Percutaneous radiofrequency ablation of pulmonary tumors--is there a difference between treatment under general anaesthesia and under conscious sedation?

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.

2024 multidisciplinary consensus on image-guided lung tumor ablation from the Taiwan Academy of Tumor Ablation

In this article, the multidisciplinary team of the Taiwan Academy of Tumor Ablation, who have expertise in treating lung cancer, present their perspectives on percutaneous image-guided thermal ablation (IGTA) of lung tumors. The modified Delphi technique was applied to reach a consensus on clinical practice guidelines concerning ablation procedures, including a comprehensive literature review, selection of panelists, creation of a rating form and survey, and arrangement of an in-person meeting where panelists agreed or disagreed on various points. The conclusion was a final rating and written summary of the agreement. The multidisciplinary expert team agreed on 10 recommendations for the use of IGTA in the lungs. These recommendations include terms and definitions, line of treatment planning, modality, facility rooms, patient anesthesia settings, indications, margin determination, post-ablation image surveillance, qualified centers, and complication ranges. In summary, IGTA is a safe and feasible approach for treating primary and metastatic lung tumors, with a relatively low complication rate. However, decisions regarding the ablation technique should consider each patient's specific tumor characteristics.

Chest tube placement incidence when using gelatin sponge torpedoes after pulmonary radiofrequency ablation

Purpose

To assess the efficacy of the gelatin torpedoes embolization technique after lung neoplastic lesions percutaneous radiofrequency ablation (PRFA) to reduce chest tube placement rate and hospital length of stay, and the safety of this embolization technique.

Materials and methods

A total of 114 PRFA of lung neoplastic lesions performed in two centers between January 2017 and December 2022 were retrospectively reviewed. Two groups were compared, with 42 PRFA with gelatin torpedoes embolization technique (gelatin group) and 72 procedures without (control group). Procedures were performed by one of seven interventional radiologists using LeVeen CoAccess™ probe. Multivariate analyses were performed to identify risk factors for chest tube placement and hospital length of stay.

Results

There was a significantly lower chest tube placement rate in the gelatin group compared to the control group (3 [7.1 %] vs. 27 [37.5 %], p < 0,001). Multivariate analysis showed a significant association between chest tube placement and gelatin torpedoes embolization technique (OR: 0.09; 95 % CI: 0.02-0.32; p = 0.0006). No significant difference was found in hospital length of stay between the two groups. Multivariate analysis did not show a significant relationship between hospital length of stay and gelatin torpedoes embolization technique. No embolic complication occurred in the gelatin group.

Conclusion

Gelatin torpedoes embolization technique after PRFA of lung neoplastic lesions resulted in significantly reduced chest tube placement rate in our patient population. No significant reduction in hospital length of stay was observed. No major complication occurred in the gelatin group.

High-Frequency Jet Ventilation Versus Spontaneous Respiration for Percutaneous Cryoablation of Lung Tumors: Comparison of Adverse Events and Procedural Efficiency

BACKGROUND. High-frequency jet ventilation (HFJV) facilitates accurate probe placement in percutaneous ablation of lung tumors but may increase risk for adverse events, including systemic air embolism. OBJECTIVE. The purpose of this study was to compare major adverse events and procedural efficiency of percutaneous lung ablation with HFJV under general anesthesia to spontaneous respiration (SR) under moderate sedation. METHODS. This retrospective study included consecutive adults who underwent CT-guided percutaneous cryoablation of one or more lung tumors with HFJV or SR between January 1, 2017, and May 31, 2023. We compared major adverse events (Common Terminology Criteria for Adverse Events grade ≥ 3) within 30 days postprocedure and hospital length of stay (HLOS) of 2 days or more using logistic regression analysis. We compared procedure time, room time, CT guidance acquisition time, CT guidance radiation dose, total radiation dose, and pneumothorax using generalized estimating equations. RESULTS. Overall, 139 patients (85 women, 54 men; median age, 68 years) with 310 lung tumors (82% metastases) underwent 208 cryoablations (HFJV, n = 129; SR, n = 79). HFJV showed greater rates than SR for the treatment of multiple tumors per session (43% vs 19%, respectively; p = .02) and tumors in a nonperipheral location (48% vs 24%, p < .001). Major adverse event rate was 8% for HFJV and 5% for SR (p = .46). No systemic air embolism occurred. HLOS was 2 days or more in 17% of sessions and did not differ significantly between HFJV and SR (p = .64), including after adjusting for probe number per session, chronic obstructive pulmonary disease, and operator experience (p = .53). Ventilation modalities showed no significant difference in procedure time, CT guidance acquisition time, CT guidance radiation dose, or total radiation dose (all p > .05). Room time was longer for HFJV than SR (median, 154 vs 127 minutes, p < .001). For HFJV, the median anesthesia time was 136 minutes. Ventilation modalities did not differ in the frequencies of pneumothorax or pneumothorax requiring chest tube placement (both p > .05). CONCLUSION. HFJV appears to be as safe as SR but had longer room times. HFJV can be used in complex cases without significantly impacting HLOS of 2 days or more, procedure time, or radiation exposure. CLINICAL IMPACT. Selection of the ventilation modality during percutaneous lung ablation should be based on patient characteristics and anticipated procedural requirements as well as operator preference.

