Salvage Therapy for Locoregional Recurrence After Stereotactic Ablative Radiotherapy for Early-Stage NSCLC

Evaluation of chest CT-scans following lung stereotactic ablative radiotherapy: Challenges and new insights

Stereotactic ablative radiotherapy (SABR) is increasingly used for the treatment of early-stage non-small cell lung cancer (ES-NSCLC) and for pulmonary metastases. In patients with ES-NSCLC, SABR is highly successful with reported 5-year local control rates of approximately 90%. However, the assessment of local control following lung SABR can be challenging as radiological changes arising from radiation-induced lung injury (RILI) can be observed in up to 90% of patients. These so-called 'benign' radiological changes evolve with time and are often asymptomatic. Several radiological and metabolic features have been explored to help distinguish RILI from local recurrences (LR). These include the Response Evaluation Criteria for Solid Tumors (RECIST), high-risk features (HRF's) and maximum standardized uptake value (SUVmax) on FDG-PET-CT. However, use of some of these approaches have poor predictive values and low specificity for recurrence. A proposed new workflow for the evaluation of post-lung SABR radiological changes will be reviewed which uses the presence of so-called 'actionable radiological features' to trigger changes to imaging schedules and identifies the need for a multidisciplinary board review. Furthermore, this critical review of post-lung SABR imaging will highlight current challenges, new insights, and unknowns in this field.

Multimodality Management of Thoracic Tumors: Initial Experience With a Multidisciplinary Thoracic Ablation Conference

BACKGROUND

This study aimed to describe lesion-specific management of thoracic tumors referred for consideration of image-guided thermal ablation (IGTA) at a newly established multidisciplinary ablation conference.

METHODS

This retrospective single-center cohort study included consecutive patients with non-small cell lung cancer (NSCLC) or thoracic metastases evaluated from June 2020 to January 2022 in a multidisciplinary conference. Outcomes included the management recommendation, treatments received (IGTA, surgical resection, stereotactic body radiation therapy [SBRT], multimodality management), and number of tumors treated per patient. Pearson's chi-square test was used to assess for a change in management, and Poisson regression was used to compare the number of tumors by treatment received.

RESULTS

The study included 172 patients (58 % female; median age, 69 years; 56 % thoracic metastases; 27 % multifocal primary lung cancer; 59 % ECOG 0 [range, 0-3]) assessed in 206 evaluations. For the patients with NSCLC, IGTA was considered the most appropriate local therapy in 12 %, equal to SBRT in 22 %, and equal to lung resection in 3 % of evaluations. For the patients with thoracic metastases, IGTA was considered the most appropriate local therapy in 22 %, equal to SBRT in 12 %, and equal to lung resection in 3 % of evaluations. Although all patients were referred for consideration of IGTA, less than one third of patients with NSCLC or thoracic metastases underwent IGTA (p < 0.001). Multimodality management allowed for treatment of more tumors per patient than single-modality management (p < 0.01).

CONCLUSIONS

Multidisciplinary evaluation of patients with thoracic tumors referred for consideration of IGTA significantly changed patient management and facilitated lesion-specific multimodality management.

Salvage percutaneous high-dose-rate brachyablation after stereotactic body radiation therapy for early-stage non-small cell lung cancer

Patients with primary tumor progression after stereotactic body radiation therapy (SBRT) for stage I non-small cell lung cancer (NSCLC) have a second chance at complete tumor eradication with salvage local therapies, including lung resection, repeat course of SBRT, and percutaneous ablative therapies. In this paper, we presented our institution's initial experience with percutaneous high-dose-rate (HDR) brachyablation for a relapsed stage I NSCLC that had been treated with SBRT 4.3 years earlier. Lung tumor measuring approximately 5 cm in maximum tumor dimension at the time of relapse was histopathologically confirmed to be persistent squamous cell carcinoma, and successfully treated with a single fraction of 24 Gy with HDR brachyablation. Treatment was delivered via two percutaneous catheters inserted under CT-guidance, and treated in less than 20 minutes. The patient was discharged home later the same day without the need for a chest tube, and has been monitored with serial surveillance scans every 3 to 6 months without evidence of further lung cancer progression or complications at 2.8 years post-HDR brachyablation procedure and 7.8 years after initial SBRT.

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.

