Randomized Phase II Study Comparing Prophylactic Cranial Irradiation Alone to Prophylactic Cranial Irradiation and Consolidative Extracranial Irradiation for Extensive-Disease Small Cell Lung Cancer (ED SCLC): NRG Oncology RTOG 0937

Role of stereotactic radiotherapy in the management of small-cell lung cancer

Small-cell lung cancer is the most aggressive form of lung neoplasia, treated in recent decades with chemoradiotherapy in case of limited stage and chemotherapy alone at the metastatic stage. In the last few years, the advent of immunotherapy has changed the landscape in the treatment of non-small-cell lung cancer, and to a lesser degree in small-cell lung cancer. Despite the recent advances in research, small-cell lung cancer is still considered an aggressive and lethal disease characterized by high recurrence or metastatic potential. As stereotactic radiotherapy has established itself as the standard of care in the early stage of inoperable non-small-cell lung cancer and in metastatic disease to treat brain and extracranial metastases, these same issues now arise in the management of small-cell lung cancer. This article aims to review the current knowledge and the potential of stereotactic radiotherapy in small-cell lung cancer.

Adebrelimab plus chemotherapy and sequential thoracic radiotherapy as first-line therapy for extensive-stage small-cell lung cancer (ES-SCLC): a phase II trial

Background

This phase II prospective trial aimed to investigate the efficacy and safety of adebrelimab (PD-L1 antibody) plus first-line chemotherapy followed by sequential thoracic radiotherapy (TRT) combined with adebrelimab in extensive-stage small-cell lung cancer (ES-SCLC). Biomarkers associated with potential therapeutic effects were also explored.

Methods

Patients with previously untreated ES-SCLC were enrolled at Shandong Cancer Hospital and Institute (Jinan, China). Patients received 4-6 cycles of adebrelimab (20 mg/kg, D1, Q3W) combined with EP/EC (etoposide, 100 mg/m2, D1-3, Q3W and cisplatin, 75 mg/m2, D1, Q3W or carboplatin, AUC = 5, D1, Q3W). Then patients with response sequentially underwent consolidative TRT (≥30 Gy in 10 fractions or ≥50 Gy in 25 fractions, involved-field irradiation), and maintenance adebrelimab until disease progression or intolerable adverse events (AEs). The primary endpoint was overall survival (OS). Genomic and circulating tumour DNA (ctDNA) profiling were also analyzed with tumour tissues and peripheral blood. This trial was registered with ClinicalTrials.gov, NCT04562337.

Findings

From October 2020 to April 2023, 67 patients diagnosed with ES-SCLC were enrolled and received at least one dose of study treatment. All patients were included in the efficacy and safety analyses. 45 patients received sequential TRT as planned. The median OS and progression-free survival (PFS) was 21.4 months (95% CI: 17.2-not reached months) and 10.1 months (95% CI: 6.9-15.5 months), respectively. The confirmed objective response rate was 71.6% (48/67, 95% CI: 59.3-82.0%) and disease control rate was 89.6% (60/67, 95% CI: 79.7-95.7%). There were no treatment-related deaths. The most common grade 3 or higher treatment-related adverse events (TRAEs) were hematological toxicities. The incidence of any grade and G3+ pneumonitis was 25% (17/67) and 6% (4/67), respectively. No unexpected adverse events were observed. Patients without co-mutations of TP53/RB1 in both tissue and peripheral blood displayed longer PFS (tissue, P = 0.071; ctDNA, P = 0.060) and OS (tissue, P = 0.032; ctDNA, P = 0.031).

Interpretation

Adebrelimab plus chemotherapy and sequential TRT as first-line therapy for ES-SCLC showed promising efficacy and acceptable safety.

Funding

This study was funded by the National Natural Science Foundation of China (82172865), Jiangsu Hengrui Pharmaceuticals Co., Ltd. and Amoy Diagnostics Co., Ltd.