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.

Radiofrequency ablation for stage <IIB non-small cell lung cancer: Opportunities, challenges, and the road ahead

Pulmonary carcinoma represents the second common cancer for human race while its mortality rate ranked the first all over the world. Surgery remains the primary option for early-stage non-small cell lung cancer (NSCLC) in some surgical traditions. Nevertheless, only less than half of patients are operable subjected to the limited lung function and multiple primary/metastatic lesions. Recent improvements in minimally invasive surgical techniques have made the procedure accessible to more patients, but this percentage still does not exceed half. In recent years, radiofrequency ablation (RFA), one of the thermal ablation procedures, has gradually advanced in the treatment of lung cancer in addition to being utilized to treat breast and liver cancer. Several guidelines, including the American College of Chest Physicians (ACCP), include RFA as an option for some patients with NSCLC although the level of evidence is mostly limited to retrospective studies. In this review, we emphasize the use of the RFA technique in patients with early-stage NSCLC and provide an overview of the RFA indication population, prognosis status, and complications. Meanwhile, the advantages and disadvantages of RFA proposed in existing studies are compared with surgical treatment and radiotherapy. Due to the high rate of gene mutation and immunocompetence in NSCLC, there are considerable challenges to clinical translation of combining targeted drugs or immunotherapy with RFA that the field has only recently begun to fully appreciate.

A comparative study of esketamine-dexmedetomidine and sufentanil-dexmedetomidine for sedation and analgesia in lung tumor percutaneous radiofrequency ablation (PRFA): a randomized double-blind clinical trial

OBJECTIVE

To observe and evaluate the effectiveness and safety of Esketamine or Sufentanil combined with Dexmedetomidine for sedation and analgesia in lung tumor percutaneous radiofrequency ablation (PRFA) to provide a clinical basis for the optimization of sedation and analgesia in lung tumor PRFA protocols outside the operating room.

METHODS

In this trial, 44 patients aged 37 to 84 undergoing lung tumor PRFA were enrolled and assigned to Group E (n = 22, Esketamine 0.2 mg/kg) or Group S (n = 22,Sufentanil 0.1 μg/kg ). Dexmedetomidine was infused intravenously as a sedative in both groups. The modified observer's assessment of alertness and sedation scale (MOAAS), physical movement pain scale, intraoperative vital signs, anesthesia recovery time, radiologist and patient satisfaction rates, incidence of respiratory depression, and incidence of postoperative nausea and vomiting were recorded.

RESULTS

Although there was no significant difference in the physical movement pain scale, blood oxygen saturation or incidence of perioperative adverse events between the two groups during ablation, the MOAAS, mean arterial pressure (MAP) and heart rate (HR) were higher in Group E than in Group S. The anesthesia recovery time was shorter in Group E than in Group S, and radiologist satisfaction was better in Group E than in Group S, but there was no significant difference between the two groups in terms of patient satisfaction.

CONCLUSION

Esketamine or Sufentanil combined with Dexmedetomidine is safe for lung tumor PRFA. However, in elderly patients with multiple underlying diseases, low-dose Esketamine combined with Dexmedetomidine has fewer hemodynamic effects on patients, milder respiratory depression, shorter recovery time, and better radiologist satisfaction because of its better controllability of sedation depth.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (Registration number#ChiCTR ChiCTR21000500 21); Date of Registration: 16/08/2021.

Factors Associated with Hospital Length of Stay and Adverse Events following Percutaneous Ablation of Lung Tumors

PURPOSE

To explore the association between risk factors established in the surgical literature and hospital length of stay (HLOS), adverse events, and hospital readmission within 30 days after percutaneous image-guided thermal ablation of lung tumors.

