Efficacy and safety of artificial pneumothorax with position adjustment for CT-guided percutaneous transthoracic microwave ablation of small subpleural lung 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.

Identifying symptom clusters and temporal interconnections in patients with lung tumors after CT-guided microwave ablation: A network analysis

PURPOSE

To explore symptom clusters and interrelationships using a network analysis approach among symptoms in patients with lung tumors who underwent computed tomography (CT)-guided microwave ablation (MWA).

METHODS

A longitudinal study was conducted, and 196 lung tumor patients undergoing MWA were recruited and were measured at 24 h, 48 h, and 72 h after MWA. The Chinese version of the MD Anderson Symptom Inventory and the Revised Lung Cancer Module were used to evaluate symptoms. Network analyses were performed to explore the symptom clusters and interrelationships among symptoms.

RESULTS

Four stable symptom communities were identified within the networks. Distress, weight loss, and chest tightness were the central symptoms. Distress, and weight loss were also the most key bridge symptoms, followed by cough. Three symptom networks were temporally stable in terms of symptom centrality, global connectivity, and network structure.

CONCLUSION

Our findings identified the central symptoms, bridge symptoms, and the stability of symptom networks of patients with lung tumors after MWA. These network results will have important implications for future targeted symptom management intervention development. Future research should focus on developing precise interventions for targeting central symptoms and bridge symptoms to promote patients' health.

Retrospective cohort study on the correlation analysis among peri-procedural factors, complications, and local tumor progression of lung tumors treated with CT-guided microwave ablation

BACKGROUND

Despite adherence to guidelines, recurrence of lesions remains possible in lung tumor microwave ablation (MWA) even when termination is enabled by 5-10 mm ground glass changes. Limited evidence exists regarding the correlation between timely management of perioperative complications (including pneumothorax, pleural effusion, hemorrhage, cavity formation, and infection) and local tumor progression. This retrospective study aimed to investigate the relationship among peri-procedural factors, complications, and local tumor progression in 164 cases of lung tumors treated with computed tomography-guided MWA (CT-MWA), and improve the local prognosis and reduce the complication rate of CT-guided lung tumor ablation.

METHODS

We reviewed 164 consecutive patients who underwent CT-MWA at Fudan University Shanghai Cancer Center's Minimally Invasive Therapy Center for lung cancer from September 2019 to May 2020. Correlative analysis was performed between peri-procedural factors, complications and outcomes (local tumor progression rates). Patients who have had prior surgery or previous MWA were excluded. Ablation was the first treatment of choice, and all patients who have had other treatments were excluded. Patients were followed every 3 months with CT. Outcomes of ablation including complications and local tumor progression were evaluated. Peri-procedural factors included demographical factors, tumor features, ablation parameters, management of intra-procedural pneumothorax, and CT features. Complications included pneumothorax, post-procedural refractory infection, and pleural effusion.

RESULTS

The study included 98 males and 68 females, with an average age of 56.1 years. Local tumor progression rate was negatively correlated with intra-procedural management of pneumothorax (R=-0.550, P=0.0003) and Hounsfield unit (HU) difference between HU before and after procedure (R=-0.855, P=0.006), and positively correlated with the average HU value of immediate post-procedural CT at the measurement points (R=0.857, P=0.00002). The correlation analysis results also showed a positive correlation between infection after procedure and pneumothorax (R=0.340, P=0.0001).

CONCLUSIONS

A greater difference between HU before and after the procedure or a decrease in CT values immediately after ablation may predict a higher rate of local complete ablation. Prompt management of intraoperative pneumothorax may lower local tumor progression rates and decrease incidence of post-procedural infection.

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.