[Local Therapy in Stage IV Lung Cancer with Oligopersistent or Oligoprogessive Disease]

Oligopersistent and oligoprogressive disease are defined as distinct situations of metastastatic lung cancer. Oligopersistence describes a situation in which a limited number of metastases remain following effective systemic therapy. Oligoprogression represents a largely controlled tumour disease with a few metastases showing significant progression. In the oligopersistence, treatment aims to establish complete tumour control with subsequent improvement of the prognosis by means of additional local ablative treatment of all remaining lesions. In the oligoprogressive situation, local ablative treatment aims to reestablish complete tumour control while continuing systemic therapy. The concepts are based on ideas that were introduced in oncology more than 30 years ago by Hellman and Weichselbaum by using the term oligometastases. Multimodal therapy concepts have gained importance in the situation of oligopersistence and oligoprogression, particularly due to molecular targeted therapies for oncogene-driven lung cancer and chemo-immunotherapy regimes with high response rates and long response duration. The available evidence will be presented and explained by case studies.

Phase III, multicenter, randomized trial of 45 Gy versus 30 Gy thoracic radiation for extensive-stage small cell lung cancer (ES-SCLC): Study protocol

BACKGROUND

Consolidative thoracic radiotherapy (cTRT) has previously shown benefit to patients with extensive stage small cell lung cancer (ES-SCLC) who respond to chemotherapy. However, the optimum dose of cTRT is unknown. The purpose of this randomized trial is to compare the efficacy of 45 Gy in 15 fractions with 30 Gy in 10 fractions cTRT in ES-SCLC.

METHODS

This phase III, multicenter, randomized trial is designed to evaluate the safety and efficacy of different cTRT dose in ES-SCLC. Eligible patients with pathologically confirmed ES-SCLC who responded to 4-6 cycles of etoposide plus cisplatin (EP) or carboplatin (EC) chemotherapy were randomized 1:1 to receive either 30 Gy in 10 fractions (standard dose) or 45 Gy in 15 fractions (high dose) cTRT. The primary endpoint is 2-year overall survival (OS). Secondary endpoints include 2-year progression-free survival (PFS), 2-year local control (LC) and treatment related toxicity as measured by adverse events according to the Common Terminology Criteria for Adverse Events (version 4.0).

DISCUSSION

The present study is the first randomized phase III trial designed to evaluate the efficacy of higher versus lower dose cTRT in ES-SCLC, providing evidence for future clinical practice in prolonging survival of patients with ES-SCLC.

Intrathoracic Progression Is Still the Most Dominant Failure Pattern after First-Line Chemo-immunotherapy in Extensive-Stage Small-Cell Lung Cancer: Implications for Thoracic Radiotherapy

PURPOSE

This study aimed to compare the failure patterns before and after the introduction of immunotherapy and to determine the role of thoracic radiotherapy (TRT) in extensive-stage small-cell lung cancer (ES-SCLC) treatment.

MATERIALS AND METHODS

We retrospectively reviewed 294 patients with ES-SCLC, of which 62.2% underwent chemotherapy alone, 13.3% underwent chemotherapy followed by consolidative TRT (TRT group), and 24.5% underwent chemotherapy with immune checkpoint inhibitor (ICI group). We performed propensity-score matching (PSM) to compare each treatment group.

RESULTS

The median follow-up duration was 10.4 months. At the first relapse, in the cohort showing objective response, the proportion of cases showing intrathoracic progression was significantly lower in the TRT group (37.8%) than in the chemotherapy-alone (77.2%, p < 0.001) and the ICI (60.3%, p=0.03) groups. Furthermore, in the subgroup analysis, TRT showed benefits related to intrathoracic progression-free survival (PFS) in comparison with ICI in patients with less than two involved extrathoracic sites (p=0.008) or without liver metastasis (p=0.02) or pleural metastasis (p=0.005) at diagnosis. After PSM, the TRT group showed significantly better intrathoracic PFS than both chemotherapy-alone and ICI groups (p < 0.001 and p=0.04, respectively), but showed no significant benefit in terms of PFS and overall survival in comparison with the ICI group (p=0.17 and p=0.31, respectively).