MATERIALS AND METHODS

This bi-institutional retrospective cohort study included 131 consecutive adult patients (67 men [51%]; median age, 65 years) with 180 primary or metastatic lung tumors treated in 131 sessions (74 cryoablation and 57 microwave ablation) from 2006 to 2019. Age-adjusted Charlson Comorbidity Index, sex, performance status, smoking status, chronic obstructive pulmonary disease (COPD), primary lung cancer versus pulmonary metastases, number of tumors treated per session, maximum axial tumor diameter, ablation modality, number of pleural punctures, anesthesia type, pulmonary artery-to-aorta ratio, lung densitometry, sarcopenia, and adipopenia were evaluated. Associations between risk factors and outcomes were assessed using univariable and multivariable generalized linear models.

RESULTS

In univariable analysis, HLOS was associated with current smoking (incidence rate ratio [IRR], 4.54 [1.23-16.8]; P = .02), COPD (IRR, 3.56 [1.40-9.04]; P = .01), cryoablations with ≥3 pleural punctures (IRR, 3.13 [1.07-9.14]; P = .04), general anesthesia (IRR, 10.8 [4.18-27.8]; P < .001), and sarcopenia (IRR, 2.66 [1.10-6.44]; P = .03). After multivariable adjustment, COPD (IRR, 3.56 [1.57-8.11]; P = .003) and general anesthesia (IRR, 12.1 [4.39-33.5]; P < .001) were the only risk factors associated with longer HLOS. No associations were observed between risk factors and adverse events in multivariable analysis. Tumors treated per session were associated with risk of hospital readmission (P = .03).

CONCLUSIONS

Identified preprocedural risk factors from the surgical literature may aid in risk stratification for HLOS after percutaneous ablation of lung tumors, but were not associated with adverse events.

Single ultrasound-guided thoracic paravertebral block with a large volume of anesthetic for microwave ablation of lung tumors

Objective

To compare single ultrasound-guided thoracic paravertebral block (TPVB) using a large volume of anesthetic with local anesthesia (LA) in computed tomography (CT)-guided pulmonary microwave ablation.

Subjects and methods

Eighty patients who underwent CT-guided microwave ablation of pulmonary tumors were randomly divided into the TPVB group and the LA group. Patients of the TPVB group were anesthetized with a single injection of a large volume (40 ml) of 0.375% ropivacaine injection at T4, and those of the LA group had local infiltration by the surgeon at the puncture site, and emergency rescue with propofol injection was administered when the patient could not tolerate pain in either group. The following variables were recorded in both groups: general conditions; volume of propofol injection for emergency rescue during ablation; visual analog scale (VAS) scores during ablation and at 0, 2, 12, and 24 h after ablation; the need to use analgesics for rescue within 24 h after ablation; number of ablations; number of punctures performed by the surgeon; patient’s movements during puncturing; and puncturing-associated complications.

Results

Compared with the TPVB group, the amount of emergency use of propofol injection was significantly more in the LA group (P < 0.05). There were no significant differences in the VAS scores recorded intraoperatively and at 0, 2, 12, and 24 h after ablation between the two groups (P > 0.05). There was a significant difference in the patient’s movements upon puncturing between the two groups (P < 0.05), but there were no significant differences in the numbers of punctures and ablations between the two groups (P > 0.05). The number of patients using analgesics within 24 h after the operation was also more in the LA group than in the TPVB group, and the difference between the two groups was statistically significant (P < 0.05).

Conclusion

Single ultrasound-guided TPVB with a large volume of anesthetic offers effective analgesia for microwave ablation of lung tumors, helping the patient cooperate with the operating surgeon to reduce injury from multiple lung punctures. Further studies are recommended to validate these findings.

Safety and efficacy of microwave ablation to treat pulmonary nodules under conscious analgosedation with sufentanil: A single-center clinical experience

PURPOSE

The present study was designed to evaluate the safety and efficacy of computed tomography-guided percutaneous microwave ablation (MWA) to treat pulmonary nodules under conscious analgosedation with sufentanil.

MATERIALS AND METHODS

February to May 2021, 124 patients with 151 pulmonary nodules were enrolled in this study. The patients underwent 124 sessions of MWA. Sufentanil (0.25 μg/kg) was injected intravenously before MWA.

RESULTS

The technical success was 100% and no procedure-related deaths. The dosage of sufentanil was 16.6 ± 3.0 μg. The mean tumor diameter in the enrolled patients was 1.3 ± 0.8 cm. The intraoperative mean numerical rating scale (NRS) was 2.2 ± 1.7. Among the patients with NRS >3, seven patients had nodules adjacent to the pleura, while in ten patients, they were not adjacent. The mean systolic, diastolic blood pressure, and heart rate of patients were 139.1 ± 23.5 mmHg, 77.8 ± 12.3, and 76.1 ± 13.4 times/min, respectively, before sufentanil injection. The mean lowest systolic, lowest diastolic blood pressure, and lowest heart rate intraoperative were 132.9 ± 22.0 mmHg, 76.1 ± 12.1, and 74.0 ± 13.5 times/min. Twenty-six patients had mild adverse events including nausea (6.45%, 8/124), dizziness (2.42%, 3/124), vomiting(4.03%, 5/124), nausea and dizziness (2.42%, 3/124), nausea with vomiting and dizziness (2.42%, 3/124), urinary retention (1.61%, 2/124) and respiratory depression (0.81%, 1/124).

