Comparison of the Effectiveness of Radiofrequency Ablation With Stereotactic Body Radiation Therapy in Inoperable Stage I Non-Small Cell Lung Cancer: A Systemic Review and Pooled Analysis

Advancements in the application of ablative therapy and its combination with immunotherapy in anti-cancer therapy

Cancer is a significant health issue impacting humans. Currently, systemic therapies such as chemotherapy have significantly increased the life expectancy of cancer patients. However, some patients are unable to endure systemic treatment due to its significant adverse effects, leading to an increased focus on local therapies including radiation and ablation therapy. Ablation therapy is a precise, low-toxicity, and minimally invasive localized therapy that is increasingly acknowledged by clinicians and cancer patients. Many cancer patients have benefited from it, with some achieving full recovery. Currently, numerous studies have shown that ablation therapy is effective due to its ability to kill cancer cells efficiently and activate the body's anti-cancer immunity. It can also convert "cold cancers" into "hot cancers" and enhance the effectiveness of immunotherapy when used in combination. In this article, we categorize ablation therapy into thermal ablation, cryoablation, photodynamic therapy (PDT), irreversible electroporation (IRE), etc. Thermal ablation is further divided into Radiofrequency ablation (RFA), microwave ablation (WMA), high-frequency focused ultrasound (HIFU), photothermal therapy (PTT), magnetic heat therapy (MHT), etc. We systematically review the most recent advancements in these ablation therapies that are either currently used in clinic or are anticipated to be used in clinic. Then, we also review the latest development of various ablative therapies combined with immunotherapy, and its future development. CLINICAL RELEVANCE STATEMENT: Ablation therapy, an invasive localized treatment, offers an alternative to systemic therapies for cancer patients who cannot tolerate their adverse effects. Its ability to kill cancer cells efficiently and activate anti-cancer immunity. This article reviews recent advancements in ablation therapies, including thermal, cryoablation, PDT, and IRE, and their potential clinical applications, both standalone and in combination with immunotherapy.

Computed Tomography-Guided Radiofrequency Ablation Combined With Video-Assisted Thoracoscopic Surgery for Multiple Pulmonary Nodules: A Retrospective Study From the National Cancer Center in China

BACKGROUND

Recently, the incidence of multiple pulmonary nodules (MPNs) is gradually rising. Therefore, this study aims to evaluate the safety and efficacy of computed tomography (CT)-guided radiofrequency ablation (RFA) combined with video-assisted thoracoscopic surgery (VATS) for patients with MPNs.

MATERIAL AND METHODS

The clinicopathological data and perioperative results of the patients with MPNs who underwent RFA combined with VATS at our center from October 2022 to September 2024 were reviewed. The primary endpoints were the safety and feasibility of this combined technique.

RESULTS

A total of 105 patients were enrolled in this study, including 30 males and 75 females with a mean age of 55.1 years. In total, 293 lesions were treated, 113 of which were ablated and 180 were surgically resected. The mean nodule size was 6.58 mm for ablated nodules and 10.3 mm for resected nodules. Of the 113 nodules treated using RFA, 112 were ground-glass nodules. The median ablation time and power of RFA were 5 min and 60 W, respectively. Of the 180 surgically resected nodules, 169 had ground-glass opacity. Total postoperative complication morbidity was 9.5% (10/105), with major complications (Clavien-Dindo classification ≥ 3) in 1.0% (1/105). No perioperative deaths occurred, and the median hospital stay was 5 days (range, 5-7 days). Notably, no recurrence has been observed in any patients during the short-term follow-up period.

CONCLUSIONS

Our study demonstrated that CT-guided RFA combined with VATS is a safe and feasible therapeutic technique for the patients with MPNs. Given the increasing incidence of MPNs, this combination strategy holds significant potential for clinical application.

The Treatment of Patients with Early-Stage Non-Small Cell Lung Cancer Who Are Not Candidates or Decline Surgical Resection: The Role of Radiation and Image-Guided Thermal Ablation

The standard of care for early-stage NSCLC has historically been surgical resection. Given the association of lung cancer with smoking, a large number of early-stage patients also have active smoking-related medical comorbidities such as COPD precluding surgery. The current approach for treating such inoperable patients is frequently considered to be stereotactic body radiation therapy (SBRT). SBRT (also known as stereotactic ablative radiation therapy or SABR) is a curative modality that precisely delivers very high dose radiation in few (typically <5) sessions. That said, because of their minimal invasiveness and repeatable nature, image-guided thermal ablation therapies such as radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) have also been used to treat early-stage lung tumors. For those patients deemed to have "high operative risk" (i.e., those who cannot tolerate lobectomy, but are candidates for sublobar resection), the appropriateness of potential alternatives [e.g., SBRT; ablation] to surgery is an active area of investigation. In the absence of completed randomized phase III trials, the approach to comparing outcomes between surgery, SBRT, or ablative therapies by their efficacy or equivalence is complex. An overview of the role of SBRT and other non-surgical modalities in the management of early-stage lung cancer is the subject of the present review.

Advancements in lung cancer: a comprehensive perspective on diagnosis, staging, therapy and follow-up from the SAKK Working Group on Imaging in Diagnosis and Therapy Monitoring

In 2015, around 4400 individuals received a diagnosis of lung cancer, and Switzerland recorded approximately 3200 deaths related to lung cancer. Advances in detection, such as lung cancer screening and improved treatments, have led to increased identification of early-stage lung cancer and higher chances of long-term survival. This progress has introduced new considerations in imaging, emphasising non-invasive diagnosis and characterisation techniques like radiomics. Treatment aspects, such as preoperative assessment and the implementation of immune response evaluation criteria in solid tumours (iRECIST), have also seen advancements. For those undergoing curative treatment for lung cancer, guidelines propose follow-up with computed tomography (CT) scans within a specific timeframe. However, discrepancies exist in published guidelines, and there is a lack of universally accepted recommendations for follow-up procedures. This white paper aims to provide a certain standard regarding the use of imaging on the diagnosis, staging, treatment and follow-up of patients with lung cancer.

Efficacy and Safety of Thermal Ablation for Patients With Stage I Non-small Cell Lung Cancer

RATIONALE AND OBJECTIVES

The objective of this study was to measure the safety and efficacy of thermal ablation, including radiofrequency ablation (RFA) and microwave ablation (MWA), for patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

The databases PubMed was searched from inception to November 2023 to identify relevant studies. Statistical analyses were performed with R version 3. 6. 3.

RESULTS

Thirty-three studies involving 1400 patients were finally included. According to our study, the incidence of patients with stage I NSCLC who were older than 60 years old was 98 % (95 % CI [94-100 %]); the lesions were mostly located in RUL (Right Upper Lobe) and LUL (Left Upper Lobe), and the incidence of the two sites was 29 % (95 % CI [23-35 %]) and 27 % (95 % CI [21-33 %]), respectively; the types of lung cancers mainly included adenocarcinoma, squamous carcinoma, and large-cell lung cancer, of which adenocarcinoma accounted for the largest proportion of 63 % (95 % CI [56-70 %]); the causes of death were mainly categorized into cancer-related (57 %, 95 %CI[40-74 %]) and noncancer-related (40 %, 95 %CI [23-58 %]); the common complications in the postoperative period were pneumothorax and pain, with the incidence of 33 % (95 %CI[24-44 %]) and 33 % (95 %CI[19-50 %]), and the rate of the postoperative complications in MWA was slightly higher than those in RFA; the local recurrence rate was 23 % (95 %CI[17-29 %]) and the distant recurrence rate was 18 % (95 %CI[7-32 %]); the pooling result showed the rate of 1-, 2-, 3-, and 5-year survival rate were 96 %, 81 %, 68 %, and 42 %, the Cancer-specific survival (CSS) rates at 1, 2, 3, and 5 years were 98 %, 88 %, 75 %, and 58 %, Disease-free survival (DFS) rates at 1, 2, 3, and 5 years were 87 %, 63 %, 57 %, and 42 %, there were no significant differences existed between the RFA group and MWA group in survival rate, CSS and DFS.

CONCLUSION

Ablation therapy is safe and effective for stage I NSCLC patient. MWA and RFA have comparable efficacy, safety, and prognosis, which could be recommended for patients with stageⅠNSCLC, especially for patients who cannot tolerate open surgery.

Lung Needle Biopsy and Lung Ablation: Indications, Patient Management, and Postprocedure Imaging Findings

The clinical role and use of percutaneous transthoracic needle biopsy (TTNB) and ablation of lung tumors are evolving. Here we discuss important considerations for referring providers, including current and emerging indications supported by guidelines, critical aspects of pre and postprocedure patient management, and expected postprocedure imaging findings.

Sublobar Resection, Stereotactic Body Radiation Therapy, and Percutaneous Ablation Provide Comparable Outcomes for Lung Metastasis-Directed Therapy

BACKGROUND

Prolonged survival of patients with metastatic disease has furthered interest in metastasis-directed therapy (MDT).