Radiotherapy modification based on artificial intelligence and radiomics applied to (18F)-fluorodeoxyglucose positron emission tomography/computed tomography

Over the last decades, the refinement of radiation therapy techniques has been associated with an increasing interest for individualized radiation therapy with the aim of increasing or maintaining tumor control and reducing radiation toxicity. Developments in artificial intelligence (AI), particularly machine learning and deep learning, in imaging sciences, including nuclear medecine, have led to significant enthusiasm for the concept of "rapid learning health system". AI combined with radiomics applied to (18F)-fluorodeoxyglucose positron emission tomography/computed tomography ([18F]-FDG PET/CT) offers a unique opportunity for the development of predictive models that can help stratify each patient's risk and guide treatment decisions for optimal outcomes and quality of life of patients treated with radiation therapy. Here we present an overview of the current contribution of AI and radiomics-based machine learning models applied to (18F)-FDG PET/CT in the management of cancer treated by radiation therapy.

Regional lymph node recurrence after stereotactic body radiation therapy for lung cancer: Patterns of recurrence, treatment approaches, and clinical outcomes (KROG 21-09)

PURPOSE

To present the multi-institutional data on patterns of recurrence, treatment approaches, and clinical outcomes for regional lymph node (LN) recurrence after stereotactic body radiation therapy (SBRT) for primary lung cancer.

MATERIALS AND METHODS

The medical records of 114 patients who experienced regional LN recurrence as the first recurrence after lung SBRT were retrospectively reviewed. Patterns of recurrence were classified as local recurrence, regional recurrence, and distant metastasis. Clinical outcomes including progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

Half of the patients had regional LN recurrence only. The most common simultaneous recurrence was distant metastasis (38.6 %). Common sites of regional recurrence were ipsilateral hilar (47.2 %), ipsilateral upper mediastinal (40.6 %), and subcarinal (42.5 %) LN stations. 24 (21.1 %) patients underwent salvage radiation therapy (RT), and 44 (38.6 %) patients underwent palliative treatment. Better OS was observed in the salvage RT group (p = 0.025). The 1-year PFS and OS rates were 27.7 % and 55.2 %, respectively, with salvage RT, 14.0 % and 39.9 %, respectively, with palliative treatment, and 22.8 % and 26.8 %, respectively, with no additional treatment. Multivariate analysis showed that salvage RT (PFS, HR 0.463, p = 0.050; OS, HR 0.312, p = 0.002), palliative treatment (PFS, HR 0.436, p = 0.013; OS, HR 0.553, p = 0.050), and simultaneous distant metastasis (PFS, HR 2.335, p = 0.005; OS, HR 1.726, p = 0.054) affected clinical outcomes.

CONCLUSION

Many cases of regional LN recurrence are confined to the locoregional area of patients, and appropriate treatment can improve the prognosis of these patients.

Salvage surgery in lung cancer following definitive therapies

Salvage surgery refers to operative resection of persistent or recurrent disease in patients initially treated with intention-to-cure nonoperative management. In non-small-cell lung cancer, salvage surgery may be effective in treating selected patients with locally progressive tumors, recurrent local or locoregional disease, or local complications after nonoperative therapy. Importantly, those patients who may be candidates for salvage surgery are evolving, in terms of disease stage as well as the types of attempted definitive therapy received.

Local thermal ablative therapies for extracranial oligometastatic disease of non-small-cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Clinically, 40-50% of patients with NSCLC are found to have systemic metastasis at the initial diagnosis. Meanwhile, 30-75% of patients with lung cancer who have undergone radical surgical resection have local recurrence and distant metastases. However, not all distant metastases are multiple, and some are potentially curable. In this study, among the patients with NSCLC having distant organ metastasis, approximately 7% showed extrapulmonary solitary metastasis and remained in this relatively stable state for a long time. This form of metastasis is known as NSCLC oligometastases. This review describes the concept and classification of oligometastases, as well as the local treatment and prognosis of extracranial oligometastases.

Oligorecurrent Non-Small-Cell Lung Cancer Treated by Chemo-Radiation Followed by Immunotherapy and Intracranial Radiosurgery: A Case Report and Mini Review of Literature

Locally advanced non-small-cell lung cancer still represents a "grey zone" in terms of the best treatment choice and optimal clinical outcomes. Indeed, most patients may be suitable to receive different treatments with similar outcomes such as chemo-radiotherapy (CHT-RT) followed by immunotherapy (IO) or surgery followed by adjuvant local/systemic therapies. We report a clinical case of a patient submitted to primary thoracic surgery who developed a mediastinal nodal recurrence successfully treated by CHT-RT-IO. Subsequently, a single brain lesion was found to have been successfully treated by single fraction stereotactic ablative radiotherapy. The patient is still on follow-up and she is free from disease having a good quality of life. In this report, we also perform a mini review about the role of CHT-RT followed by IO in treating loco-regional relapse after surgery. The role of SABR after IO is also evaluated, finding that it is safe and well tolerated. More robust and larger clinical data are needed in this particular setting to better define the role of the combination of systemic and local treatments in the management of intrathoracic and intracranial relapse for patients already submitted to CHT-RT followed by immunotherapy.