CONCLUSION

Sufentanil is a feasible, safe, and effective analgesic for MWA in patients with pulmonary nodules. It can be used for clinical promotion.

Image-guided percutaneous ablation for the treatment of lung malignancies: current state of the art

Image-guided percutaneous lung ablation has proven to be a valid treatment alternative in patients with early-stage non-small cell lung carcinoma or oligometastatic lung disease. Available ablative modalities include radiofrequency ablation, microwave ablation, and cryoablation. Currently, there are no sufficiently representative studies to determine significant differences between the results of these techniques. However, a common feature among them is their excellent tolerance with very few complications. For optimal treatment, radiologists must carefully select the patients to be treated, perform a refined ablative technique, and have a detailed knowledge of the radiological features following lung ablation. Although no randomized studies comparing image-guided percutaneous lung ablation with surgery or stereotactic radiation therapy are available, the current literature demonstrates equivalent survival rates. This review will discuss image-guided percutaneous lung ablation features, including available modalities, approved indications, possible complications, published results, and future applications.

Ultrasound-Guided Thoracic Paravertebral Block for Pulmonary Radiofrequency Ablation

Surgical resection is the treatment of choice both for early-stage lung cancer and pulmonary metastatic disease. For patients with lung tumors who are not eligible for surgery, the minimally invasive modality of radiofrequency ablation (RFA) may be curative and, thus, should be considered. However, opinions regarding the optimal anesthetic technique for pulmonary RFA differ. Here the authors report their experience with the use of ultrasound-guided paravertebral block in minimally-sedated patients undergoing pulmonary RFA. This retrospective study was conducted at a single institution. The 17 consecutive patients underwent 19 pulmonary RFA procedures for primary lung tumor or lung metastases. In all patients, RFA was performed according to the protocol of the hospital. Anesthesia in patients receiving RFA for lung tumors consisted of a thoracic paravertebral block (TPVB), performed between T4 and T8, with minimal sedation. This approach allowed intraoperative communication with the patient and apnea pauses as needed. There were no complications after TPVB, which was well-tolerated by all patients. Only two patients required an alfentanil bolus during RFA because of pleuritic pain. No patient required conversion from sedation to general anesthesia. There were no episodes of hemodynamic instability or desaturation (SaO₂ ≤95%), and excessive sedation prevented patient collaboration in only one patient. In conclusion, ultrasound-guided single-injection TPVB is a safe and effective anesthetic technique for high-risk patients undergoing RFA for a primary lung tumor or lung metastases.

Role of Thermal Ablation in Colorectal Cancer Lung Metastases

Simple Summary

For a long time, surgery has been the only local treatment for pulmonary metastases. Percutaneous thermal ablation appeared in the early 2000s as a minimally invasive alternative technique to surgery for patients who were not eligible for surgery or wanted to preserve quality of life. In this review, we discuss the role of thermal ablation in the management of lung metastases of colorectal cancer, and present the main results of the literature concerning oncological outcomes (local tumor control, survival) based on 12 relevant original studies each involving a minimum of 50 patients, with a minimal follow-up of 12 months.

Abstract

Background: Consensus guidelines of the European Society for Medical Oncology (ESMO) (2016) provided recommendations for the management of lung metastases. Thermal ablation appears as a tool in the management of these secondary pulmonary lesions, in the same manner as surgical resection or stereotactic ablative radiotherapy (SABR). Methods: Indications, technical considerations, oncological outcomes such as survival (OS) or local control (LC), prognostic factors and complications of thermal ablation in colorectal cancer lung metastases were reviewed and put into perspective with results of surgery and SABR. Results: LC rates varied from 62 to 91%, with size of the metastasis (<2 cm), proximity to the bronchi or vessels, and size of ablation margins (>5 mm) as predictive factors of LC. Median OS varied between 33 and 68 months. Pulmonary free disease interval <12 months, positive carcinoembryonic antigen, absence of neoadjuvant chemotherapy and uncontrolled extra-pulmonary metastases were poor prognostic factors for OS. While chest drainage for less than 48 h was required in 13 to 47% of treatments, major complications were rare. Conclusions: Thermal ablation of a selected subpopulation of patients with colorectal cancer lung metastases is safe and can provide excellent LC and delay systemic chemotherapy.