RESEARCH QUESTION

There is a paucity of data comparing lung MDT modalities. Do outcomes among sublobar resection (SLR), stereotactic body radiation therapy (SBRT), and percutaneous ablation (PA) for lung metastases vary in terms of local control and survival?

STUDY DESIGN AND METHODS

Medical records of patients undergoing lung MDT at a single cancer center between January 2015 and December 2020 were reviewed. Overall survival, local progression, and toxicity outcomes were collected. Patient and lesion characteristics were used to generate multivariable models with propensity weighted analysis.

RESULTS

Lung MDT courses (644 total: 243 SLR, 274 SBRT, 127 PA) delivered to 511 patients were included with a median follow-up of 22 months. There were 47 local progression events in 45 patients, and 159 patients died. Two-year overall survival and local progression were 80.3% and 63.3%, 83.8% and 9.6%, and 4.1% and 11.7% for SLR, SBRT, and PA, respectively. Lesion size per 1 cm was associated with worse overall survival (hazard ratio, 1.24; P = .003) and LP (hazard ratio, 1.50; P < .001). There was no difference in overall survival by modality. Relative to SLR, there was no difference in risk of local progression with PA; however, SBRT was associated with a decreased risk (hazard ratio, 0.26; P = .023). Rates of severe toxicity were low (2.1%-2.6%) and not different among groups.

INTERPRETATION

This study performs a propensity weighted analysis of SLR, SBRT, and PA and shows no impact of lung MDT modality on overall survival. Given excellent local control across MDT options, a multidisciplinary approach is beneficial for patient triage and longitudinal management.

Nanoparticle/Engineered Bacteria Based Triple-Strategy Delivery System for Enhanced Hepatocellular Carcinoma Cancer Therapy

Background

New treatment modalities for hepatocellular carcinoma (HCC) are desperately critically needed, given the lack of specificity, severe side effects, and drug resistance with single chemotherapy. Engineered bacteria can target and accumulate in tumor tissues, induce an immune response, and act as drug delivery vehicles. However, conventional bacterial therapy has limitations, such as drug loading capacity and difficult cargo release, resulting in inadequate therapeutic outcomes. Synthetic biotechnology can enhance the precision and efficacy of bacteria-based delivery systems. This enables the selective release of therapeutic payloads in vivo.

Methods

In this study, we constructed a non-pathogenic Escherichia coli (E. coli) with a synchronized lysis circuit as both a drug/gene delivery vehicle and an in-situ (hepatitis B surface antigen) Ag (ASEc) producer. Polyethylene glycol (CHO-PEG2000-CHO)-poly(ethyleneimine) (PEI25k)-citraconic anhydride (CA)-doxorubicin (DOX) nanoparticles loaded with plasmid encoded human sulfatase 1 (hsulf-1) enzyme (PNPs) were anchored on the surface of ASEc (ASEc@PNPs). The composites were synthesized and characterized. The in vitro and in vivo anti-tumor effect of ASEc@PNPs was tested in HepG2 cell lines and a mouse subcutaneous tumor model.

Results

The results demonstrated that upon intravenous injection into tumor-bearing mice, ASEc can actively target and colonise tumor sites. The lytic genes to achieve blast and concentrated release of Ag significantly increased cytokine secretion and the intratumoral infiltration of CD4/CD8+T cells, initiated a specific immune response. Simultaneously, the PNPs system releases hsulf-1 and DOX into the tumor cell resulting in rapid tumor regression and metastasis prevention.

Conclusion

The novel drug delivery system significantly suppressed HCC in vivo with reduced side effects, indicating a potential strategy for clinical HCC therapy.

Enhancing precision in lung tumor ablation through innovations in CT-guided technique and angle control

BACKGROUND

This retrospective study aimed to evaluate the precision and safety outcomes of image-guided lung percutaneous thermal ablation (LPTA) methods, focusing on radiofrequency ablation (RFA) and microwave ablation (MWA). The study utilized an innovative angle reference guide to facilitate these techniques in the treatment of lung tumors.

METHODS

This study included individuals undergoing LPTA with the assistance of laser angle guide assembly (LAGA) at our hospital between April 2011 and March 2021. We analyzed patient demographics, tumor characteristics, procedure details, and complications. Logistic regressions were employed to assess risk factors associated with complications.

RESULTS

A total of 202 patients underwent ablation for 375 lung tumors across 275 sessions involving 495 ablations. Most procedures used RFA, especially in the right upper lobe, and the majority of ablations were performed in the prone position (49.7%). Target lesions were at a median depth of 39.3 mm from the pleura surface, and remarkably, 91.9% required only a single puncture. Complications occurred in 31.0% of ablations, with pneumothorax being the most prevalent (18.3%), followed by pain (12.5%), sweating (6.5%), fever (5.0%), cough (4.8%), hemothorax (1.6%), hemoptysis (1.2%), pleural effusion (2.0%), skin burn (0.6%), and air emboli (0.2%). The median procedure time was 21 min. Notably, smoking/chronic obstructive pulmonary disease emerged as a significant risk factor for complications.

CONCLUSION

The LAGA-assisted LPTA enhanced safety by improving accuracy and reducing risks. Overall, this investigation contributes to the ongoing efforts to refine and improve the clinical application of these thermal ablation techniques in the treatment of lung tumors.

Treatment strategies for malignant pulmonary nodule: beyond lobectomy. Point-counterpoint

PURPOSE OF REVIEW

Technological advancement in low-dose computed tomography resulted in an increased incidental discovery of early-stage lung cancer and multifocal ground glass opacity. The demand for parenchyma-preserving treatment strategies is greater now than ever. Pulmonary ablative therapy is a groundbreaking technique to offer local ablative treatment in a lung-sparing manner. It has become a promising technique in lung cancer management with its diverse applicability. In this article, we will review the current development of ablative therapy in lung and look into the future of this innovative technique.

RECENT FINDINGS

Current literature suggests that ablative therapy offers comparable local disease control to other local therapies and stereotactic body radiation therapy (SBRT), with a low risk of complications. In particular, bronchoscopic microwave ablation (BMWA) has considerably fewer pleural-based complications due to the avoidance of pleural puncture. BMWA can be considered in the multidisciplinary treatment pathway as it allows re-ablation and allows SBRT after BMWA.

SUMMARY

With the benefits which ablative therapy offers and its ability to incorporate into the multidisciplinary management pathway, we foresee ablative therapy, especially BMWA gaining significance in lung cancer treatment. Future directions on developing novel automated navigation platforms and the latest form of ablative energy would further enhance clinical outcomes for our patients.

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.

Comparison of outcome after stereotactic ablative radiotherapy of patients with metachronous lung versus primary lung cancer

BACKGROUND

Early-stage lung cancer, primarily treated with surgery, often occur in poor surgical candidates (impaired respiratory function, prior thoracic surgery, severe comorbidities). Stereotactic ablative radiotherapy (SABR) is a non-invasive alternative that provides comparable local control. This technique is particularly relevant for surgically resectable metachronous lung cancer, in patients unable to undergo surgery.. The objective of this study is to evaluate the clinical outcome of patients treated with SABR for stage I metachronous lung cancer (MLC) versus stage I primary lung cancer (PLC).

PATIENTS AND METHODS

137 patients treated with SABR for stage I non-small cell lung cancer were retrospectively reviewed, of which 28 (20.4%) were MLC and 109 (79.6%) were PLC. Cohorts were evaluated for differences in overall survival (OS), progression-free survival (PFS), metastasis-free survival, local control (LC), and toxicity.

RESULTS

After SABR, patients treated for MLC have comparable median age (76.6 vs 78.6, p = 0.2), 3-year LC (83.6% vs. 72.6%, p = 0.2), PFS (68.7% vs. 50.9%, p = 0.9), and OS (78.6% vs. 52.1%, p = 0.9) as PLC, along with similar rates of total (54.1% vs. 42.9%, p = 0.6) and grade 3 + toxicity (3.7% vs. 3.6%, p = 0.9). Previous treatment of MLC patients was either surgery (21/28, 75%) or SABR (7/28, 25%). The median follow-up was 53 months.

CONCLUSION

SABR is a safe and effective approach for localized metachronous lung cancer.

Stereotactic body radiation therapy and thermal ablation for treatment of NSCLC: A systematic literature review and meta-analysis

RATIONALE

Stereotactic body radiation therapy (SBRT) is the standard of care for inoperable early stage non-small cell lung cancer (NSCLC). Use of image guided thermal ablation (IGTA; including microwave ablation [MWA] and radiofrequency ablation [RFA]) has increased in NSCLC, however there are no studies comparing all three.

OBJECTIVE

To compare the efficacy of IGTA (including MWA and RFA) and SBRT for the treatment of NSCLC.