Artificial Pneumothorax Using the Liver-Directed Approach and Seldinger's Technique: Technical Feasibility and Safety

Purpose This study aimed to evaluate the technical feasibility and safety of artificial pneumothorax induction for percutaneous procedures using the liver-directed approach and Seldinger's technique. Materials and methods The data of 25 consecutive patients who underwent percutaneous procedures after inducing artificial pneumothorax were reviewed retrospectively. The liver surface was punctured with an 18-gauge indwelling needle via the intercostal space in the inferior thoracic cavity under ultrasound guidance, avoiding the lung parenchyma and leaving the catheter in place. After a deep inhalation pulled the catheter tip into the pleural cavity, a hydrophilic guidewire was inserted through the catheter. Finally, a small-diameter catheter was inserted into the pleural cavity over the guidewire to induce artificial pneumothorax. Procedure time (the time from local anesthesia to completion of the procedure), technical success (successful induction of artificial pneumothorax), clinical success (successful completion of the percutaneous procedure), and complications (categorized according to the Clavien-Dindo classification) were evaluated in this study. Results The artificial pneumothorax induction was successful in all cases. Clinical success was achieved in 23 of 25 procedures (92%). No severe complications were observed. Conclusion The liver-directed approach and Seldinger's technique for inducing artificial pneumothorax was safe and feasible for avoiding lung injury.

Clinical practice guidelines on image-guided thermal ablation of primary and metastatic lung tumors (2022 edition)

The main contents of the Clinical Practice Guidelines on Image-Guided Thermal Ablation (IGTA) of Primary and Metastatic Lung Tumors (2022 Edition) include the following: epidemiology of primary and metastatic lung tumors; the concepts of the IGTA and common technical features; procedures, indications, contraindications, outcomes evaluation, and related complications of IGTA on primary and metastatic lung tumors; and limitations and future development.

Local ablation of pulmonary malignancies abutting pleura: Evaluation of midterm local efficacy and safety

Objective

To retrospectively evaluate the efficacy and safety of local ablation treatment for adjacent pleural lung tumors.

Materials and methods

Sixty-two patients who underwent pulmonary nodule ablation at the Affiliated Cancer Hospital of Zhengzhou University were enrolled between January 2016 and December 2020. All patients were followed up with enhanced computed tomography or magnetic resonance imaging within 48 h after treatment and 2, 4, 6, 9, and 12 months after treatment. All patients were followed for at least 12 months.

Results

A total of 84 targeted tumors (62 patients) underwent 94 ablations. In the 12-month follow-up images, 69 of the 84 targeted tumors were completely ablated, 15 had incomplete ablation, and the 12-month incomplete ablation rate was 17.8% (15/84). Of the 15 incompletely ablated tumors, six had partial responses, five had stable disease, and four had progressive disease. The most common adverse event was pneumothorax, with an incidence of 54.8% (34/62). The second most common complication was pleural effusion, with an incidence rate of 41.9% (26/62). The incidence of needle-tract bleeding was 21% (13/62) and all patients were cured using hemostatic drugs. Serious complications were bronchopleural fistula in four patients (6.5%, 4/62) and needle tract metastasis in one patient. Four cases of bronchopleural fistula were found in the early stages and were cured after symptomatic treatment.

Conclusion

Local ablation is effective for the treatment of adjacent pleural lung tumors, and its operation is safe and controllable.

Microwave ablation with local pleural anesthesia for subpleural pulmonary nodules: our experience

Objectives

To explore the efficacy and safety of local pleural anesthesia (LPA) for relieving pain during microwave ablation (MWA) of pulmonary nodules in the subpleural regions.

Materials and Methods

From June 2019 to December 2021, 88 patients with 97 subpleural nodules underwent percutaneous CT-guided MWA. Patients were divided into two groups according to whether LPA was applied; 53 patients with local pleural anesthesia during MWA; and 35 patients with MWA without LPA. The differences in technical success, pre-and post- and intra-operative visual analog scale (VAS) pain scores, complications of the procedure, and local progression-free survival (LPFS) between the two groups were assessed. Thus, to evaluate the efficacy and safety of MWA combined with LPA for treating subpleural nodules.