Anesthesia for Percutaneous Radiofrequency Tumor Ablation (PRFA): A Review of Current Practice and Techniques

Percutaneous radiofrequency ablation (PRFA) of solid tumors is a minimally invasive procedure used to treat primary or metastatic cancer lesions via needle targeted thermal energy transfer. Some of the most common tumor lesions treated using PRFA include those within the liver, lungs and kidneys. Additionally, bone, thyroid, and breast lesions can also be treated. In most cases, this procedure is performed outside of the operating room in a specialized radiology suite. As a result, the clinician must adapt in many cases to the specific environmental issues attendant to providing anesthesia outside the operating room, including the lack of availability of an anesthesia machine in some cases, and frequently a lack of adequate scavenging and other specialized monitoring and equipment. At this time, routine practice and anesthetic prescriptions for PRFA can vary widely, ranging from patients receiving local anesthesia alone, to monitored anesthesia care, to regional anesthesia, to combined regional and general anesthesia. The choice of anesthetic technique will depend on tumor location and practitioner experience. This review aims to summarize the current state of the art in terms of anesthetic techniques for patients undergoing PRFA of solid tumors.

Percutaneous Radiofrequency Ablation of Pulmonary Metastasis and Thoracic Paravertebral Block Under Computed Tomographic Scan Guidance: A Case Report

Pain during and after pulmonary percutaneous radiofrequency ablation (RFA) may be severe enough to require opioids. Thoracic paravertebral block (TPVB) is a regional anesthetic technique that can relieve pain during and after abdominal or thoracic painful procedures. We report the use of TPVB to relieve postprocedural pain in a 50-year-old woman after RFA of lung metastasis. The TPVB was performed under computed tomographic guidance by the anesthesiologist. The patient was pain free (rest and mobilization) during the first postoperative 36 hours. TPVB may represent an easy, safe, and effective strategy to prevent or treat postoperative pain after pulmonary RFA.

Chinese expert consensus workshop report: Guidelines for thermal ablation of primary and metastatic lung tumors

Although surgical resection is the primary means of curing both primary and metastatic lung cancers, about 80% of lung cancers cannot be removed by surgery. As most patients with unresectable lung cancer receive only limited benefits from traditional radiotherapy and chemotherapy, many new local treatment methods have emerged, including local ablation therapy. The Minimally Invasive and Comprehensive Treatment of Lung Cancer Branch, Professional Committee of Minimally Invasive Treatment of Cancer of the Chinese Anti-Cancer Association has organized multidisciplinary experts to develop guidelines for this treatment modality. These guidelines aim at standardizing thermal ablation procedures and criteria for selecting treatment candidates and assessing outcomes; and for preventing and managing post-ablation complications.

Lung radiofrequency and microwave ablation: a review of indications, techniques and post-procedural imaging appearances

Lung ablation can be used to treat both primary and secondary thoracic malignancies. Evidence to support its use, particularly for metastases from colonic primary tumours, is now strong, with survival data in selected cases approaching that seen after surgery. Because of this, the use of ablative techniques (particularly thermal ablation) is growing and the Royal College of Radiologists predict that the number of patients who could benefit from such treatment may reach in excess of 5000 per year in the UK. Treatment is often limited to larger regional centres, and general radiologists often have limited awareness of the current indications and the techniques involved. Furthermore, radiologists without any prior experience are frequently expected to interpret post-treatment imaging, often performed in the context of acute complications, which have occurred after discharge. This review aims to provide an overview of the current indications for pulmonary ablation, together with the techniques involved and the range of post-procedural appearances.

High-frequency jet ventilation under general anesthesia facilitates CT-guided lung tumor thermal ablation compared with normal respiration under conscious analgesic sedation

PURPOSE

To determine whether technical difficulty of computed tomography (CT)-guided percutaneous lung tumor thermal ablations is altered with the use of high-frequency jet ventilation (HFJV) under general anesthesia (GA) compared with procedures performed with normal respiration (NR) under conscious sedation (CS).

MATERIALS AND METHODS

Thermal ablation treatment sessions performed with NR under CS or HFJV under GA with available anesthesia records and CT fluoroscopic images were retrospectively reviewed; 13 and 33 treatment sessions, respectively, were identified. One anesthesiologist determined the choice of anesthesiologic technique independently. Surrogate measures of procedure technical difficulty--time duration, number of CT fluoroscopic acquisitions, and radiation dose required for applicator placement for each tumor--were compared between anesthesiologic techniques. The anesthesiologist time and complications were also compared. Parametric and nonparametric data were compared by Student independent-samples t test and χ(2) test, respectively.