METHODS

Published literature databases were systematically searched for studies assessing MWA, RFA, or SBRT. Local tumor progression (LTP), disease-free survival (DFS), and overall survival (OS) were assessed with single-arm pooled analyses and meta-regressions in NSCLC patients and a stage IA subgroup. Study quality was assessed with a modified methodological index for non-randomized studies (MINORS) tool.

RESULTS

Forty IGTA study-arms (2,691 patients) and 215 SBRT study-arms (54,789 patients) were identified. LTP was lowest after SBRT at one and two years in single-arm pooled analyses (4% and 9% vs. 11% and 18%) and at one year in meta-regressions when compared to IGTA (OR = 0.2, 95%CI = 0.07-0.63). MWA patients had the highest DFS of all treatments in single-arm pooled analyses. In meta-regressions at two and three-years, DFS was significantly lower for RFA compared to MWA (OR = 0.26, 95%CI = 0.12-0.58; OR = 0.33, 95%CI = 0.16-0.66, respectively). OS was similar across modalities, timepoints, and analyses. Older age, male patients, larger tumors, retrospective studies, and non-Asian study region were also predictors of worse clinical outcomes. In high-quality studies (MINORS score ≥ 7), MWA patients had better clinical outcomes than the overall analysis. Stage IA MWA patients had lower LTP, higher OS, and generally lower DFS, compared to the main analysis of all NSCLC patients.

CONCLUSIONS

NSCLC patients had comparable outcomes after SBRT and MWA, which were better than those with RFA.

Safety and Effectiveness of Percutaneous Image-Guided Thermal Ablation of Juxtacardiac Lung Tumors

PURPOSE

To evaluate the safety and effectiveness of percutaneous image-guided thermal ablation (IGTA) for juxtacardiac lung tumors.

MATERIALS AND METHODS

This bi-institutional retrospective cohort study included 23 consecutive patients (13 [57%] male; mean age, 55 years ± 18) with 30 juxtacardiac lung tumors located ≤10 mm from the pericardium treated in 28 IGTA sessions (25 sessions of cryoablation and 3 sessions of microwave ablation) between April 2008 and August 2022. The primary outcome was any adverse cardiac event within 90 days after ablation. Secondary outcomes included noncardiac adverse events, local tumor progression-free survival (LT-PFS), and the cumulative incidence of local tumor progression with death as a competing risk. Two tumors treated without curative intent or follow-up imaging were considered in the safety analysis but not in the progression analysis.

RESULTS

The median imaging follow-up duration was 22 months (interquartile range [IQR], 10-53 months). Primary technical success was achieved in 25 (89%) ablations. No adverse cardiac events attributable to IGTA occurred. One patient experienced a phrenic nerve injury. The median LT-PFS duration was 59 months (IQR, 32-73 months). At 1, 3, and 5 years, LT-PFS was 90% (95% CI, 78%-100%), 74% (CI, 53%-100%), and 45% (CI, 20%-97%), respectively, and the cumulative incidence of local tumor progression was 4.3% (CI, 0.29%-19%), 11% (CI, 1.6%-30%), and 26% (CI, 3.3%-58%), respectively.

CONCLUSIONS

IGTA is safe and effective for lung tumors located ≤10 mm from the pericardium. No adverse cardiac events were not observed within 90 days after ablation.

Primary and Metastatic Lung Cancer: Rationale, Indications, and Outcomes of Thermal Ablation

The widespread use of imaging as well as the efforts conducted through screening campaigns has dramatically increased the early detection rate of lung cancer. Historically, the management of lung cancer has heavily relied on surgery. However, the increased proportion of patients with comorbidities has given significance to less invasive therapeutic options like minimally invasive surgery and image-guided thermal ablation, which could precisely target the tumor without requiring general anesthesia or a thoracotomy. Thermal ablation is considered low-risk for lung tumors smaller than 3 cm that are located in peripheral lung and do not involve major blood vessels or airways. The rationale for ablative therapies relies on the fact that focused delivery of energy induces cell death and pathologic necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid and uterine lesions. In the lung, and specifically in the setting of metastatic disease, the 3 main indications for lung ablation are to serve as (1) curative intent, (2) as a strategy to achieve a chemo-holiday in oligometastatic disease, and (3) in oligoprogressive disease. Following these premises, the current paper aims to review the rationale, indications, and outcomes of thermal ablation as a form of local therapy in the treatment of primary and metastatic lung disease.

Percutaneous image-guided thermal ablation of lung cancer: What is the evidence?

Thermal ablation techniques have now been used for more than twenty years in the treatment of primary lung tumours, predominantly non-small cell lung cancer (NSCLC). Although primarily used for the treatment of early-stage disease in non-surgical patients, thermal ablation is now also being used in selected patients with oligometastatic and oligoprogressive disease. This review discusses the techniques available for thermal ablation, the evidence for use of thermal ablation in primary lung tumours in early- and advanced-stage disease and compares thermal ablation to alternative treatment strategies.

Image-Guided Percutaneous and Transarterial Therapies for Primary and Metastatic Lung Cancer

Lung cancer is the leading cause of cancer mortality in the world. A significant proportion of patients with lung cancer are not candidates for surgery and must resort to other treatment alternatives. Rapid technological advancements in fields like interventional radiology have paved the way for valid treatment modalities like image-guided percutaneous and transarterial therapies for treatment of both primary and metastatic lung cancer. The rationale of ablative therapies relies on the fact that focused delivery of energy induces tumor destruction and pathological necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid, or uterine lesions. In the lung, the 3 main indications for lung ablation include local curative intent, a strategy to achieve a chemoholiday in oligometastatic disease, and recently, oligoprogressive disease. Transarterial therapies include a set of catheter-based treatments that involve delivering embolic and/or chemotherapeutic agents directed into the target tumor via the supplying arteries. This article provides a comprehensive review of the various techniques available and discusses their applications and associated complications in primary and metastatic lung cancer.

Safety and Efficacy Outcomes From a Single-Center Study of Image-Guided Percutaneous Microwave Ablation for Primary and Metastatic Lung Malignancy

Introduction

Image-guided percutaneous microwave ablation (MWA) is becoming a more common treatment option for patients with primary and metastatic lung malignancies. Nevertheless, there is limited literature on the safety and efficacy of MWA compared with standard-of-care therapy, including surgical resection and radiation. This study will report the long-term outcomes after MWA for pulmonary malignancies and investigate the factors related to efficacy, including lesion size, location, and ablation power.

Methods

Retrospective single-center study analyzing 93 patients who underwent percutaneous MWA for primary or metastatic lung malignancies. Outcomes included immediate technical success, local tumor recurrence, overall survival, disease-specific survival, and complications.

Results

At a single institution, 190 lesions (81 primary and 109 metastatic) were treated in 93 patients. Immediate technical success was achieved in all cases. Freedom from local recurrence was 87.6%, 75.3%, and 69.2% and overall survival was 87.7%, 76.2%, and 74.3% at 1 year, 2 years, and 3 years, respectively. Disease-specific survival was 92.6%, 81.8%, and 81.8%. The most common complication was pneumothorax, which occurred in 54.7% (104 of 190) of procedures, with 35.2% (67 of 190) requiring a chest tube. No life-threatening complications occurred.

Conclusions

Percutaneous MWA seems safe and effective for treatment of primary and metastatic lung malignancies and should be considered for patients with limited metastatic burden and lesions less than 3 cm in size.

Effect of Ablative Dose Irradiation on Redistribution and Radioresponse in a Mouse Xenograft Model

We investigated the effects of ablative dose irradiation on redistribution and radioresponse after the second irradiation in a mouse xenograft model, assuming stereotactic body radiotherapy (SBRT). A human tongue cancer cell line, SAS-Fucci, expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci) that visualizes the cell cycle, was employed in this study. Tumor xenografts formed subcutaneously in nude mice (approximately 6 mm in diameter), with essentially no hypoxic regions, were irradiated at 10 Gy and G2 arrest kinetics were determined using histology sections and a real-time detection method. The second irradiation (10 Gy) was given at intervals of 0 h, 3 h, 1 day, and 4 days after the first irradiation, and tumor regrowth curves were obtained. It was revealed that the ratio of G2-arrested cells showed a much higher peak at 1 day postirradiation compared to 2 Gy, assuming conventional radiotherapy, and gradually decreased thereafter up to 4 days. Tumors irradiated at intervals of 0 h and 1 day demonstrated significantly higher radioresponses than other timings. We conclude that redistribution could contribute to the efficacy of SBRT.

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

OBJECTIVES

In the present study, we aim to show the results of microwave ablation (MWA) for medically inoperable stage I non-small cell lung cancers (NSCLCs) with long-term follow-up.