Stereotactic body proton therapy for non-small cell lung cancer: Clinical indications and recommendations

Stereotactic body radiation therapy (SBRT) has emerged as a standard treatment approach for early-stage lung cancer and intrathoracic oligometastatic or oligoprogressive disease. While local control is often excellent with this modality when delivered with photon therapy, toxicities for select patients can be significant. Proton therapy offers a unique opportunity to widen the therapeutic window when treating patients with thoracic malignancies requiring or benefitting from ultra-high doses per fraction. Thoracic proton SBRT may be particularly beneficial in cases requiring dose escalation, for tumors >5 cm, for central or ultra-central tumors, for reirradiation, in patients with interstitial lung diseases, and when combining radiation with immunotherapy. These clinical indications are detailed, along with supporting literature and clinical recommendations. Other considerations, future directions and potential benefits of proton SBRT, including sparing lymphocytes, when delivered as intensity-modulated proton therapy or as FLASH, and for the treatment of locally advanced non-small cell lung cancer or in patients with homologous recombination repair deficiencies, are also discussed.

Isolated Nodal Recurrence After Definitive Stereotactic Ablative Radiation Therapy for Non-Small Cell Lung Cancer

PURPOSE

Stereotactic ablative radiation therapy (SABR) results in high rates of primary tumor control for early-stage non-small cell lung cancer (NSCLC). For patients with isolated hilar or mediastinal nodal recurrence (INR) after SABR, the optimal salvage treatment strategy is unclear. The purpose of this study was to determine the rate of INR after SABR for early-stage NSCLC and to describe patterns of care and treatment outcomes after salvage therapy.

METHODS AND MATERIALS

This retrospective cohort study included 342 patients with stage T1-3N0M0 NSCLC treated with definitive SABR from 2003 to 2018. We evaluated the incidence of INR and baseline factors between patients who did and did not experience INR. Among patients who experienced INR, we described treatment patterns and outcomes including overall survival (OS) and progression free survival (PFS) from the time of nodal failure using the Kaplan-Meier method.

RESULTS

With a median follow-up of 3.3 years, the 3-year INR rate was 10.6% (95% CI, 6.6%-13.4%). Among the 34 patients experiencing INR, the 3-year rates of OS and PFS were 39.3% (24.4%-63.3%) and 26.7% (14.1%-0.3%), respectively. The 34 patients with INR were treated with radiation therapy alone (26.7%), concurrent chemoradiation therapy (43.3%), chemotherapy alone (13.3%), or observation (16.7%). Patients treated with concurrent chemoradiation therapy had the best survival outcomes, with a 3-year OS and PFS of 81.5% (61.1%-100.0%) and 63.9% (40.7%-100.0%), respectively. Of the patients treated with salvage radiation therapy or concurrent chemoradiation therapy, 14.3% experienced grade 3 toxic effects, and no patients had grade ≥4 toxic effects.

CONCLUSIONS

In this study, INR occurred in approximately 10% of patients treated with SABR for early-stage NSCLC. The highest rates of OS and PFS among patients with INR were observed in those treated with salvage chemoradiation therapy.

Stereotactic Ablative Radiotherapy in the Treatment of Early-Stage Lung Cancer - A Done Deal?

Stereotactic ablative radiotherapy (SABR) is an important curative-intent treatment option for early-stage non-small cell lung cancer. It offers good cancer control without invasive surgery and has become the standard of care for medically inoperable patients. The literature on SABR for early-stage non-small cell lung cancer is substantial and continues to grow. However, there remain areas of controversy where data are limited - notably the use of SABR in medically operable patients. Other areas of some debate include the treatment of central/ultra-central and large (>5 cm) lesions, as well as treatment with co-existing interstitial lung disease. This review article provides an overview of the current literature together with a discussion of future directions.

[Stereotactic radiotherapy for localized primary lung tumours of stage T1-T2]

The historical treatment for stage I non-small cell lung cancer is surgical. Parenchymal amputation is not always possible due to cardiopulmonary comorbidities and stereotactic radiotherapy is one of the alternatives to an invasive procedure. The excellent results observed for inoperable tumors raised the question of this treatment in operable patients. This article presents the data in these two situations and the future perspectives.

