Ablation Of Lung Tumors Research Articles

Is Cryotherapy the Optimal Technology for Ablation of Lung Tumors?

I o p c v i t s a 1 t Primary lung cancer is the leading cause of cancer death in the United States. Lobectomy is the treatment of choice for early-stage non–small-cell lung cancer. For patients who are not suitable surgical candidates, nonsurgical treatment options include radiation therapy and image-guided thermal ablation. Pulmonary metastases are present in 25%–30% of patients who die from cancer, regardless of the type of primary cancer. For patients in whom all metastases can be surgically removed from both lungs, metastasectomy improves cancer-specific survival. For patients who may not be good surgical candidates, image-guided thermal ablation may serve as a good alternative treatment option. Most investigators have focused on ablation of lung tumors with the use of commercially available radiofreqency (RF) ablation devices that were developed and marketed for ablation of liver tumors (1). There are few serious technical challenges for application of RF energy in the lung tissue. These include high electrical resistance of air, poor thermal conductivity of aerated lung, and the heat-sink effect of the blood and air flow in the well perfused and aerated lung tissue (2). There is very little experience with microwave ablation for treatment of lung tumors. Unlike RF ablation, microwave energy is not limited by the low thermal conductivity of the lung or increased impedance of charred tissues. The energy can be

Ablation of lung tumours

Radiofrequency, laser, microwave and cryotherapy have all been used for the ablation of lung tumours. However, radiofrequency ablation (RFA) and microwave ablation are the most widely used technologies. RFA has been successfully applied to tumour measuring from <3 to 3.5 cm, either primary or secondary. Lung function usually recovers to pre-ablation values following an initial reduction and the complication profile is well understood.

Microwave Ablation of Lung Tumours – Clinical Update

Thermal ablation offers an intriguing therapeutic option to improve local tumour control and survival in patients with early-stage non-small cell lung cancer or patients with limited metastatic disease from non-lung primaries who are not candidates for surgery, either because of poor cardiopulmonary reserve, anatomic constraints limiting resection, failure of traditional therapies, or refusal of operative approaches. The new field of interventional oncology needs adequate knowledge of the therapeutic tools, advantages and limitations of each method, when and how to apply them, as well as of the new integrative protocols that improve their efficacy. This article provides a clinical review of the role of microwave ablation therapy of primary and metastatic tumours.

Radiofrequency ablation of lung tumours

Pulmonary radiofrequency ablation (RFA) has become an increasingly adopted treatment option for primary and metastatic lung tumours. It is mainly performed in patients with unresectable or medically inoperable lung neoplasms. The immediate technical success rate is over 95%, with a low periprocedural mortality rate and 8–12% major complication rate. Pneumothorax represents the most frequent complication, but requires a chest tube drain in less than 10% of cases. Sustained complete tumour response has been reported in 85–90% of target lesions. Lesion size represents the most important risk factor for local recurrence. Survival data are still scarce, but initial results are very promising. In patients with stage I non-small-cell lung cancer, 1- and 2-year survival rates are within the ranges of 78–95% and 57–84%, respectively, with corresponding cancer-specific survival rates of 92% and 73%. In selected cases, the combination of RFA and radiotherapy could improve these results. In patients with colorectal lung metastasis, initial studies have reported survival data that compare favourably with the results of metastasectomy, with up to a 45% 5-year survival rate. Further studies are needed to understand the potential role of RFA as a palliative treatment in more advanced disease and the possible combination of RFA with other treatment options.

