor, mainly proinflammatory cytokines, and T cell infiltration. The other three patients' TMEs were cold tumors, where immunosuppressive cells occupied a large proportion, including tumor-associated macrophages and cancer cells. Despite a high level of heterogeneity among their tumor microenvironment compositions, disease type and stage, and basic physical conditions, all four patients presented a stable disease (SD) without any cancer cell detected in the TME of cancer tissues after PMCT. In conclusion, this report uniquely contributed to the knowledge of the PMCT adaptation to tumor heterogeneity. Therefore, PMCT is promising to demonstrate a stable and robust antitumor efficacy in unresectable lung cancers with various TMEs.

CT-guided microwave ablation in patients with lung metastases from breast cancer

Background

Computed tomography (CT)‐guided percutaneous microwave ablation (MWA) is a very common ablation method that shows a good local tumor control rate in primary and secondary lung tumors. At present, few reports have explored the safety and efficacy of MWA for lung metastases from breast cancer.

Methods

From January 2012 to January 2018, 32 breast cancer patients with 46 pulmonary metastases received CT‐guided percutaneous MWA. The study was approved by the local institutional review board. The clinical efficacy and complications of MWA were investigated.

Results

The median follow‐up time was 32 months and the main effective rate was 97.8% (45/46). Five of 46 lesions had local progression (10.9%), with a median progression time of 10 months. The 1‐, 3‐, and 5‐year overall survival (OS) rates were 96.9%, 53.3%, and 17.8%, respectively. The median OS time was 36 months. Among 46 MWA treatments, 11 (23.9%) had massive pneumothorax, two (4.3%) had massive pleural effusion, and two (4.3%) had a pulmonary infection.

Conclusion

CT‐guided percutaneous MWA may be safe and effective for treating lung metastases from breast cancer.

Transbronchial microwave ablation of lung nodules with electromagnetic navigation bronchoscopy guidance-a novel technique and initial experience with 30 cases

Background

Microwave ablation of lung nodules may provide a faster, larger and more predictable ablation zone than other energy sources, while bronchoscopic transbronchial ablation has theoretical advantage of fewer pleural-based complications than percutaneous approach. Our study aims to determine whether the novel combination of bronchoscopic approach and microwave ablation in management of lung nodules is technically feasible, safe and effective.

Methods

This is a retrospective analysis of a single center experience in electromagnetic navigation bronchoscopy microwave ablation in hybrid operating room. Patients had high surgical risks while lung nodules were either proven malignant or radiologically suspicious. Primary endpoints include technical feasibility and safety.

Results

Total of 30 lung nodules from 25 patients were treated. Mean nodule size was 15.1 mm, and bronchus directly leads to the nodules (bronchus sign positive) in only half of them. Technical success rate was 100%, although some nodules required double ablation for adequate coverage. Mean minimal ablation margin was 5.51 mm. The mean actual ablation zone volume was -21.4% compared to predicted, likely due to significant tissue contraction ranging from 0-43%. There was no significant heat sink effect. Mean hospital stay was 1.73 days, and only 1 patient stayed for more than 3 days. Complications included pain (13.3%), pneumothorax requiring drainage (6.67%), post-ablation reaction (6.67%), pleural effusion (3.33%) and hemoptysis (3.33%). After median follow up of 12 months, none of the nodules had evidence of progression.

Conclusions

Bronchoscopic transbronchial microwave ablation is safe and feasible for treatment of malignant lung nodules. Prospective study on clinical application of this novel technique is warranted.

Bronchoscopic treatments for early-stage peripheral lung cancer: Are we ready for prime time?

Lung cancer is the leading cause of cancer-related death worldwide and surgical lobectomy remains the preferred therapy for patients with early-stage NSCLC. Medical comorbidities and advanced age preclude resection in many patients and minimally invasive ablative therapies are needed for treatment. Stereotactic ablative radiation is established as an effective modality in this patient group, although may be contraindicated in some patients with prior radiation exposure, comorbidities or centrally positioned tumours. Percutaneous ablative methods are available, although are frequently associated with significant complications. Numerous endoscopic ablative techniques are under evaluation. With a more favourable safety profile and the ability to provide diagnosis and staging information potentially within a single procedure, there is a strong rationale for development of bronchoscopic ablative modalities. In the following article, the authors aim to explore the role bronchoscopic ablation may play in treatment of peripheral lung tumours, and to describe a pathway to establishing these modalities as part of routine care. The current status of several bronchoscopic ablative options is discussed in detail.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

The safety and efficacy of microwave ablation for the treatment of CRC pulmonary metastases

PURPOSE

Microwave ablation (MWA) is a recently developed thermal ablation technique that has been used for the treatment of different types of tumours. In the present study, we retrospectively evaluated the safety and efficacy of CT-guided percutaneous MWA for the treatment of colorectal cancer (CRC) pulmonary metastases.

MATERIALS AND METHODS

From June 2010 to June 2015, 48 unresectable lesions in 32 patients with CRC pulmonary metastases were subjected to CT-guided MWA. Imaging follow-up was with contrast-enhanced CT and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT.

RESULTS

Oncologic imaging showed that 42 (87.5%) of the 48 lesions in the 32 patients were completely ablated. Needle track metastatic seeding was not found, and no patient deaths occurred within 30 d after ablation. The mean hospital stay was 3 d (range, 2-7 d). Pneumothorax was the most frequent complication and occurred in 6 (12.5%) of the 48 lesions. The median survival time was 31 months (95% CI: 15.4-46.6). The 1-, 2- and 3-year survival rates were 79.5%, 63.1% and 44.4%, respectively. Univariate Cox regression analysis showed that tumour size, disease-free interval (DFI) and number of tumours were significantly related to the overall survival time (p = .007, p = .022 and p = .030, respectively). Multivariate analysis showed that tumour size was an independent prognostic factor for survival (p = .017).

CONCLUSION

CT-guided percutaneous MWA is a safe and effective minimally invasive method for treating CRC pulmonary metastases.

Microwave Ablation and Immune Activation in the Treatment of Recurrent Colorectal Lung Metastases: A Case Report

We present a patient with colorectal metastases confined to the lungs and treated with multiple resections until this was not an option anymore, followed by stereotactic body radiation therapy until this option was drained. Then, the patient was successfully treated with multiple microwave ablations combined with immunological activation targeting the programmed cell death 1 receptor (PD-1), possibly instigating a powerful abscopal effect. Techniques, doses, and radiological findings are presented.