[18F]FDG-PET/CT radiomics and artificial intelligence in lung cancer: Technical aspects and potential clinical applications

Lung cancer is the second most common cancer and the leading cause of cancer-related death worldwide. Molecular imaging using [¹⁸F]fluorodeoxyglucose Positron Emission Tomography and/or Computed Tomography ([¹⁸F]FDG-PET/CT) plays an essential role in the diagnosis, evaluation of response to treatment, and prediction of outcomes. The images are evaluated using qualitative and conventional quantitative indices. However, there is far more information embedded in the images, which can be extracted by sophisticated algorithms. Recently, the concept of uncovering and analyzing the invisible data extracted from medical images, called radiomics, is gaining more attention. Currently, [¹⁸F]FDG-PET/CT radiomics is growingly evaluated in lung cancer to discover if it enhances the diagnostic performance or implication of [¹⁸F]FDG-PET/CT in the management of lung cancer. In this review, we provide a short overview of the technical aspects, as they are discussed in different articles of this special issue. We mainly focus on the diagnostic performance of the [¹⁸F]FDG-PET/CT-based radiomics and the role of artificial intelligence in non-small cell lung cancer, impacting the early detection, staging, prediction of tumor subtypes, biomarkers, and patient's outcomes.

Quantifying the rate and predictors of occult lymph node involvement in patients with clinically node-negative non-small cell lung cancer

PURPOSE

It is essential to evaluate the risk of occult lymph node (LN) disease in early-stage non-small cell lung cancer (NSCLC), especially because delivering stereotactic ablative radiotherapy (SABR) assumes no occult spread. This study was designed to assist clinicians in roughly quantifying this risk for cN0 NSCLC.

METHODS

The National Cancer Data Base was queried for cN0 cM0 lung squamous cell or adenocarcinoma who underwent surgery and LN dissection without neoadjuvant therapy. Statistics included multivariable logistic regression to evaluate factors associated with pN + disease.

RESULTS

109,964 patients were included. For tumors with size ≤1.0, 1.1-2.0, 2.1-3.0, 3.1-4.0, 4.1-5.0, 5.1-6.0, 6.1-7.0, and >7.0 cm, the pN + rate was 4.4, 7.7, 12.9, 18.0, 20.2, 22.5, 24.4, and 26.4%, respectively. When examining patients with more complete LN dissections (defined as removal of at least 10 LNs), the respective values were 6.6, 11.5, 17.6, 25.3, 26.8, 29.7, 30.7, and 31.6%. Moderately-poorly differentiated disease and adenocarcinomas were associated with a higher rate of pN + disease (p < .001 for both). For every cm increase in tumor size, the relative occult nodal risk increased by 10-14% (p < .001). For every elapsed day from initial diagnosis, the relative risk increased by ∼1% (p < .001). Graphs with best-fit lines were created based on tumor size, histology, and differentiation to aid physicians in estimating the pN + risk.

CONCLUSIONS

This nationwide study can allow clinicians to roughly estimate the rate of occult LN disease in cN0 NSCLC. These data can also assist in guiding enrollment on randomized trials of SABR ± immunotherapy, individualizing follow-up imaging surveillance, and patient counseling to avoid post-diagnosis delays.

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.

An algorithm for thoracic re-irradiation using biologically effective dose: a common language on how to treat in a "no-treat zone"

Background

Re-irradiation (re-RT) is a technically challenging task for which few standardized approaches exist. This is in part due to the lack of a common platform to assess dose tolerance in relation to toxicity in the re-RT setting. To better address this knowledge gap and provide new tools for studying and developing thresholds for re-RT, we developed a novel algorithm that allows for anatomically accurate three-dimensional mapping of composite biological effective dose (BED) distributions from nominal doses (Gy).

Methods

The algorithm was designed to automatically convert nominal dose from prior treatment plans to corresponding BED value maps (voxel size 2.5 mm³ and α/β of 3 for normal tissue, BED₃). Following the conversion of each plan to a BED₃ dose distribution, deformable registration was used to create a summed composite re-irradiation BED₃ plan for each patient who received two treatments. A proof-of-principle analysis was performed on 38 re-irradiation cases of initial stereotactic ablative radiotherapy (SABR) followed by either re-SABR or chemoradiation for isolated locoregional recurrence of early-stage non-small cell lung cancer.

Results

Evaluation of the algorithm-generated maps revealed appropriate conversion of physical dose to BED at each voxel. Of 14 patients receiving repeat SABR, there was one case each of grade 3 chest wall pain (7%), pneumonitis (7%), and dyspnea (7%). Of 24 patients undergoing repeat fractionated radiotherapy, grade 3 events were limited to two cases each of pneumonitis and dyspnea (8%). Composite BED₃ dosimetry for each patient who experienced grade 2–3 events is provided and may help guide development of precise cumulative dose thresholds for organs at risk in the re-RT setting.