RESULTS

Patients treated with HFJV under GA had higher American Society of Anesthesiologists classifications (mean, 2.66 vs 2.23; P = .009) and smaller lung tumors (16.09 mm vs 27.38 mm; P = .001). The time duration (220.30 s vs 393.94 s; P = .008), number of CT fluoroscopic acquisitions (10.31 vs 19.13; P = .023), and radiation dose (60.22 mGy·cm vs 127.68 mGy·cm; P = .012) required for applicator placement were significantly lower in treatment sessions performed with HFJV under GA. There was no significant differences in anesthesiologist time (P = .20), rate of pneumothorax (P = .62), or number of pneumothoraces requiring active treatment (P = .19).

CONCLUSIONS

HFJV under GA appears to reduce technical difficulty of CT-guided percutaneous applicator placement for lung tumor thermal ablations, with similar complication rates compared with treatment sessions performed with NR under CS. The technique is safe and may facilitate treatment of technically challenging tumors.

Modern diagnostic and therapeutic interventional radiology in lung cancer

Imaging has an important role in the multidisciplinary management of primary lung cancer. This article reviews the current state-of-the-art imaging modalities used for the evaluation, staging and post-treatment follow-up and surveillance of lung cancers, and image-guided percutaneous techniques for biopsy to confirm the diagnosis and for local therapy in non-surgical candidates.

Radiofrequency ablation of thoracic tumours: lessons learned with ablation of 100 lesions

PURPOSE

Our aim was to analyse the results of our first 100 radiofrequency ablation (RFA) procedures, of primary (nonsmall-cell lung cancers, NSCLC) and secondary (MTS) lung cancers to assess what lessons could be learned from our experience.

MATERIALS AND METHODS

We analysed 100 lesions (mean size 23 mm) in 81 patients (25 NSCLC/56 MTS). On the basis of the clinical-radiological evolution, we analysed complete ablation (CA) versus partial ablation (PA) at the first computed tomography (CT) scan and during the follow-up (mean 23 months), time to progression (TTP) and survival. Possible predictive factors for local effectiveness and survival were sought.

RESULTS

At the first CT scan CA was obtained in 88 %; the difference between the mean diameter of lesions achieving CA and PA was significant (20 versus 38 mm; p = 0.0001). A threshold of 30 mm (p = 0.0030) and the histological type (NSCLC 75 %/MTS 94 %; p = 0.0305) were also predictive of CA. A total of 18.4 % of the CA recurred (average TTP 19 months). Survival at 1, 2 and 3 years was 84.5, 65.4 and 51.5 %, respectively. The predictors of survival at 3 years were the coexistence of other MTS (p = 0.0422) and a diameter <20 mm (p = 0.0323), but not the local effectiveness of RFA.

CONCLUSION

RFA for thoracic malignancies is accurate for lesions up to 30 mm, especially if metastatic; survival is more closely related to staging factors than to the local effectiveness of RFA.

Thermal ablation in the treatment of lung cancer: present and future

Surgery is considered the best choice for stage I non-small cell lung cancer and also in treatment of selected patients with lung metastasis. However, surgery is often a high-risk procedure because of severe medical comorbidities affecting this cohort of patients. Thermal ablation (TA) has recently been proposed to achieve destruction of lung tumours whilst avoiding the use of general anaesthesia, thereby limiting the invasiveness of the procedure. For pulmonary malignancies, there are two methods of TA based on tissue heating: radio frequency ablation (RFA) and microwave ablation (MWA). Both are mini-invasive procedures, delivering energy to the tumour through single or multiple percutaneous needles introduced under guidance of computed tomography. The procedure may be performed under conscious sedation or general anaesthesia to avoid pain caused by needle insertion and tissue heating. Local efficacy is directly correlated to tumour target size: for RFA, tumours smaller than 2 cm can be completed ablated in 78-96% of cases; for MWA-according to the largest available study-95% of initial ablations are reported to be successful for tumours smaller than 5 cm. Very few series provide survival data beyond 3 years. For nodules smaller than 3 cm, the registered survival rate is higher: 50% at five years. The data collected in the last 10 years allow us to conclude that TA is an established alternative treatment for patients who cannot undergo surgery because of their compromised general condition. In the case of pulmonary metastasis, most authors agree to offer TA only if lesions are smaller than 5 cm.

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.

Radiofrequency ablation of pulmonary tumors

The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

Lung tumor radiofrequency ablation: where do we stand?