METHODS

From Feb 2011 to Mar 2016, patients with histologically proven clinical stage I NSCLC were treated with CT-guided MWA and retrospectively analyzed. The primary end point was overall survival (OS). Secondary end points included disease-free survival (DFS), cancer-specific survival (CSS), and complications.

RESULTS

A total of 105 patients with 105 lesions underwent MWA. The mean age was 70.7 years (range: 40-86 years), and the mean diameter of all lesions was 2.40 cm (range: 0.9-4.0 cm). Adenocarcinoma was the most common histological type (77, 73.3%), followed by squamous cell carcinomas (21, 20%) and undefined NSCLC (7, 6.7%). With a median follow-up of 54.8 months, the median DFS was 36.0 months, and 1-, 3-, and 5-year DFS rates were 89.5%, 49.4%, and 42.7%, respectively. The median CSS and OS were 89.8 and 64.2 months, respectively. The OS rate was 99% at 1 year, 75.6% at 3 years, and 54.1% at 5 years, while the CSS rates were 99%, 78.9%, and 60.9%, respectively. Patients with stage IB lesions had significant shorter DFS (22.3 months vs. undefined, HR: 11.5, 95%CI: 5.85-22.40) and OS (37.3 vs. 89.8 months, HR: 8.64, 95% CI: 4.49-16.60) than IA disease.

CONCLUSION

MWA is a safe, effective, and potentially curative therapy for medically inoperable stage I NSCLC patients.

KEY POINTS

• In this multicenter retrospective study which included 105 patients, we found the median overall survival (OS) was 64.2 months. The OS rate was 99% at 1 year, 75.6% at 3 years, and 54.1% at 5 years. • Procedures were technically successful and well tolerated in all patients. Most MWA complications were mild or moderate.

Percutaneous local tumor ablation vs. stereotactic body radiotherapy for early-stage non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

Percutaneous local tumor ablation (LTA) and stereotactic body radiotherapy (SBRT) have been regarded as viable treatments for early-stage lung cancer patients. The purpose of this study was to compare the efficacy and safety of LTA with SBRT for early-stage non-small cell lung cancer (NSCLC).

METHODS

PubMed, Embase, Cochrane library, Ovid, Google scholar, CNKI, and CBMdisc were searched to identify potential eligible studies comparing the efficacy and safety of LTA with SBRT for early-stage NSCLC published between January 1, 1991, and May 31, 2021. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were applied to estimate the effect size for overall survival (OS), progression-free survival (PFS), locoregional progression (LP), and adverse events.

RESULTS

Five studies with 22,231 patients were enrolled, including 1443 patients in the LTA group and 20,788 patients in the SBRT group. The results showed that SBRT was not superior to LTA for OS (HR = 1.03, 95% CI: 0.87-1.22, P = 0.71). Similar results were observed for PFS (HR = 1.09, 95% CI: 0.71-1.67, P = 0.71) and LP (HR = 0.66, 95% CI: 0.25-1.77, P = 0.70). Subgroup analysis showed that the pooled HR for OS favored SBRT in patients with tumors sized >2 cm (HR = 1.32, 95% CI: 1.14-1.53, P = 0.0003), whereas there was no significant difference in patients with tumors sized ≤2 cm (HR = 0.93, 95% CI: 0.64-1.35, P = 0.70). Moreover, no significant differences were observed for the incidence of severe adverse events (≥grade 3) (OR = 1.95, 95% CI: 0.63-6.07, P = 0.25) between the LTA group and SBRT group.

CONCLUSIONS

Compared with SBRT, LTA appears to have similar OS, PFS, and LP. However, for tumors >2 cm, SBRT is superior to LTA in OS. Prospective randomized controlled trials are required to determine such findings.

INPLASY REGISTRATION NUMBER

INPLASY202160099.

A guide for managing patients with stage I NSCLC: deciding between lobectomy, segmentectomy, wedge, SBRT and ablation-part 4: systematic review of evidence involving SBRT and ablation

Background

Clinical decision-making for patients with stage I lung cancer is complex. It involves multiple options [lobectomy, segmentectomy, wedge, stereotactic body radiotherapy (SBRT), thermal ablation], weighing multiple outcomes (e.g., short-, intermediate-, long-term) and multiple aspects of each (e.g., magnitude of a difference, the degree of confidence in the evidence, and the applicability to the patient and setting at hand). A structure is needed to summarize the relevant evidence for an individual patient and to identify which outcomes have the greatest impact on the decision-making.

Methods

A PubMed systematic review from 2000-2021 of outcomes after SBRT or thermal ablation vs. resection is the focus of this paper. Evidence was abstracted from randomized trials and non-randomized comparisons with at least some adjustment for confounders. The analysis involved careful assessment, including characteristics of patients, settings, residual confounding etc. to expose degrees of uncertainty and applicability to individual patients. Evidence is summarized that provides an at-a-glance overall impression as well as the ability to delve into layers of details of the patients, settings and treatments involved.

Results

Short-term outcomes are meaningfully better after SBRT than resection. SBRT doesn't affect quality-of-life (QOL), on average pulmonary function is not altered, but a minority of patients may experience gradual late toxicity. Adjusted non-randomized comparisons demonstrate a clinically relevant detriment in long-term outcomes after SBRT vs. surgery. The short-term benefits of SBRT over surgery are accentuated with increasing age and compromised patients, but the long-term detriment remains. Ablation is associated with a higher rate of complications than SBRT, but there is little intermediate-term impact on quality-of-life or pulmonary function tests. Adjusted comparisons show a meaningful detriment in long-term outcomes after ablation vs. surgery; there is less difference between ablation and SBRT.

Conclusions

A systematic, comprehensive summary of evidence regarding Stereotactic Body Radiotherapy or thermal ablation vs. resection with attention to aspects of applicability, uncertainty and effect modifiers provides a foundation for a framework for individualized decision-making.

Image-Guided Percutaneous Ablation for Primary and Metastatic Tumors

Image-guided percutaneous ablation methods have been further developed during the recent two decades and have transformed the minimally invasive and precision features of treatment options targeting primary and metastatic tumors. They work by percutaneously introducing applicators to precisely destroy a tumor and offer much lower risks than conventional methods. There are usually shorter recovery periods, less bleeding, and more preservation of organ parenchyma, expanding the treatment options of patients with cancer who may not be eligible for resection. Image-guided ablation techniques are currently utilized for the treatment of primary and metastatic tumors in various organs including the liver, pancreas, kidneys, thyroid and parathyroid, prostate, lung, bone, and soft tissue. This article provides a brief review of the various imaging modalities and available ablation techniques and discusses their applications and associated complications in various organs.

Microwave Ablation versus Stereotactic Body Radiotherapy for Stage I Non-Small Cell Lung Cancer: A Cost-Effectiveness Analysis

PURPOSE

To assess the cost-effectiveness of microwave ablation (MWA) and SBRT for patients with inoperable stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

A literature search was performed in MEDLINE with broad search clusters. A decision-analysis model was constructed over a 5-year period. The model incorporated treatment-related complications and long-term recurrence. All clinical parameters were derived from the literature with preference to long-term prospective trials. A healthcare payers' perspective was adopted. Outcomes were measured in quality-adjusted life years (QALY) extracted from prior studies and United States dollars from Medicare reimbursements and prior studies. Base case calculations, probabilistic sensitivity analysis with 10,000 Monte Carlo simulations, and multiple one- and two-way sensitivity analyses were performed.

RESULTS

MWA yielded a health benefit of 2.31 QALY at a cost of $195,331, whereas SBRT yielded a health benefit of 2.33 QALY at a cost of $225,271. The incremental cost-effectiveness ratio was $1,480,597/QALY, indicating that MWA is the more cost-effective strategy. The conclusion remains unchanged in probabilistic sensitivity analysis with MWA being the optimal cost strategy in 99.84% simulations. One-way sensitivity analyses revealed that MWA remains cost-effective when its annual recurrence risk is below 18.4% averaged over 5 years, when the SBRT annual recurrence risk is above 1.44% averaged over 5 years, or when MWA is at least $7,500 cheaper than SBRT.

CONCLUSION

Microwave ablation appears to be a more cost-effective than stereotactic body radiotherapy for patients with inoperable stage I non-small cell lung cancer.

Update on Image-Guided Thermal Lung Ablation: Society Guidelines, Therapeutic Alternatives, and Postablation Imaging Findings

Percutaneous image-guided thermal ablation (IGTA) has been endorsed by multiple societies as a safe and effective lung-preserving treatment for primary lung cancer and metastases involving the lung and chest wall. This article reviews the role of IGTA in the care continuum of patients with thoracic neoplasms and discusses strategies to identify the optimal local therapy considering patient and tumor characteristics. The advantages and disadvantages of percutaneous thermal ablation compared to surgical resection and stereotactic body radiotherapy are summarized. Principles of radiofrequency ablation, microwave ablation, and cryoablation, as well as the emerging use of transbronchial thermal ablation, are described. Specific considerations are presented regarding the role of thermal ablation for early-stage non-small cell lung cancer (NSCLC), multifocal primary NSCLC, pulmonary metastases, salvage of recurrent NSCLC after surgery or radiation, and pain palliation for tumors involving the chest wall. Recent changes to professional society guidelines regarding the role of thermal ablation in the lung, including for treatment of oligometastatic disease, are highlighted. Finally, recommendations are provided for imaging follow-up after thermal ablation of lung tumors, accompanied by examples of expected postoperative findings and patterns of disease recurrence.