Conclusions

This novel algorithm successfully created a voxel-by-voxel composite treatment plan using BED values. This approach may be used to more precisely examine dosimetric predictors of toxicities and to establish more accurate normal tissue constraints for re-irradiation.

A systematic review into the radiological features predicting local recurrence after stereotactic ablative body radiotherapy (SABR) in patients with non-small cell lung cancer (NSCLC): Local recurrence features of NSCLC post-SABR

BACKGROUND AND PURPOSE

Post-treatment surveillance for local recurrence (LR) following SABR can include both fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT). Radiation-induced lung injury (RILI) shares a similar appearance to LR after treatment making the detection of LR on imaging difficult for clinicians. We aimed to summarise radiological features of CT and FDG-PET predicting LR, and to evaluate radiomics as another tool for detecting LR.

METHODS AND MATERIALS

We searched MEDLINE, EMBASE and PubMed databases for published studies and Web of Science, Wiley Online and Science Direct databases for conference abstracts that had patient populations with NSCLC and reported post-SABR radiological features of FDG-PET or CT and radiomics from either FDG-PET or CT. Studies for inclusion were independently reviewed by two authors.

RESULTS

Across 32 relevant studies, the incidence of LR was 13% (222/1726). On CT, certain gross radiological appearances, and kinetic features of changes in size, diameter, volume or 3 consecutive rises in volume of mass-like consolidation are suggestive of LR. Particular regard should be made for the presence of any ≥3 high-risk features (HRF) on CT or the individual HRF of enlarging opacity at ≥12 month's post-SABR as being highly suspicious of LR. On FDG-PET a relative reduction of <5% of SUV_max from baseline in the first 12 months or cut-offs of SUV_max >5 and SUV_mean >3.44 after 12 months can indicate LR. There is limited evidence available to corroborate radiomic features suggestive of LR.

CONCLUSION

This research has identified common features of LR compared to RILI which may aid in early and accurate detection of LR post-SABR; further research is required to validate these findings.

Current Management of Oligometastatic Lung Cancer and Future Perspectives: Results of Thermal Ablation as a Local Ablative Therapy

A growing body of evidence shows improved overall survival and progression-free survival after thermal ablation in non-small cell lung carcinoma (NSCLC) patients with a limited number of metastases, combined with chemotherapy or tyrosine kinase inhibitors or after local recurrence. Radiofrequency ablation and microwave ablation are the most evaluated modalities, and target tumor size <3 cm (and preferably <2 cm) is a key factor of technical success and efficacy. Although thermal ablation offers some advantages over surgery and radiotherapy in terms of repeatability, safety, and quality of life, optimal management of these patients requires a multidisciplinary approach, and further randomized controlled trials are required to help refine patient selection criteria. In this article, we present a comprehensive review of available thermal ablation modalities and recent results supporting their use in oligometastatic and oligoprogressive NSCLC disease along with their potential future implications in the emerging field of immunotherapy.

Stereotactic ablative radiotherapy for operable stage I non-small-cell lung cancer (revised STARS): long-term results of a single-arm, prospective trial with prespecified comparison to surgery

BACKGROUND

A previous pooled analysis of the STARS and ROSEL trials showed higher survival after stereotactic ablative radiotherapy (SABR) than with surgery for operable early-stage non-small-cell lung cancer (NSCLC), but that analysis had notable limitations. This study reports long-term results of the revised STARS trial, in which the SABR group was re-accrued with a larger sample size, along with a protocol-specified propensity-matched comparison with a prospectively registered, contemporary institutional cohort of patients who underwent video-assisted thoracoscopic surgical lobectomy with mediastinal lymph node dissection (VATS L-MLND).

METHODS

This single-arm prospective trial was done at the University of Texas MD Anderson Cancer Center (Houston, TX, USA) and enrolled patients aged 18 years or older with a Zubrod performance status of 0-2, newly diagnosed and histologically confirmed NSCLC with N0M0 disease (squamous cell, adenocarcinoma, large cell, or NSCLC not otherwise specified), and a tumour diameter of 3 cm or less. This trial did not include patients from the previous pooled analysis. SABR dosing was 54 Gy in three fractions (for peripheral lesions) or 50 Gy in four fractions (for central tumours; simultaneous integrated boost to gross tumour totalling 60 Gy). The primary endpoint was the 3-year overall survival. For the propensity-matching analysis, we used a surgical cohort from the MD Anderson Department of Thoracic and Cardiovascular Surgery's prospectively registered, institutional review board-approved database of all patients with clinical stage I NSCLC who underwent VATS L-MLND during the period of enrolment in this trial. Non-inferiority could be claimed if the 3-year overall survival rate after SABR was lower than that after VATS L-MLND by 12% or less and the upper bound of the 95% CI of the hazard ratio (HR) was less than 1·965. Propensity matching consisted of determining a propensity score using a multivariable logistic regression model including several covariates (age, tumour size, histology, performance status, and the interaction of age and sex); based on the propensity scores, one patient in the SABR group was randomly matched with one patient in the VATS L-MLND group using a 5:1 digit greedy match algorithm. This study is registered with ClinicalTrials.gov, NCT02357992.