Residual tumor after laser ablation of human non-small-cell lung cancer demonstrated by ex vivo staining: correlation with invasive temperature measurements

Histology is the gold standard for confirming thermally induced necrosis. Generally, however, no specimen is obtained from thermal ablation therapy for pathological examination. The aim of this study was to provide evidence for the relationship between temperatures reached and resulting tissue coagulation during laser ablation in a near-physiological ex vivo lung tumor model by combining viability staining and direct temperature measurement. In all, 17 human lung specimens with primary non-small-cell lung cancer (NSCLC) were examined in this study. Organs were resected with curative intent from patients of either gender (5 female, 12 male) with an average age of 65 years (51-78). Here, 11/17 specimens were subjected to interstitial laser thermal ablation in an ex vivo lung perfusion and ventilation model after surgery. A control group of 6/17 specimens was tested for viability without laser ablation. Tissue temperature was measured invasively in real-time during the ablation process using thermocouples. Afterwards, representative slices of all 17 specimens were tested for viability with triphenyltetrazolium chloride (TTC). Maximum tissue temperature Tmax[°C] measured at a distance of 10 and 20 mm from the laser tip and time of temperature exposure were correlated with the diameter of the induced coagulation as ascertained with viability staining. CH evaluated the results. Mean maximum temperature was 75.9°C ± 14.4°C at a distance of 10 mm from the laser tip and 50.3°C ± 14.6°C at a distance of 20 mm, respectively. The mean distance between the coagulation margin and the laser tip was 17.8 mm ± 7.3 mm. We found that coagulation size correlated positively with temperature. There was a clear trend towards the correlation of time over 44°C and ablation depth. Maximum temperatures did not significantly correlate with coagulation size. Laser ablation of lung tumors using the IHLP (isolated human lung perfusion) model represents a possible method for evaluating ex vivo the interrelationships of temperature, time of temperature exposure, and resulting coagulation.

Radiofrequency Ablation of Lung Metastases Close to Large Vessels during Vascular Occlusion: Preliminary Experience

Purpose To report an initial prospective evaluation of the technical feasibility, efficacy, and safety of combining percutaneous temporary balloon occlusion (PBO) of a large pulmonary artery adjacent to a metastatic lung tumor treated with percutaneous radiofrequency (RF) ablation. Materials and Methods In six patients, lung RF ablation with a multitined, expandable electrode with simultaneous PBO via femoral access was attempted with the use of digital angiography and multidetector computed tomography (CT). Follow-up imaging was obtained immediately after treatment, at 1–2 days, and at 2, 6, 9, and 12 months; positron emission tomography/CT was performed at 4 months. Results Metastases targeted measured 17–37 mm (22 ± 8) and were in contact with a pulmonary artery 3–5 mm. Temporary occlusion of the pulmonary arterial branch in contact with the tumor was technically possible in five of six patients. Postablation CT scans obtained within 2 days of the procedure showed ablation zones measuring 37–57 mm (47 ± 8) in their shortest diameter. Three patients developed lung infarction within 1 month after RF ablation, and two had to be readmitted. At 3 months after the procedure, four patients had persistent occlusion of the balloon-occluded vessel. No uptake was demonstrated 4 months after ablation; at 12 months, all tumors showed complete ablation on CT. Conclusions RF ablation of lung tumors with PBO is a feasible technique, but it induces atelectasia and long-lasting vascular occlusion responsible for a high rate of readmission. The results of this small study warrant careful further exploration of the benefits of the technique, compared with RF ablation without PBO or other methods of ablative therapy.

Abstract No. 291: Radiofrequency ablation of the lung tumors can be safely performed in patients previously treated with radiation therapy

Abstract No. 291: Radiofrequency ablation of the lung tumors can be safely performed in patients previously treated with radiation therapy