Results

In this study, the procedures in all patients of both groups achieved technical success according to pre-operative planning. There was no statistically significant difference in the pre-operative VAS pain scores between the two groups. Intra-operative VAS scores were significantly higher in the non-LPA (NLPA) group than in the LPA group. They remained significantly higher in the NLPA group than in the LPA group during the short postoperative period. Analgesics were used more in the NLPA group than in the LPA group intra- and postoperatively, with a statistically significant difference, especially during the MWA procedures. The overall LPFS rates were 100%, 98.333%, 98.333%, and 98.333% at 1, 3, 6, and 12 months postoperatively in the LPA group and 100%, 97.297%, 94.595%, and 94.595% postoperatively in the NLPA group, respectively. Tumor recurrence occurred in one and two patients with lung adenocarcinoma in the LPA and NLPA groups. The incidence of pneumothorax was significantly higher in the NLPA group (25,714%, 9/35) than in the LPA group (15.094%, 8/53), and there were three cases of pleural effusion (blood collection) and one case of pulmonary hemorrhage in the NLPA group.

Conclusion

Percutaneous CT-guided MWA is a safe and effective treatment for subpleural pulmonary nodules. Applying a combined LPA technique can reduce the patient's pain and complications during and after the MWA. The long-term efficacy must be verified in more patients and a longer follow-up.

Optimization of pleural multisite anesthetic technique during CT-guide microwave ablation of peripheral lung malignancy for improving treatment tolerance

OBJECTIVE

To assess the effect and safety of subpleural multisite anesthesia based on the area of thermal radiation during CT-guided lung malignancy microwave ablation (MWA) on the incidence of moderate or severe pain and the analgesic drug usage.

MATERIALS AND METHODS

Consecutive patients with lung malignancies were retrospectively evaluated between January 2016 and December 2019. Patients undergoing CT-guided lung malignancy MWA were either given in the method of (a) standard subpleural puncture point anesthesia between January 2016 and June 2018 and (b) subpleural multisite anesthesia based on the area of thermal radiation between July 2018 and December 2019. The relationship between local anesthesia mode and moderate or severe pain, and pain medications usage was assessed by using multivariable logistic regression models.

RESULTS

A total of 243 consecutive patients were included in the study. Moderate or severe pain occurred in 84 of 124 (67.7%) patients with subpleural puncture point anesthesia and in 20 of 119 (16.8%) patients with subpleural anesthesia in the area of thermal radiation (p=.001). The intravenous pain medication was required in 56 of 124 (45.2%) patients with subpleural puncture point anesthesia and in 9 of 119 (7.6%) patients with subpleural multisite anesthesia based on the area of thermal radiation (p=.001). Local anesthesia methods (p = 0.001), pleura-to-lesion distance (p=.02) and tumor size (p=.015) were independent risk factors for developing moderate or severe pain. There were no differences in adverse events and local tumor progression rate.

CONCLUSIONS

Subpleural multisite anesthesia based on the area of thermal radiation for peripheral lung malignancy MWA can result in lower intraprocedural pain compared with the subpleural puncture point anesthesia. Thus, a subpleural multisite anesthesia technique may be most helpful when performing MWA of peripheral malignancy in patients who are not sedated with general or intravenous anesthesia.

Assessment and Prognostic Value of Immediate Changes in Post-Ablation Intratumor Density Heterogeneity of Pulmonary Tumors via Radiomics-Based Computed Tomography Features

Objectives

To retrospectively observe the instantaneous changes in intratumor density heterogeneity after microwave ablation (MWA) of lung tumors and to determine their prognostic value in predicting treatment response and local tumor progression (LTP).

Methods

Pre- and post-MWA computed tomography (CT) images of 50 patients (37-males; 13-females; mean-age 65.9 ± 9.7y, 39 primary and 11 metastasis) were analyzed to evaluate changes in intratumor density. Global, regional, and local scale radiomics features were extracted to assess intratumor density heterogeneity. In four to six weeks, chest enhanced CT was used as the baseline evaluation of treatment response. The correlations between the parametric variation immediately after ablation and the visual score of ablation response (Rvisu) were analyzed by nonparametric Spearman correlation analysis. The 1-year LTP discrimination power was assessed using the area under the receiver operating characteristic (ROC) curves. A Cox proportional hazards regression model was used to identify the independent prognostic features.