Today, radiofrequency ablation (RFA) of primary and metastatic lung tumor is increasingly used. Because RFA is most often used with curative intent, preablation workup must be a preoperative workup. General anesthesia provides higher feasibility than conscious sedation. The electrode positioning must be performed under computed tomography for sake of accuracy. The delivery of RFA must be adapted to tumor location, with different impedances used when treating tumors with or without pleural contact. The estimated rate of incomplete local treatment at 18 months was 7% (95% confidence interval, 3-14) per tumor, with incomplete treatment depicted at 4 months (n = 1), 6 months (n = 2), 9 months (n = 2), and 12 months (n = 2). Overall survival and lung disease-free survival at 18 months were, respectively, 71 and 34%. Size is a key point for tumor selection because large size is predictive of incomplete local treatment and poor survival. The ratio of ablation volume relative to tumor volume is predictive of complete ablation. Follow-up computed tomography that relies on the size of the ablation zone demonstrates the presence of incomplete ablation. Positron emission tomography might be an interesting option. Chest tube placement for pneumothorax is reported in 8 to 12%. Alveolar hemorrhage and postprocedure hemoptysis occurred in approximately 10% of procedures and rarely required specific treatment. Death was mostly related to single-lung patients and hilar tumors. No modification of forced expiratory volume in the first second between pre- and post-RFA at 2 months was found. RFA in the lung provides a high local efficacy rate. The use of RFA as a palliative tool in combination with chemotherapy remains to be explored.

Radiofrequency thermocoagulation of lung tumours. Where we are, where we are headed

Only 25% of all lung cancers are diagnosed in an early stage allowing surgical treatment. Primary tumours usually concerning lung metastasis are breast, colon, kidney, uterus/cervix, prostate, and head and neck tumours. During recent years many publications have confirmed the effectiveness and reliability of lung radiofrequency ablation (RFA) alone or together with other techniques (chemotherapy, radiotherapy...). Results suggest that survival increase and curative rates of lung radiofrequency are similar to those achieved by more aggressive procedures and present lower rates of complications. Pneumothorax, pleural effusion and alveolar haemorrhage are the most frequent complications. Indications for lung RFA must be individually evaluated by lung cancer committees. Percutaneous lung RFA may be useful in patients with pulmonary primary tumours and metastases, especially in those with nodules smaller than 3 cm and a peripheral location (>1 cm from the hilum). PET/CT seems to be the most accurate technique in patient follow up.

Radiofrequency ablation in combination with osteoplasty in the treatment of painful metastatic bone disease

PURPOSE

To evaluate the feasibility and effectiveness of combining radiofrequency (RF) ablation and osteoplasty for pain reduction in the treatment of painful osteolytic metastases.

MATERIALS AND METHODS

Within 5 years, 22 patients (15 men and seven women; median age, 64 years) with 28 lesions located in the thoracic and lumbar spine, sacrum, pelvis, acetabulum, femur, and tibia were treated. Underlying tumors were breast, lung, renal cell, thyroid, cancer of unknown primary, and multiple myeloma. RF ablation was performed with the patient under moderate sedation and computed tomographic fluoroscopy guidance and was immediately followed by cement injection. Pain relief was evaluated with the visual analogue scale (VAS) score and the extent to which analgesics could be reduced. Clinical success was defined as a substantial reduction in pain and/or a reduced demand for analgesics, and technical success was defined as distribution of cement between both endplates of a vertebral body or at least 75% filling of osteolyses in other bones.

RESULTS

Technical success and pain relief was achieved in all patients. Pain ratings with the VAS decreased from a mean of 8.5 to a mean of 5.5 after 24 hours (P < .01), and a further decrease was detected after 3 months to 3.5 (P < .01). The amount or strength of analgesics was reduced in 15 patients and remained unchanged in five. In two patients, the amount of analgesics increased due to tumor progression elsewhere. No major complication, no clinically obvious fracture of a formerly treated bone or treatment-related death, occurred.

CONCLUSIONS

RF ablation and osteoplasty can be combined within one session and is both feasible and useful for the treatment of osteolytic bone metastases with regard to pain relief.

Radiofrequency ablation for primary lung cancer and pulmonary metastases

Lung cancer remains one of the leading causes of death throughout the world. Although surgery is the gold standard treatment for lung cancer, the majority of patients are not resectable at the time of diagnosis. Even among patients who are potentially resectable, many are treated nonoperatively because of inadequate pulmonary reserve or advanced comorbidities. Despite aggressive multiple-drug regimens and the addition of radiation treatment, survival remains poor without surgery, and recurrence is the rule regardless of the initial treatment. Radiofrequency ablation can be performed via a percutaneous approach under conscious sedation, and side effects are generally mild and self limited, primarily consisting of pneumothorax. Radiofrequency ablation can be applied to primary pulmonary malignancies and metastatic lesions and is reported to achieve excellent local control in limited clinical series. Human and animal studies supporting the use of radiofrequency ablation for pulmonary malignancy are reviewed, and the current application of radiofrequency ablation and its limitations are described herein.