Percutaneous Radiofrequency Ablation of Lung Tumors

The aim of this study was to evaluate the literature for articles assessing radiofrequency ablation (RFA) for pulmonary malignancy. The "bottom-up" approach to evidence-based practice was applied by 2 reviewers to the retrieval and appraisal of original research articles published on pulmonary RFA between 2002 and 2009. Primary lung cancer and pulmonary metastases data were analyzed separately. The relationship between the percentage of local recurrence rate and lesion size, patient age, follow-up duration, and time to local recurrence was assessed using Spearman's rank correlation. Discrete time series were used to evaluate time trends. Secondary evidence yielded 1 review of 26 observational studies. Primary evidence yielded 46 studies that seemed suitable for detailed appraisal. A total of 2905 ablations were performed in 1584 patients. Eight studies evaluated primary lung cancers alone, 11 evaluated pulmonary metastases alone, 25 evaluated both, and 2 did not specify the histology. Results revealed trends toward increasing use of conscious sedation over general anesthesia, increasing use of multitined probes, decreasing size of nodule selection, and use of positron emission tomography/computed tomography as the optimal follow-up tool. Mean morbidity was 24.6%. The most prevalent side effects included pneumothorax (28.3%), pleural effusions (14.8%), and pain (14.1%). Procedure-related mortality ranged from 0 to 5.6, with an overall procedure-related mortality rate of 0.21%. There were 282 (12.2%) local recurrences occurring at a mean of 13 months. The mean overall survival rate was 59.4%, and the cancer-specific survival rate was 82.6%. This evidence-based practice review of pulmonary RFA shows it to be a promising treatment for pulmonary malignancy in carefully selected patient populations. Studies with higher levels of evidence, including case-control, prospective nonrandomized and randomized trials, that compare RFA with alternative contemporary local treatments are urgently needed.

Imaging follow-up of RF ablation of lung tumours

Imaging is important in the decision-making process of how to treat a lung tumour, which ideally should be a multi-disciplinary team decision. Imaging is important during radiofrequency ablation (RFA) treatment with regard to optimal placement of the electrode, the immediate post-treatment criteria and very early detection of complications of the procedure. Imaging is very important in the treatment follow-up. In lung RFA, as in many other interventional procedures, the traditional morphological imaging techniques to evaluate treatment response have difficulties and functional imaging techniques may potentially be more useful. However, larger studies showing this impact have not yet been performed.

Thermo-ablation pulmonaire : tolérance et efficacité thérapeutique dans une population constituée majoritairement de tumeurs primitives pulmonaires

Radiofrequency thermal ablation (TA) of lung tumors currently is considered an alternative to surgical management for early primary lung cancers and non-surgical lung metastases. The purpose of this study was to determine the tolerability and efficacy of this treatment in 29 consecutive patients, most of which with primary lung cancers, managed in our center. Twenty-nine patients with 32 lung tumors less than 35 mm in diameter underwent radiofrequency thermal ablation between May 2004 and July 2008. The CT examinations performed during and after the ablation were reviewed to determine lesion characteristics, complications, treatment, local recurrence rate and survival rate. Sixty-nine percent of our population consisted of primary lung cancer. The incidence of pneumothorax was 72% with 10% requiring drainage. The rate of complete response was 81%. The survival rate at 1 year was 79%. Radiofrequency thermal ablation of lung tumors is a minimally invasive technique with high rate of complete response. It can be considered in non-surgical patients with primary or metastatic lung tumors less than 35 mm in diameter.

Radiofrequency Ablation of Lung Tumours with the Patient Under Thoracic Epidural Anaesthesia

Radiofrequency ablation of lung tumours is a curative technique that is newly considered being offered to nonsurgical patients. It is of major interest because it enables local destruction of the tumour without surgery and spares healthy parenchyma. However, some patients have previous serious respiratory failure, thus ruling out mechanical ventilation. To operate with the patient under thoracic epidural is an answer to this problem. Our experience shows that the procedure is able to be performed completely without converting to general anaesthesia.

Percutaneous radiofrequency ablation for lung tumors beneath the rib under CT fluoroscopic guidance with gantry tilt

Radiofrequency (RF) ablation of lung tumors has become a treatment of choice, especially for unresectable cases. However, RF ablation of small lung lesions located just beneath the rib is difficult. To evaluate the efficacy and safety of gantry tilting for the performance of RF ablation of peripheral lesions located beneath the rib. Our study was based on 18 of 293 lesions in the lung for which RF ablation was performed under CT scan fluoroscopic guidance at our institution between October 2004 and March 2009. For these 18 lesions, RF ablation was performed with gantry tilting because a rib blocked visualization of the RF ablation route even after other attempts had been made to change the relationship between the target and the rib. All RF needles, with only one exception, were successfully advanced to hit the tumor. The commonest complication was a pneumothorax, which occurred in seven procedures. No serious complications occurred. The progression-free rates were 82.4% at 6 months, 62.5% at 12 months, and 30% at 24 months. Mean local progression-free duration was 17.6+/-11.6 months (range 4-36 months). RF ablation under CT scan fluoroscopic guidance with gantry tilt is a useful and safe technique for RF ablation of lung nodules located beneath the rib.