CONCLUSION

In ES-SCLC, intrathoracic progression was the most dominant failure pattern after immunotherapy. In the era of chemoimmunotherapy, consolidative TRT can still be considered a useful treatment strategy for locoregional control.

Sterotactic Ablative Radiotherapy in a Multicentric Series of Oligometastatic SCLC: The SAMOS Cohort

AIMS

SCLC is the most aggressive lung cancer histology with a 5-year OS <10%. At the diagnosis, almost two-thirds of the SCLC an Extended Disease presentation. Two randomized studies (CASPIAN and ImPower133) demonstrated an OS improvement, when immunotherapy was prescribed as maintenance therapy after standard chemotherapy. To date, SABR has had a limited indication in managing metastatic SCLC, although recent reports proposed it as a valid treatment option in selected patients. We propose a retrospective multicentric analysis of patients treated with SABR for oligometastatic SCLC.

METHOD

Data of patients affected by oligometastatic-SCLC treated with SABR between 2017 and 2022 in 11 Italian centers were collected. Clinical and therapeutic variables together with OS and time to next treatment were analyzed. Univariate analysis with Kaplan-Meier curve were calculated, and log-rank test were applied. Cox proportional hazard model was used for multivariate analysis.

RESULTS

Data from 93 patients and 132 metastatic lesions were analyzed. The median age was 64 years (36-86) and all but 1 had Performance Status 0 or 1. Fifty-two patients presented ED at diagnosis. The first line treatment was radiochemotherapy in 42%, CHT alone in 24% and CHT-IO in 28%, others treatment accounts for 4% and only 2% of patients underwent best supportive care. Of the 132 lesions treated with SBRT 55 were in brain, 27 in lung, 11 in liver, 10 in lymph nodes, 8 in bones and 20 in adrenal gland. Median OS was 14 months, 1 year-OS and 2 years OS were 53% and 27%, respectively. The median TtNT was 14 months for the entire population. Of all the analyzed variables only, the anatomical site of the metastases and their number showed statistical significance in the univariate analysist, confirmed in the subsequent multivariate.

CONCLUSION

SABR seems to play a role in delaying further systemic lines in oligometastatic disease and to extend the use of ongoing treatment in oligoprogressive state. Prospective studies are needed to confirm these findings.

Radiotherapy in the management of synchronous metastatic lung cancer

Metastatic lung cancer classically portends a poor prognosis. The management of metastatic lung cancer has dramatically changed with the emergence of immune checkpoint inhibitors, targeted therapy and due to a better understanding of the oligometastatic process. In metastatic lung cancers, radiation therapy which was only used with palliative intent for decades, represents today a promising way to treat primary and oligometastatic sites with a curative intent. Herein we present through a literature review the role of radiotherapy in the management of synchronous metastatic lung cancers.

Chemoimmunotherapy combined with consolidative thoracic radiotherapy for extensive-stage small cell lung cancer: A systematic review and meta-analysis

INTRODUCTION

This study aimed to evaluate the efficacy and safety of chemoimmunotherapy combined with consolidative thoracic radiation therapy (cTRT) in patients with extensive-stage small cell lung cancer (ES-SCLC).

METHODS

A meta-analysis was conducted. PubMed, Embase, Web of Science, and the Cochrane Library were searched. The study was registered in PROSPERO (registration no. CRD42023410344).