Comparison of stereotactic body radiotherapy and radiofrequency ablation for early-stage non-small cell lung cancer: a systematic review and meta-analysis

Background

Stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA) are recommended for patients with inoperable early-stage non-small cell lung cancer (NSCLC), with both offering promising results. However, it is largely unknown which of these two treatment modalities provides superior benefits for patients. Therefore, this systematic review and meta-analysis compared clinical outcomes and safety between SBRT and RFA in patients with inoperable early-stage NSCLC.

Methods

Eligible studies published between 2001 and 2020 were obtained through a comprehensive search of the PubMed, Medline, Embase, and Cochrane Library databases. Original English-language studies on the treatment of early-stage NSCLC with SBRT or RFA were included. Local control (LC) rates, overall survival (OS) rates, and adverse events were obtained by pooled analyses.

Results

Eighty-seven SBRT studies (12,811 patients) and 18 RFA studies (1,535 patients) met the eligibility criteria. For SBRT, the LC rates (with 95% confidence intervals) at 1, 2, 3, and 5 years were 98% (97-98%), 95% (95-96%), 92% (91-93%), and 92% (91-93%), respectively, which were significantly higher than those for RFA [75% (69-82%), 31% (22-39%), 67% (58-76%), and 41% (30-52%), respectively] (P<0.01). There were no significant differences in short-term OS between SBRT and RFA [1-year OS rate: 87% (86-88%) versus 89% (88-91%), P=0.07; 2-year OS rate: 71% (69-72%) versus 69% (64-74%), P=0.42]. Regarding long-term OS, the 3- and 5-year OS rates for SBRT were 58% (56-59%) and 39% (37-40%), respectively, which were significantly (P<0.01) superior to those for RFA [48% (45-51%) and 21% (19-23%), respectively]. The most common complication of SBRT was radiation pneumonitis (grade ≥2), making up 9.1% of patients treated with SBRT, while pneumothorax was the most common complication of RFA, making up 27.2% of patients treated with RFA.

Discussion

Compared with RFA, SBRT has superior LC and long-term OS rates but similar short-term OS rates. Prospective randomized trials with large sample sizes comparing the efficacy of SBRT and RFA are warranted.

Management of Early-Stage Resected Non-Small Cell Lung Cancer: Consensus Statement of the Lung cancer Consortium

BACKGROUND

Management of early-stage non-small cell lung cancer (ES-NSCLC) has evolved over the last few years especially in terms of work-up and the use of systemic therapy. This consensus statement was developed to present updated guidelines for the management of this disease.

METHODS

Multidisciplinary team (MDT) of lung cancer experts convened to discuss a set of pertinent questions with importance relevance to the management of ES-NSCLC. ES-NSCLC includes stages I, II and resected stage III. The experts included consultants in chest imaging, thoracic surgery, radiation oncology, and medical oncology. Questions were discussed in virtual meetings and then a written manuscript with supporting evidence was drafted, reviewed, and approved by the team members.

RESULTS

The Consensus Statement included 9 questions addressing work-up and management of ES-NSCLC. Background information and literature review were presented for each question followed by specific recommendations to address the questions by oncology providers. The Statement was endorsed by various oncology societies in the Gulf region.

CONCLUSION

The Consensus Statement serves as a guide for thoracic MDT members in the management of ES-NSCLC. Adaptation of these to the local setting is dictated usually by available resources and expertise, however, all efforts should be excreted to provide the optimal care to all patients whenever possible.

Computed Tomography-Guided Percutaneous Radiofrequency Ablation in Older Adults With Early-Stage Peripheral Lung Cancer: A Retrospective Cohort Study

Objectives

To evaluate the feasibility, safety, and efficacy of computed tomography(CT)-guided percutaneous radiofrequency ablation (RFA) in medically inoperable older adults with clinical stage I non-small cell lung cancer (NSCLC).

Patients and Methods

We retrospectively reviewed the records of medically inoperable older adults (≥70 years) with clinical stage I NSCLC who underwent percutaneous multi-tined electrode RFA at our institution between January 2014 and December 2018. We analyzed the patients’ characteristics, therapy response, survival, as well as the procedure-related complications.

Results

Eighteen patients (10 men and 8 women) with a mean age of 75.9 (71−85) years were treated in during the study period. The median tumor size was 25 mm (range, 19−43 mm); 10 and 8 cases involved stage T1 and T2a disease, respectively. The median follow-up duration was 25 (11–45) months. RFA was technically successful for all 18 lesions, with no treatment-related mortality. The disease control rate was 83.3% (15/18 lesions). There were 6 cases of pneumothorax: one symptomatic case requiring thoracic drainage, and five requiring no treatment. Minor complications, including pulmonary infection, chest pain, fever, and cough, were treated within 4 days (range, 1−4 days). The progression-free survival rates were 83.3%, 64.9%, and 51.9% 1, 2, and 3 years, respectively. The corresponding overall survival rates were 92.2%, 81.5%, and 54.3%, respectively.

Conclusions

CT-guided percutaneous RFA is safe and effective in medically inoperable patients with stage I NSCLC and could be an alternative therapeutic strategy, particularly in older adults with early-stage peripheral lung cancer.

Single Institution Experience of Stereotactic Body Radiation Therapy in Non-small Cell Lung Cancer: Comparison of Two Dose Regimes and a Perspective on Ideal Dose Regimens

Introduction Stereotactic body radiation therapy (SBRT) is an effective treatment for early-stage non-small cell lung cancer (NSCLC) patients who are either medically inoperable or who decline surgery. SBRT improves tumor control and overall survival (OS) in medically inoperable, early-stage, NSCLC patients. In this study, we investigated the effectiveness of two different SBRT doses commonly used and present our institutional experience. Purpose To determine the clinical outcomes between two treatment regiments (50 Gray [Gy] vs. 55 Gy in five fractions) among Stage I NSCLC patients treated with SBRT at a state academic medical center. Methods We performed a retrospective analysis of 114 patients with Stage I (T1-2 N0 M0) NSCLC treated at a state academic medical center between October 2009 and April 2019. Survival analyses with treatment regimens of 50 Gy and 55 Gy in five fractions were conducted to detect any improvement in outcomes associated with the higher dose. The primary endpoints of this study included OS, local control (LC), and disease-free survival (DFS). Log-rank test and the Kaplan-Meier method were used to analyze the survival curves of the two treatment doses. The SPSS v.24.0 (IBM Corp., Armonk, NY, USA) was used for statistical analyses. Results The 114 early-stage NSCLC patients (median age, 68 years; range 12 to 87 years) had a median follow-up of 25 months (range two to 86 months). The number of males (n = 72; 63.2 %) exceeded the number of females (n = 42; 36.8 %). The majority of patients in this study were Caucasians (n = 68; 59.6 %) and 46 patients were African Americans (40.4 %). Two-thirds of the patients (n = 76; 66.7 %) were treated with 50 Gy in five fractions, and 38 patients (33.3 %) with 55 Gy in five fractions. The one-, two-, and three-year OS and DFS rates were improved in the patients treated with 55 Gy [OS, 81.7 % vs. 72.8 %; 81.7 % vs. 58.9 %; 81.7 % vs. 46.7 % (p = 0.049)], [DFS, 69.7 % vs. 69.7 %; 61.9 % vs. 55.7 %; 61.9 % vs. 52.0 % (p = 0.842)], compared to those treated with 50 Gy. Adenocarcinoma was the most common histology in both groups (51.3 % and 68.4 %). Failure rates were elevated for the 50 Gy regimen [39 (34.2 %) vs. 12 (8.5 %)]. Three year control rates were (66.3 % vs. 96.6 %; p = 0.002) local control; (63.3 % vs. 94.4 %; p = 0.000) regional control; and (65.7 % vs. 97.1 %; p = 0.000) distant control, compared to those treated with 55 Gy. Conclusion Early-stage NSCLC patients treated with SBRT 55 Gy in five fractions did better in terms of local control, overall survival, and disease-free survival rates compared to the 50 Gy in five fractions group.

Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology

PURPOSE

To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung.

MATERIALS AND METHODS

A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 63 studies, including existing systematic reviews and meta-analysis, retrospective cohort studies, and single-arm trials were identified. The expert writing group developed and agreed on 7 recommendations on the use of image-guided thermal ablation in the lung.