FINDINGS

Between Sept 1, 2015, and Jan 31, 2017, 80 patients were enrolled and included in efficacy and safety analyses. Median follow-up time was 5·1 years (IQR 3·9-5·8). Overall survival was 91% (95% CI 85-98) at 3 years and 87% (79-95) at 5 years. SABR was tolerated well, with no grade 4-5 toxicity and one (1%) case each of grade 3 dyspnoea, grade 2 pneumonitis, and grade 2 lung fibrosis. No serious adverse events were recorded. Overall survival in the propensity-matched VATS L-MLND cohort was 91% (95% CI 85-98) at 3 years and 84% (76-93) at 5 years. Non-inferiority was claimed since the 3-year overall survival after SABR was not lower than that observed in the VATS L-MLND group. There was no significant difference in overall survival between the two patient cohorts (hazard ratio 0·86 [95% CI 0·45-1·65], p=0·65) from a multivariable analysis.

INTERPRETATION

Long-term survival after SABR is non-inferior to VATS L-MLND for operable stage IA NSCLC. SABR remains promising for such cases but multidisciplinary management is strongly recommended.

FUNDING

Varian Medical Systems and US National Cancer Institute (National Institutes of Health).

Machine Learning for the Prediction of Lymph Nodes Micrometastasis in Patients with Non-Small Cell Lung Cancer: A Comparative Analysis of Two Practical Prediction Models for Gross Target Volume Delineation

Purpose

The lymph node gross target volume (GTV) delineation in patients with non-small cell lung cancer (NSCLC) is crucial for prognosis. This study aimed to develop a predictive model that can be used to differentiate between lymph nodes micrometastasis (LNM) and non-lymph nodes micrometastasis (non-LNM).

Patients and Methods

A retrospective study involving 1524 patients diagnosed with NSCLC was collected in the First Hospital of Wuhan between January 1, 2017, and April 1, 2020. Duplicated and useless variables were excluded, and 16 candidate variables were selected for further analysis. The random forest (RF) algorithm and generalized linear (GL) algorithm were used to screen out the variables that greatly affected the LNM prediction, respectively. The area under the curve (AUC) was compared between the RF model and GL model.

Results

The RF model revealed that the variables, including pathology, degree of differentiation, maximum short diameter of lymph node, tumor diameter, pulmonary membrane invasion, clustered lymph nodes, and T stage, were more significant for LNM prediction. Multifactorial logistic regression analysis for the GL model indicated that vascular invasion, tumor diameter, degree of differentiation, pulmonary membrane invasion, and maximum standard uptake value (SUVmax) were positively associated with LNM. The AUC for the RF model and GL model was 0.83 (95% CI: 0.75 to 0.90) and 0.64 (95% CI: 0.60 to 0.70), respectively.

Conclusion

We successfully established an accurate and optimized RF model that could be used to predict LNM in patients with NSCLC. This model can be used to evaluate the risk of an individual patient experiencing LNM and therefore facilitate the choice of treatment.

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.

Developments in radiation techniques for thoracic malignancies

Radiation therapy is a cornerstone of modern lung cancer treatment alongside surgery, chemotherapy, immunotherapy and targeted therapies. Advances in radiotherapy techniques have enhanced the accuracy of radiation delivery, which has contributed to the evolution of radiation therapy into a guideline-recommended treatment in both early-stage and locally advanced nonsmall cell lung cancer. Furthermore, although radiotherapy has long been used for palliation of disease in advanced lung cancer, it is increasingly having a role as a locally ablative treatment in patients with oligometastatic disease.This review provides an overview of recent developments in radiation techniques, particularly for non-radiation oncologists who are involved in the care of lung cancer patients. Technical advances are discussed, and findings of recent clinical trials are highlighted, all of which have led to a changing perception of the role of radiation therapy in multidisciplinary care.