Interventional radiology of the thorax

Interventional radiology of the thorax encompasses an expanding variety of procedures, ranging from simple diagnostic pleural fluid aspiration to complex therapeutic procedures such as bronchial artery embolization and radiofrequency ablation of lung tumours. Physicians of many specialties will encounter patients undergoing such procedures and knowledge of possible complications is therefore desirable. We aim to briefly outline the role of the most commonly undertaken radiological thoracic interventions and review the associated complications, their subsequent management and the steps that can be taken to minimize the risk of these complications occurring.

Bronchopleural Fistula After Radiofrequency Ablation of Lung Tumours

The present article describes two cases of bronchopleural fistula (BPF) occurring after radiofrequency ablation of lung tumors. Both procedures were carried out using expandable multitined electrodes, with no coagulation of the needle track. After both ablations, ground-glass opacities encompassed the nodules and abutted the visceral pleura. The first patient had a delayed pneumothorax, and the second had a recurrent pneumothorax. Both cases of BPF were diagnosed on follow-up computed tomography chest scans (i.e., visibility of a distinct channel between the lung or a peripheral bronchus and the pleura) and were successfully treated with chest tubes alone. Our goal is to highlight the fact that BPF can occur without needle-track coagulation and to suggest that minimally invasive treatment is sufficient to cure BPFs of this specific origin.

Radiofrequency and microwave ablation of lung tumors

Lung cancer is the most common cause of cancer-related mortality in the United States. Surgical resection remains the standard treatment for early stage, non-small cell lung cancer, and limited pulmonary metastases. However, many patients with resectable disease have significant co-morbidities which preclude surgical resection. Radiofrequency and microwave ablation are emerging modalities of treatment for these high-risk patients. Here, we review the principles, common devices in use, and treatment results of ablative therapy for lung tumors.

Radiofrequency Ablation of Lung Tumors in Swine Assisted by a Navigation Device with Preprocedural Volumetric Planning

To develop an image guidance system that incorporates volumetric planning of spherical ablations and electromagnetic tracking of radiofrequency (RF) electrodes during insertion. Simulated tumors were created in three live swine by percutaneously injecting agar nodules into the lung. A treatment plan was devised for each tumor with optimization software to solve the planning problem. The desired output was the minimum number of overlapping ablation spheres necessary to ablate each tumor and the margin. The insertion plan was executed with use of the electromagnetic tracking system that guided the insertion of the probe into precomputed locations. After a 72-hour survival period, animals were killed and histopathologic sections of the tissue were examined for cell viability and burn pattern analysis. A planning algorithm to spherically cover the tumors and the margin was computed. Electromagnetic tracking allowed successful insertion of the instrument, and impedance roll-off was reached in all ablations. Depending on their size, the tumors and the tumor margins were successfully covered with two to four ablation spheres. The image registration error was 1.0 mm +/- 0.64. The overall error of probe insertion was 9.4 mm +/- 3.0 (N = 8). Analysis of histopathologic sections confirmed successful ablations of the tissue. Computer-assisted RF ablation planning and electromagnetically tracked probe insertion were successful in three swine, validating the feasibility of electromagnetic tracking-assisted tumor targeting. Image misregistration caused by respiratory motion and tissue deformation contributed to the overall error of probe insertion.