Results

Although no significant volume changes were observed after ablation, the radiomics parameters changed in different directions and degrees. The mean intensity value from baseline CT image was 30.3 ± 23.2, and the post-MWA CT image was -60.9 ± 89.8. The ratio of values change was then calculated by a unified formulation. The largest increase (522.3%) was observed for cluster prominence, while the mean CT value showed the largest decline (321.4%). The pulmonary tumors had a mean diameter of 3.4 ± 0.8 cm. Complete ablation was documented in 36 patients. Significant correlations were observed between Rvisu and quantitative features. The highest correlations were observed for changes in local features after MWA, with r ranging from 0.594 to 0.782. LTP developed in 22 patients. The Cox regression model revealed Δcontrast% and response score as independent predictors (Δcontrast%: odds ratio [OR]=5.61, p=0.001; Rvisu: OR=1.73, p=0019). ROC curve analysis showed that Δcontrast% was a better predictor of 1-year LTP. with higher sensitivity (83.5% vs. 71.2%) and specificity (87.1% vs. 76.8%) than those for Rvisu.

Conclusions

The changes in intratumor density heterogeneity after MWA could be characterized by analysis of radiomics features. Real-time density changes could predict treatment response and LTP in patients with pulmonary tumors earlier, especially for tumors with larger diameters.

Percutaneous microwave ablation of solitary presumptive pulmonary metastases in two dogs with appendicular osteosarcoma

OBJECTIVE

To describe percutaneous microwave ablation (MWA) of presumptive pulmonary metastases and the outcome of two dogs.

ANIMALS

Two dogs with pulmonary lesions after treatment of spontaneously occurring appendicular osteosarcoma.

STUDY DESIGN

Preliminary prospective clinical study.

METHODS

Two large-breed dogs were referred from tertiary veterinary hospitals 146 and 217 days after limb amputation to pursue MWA as an alternative therapy to metastasectomy. Both dogs had been receiving chemotherapy protocols at their respective referral centers.

RESULTS

A novel percutaneous approach for MWA with ultrasonographic or computed tomographic (CT) guidance was successfully performed. The only complications consisted of pneumothoraxes, requiring treatment in one dog. In the weeks after their procedures, both dogs were reported to do well at home. Dog 1 died and dog 2 was euthanized 82 and 19 days, respectively, after their MWA of confirmed (dog 1) or presumed (dog 2) metastatic disease.

CONCLUSION

Percutaneous MWA of pulmonary nodules was technically feasible in two dogs without major complications.

CLINICAL SIGNIFICANCE

Percutaneous MWA may provide a minimally invasive option for treatment of osteosarcoma pulmonary metastases. Additional studies are required to evaluate the benefits of MWA on survival and confirm histologic cell death within pulmonary neoplastic lesions.

Microwave Ablation in Primary Lung Malignancies

Lung cancer is the leading cause of cancer-related mortality worldwide. Eighty-five percent of cases correspond to non-small cell lung cancer (NSCLC) and pivotal nonsurgical options for early-stage disease include percutaneous ablation and stereotactic body radiation therapy (SBRT). Microwave Ablation (MWA) is a locoregional treatment option that has many advantages over radiofrequency ablation and has been able to overcome the limitations of this technique in the treatment of early-stage NSCLC. In this review article, we highlight the current evidence supporting the use of MWA in patients with early-stage NSCLC and discuss the technical considerations of the procedure, including optimal patient selection and planning strategies, as well as the potential complications and reported outcomes. Finally, we mention future trends involving ablation in NSCLC, including its role in combination with SBRT in central tumors, management of post-SBRT local recurrence, and its potential as an adjuvant treatment option for patients with resistance to systemic therapy or in combination with checkpoint inhibitors.