Applicability of the PACIFIC trial results in patients not eligible for the PACIFIC trial: Canadian rapid consensus statement and recommendations

BACKGROUND

The PACIFIC study established durvalumab as a standard of care for consolidation therapy in patients treated with radical intent chemoradiation for stage III inoperable non-small cell lung cancer. In clinical practice, many patients are not eligible for trials, yet radical intent chemoradiation may still be used.

METHODS

A virtual anonymous tumour board Delphi-model was used in order to generate consensus on the use of durvalumab in six clinical situations where chemoradiation is used in clinical practice and recommended in guidelines, yet not PACIFIC eligible. Two anonymous iterations were sent and recommendations were circulated for approval and comment. Results are presented using a modified PICOT format (patients, intervention, control, outcomes, and ongoing trials).

RESULTS

In three of the scenarios, consensus was reached and recommendations were for the use of consolidation durvalumab, but being respectful of potentially increased toxicity/reduced benefit in comparison to PACIFIC results (treatment of stage IIB inoperable, recurrent mediastinal disease, and residual gross disease post attempted surgical removal). There was a recommendation against using durvalumab in resected stage III disease with R1 or R0 margins, even if chemoradiation were considered. There was not consensus on the use of consolidation durvalumab in the setting of oligometastatic disease or in the setting of large cell neuroendocrine carcinoma or combined small cell carcinoma.

CONCLUSION

Treatment of 'real-world' lung cancer often involves chemoradiation in settings outside of stage III and eligible for the PACIFIC study. This paper offers recommendations in these scenarios based on a consensus approach.

Development of autoimmune diabetes with severe diabetic ketoacidosis and immune-related thyroiditis secondary to durvalumab: a case report

Immune-mediated endocrinopathies are among the most frequent immune-related adverse events (irAEs) with immune checkpoint inhibitors (ICIs) targeting programmed death-ligand 1 (PD-L1)/PD-1. However, the development of auto-immune diabetes is an uncommon event during PD(L)-1 blockade, either as monotherapy or in combination therapy. Here we report a case of a 75-year-old male with a mediastinal recurrence from a stage IA squamous cell carcinoma of the lung previously treated with stereotactic body radiotherapy (SBRT) who early developed a severe diabetic ketoacidosis (DKA) caused by new-onset auto-immune diabetes, with positive glutamic acid decarboxylase (GAD65) autoantibodies, during durvalumab consolidation therapy after concurrent chemoradiation. The patient had no personal or family history of diabetes or auto-immune diseases and was admitted after the second cycle of durvalumab to the intensive care unit (ICU) with severe DKA. During his hospitalization, insulin and fluid therapy were started and the patient had a favorable clinical course. Durvalumab treatment was interrupted and thyroiditis was verified during follow-up, without anti-thyroid antibodies, that progressed to subsequent hypothyroidism with need of thyroid hormone replacement therapy. This case highlights the rare irAE of autoimmune type 1 diabetes during anti-PD(L)-1 therapy, which can be life-threatening and requires adequate patient education and prompt medical treatment within a multidisciplinary team, including endocrinology and emergency medicine. Besides its low incidence, this case show how irAE must be taken in account about decision of ICI treatment, especially in curative setting, as they can be potentially fatal and impair overall survival. Furthermore, as reported in the present case, multiple endocrine irAEs can occur in the same patient either simultaneously or sequentially, suggesting that active surveillance is needed in those who develop endocrinopathies as a result of ICI treatment. Immune-mediated endocrinopathies are generally irreversible and cause life-long morbidity, which must be taken into consideration when deciding on further lines of treatment.

Survival Outcomes of Salvage Therapy for Local and Regionally Recurrent NSCLC

Introduction

The treatment of locally recurrent NSCLC after initial curative therapy is variable. We sought to perform a real-world analysis of curative and palliative therapeutic strategies used in locally recurrent NSCLC and explore the impact of baseline factors and the previous and recurrent treatment on outcomes.

Methods

A retrospective cohort study was done including all patients with stage I to III NSCLC who were referred to BC Cancer and received curative-intent therapy between 2005 and 2012. Patients were followed up to determine whether they developed locoregional recurrence. Two cohorts were created: curative-intent treatment at recurrence (surgery, radiotherapy with ≥50Gy ± chemotherapy, stereotactic radiosurgery) and palliative treatment. The primary outcome was overall survival (OS).