CONCLUSION

SIR considers image-guided thermal ablation to be an acceptable treatment option for patients with inoperable Stage I NSCLC, those with recurrent NSCLC, as well as patients with metastatic lung disease.

Heating technology for malignant tumors: a review

The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

Society of Interventional Radiology Quality Improvement Standards on Percutaneous Ablation of Non-Small Cell Lung Cancer and Metastatic Disease to the Lungs

PURPOSE

To provide guidance on quality improvement thresholds for outcomes and complications of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease.

MATERIALS AND METHODS

A multidisciplinary writing group conducted a comprehensive literature search to identify studies on the topic of interest. Data were extracted from relevant studies and thresholds were derived from a calculation of 2 standard deviations from the weighted mean of each outcome. A modified Delphi technique was used to achieve consensus agreement on the thresholds.

RESULTS

Data from 29 studies, including systematic reviews and meta-analyses, retrospective cohort studies, and single-arm trials were extracted for calculation of the thresholds. The expert writing group agreed on thresholds for local control, overall survival and adverse events associated with image-guided thermal ablation.

CONCLUSION

SIR recommends utilizing the indicator thresholds to review and assess the efficacy of ongoing quality improvement programs. When performance falls above or below specific thresholds, consideration of a review of policies and procedures to assess for potential causes, and to implement changes in practices, may be warranted.

Is There a Role for Percutaneous Ablation for Early Stage Lung Cancer? What Is the Evidence?

PURPOSE OF REVIEW

For patients with early stage non-small-cell lung cancer (NSCLC), thermal ablation (TA) has become in the least two decades an option of treatment used worldwide for patients with comorbidities who are not surgical candidates. Here, we review data published with different TA techniques: radiofrequency ablation (RFA), microwave ablation (MWA) and cryoablation. This paper reviews also the comparison that has been made between TA and stereotactic radiotherapy (SBRT).

RECENT FINDINGS

A majority of retrospective studies, the absence of comparative studies, and the variety of techniques make difficult to get evident data. Nevertheless, these stand-alone techniques have demonstrated local efficacy for tumors less than 3 cm and good tolerance on fragile patients. Many recent reviews and database analyses show that outcomes after TA (mainly RFA and MWA) are comparable to SBRT in terms of survival rates. For patients who are unfit for surgery, TA has demonstrated interesting results for safety, benefits in overall survival, and acceptable local control.

Long-Term Outcomes From a Phase 2 Trial of Radiofrequency Ablation Combined With External Beam Radiation Therapy for Patients With Inoperable Non-Small Cell Lung Cancer

PURPOSE

Long-term outcomes after external beam radiation therapy (EBRT) and radiofrequency ablation (RFA) for medically inoperable early-stage non-small cell lung cancer (NSCLC) are not well known.

METHODS AND MATERIALS

Patients with medically inoperable early-stage NSCLC were enrolled in a prospective single-arm, phase 2 study between June 2007 and October 2008 and were treated with RFA followed by EBRT. Radiation was delivered using hypofractionated radiation therapy (HFRT; 70.2 Gy in 26 fractions) or stereotactic body radiation therapy (54 Gy in 3 fractions).

RESULTS

Twelve patients were evaluable; 10 patients were treated with HFRT. The cumulative incidence of local progression at 5 years was 16.7% (95% confidence interval [CI], 0-37.8). Median progression-free survival was 37.8 months (95% CI, 11.1 to not reached) and median overall survival was 53.6 months (95% CI, 21.0 to not reached). There were no mortalities within 30 days after RFA and no grade ≥4 toxicity.

CONCLUSIONS

The combination of RFA with EBRT appears feasible with favorable long-term local control. However, because SBRT alone has similar or better rates of control, we do not recommend routine combined RFA and EBRT.

Effectiveness of Thermal Ablation and Stereotactic Radiotherapy Based on Stage I Lung Cancer Histology

PURPOSE

To assess whether the effectiveness of thermal ablation (TA) and stereotactic body radiotherapy (SBRT) as initial treatments for stage I lung cancer varies depending on the histological subtype.

MATERIALS AND METHODS

The 2004-2016 National Cancer Database was queried for patients with American Joint Committee on Cancer stage I lung cancer treated with TA or SBRT. Patients <18 years, those treated with surgery or chemotherapy, or those with unknown survival and follow-up were excluded. TA and SBRT patients were 1:5 propensity score matched separately for each histological subtype to adjust for confounders. Overall survival (OS) was assessed using Cox models.

RESULTS

A total of 28,425 patients were included (SBRT, n = 27,478; TA, n = 947). TA was more likely to be used in Caucasian patients, those with more comorbidities and smaller neuroendocrine tumors (NETs) of the lower lobe, and those whose treatment had taken place in the northeastern United States. After propensity score matching, a cohort with 4,085 SBRT and 817 TA patients with balanced confounders was obtained. In this cohort, OS for TA and SBRT was comparable (hazard ratio = 1.07; 95% confidence interval,0.98-1.18; P = .13), although it varied by histological subtypes: higher OS for TA was observed in patients with non-small cell NETs (vs SBRT hazard ratio = 0.48; 95% confidence interval, 0.24-0.95; P = .04). No significant OS differences between TA and SBRT were noted for adenocarcinomas, squamous cell carcinomas, small cell carcinomas, and non-neuroendocrine large cell carcinomas (each, P > .1).

CONCLUSIONS

OS following TA and SBRT for stage I lung cancer is comparable for most histological subtypes, except that OS is longer after TA in non-small cell NETs.

Radiofrequency ablation vs. stereotactic body radiotherapy for stage IA non-small cell lung cancer in nonsurgical patients

Background: Approximately 20% resectable non-small cell lung cancer (NSCLC) patients are treated non-surgically due to various reasons. The aim of the present study was to compare the effectiveness of radiofrequency ablation (RFA) and stereotactic body radiotherapy (SBRT) in patients with stage IA NSCLC who were ineligible for surgery using the surveillance, epidemiology and end-results (SEER) Database.

Methods: Using the SEER registry, we identified a total of 6,195 IA NSCLC patients who received SBRT or RFA between 2004 and 2015 because of ineligibility for surgical resection due to various reasons. Complete clinical information was available in all these patients. Overall survival (OS) and cancer-specific survival (CSS) were compared between RFA and SBRT groups by using propensity score matching (PSM), inverse probability of treatment weight (IPTW), and overlap weighting analysis. Additionally, an exploratory analysis was conducted to determine the effectiveness of RFA treatment based on the subsets of clinically relevant patients.

Results: Of the 6,195 nonsurgical IA NSCLC patients, 191 patients (3.1%) received RFA and the other 6,004 patients (96.9%) received SBRT. The one-, three- and five-year OS in the unmatched RFA and SBRT groups were 83.3%, 48.5%and 29.1% vs. 83.8%, 48.3% and 27.4%, respectively, there was similar results in the PSM, IPTW, overlap weighing analysis. Nonsurgical IA NSCLC patients receiving RFA seemed to have better five-year survival than those receiving SBRT, though the difference was not statistically significant (OS, HR; 0.986; 95% CI, 0.827-1.175, P=0.8738; CSS, HR; 0.965; 95% CI, 0.765-1.219, P=0.7663). We found that the odds of receiving RFA decreased with larger tumor size (>2, <3 cm, OR; 0.303; 95% CI, 0.191-0.479; >3 cm, OR; 0.153; 95% CI, 0.093-0.251) compared with tumor size <1 cm. In subgroup analysis, patients receiving RFA seemed to have better OS than those receiving SBRT, though the difference was not statistically significant. This specific trend was even more obvious in patients with tumors <1cm in diameter (P=0.1577).

Conclusion: In comparison with SBRT, RFA did not seem to adversely affect CSS and OS of IA NSCLC patients who were not suitable for surgical treatment. In addition, RFA seemed to offer better survival to IA NSCLC patients, especially those with tumors <1 cm.

Clinical and dosimetric predictors of radiation pneumonitis in early-stage lung cancer treated with Stereotactic Ablative radiotherapy (SABR) - An analysis of UK's largest cohort of lung SABR patients

BACKGROUND

Stereotactic Ablative Radiotherapy (SABR) is the standard treatment for early-stage medically inoperable lung cancer. Predictors of radiation pneumonitis (RP) in patients treated with SABR are poorly defined. In this study, we investigate clinical and dosimetric parameters, which can predict symptomatic RP in early-stage lung cancer patients treated with SABR.