Aspergilloma in a Cavity Formed after Percutaneous Radiofrequency Ablation for Lung Cancer

Aspergilloma in a Cavity Formed after Percutaneous Radiofrequency Ablation for Lung Cancer

Delayed and Recurrent Pneumothorax After Radiofrequency Ablation of Lung Tumors

In daily clinical work, we often face delayed or recurrent pneumothorax after radiofrequency (RF) ablation for lung tumors, but a large study on this theme has not been done. Thus, we examined the rate of delayed or recurrent pneumothorax after RF ablation for lung tumors and the risk factors associated with its occurrence. This retrospective study was based on 194 consecutive sessions of percutaneous RF ablation of 220 lung tumors in 68 patients performed under CT fluoroscopic guidance at a single institution. Numerous variables were analyzed to the assess risk factors for delayed or recurrent pneumothorax. Pneumothorax after RF ablation occurred in 82 of 194 ablation sessions (42.3%). Thirty-three of 82 sessions had either delayed pneumothorax (n = 20) or recurrent pneumothorax (n = 13). The other 49 sessions had nonprogressive pneumothorax. Only contact of the ground-glass opacity (GGO) that emerged around the ablated lesion with the pleura significantly correlated with the frequency of delayed or recurrent pneumothorax in comparisons between no pneumothorax vs delayed/recurrent pneumothorax and between nonprogressive pneumothorax vs delayed/recurrent pneumothorax. The mean (+/- SD) duration before confirmation of the presence or recurrence of pneumothorax was 24.0 +/- 66.4 h. Among the 33 sessions with delayed or recurrent pneumothorax, 4 subjects needed additional treatment. Our results indicated that delayed or recurrent pneumothorax is relatively frequently encountered after RF ablation of lung tumors. Particular care must be taken with regard to the occurrence of delayed or recurrent pneumothorax when contact of a GGO with the pleura is seen after RF ablation.

Radiofrequency Ablation of Lung Tumors: Feasibility and Safety

Percutaneous image-guided radiofrequency ablation is being promoted as a novel technique with a low morbidity rate in the treatment of inoperable lung tumors. The purpose of this study was to assess the incidence and risk factors of various complications after radiofrequency ablation of pulmonary neoplasms. The clinical and treatment-related data regarding 129 consecutive percutaneous radiofrequency ablation treatment sessions for 100 patients with inoperable lung tumors were collected prospectively. Univariate and multivariate analyses were conducted to identify significant risk factors associated with postprocedural overall morbidity, pleuritic chest pain, hemoptysis, pneumothorax, pleural effusions, and chest drain requirement. There was no postprocedural mortality. The overall morbidity rate was 43% (n = 55 of 129). The most common adverse effect was pneumothorax, occurring in 32% (n = 41 of 129) of treatment sessions. Other significant complications included pleuritic chest pain (18%, n = 23 of 129), hemoptysis (7%, n = 9 of 129), pleural effusions (12%, n = 15 of 129), and chest drain insertion (20%, n = 26 of 129). Both univariate and multivariate analyses identified more than two lesions ablated per session as a significant risk factor for overall morbidity, pneumothorax, and chest drain insertion, but not for pleuritic pain, hemoptysis, and pleural effusions. Length of the ablation probe trajectory greater than 3 cm was an additional independent risk factor for overall morbidity and pneumothorax. Hilar location of lung tumor/s was the only independent risk factor associated with the increased incidence of hemoptysis. Radiofrequency ablation for lung tumors can be considered as a safe and technically feasible procedure with acceptable incidence of complications.

Percutaneous Computed Tomography–Guided Radiofrequency Ablation of Lung Tumors Complicated With Idiopathic Interstitial Pneumonia

We report 3 patients with lung cancer complicated with interstitial pneumonia who were treated by percutaneous computed tomography-guided radiofrequency ablation. Patient 1 recovered from a pneumothorax without chest drainage. Patient 2 presented with a progressive pneumothorax after discharge from the hospital and required readmission for air drainage. In patient 3, the pneumothorax did not improve by chest drainage and pleurodesis, and the patient died of acute exacerbation of interstitial pneumonia. Radiofrequency ablation of intractable lung cancer with complicating interstitial pneumonia requires careful consideration because a progressive pneumothorax may require surgical intervention or result in acute exacerbation of interstitial pneumonia.