Results

A total of 1571 patients received curative-intent therapy during the study period. Of these, 179 (11%) developed a local and regional recurrence. A total of 51 patients (28%) were treated with curative intent at recurrence (12 surgery, 39 radiotherapy ± chemotherapy), and 128 (72%) received palliative treatment only. Patients receiving curative-intent therapy were more likely to have an Eastern Cooperative Oncology Group performance status of 0 to 1 (90% versus 58%), earlier stage at diagnosis (51% stage I) and receive more aggressive staging investigations at recurrence, pathologic confirmation (75% versus 27%) and positron emission tomography (77% versus 27%). OS was longer in the cohort receiving curative-intent therapy, with an OS of 34.3 months versus 9.8 months (p < 0.001) in palliative treatment.

Conclusions

In this real-world population, isolated locoregional recurrences occurred in 11% of patients. Curative-intent treatment at recurrence is associated with a reasonable chance of long-term survival, making aggressive therapy of locoregional recurrences an important treatment consideration.

Propensity score adjusted analysis of patients with isolated locoregional recurrence versus de novo locally advanced NSCLC treated with definitive therapy

OBJECTIVES

Definitive intent treatment of isolated locoregional recurrence (iLR) for non-small cell lung cancer (NSCLC) is becoming more common. This study explores outcomes associated with the definitive local treatment of iLR and compares these outcomes to newly diagnosed locally advanced NSCLC (LA-NSCLC) patients.

MATERIALS AND METHODS

Patients with NSCLC treated with curative therapy between 2008 and 2019 at a tertiary academic institution were screened for iLR treated with subsequent definitive salvage therapy. Progression free survival (PFS), time to distant metastasis (TTDM), and overall survival (OS) were calculated via Kaplan-Meier methodology. Clinical outcomes were compared to a separate group of patients with de novo LA-NSCLC after adjusting for propensity score (PS).

RESULTS

Sixty five cases of definitively salvaged iLR were compared to 302 patients with de novo LA-NSCLC. Most patients were treated with chemoradiotherapy (83.1% in iLR, 74.5% in LA-NSCLC). The median PFS, TTDM, and OS for the iLR cohort was 16.7 months (95% CI: 9.6-24.7), 35.8 months (95% CI: 17.1-NR), and 49.5 months (95% CI: 30.1-NR), respectively. After adjusting for PS, the iLR group was no different from the LA-NSCLC group in risk for progression (HR 0.78, 95% CI: 0.53-1.16, p = 0.22), distant metastasis (HR 0.81, 95% CI: 0.52-1.27, p = 0.36), or death (HR 0.90, 95% CI: 0.47-1.73, p = 0.75). Patterns of failure did not different significantly between groups. In the iLR cohort, patients with older age (HR 1.06, 95 CI: 1.01-1.10, p = 0.01) had a higher risk of death on multivariate analysis.

CONCLUSION

To our knowledge, this is the first report that compares the definitive treatment of iLR to de novo LA-NSCLC. When treated with definitive local therapy, patients with iLR had no difference in clinical outcomes from de novo LA-NSCLC. The use of curative local therapy according to a LA-NSCLC paradigm is advisable in patients with iLR of NSCLC for whom definitive therapy is feasible.

Salvage stereotactic body radiotherapy for post-operative oligo-recurrence of non-small cell lung cancer: A single-institution analysis of 59 patients

A standard treatment for patients with early-stage non-small cell lung cancer (NSCLC) who undergo surgery, and subsequently develop local failure or intrathoracic oligo-recurrence, has not yet been established. The present study aimed to assess the feasibility of stereotactic body radiotherapy (SBRT) for this subgroup of patients. Consequently, a retrospective analysis was conducted of patients with NSCLC recurrence who were treated with SBRT, and previously underwent curative surgical resection between October 2011 and October 2016. Post-SBRT survival [overall survival (OS); progression-free survival (PFS); and local control (LC)] and toxicity were analyzed. Prognostic factors for OS were identified using univariate and multivariate analysis. A total of 52 patients and 59 tumors were analyzed. The median follow-up time was 25 months (35 months for surviving patients), and median OS following salvage SBRT was 32 months. The 1- and 3-year OS rates were 84.4 and 67.8%, respectively. 1- and 3-year PFS rates were 80.8 and 58.7%, respectively. Only 4 patients (7.7%) developed local failure. Median LC was 71 months and 1- and 3-year LC rate were 97.9 and 94.9%, respectively. A total of 4 patients experienced grade 3 or higher adverse events (AEs) and two experienced grade 5 AEs (pneumonitis and hemoptysis). Central tumor location and the possibility of re-operation were independent prognostic factors for OS. The present study indicated that post-operative salvage SBRT is a promising therapeutic option for patients with NSCLC with locoregional or intrathoracic oligo-recurrence. We regard toxicity was also acceptable. However, further research is required on the appropriate selection of subjects, and stratification of the analysis by certain risk factors would increase the accuracy of the conclusions.