A combination therapy of ethanol injection and radiofrequency ablation under general anesthesia for the treatment of hepatocellular carcinoma

AIM: To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thoracoscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment of hepatocellular carcinoma (HCC).

METHODS: Time-lag performance of RFA after ethanol injection (Time-lag PEI-RFA) was performed in all cases. The volume of coagulated necrosis and the applied energy for total and per unit volume coagulated necrosis were examined in the groups treated under general (group G) or local anesthesia (group L).

RESULTS: The results showed that the total applied energy and the applied energy per unit volume of whole and marginal, coagulated necrosis were significantly larger in group G than those in the group L, resulting in a larger volume of coagulated necrosis in the group G. The rate of local tumor recurrence within one year was extremely low in group G.

CONCLUSION: These results suggest that EI-RFA, under general anesthesia, may be effective for the treatment of HCC because a larger quantity of ethanol and energy could be applied during treatment under pain-free condition for the patients.

Radiofrequency ablation of pulmonary tumours: current status

Radiofrequency ablation (RFA) for thoracic tumours has emerged as a minimally invasive therapy option for primary and secondary lung tumours and has gained increasing acceptance for pain palliation. The procedure is well tolerated and the complication rates are low. RFA provides the opportunity for localized tissue destruction of limited tumour volumes with medium and long term follow-up data suggesting that survival figures do parallel those of non-surgical treatment modalities. The purpose of this article is to review the status of RFA in lung tumours, to emphasize its place in symptomatic palliation and to discuss its potential role in conjunction with radiation or systemic therapy.

Frequency and risk factors of various complications after computed tomography-guided radiofrequency ablation of lung tumors

OBJECTIVE

To retrospectively determine the frequency and risk factors of various side effects and complications after percutaneous computed tomography-guided radiofrequency (RF) ablation of lung tumors.

METHODS

We reviewed and analyzed records of 112 treatment sessions in 57 of our patients (45 men and 12 women) with unresectable lung tumors treated by ablation. Risk factors, including sex, age, tumor diameter, tumor location, history of surgery, presence of pulmonary emphysema, electrode gauge, array diameter, patient position, maximum power output, ablation time, and minimum impedance during ablation, were analyzed using univariate and multivariate analyses.

RESULTS

Total rates of side effects and minor and major complications occurred in 17%, 50%, and 8% of treatment sessions, respectively. Side effects, including pain during ablation (46% of sessions) and pleural effusion (13% of sessions), occurred with RF ablation. Minor complications, including pneumothorax not requiring chest tube drainage (30% of sessions), subcutaneous emphysema (16% of sessions), and hemoptysis (9% of sessions) also occurred after the procedure. Regarding major complications, three patients developed fever >38.5 degrees C; three patients developed abscesses; two patients developed pneumothorax requiring chest tube insertion; and one patient had air embolism and was discharged without neurologic deficit. Univariate and multivariate analyses suggested that a lesion located < or =1 cm of the chest wall was significantly related to pain (p < 0.01, hazard index 5.76). Risk factors for pneumothorax increased significantly with previous pulmonary surgery (p < 0.05, hazard index 6.1) and presence of emphysema (p <0.01, hazard index 13.6).

CONCLUSION

The total complication rate for all treatment sessions was 58%, and 25% of patients did not have any complications after RF ablation. Although major complications can occur, RF ablation of lung tumors can be considered a safe and minimally invasive procedure.

[Interventional oncology for lung tumors]

Lung tumors and pulmonary metastases together are the most common cause of cancer-related death in men and the second most frequent in women. Up to now, surgical resection has remained the gold standard in the treatment of pulmonary tumors, being the only treatment option that was potentially curative and offered the possibility of a significant increase in life expectancy after successful therapy. Over the past decade, percutaneous radiofrequency ablation (RFA) has gained worldwide acceptance in the treatment of primary and secondary tumors of the liver with curative intent, so that indications for RFA have been extended to embrace tumors in other organs, e.g. the lung. Since the first case results were described, the number of publications dealing with the treatment of lung tumors using thermal ablative therapies has increased significantly. The aims of the present article are to give a short overview of emerging therapies such as cyberknife surgery and also, especially, to describe the indications for and technique of RFA, to discuss the ideal method of follow-up, and to highlight possible complications of the therapy and the current results of RFA of primary and secondary lung tumors. In addition, the value of combining RFA with other therapy modes (especially chemotherapy and radiation therapy)is briefly treated.