MATERIALS AND METHODS

Patients treated with lung SABR between May 2009 and August 2018, in a single United Kingdom (UK) radiotherapy center were included. The patient's baseline characteristics, treatment details, and toxicity were retrieved from the electronic medical record. Dosimetric data was extracted from Xio and Monaco treatment planning systems. Patients were treated according to the UK SABR consortium guidelines. RP was graded retrospectively using Common Terminology Criteria for Adverse Events (CTCAE) version 4.0, based on available clinical and imaging information. Univariate and multivariate binary logistic regression was performed to determine predictive factors for grade ≥ 2 radiation pneumonitis, using Statistical Package for the Social Sciences (SPSS) statistics version 21 software. The goodness of fit was assessed using the Hosmer and Lemeshow test. The optimal diagnostic threshold was tested using the Receiver operating characteristics (ROC) curve. The chi-square test was carried out to test the different risk factors against the likelihood of developing grade ≥ 2 pneumonitis.

RESULTS

A total of 1266 patients included in the analysis. The median age of patients was 75 years. Six hundred sixty-six patients (52.6%) were female. Median follow up was 56 months. Sixty-five percent of patients received 55 Gy in 5 fractions. Forty-three percent of patients had Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 2 and 16.2% had PS of 3. The Median Charlson comorbidity index was 6 (range 2-11). Median Standardized Uptake Value (SUV) max of the tumor was 6.5. Four hundred two patients (31.8%) had confirmed histological diagnosis; other patients were treated based on a radiological diagnosis. The median tumor size was 20 mm (range 4 mm-63 mm). Median Planning Target Volume (PTV) was 30.3 cc. Median values of R100, R50, and D2cm were 1.1, 5.6, 32.8 Gy. The median value of mean lung dose, V20, and V12.5 were 3.9 Gy, 5 %and 9.3% respectively. Eighty-five (6.7%) patients developed symptomatic RP (grade ≥ 2) with only 5(0.4%) developing grade 3 RP. Five percent of patients developed rib fractures but only 28% of these were symptomatic. On univariate analysis lower lobe tumor location, larger tumor size, PTV, mean lung dose, lung V20Gy, and V12.5 Gy were significantly associated with grade ≥ 2 RP. On multivariate analysis, only mean lung dose was associated with grade ≥ 2 pneumonitis. ROC curve analysis showed optimal diagnostic threshold for tumour size, PTV, mean lung dose, V20 and V12.5; are 22.5 mm ((Area Under Curve (AUC)-0.565)), 27.15 cc (AUC-0.58), 3.7 Gy (AUC-0.633), 4.6% (AUC-0.597), 9.5% (AUC-0.616). The incidence of ≥grade 2 RP was significantly high for values higher than the ROC threshold.

CONCLUSION

SABR treatment resulted in a very low rate of grade 3 pneumonitis. Lower lobe tumor location, larger tumor size, PTV, mean lung dose, V20, and V12.5 were found to be significant predictors of symptomatic radiation pneumonitis.

Computerized tomography-Guided Microwave Ablation of Patients with Stage I Non-small Cell Lung Cancers: A Single-Institution Retrospective Study

Objectives:

The objective of the study was to retrospectively investigate the safety and efficacy of computerized tomography-guided microwave ablation (MWA) in the treatment of Stage I non-small cell lung cancers (NSCLCs).

Material and Methods:

This retrospective, single-center study evaluated 21 patients (10 males and 11 females; mean age 73.8 ± 8.2 years) with Stage I peripheral NSCLCs treated with MWA between 2010 and 2020. All patients were surveyed for metastatic disease. Clinical success was defined as absence of FDG avidity on follow-up imaging. Tumor growth within 5 mm of the original ablated territory was defined as local recurrence. Welch t-test and Fisher’s exact test were used for univariate analysis. Hazard ratio (HR) and odds ratio (OR) were determined using Cox regression and Firth logistic regression. Significance was P < 0.05. Data are expressed as mean ± standard deviation.

Results:

Ablated tumors had longest dimension 17.4 ± 5.4 mm and depth 19.7 ± 15.1 mm from the pleural surface. Median follow-up was 20 months (range, 0.6–56 months). Mean overall survival (OS) following lung cancer diagnosis or MWA was 26.2 ± 15.4 months (range, 5–56 months) and 23.7 ± 15.1 months (range, 3–55 months). OS at 1, 2, and 5 years was 67.6%, 61.8%, and 45.7%, respectively. Progression-free survival (PFS) was 19.1 ± 16.2 months (range, 1–55 months). PFS at 1, 2, and 5 years was 44.5%, 32.9%, and 32.9%, respectively. Technical success was 100%, while clinical success was observed in 95.2% (20/21) of patients. One patient had local residual disease following MWA and was treated with chemotherapy. Local control was 90% with recurrence in two patients following ablation. Six patients (28.6%) experienced post-ablation complications, with pneumothorax being the most common event (23.8% of patients). Female gender was associated with 90% reduction in risk of death (HR 0.1, P = 0.014). Tumor longest dimension was associated with a 10% increase in risk of death (P = 0.197). Several comorbidities were associated with increased hazard. Univariate analysis revealed pre-ablation forced vital capacity trended higher among survivors (84.7 ± 15.2% vs. 73 ± 21.6%, P = 0.093). Adjusted for age and sex, adenocarcinoma, and neuroendocrine histology trended toward improved OS (OR: 0.13, 0.13) and PFS (OR: 0.88, 0.37) compared to squamous cell carcinoma.

Conclusion:

MWA provides a safe and effective alternative to stereotactic brachytherapy resulting in promising OS and PFS in patients with Stage I peripheral NSCLC. Larger sample sizes are needed to further define the effects of underlying comorbidities and tumor biology.

Alternatives to Surgery for Early-Stage Non-Small Cell Lung Cancer: Thermal Ablation

Thermal ablation involves the application of heat or cold energy to the lung under image guidance to eradicate tumors. It is indicated for treatment of early-stage non-small cell lung cancer in nonsurgical patients. Ablation technologies have advanced, such that nearly all small tumors can now be treated safely and effectively. Ablation does not cause a lasting decline in pulmonary function tests and may therefore be used to treat multiple synchronous and metachronous lung tumors, a chief advantage over other treatments. Large series with intermediate- and long-term data have been reported showing favorable overall survival, similar to radiation therapy.

Long-term Survival Results following Endobronchial RF Ablation in a Healthy-Porcine Model

This paper presents results from long-term survival study where healthy swine were ablated with a novel technology designed for treating early-stage non-small cell lung cancer using an endobronchial flexible catheter.Methods - The radiofrequency ablation (RFA) system has been presented previously and consisted of an ablation catheter, radiofrequency generator, irrigation pump for infusion of hypertonic saline (HS) and a laptop. The catheter carried an occlusion balloon, a 5 mm long RF electrode, with irrigation holes, and a 1 mm long electrode for bipolar impedance measurements. The outer diameter (OD) was 1.4 mm for compatibility with current bronchoscopes, navigation systems and radial EBUS. Nine swine were treated in this study with survival times of 1, 4 and 12 weeks (N=3 at each time point). In all animals, the treatment sites consisted of one location in the upper right lung (RUL) and another one in the lower right lung (RLL). CTs were taken pre-op, immediately post-op and at every 2 weeks post treatment. Ablation times ranged from 6 to 8 min and average applied power was 68 W (range 63 - 72 W).Results - At 1-week survival, large zones of necrotic tissue were observed in all respective 6 ablations. Ablation volumes had an average diameter of 3.2 cm at RUL locations and 3.8 cm in RLLs (likely due to longer RLL ablation durations). As time progressed, the necrotic tissue was gradually replaced with fibrotic tissue. At 4-week survival, the replacement was almost complete in all respective 3 animals. As a result, ablation volumes decreased to an average diameter of 1.3 cm at RUL locations and 2.3 cm in RLLs (likely due to longer RLL ablation durations). At 12-week survival, as the replacement process continued, histopathology revealed zones of residual necrotic tissue that were further reduced in size. Ablation zones had been resorbed and contracted by fibrous scar tissue. The average volume of the treatment effect decreased to 1.1 cm (RUL) and to 1.6 cm (RLL) in equivalent diameter. There were no complications in any of the nine animals.Conclusion - In healthy swine lungs, RFA with a 1.4-mm OD, radial-EBUS-sheath-compatible, endobronchial catheter was effective and safe. This system and therapeutic approach may be considered for further evaluation in minimally invasive treatment of tumorous lung nodules.

Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society Guidelines for the Diagnosis and Management of Patients With Lung Neuroendocrine Tumors: An International Collaborative Endorsement and Update of the 2015 European Neuroendocrine Tumor Society Expert Consensus Guidelines

Lung neuroendocrine tumors (LNETs) are uncommon cancers, and there is a paucity of randomized evidence to guide practice. As a result, current guidelines from different neuroendocrine tumor societies vary considerably. There is a need to update and harmonize global consensus guidelines. This article reports the best practice guidelines produced by a collaboration between the Commonwealth Neuroendocrine Tumour Research Collaboration and the North American Neuroendocrine Tumor Society. We performed a formal endorsement and updating process of the 2015 European Neuroendocrine Tumor Society expert consensus article on LNET. A systematic review from January 2013 to October 2017 was conducted to procure the most recent evidence. The stepwise endorsement process involved experts from all major subspecialties, patients, and advocates. Guided by discussion of the most recent evidence, each statement from the European Neuroendocrine Tumor Society was either endorsed, modified, or removed. New consensus statements were added if appropriate. The search yielded 1109 new publications, of which 230 met the inclusion criteria. A total of 12 statements were endorsed, 22 statements were modified or updated, one was removed, and two were added. Critical answered questions for each topic in LNET were identified. Through the consensus process, guidelines for the management of patients with local and metastatic neuroendocrine tumors have been updated to include both recent evidence and practice changes relating to technological and definitional advances. The guidelines provide clear, evidence-based statements aimed at harmonizing the global approach to patients with LNETs, on the basis of the principles of person-centered and LNET-specific care. The importance of LNET-directed research and person-centered care throughout the diagnosis, treatment, and follow-up journey is emphasized along with directions for future collaborative research.

Cost-Effectiveness Analysis of Stereotactic Ablative Body Radiation Therapy Compared With Surgery and Radiofrequency Ablation in Two Patient Cohorts: Metastatic Liver Cancer and Hepatocellular Carcinoma

AIMS

To compare the cost-effectiveness of stereotactic ablative body radiation therapy (SABR) with radiofrequency ablation and surgery in adult patients with metastatic liver cancer and hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Two patient cohorts were assessed: liver oligometastases and HCC. For each patient cohort, a decision analytic model was constructed to assess the cost-effectiveness of interventions over a 5-year horizon. A Markov process was embedded in the decision model to simulate the possible prognosis of cancer. Data on transition probabilities, survival, side-effects, quality of life and costs were obtained from published sources and the SABR Commissioning through Evaluation (CtE) scheme. The primary outcome was the incremental cost-effectiveness ratio with respect to quality-adjusted life-years. The robustness of the results was examined in a sensitivity analysis. Analyses were conducted from a National Health Service and Personal Social Services perspective.

RESULTS

In the base case analysis, which assumed that all three interventions were associated with the same cancer progression rates and mortality rates, SABR was the most cost-effective intervention for both patient cohorts. This conclusion was sensitive to the cancer progression rate, mortality rate and cost of interventions. Assuming a willingness-to-pay threshold of £20 000 per quality-adjusted life-year, the probability that SABR is cost-effective was 57% and 50% in liver oligometastases and HCC, respectively.

CONCLUSIONS

Our results indicate a potential for SABR to be cost-effective for patients with liver oligometastases and HCC. This finding supports further investigation in clinical trials directly comparing SABR with surgery and radiofrequency ablation.

[Advances and Challenges of Local Thermal Ablation in Non-small Cell Lung Cancer]

非小细胞肺癌（non-small cell lung cancer, NSCLC）是原发性肺癌的主要类型，手术切除、放化疗、靶向治疗及免疫治疗等是其主要的治疗模式。近年来，热消融在各期NSCLC的临床应用中受到越来越多的关注。热消融作为一种安全、高效的局部治疗手段，合理的临床应用可以给NSCLC患者带来更多的临床获益。然而其在NSCLC中的应用仍然存在许多尚待研究探讨的问题。本文对近年来热消融在NSCLC中的应用现状作以综述，旨在探讨目前存在的争议问题和未来研究方向。

Comorbidity and early death in Danish stage I lung cancer patients - an individualised approach

Background: Comorbidity is an important prognostic marker and a treatment indicator for lung cancer patients. Register-based studies often describe the burden of comorbidity by the Charlson comorbidity index (CCI) based on hospital discharge data. We assessed the association between somatic and psychiatric comorbidity and death within one year in early lung cancer and, furthermore, the burden of comorbidity according to treatment type.Material and methods: We conducted a population-based matched case-control study of stage I lung cancer identifying all treated patients who died (all-cause) within one year after diagnosis (early death group, cases). On the basis of data from the Danish Lung Cancer Registry these patients were then matched with two controls who survived more than one year (survivors). Through a review of the medical records, we validated inclusion criteria and collected data on somatic and psychiatric comorbidity. We assessed the association between comorbidity and early death with multivariate conditional logistic regression.Results: We included 221 cases and 410 controls. The mean CCI score in the early death group was 2.3 vs. 1.3 in the survivor group (p < .001). Still, 22% vs. 30% had a CCI score of zero (p = .04) with an average number of comorbidities among these patients of 1.63 vs. 1.06 respectively (p = .006). Among women, 23% in the early death group had depression vs. 13% in the survivor group, corresponding to an unadjusted odds ratio (OR) of 2.0 (CI 95% 1.0-3.7). However, in an adjusted analysis (incl. somatic comorbidities) the OR was 1.7 (CI 95% 0.8-3.5). Patients undergoing oncological therapy were older and tended to have more somatic comorbidities than the surgically treated patients.Conclusion: Comorbidity remains a significant prognostic marker even for stage I lung cancer patients with a CCI score of zero. The suggested association between early death and depression among women needs to be studied further.

Survival Outcomes of Treatment with Radiofrequency Ablation, Stereotactic Body Radiotherapy, or Sublobar Resection for Patients with Clinical Stage I Non-Small-Cell Lung Cancer: A Single-Center Evaluation

PURPOSE

To retrospectively compare the outcomes of radiofrequency (RF) ablation, stereotactic body radiotherapy (SBRT), and sublobar resection (SLR) in patients with stage I non-small-cell lung cancer (NSCLC) at a single center.

MATERIALS AND METHODS

Overall, 289 patients (38 RF ablation, 58 SBRT, and 193 SLR) were included. Kaplan-Meier curves were generated, multiple propensity score was estimated using a multinomial logistic regression model, and relationships between treatments and outcomes were assessed using a Cox proportional hazard model. Hazard ratios (HRs) for death from any cause and disease progression or death from any cause were examined by a crude model, an inverse probability of treatment weighting (IPTW) model, and an IPTW model adjusted for missing variables.

RESULTS

The 5-year overall and progression-free survival rates were 58.9% and 39.9%, respectively, for RF ablation; 42.0% and 34.9%, respectively, for SBRT; and 85.5% and 75.9%, respectively, for SLR. Significantly longer survival time and lower HR were observed for SLR than other treatments. However, after statistical adjustment, these relationships were not significant except for reduced HR of disease progression or death from any cause of SLR compared to RF ablation in the IPTW model. The median hospital stays for RF ablation, SBRT, and SLR were 6.5, 6, and 16 days, respectively. Adverse events of grade 3 or higher occurred only in 11 SLR cases.

CONCLUSIONS

SLR achieved the longest survival. However, after statistical adjustment, there were no significant outcome differences among RF ablation, SBRT, and SLR, except for 1 model. RF ablation or SBRT may be alternative treatments for selected patients with early-stage NSCLC.

Stereotactic Body Radiation Therapy of Adrenal Metastases: A Pooled Meta-Analysis and Systematic Review of 39 Studies with 1006 Patients

PURPOSE

To perform a systematic review and pooled meta-analysis of adrenal metastasis stereotactic body radiation therapy (SBRT) outcomes, treatment characteristics, and toxicity to define the efficacy and propose guidelines for intervention.

METHODS AND MATERIALS

We performed a comprehensive literature search of the Embase and PubMed databases of studies reporting outcome or toxicity data for photon-based SBRT of adrenal metastases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We then conducted a meta-analysis to estimate pooled overall response, local control (LC), and overall survival and analyzed these outcomes in the context of dosimetric parameters and toxicity using metaregression.

RESULTS

Thirty-nine studies published between 2009 and 2019 reporting outcomes on 1006 patients were included. The median follow-up was 12 months, and the median biological equivalent dose (BED10, alpha/beta = 10) was 67 Gy. The pooled overall response was 54.6% (95% confidence interval [CI], 46.5%-62.5%). The pooled 1- and 2-year rates of LC were 82% (95% CI, 74%-88%) and 63% (95% CI, 50%-74%), respectively, and the pooled 1- and 2-year overall survival rates were 66% (95% CI, 57%-74%) and 42% (95% CI, 31%-53%), respectively. There was a strong positive association between SBRT dose and 1- and 2-year LC (P < .0001, P = .0002) and an association with 2-year OS (P = .03). Based on a metaregression of dose and LC, BED10 of 60 Gy, 80 Gy, and 100 Gy predicted 1-year LC of 70.5%, 84.8%, and 92.9% and 2-year LC of 47.8%, 70.1%, and 85.6%, respectively. The overall rate of grade 3 or higher toxicity was 1.8%.

CONCLUSIONS

SBRT of adrenal metastases provides good 1-year LC with an excellent safety profile, and dose escalation may be associated with improved LC. Prospective studies are needed to validate these findings and determine whether there are subsets of patients for whom adrenal metastasis-directed SBRT may confer a survival advantage.