RESULTS

A total of 4677 studies were initially screened and 15 studies encompassing a total of 1033 patients were included. Chemoimmunotherapy combined with cTRT significantly improved survival (HR = 0.52, 95 % CI: 0.39, 0.68) with favorable 6-month (0.89, 95 % CI: 0.77, 1.00) and 1-year (0.77, 95 % CI: 0.72, 0.82) OS, without affecting ≥3 grade TRAEs (RR = 1.29, 95 % CI: 0.85, 1.98). Pooled 6-month and 1-year PFS were 0.67 (95 % CI: 0.47, 0.86) and 0.38 (95 % CI: 0.22, 0.55), respectively. Incidence of ≥3 grade TRAEs was 0.24 (95 % CI: 0.08, 0.39) and radiation pneumonitis was 0.03 (95 % CI: 0.01, 0.06).

CONCLUSIONS

Chemoimmunotherapy combined with cTRT improves survival and shows favorable outcomes in ES-SCLC patients, with manageable adverse events. Further research with larger samples is needed to confirm these findings.

The Era of Immunotherapy in Small-Cell Lung Cancer: More Shadows Than Light?

Small-cell lung cancer is an extremely chemo-sensitive disease; the addition of immunotherapy to chemotherapy has demonstrated a slight clinical benefit in pivotal trials, even with a statistically significant difference in terms of survival outcomes when compared to chemotherapy alone. In this scenario, the role of radiotherapy as a consolidation treatment in thoracic disease or as a prophylactic therapy in the brain should be clarified. In addition, due to the frailty and the poor prognostic characteristics of these patients, the need for predictive biomarkers that could support the use of immunotherapy is crucial. PD-L1 and TMB are not actually considered definitive biomarkers due to the heterogeneity of results in the literature. A new molecular classification of small-cell lung cancer based on the expression of key transcription factors seems to clarify the disease behavior, but the knowledge of this molecular subtype is still insufficient and the application in clinical practice far from reality; this classification could lead to a better understanding of SCLC disease and could provide the right direction for more personalized treatment. The aim of this review is to investigate the current knowledge in this field, evaluating whether there are predictive biomarkers and clinical patient characteristics that could help us to identify those patients who are more likely to respond to immunotherapy.

The Impact of Prophylactic Cranial Irradiation and Consolidative Thoracic Radiation Therapy for Extensive Stage Small-Cell Lung Cancer in the Transition to the Chemo-Immunotherapy Era: A Single Institution Series

INTRODUCTION

Extensive-stage small-cell lung cancer (ES-SCLC) continues to have poor survival due to its aggressive behavior, despite improvements with incorporation of immunotherapy with standard chemotherapy. Controversy exists regarding the role of consolidative thoracic radiation therapy (TRT) and prophylactic cranial irradiation (PCI) in ES-SCLC due to high recurrence rates. We report our institutional result of the benefit of PCI and TRT in ES-SCLC.

METHODS

Patients with ES-SCLC without intracranial metastasis at diagnosis (N = 163) were included. All patients completed systemic therapy with or without immunotherapy based on time of standard of care. Cohorts were divided by systemic therapy use and further subdivided by treatment with PCI and TRT. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method with log-rank test for comparison. The effects of TRT and PCI were estimated by multivariable (MVA) Cox regression.

RESULTS

Seventy-four patients (45.4%) received TRT, and 33.1% (n = 54) received PCI. The median follow-up was 11 months (3-85 months). PCI improved median OS to 15 months from 10 months, P = .02) and median PFS to 8.5 months from 5 months (P = .02) which remained significant on MVA, P = .02 and P = .02, respectively. TRT improved OS on UVA (P = 0.002) but was not significant on MVA. TRT did not improve PFS.

CONCLUSION

This study including chemotherapy and chemo-immunotherapy suggests improved outcomes with addition of PCI in patients with ES-SCLC while TRT did not show benefit to either OS or PFS. A future trial is needed to evaluate the role of TRT and PCI in the era of chemo-immunotherapy.

Advancing immunotherapy in small cell lung cancer

Small cell lung cancer (SCLC) is a rapidly progressive neuroendocrine carcinoma that, until recently, had a very small armamentarium of effective treatments. Advances in DNA sequencing and whole transcriptomics have delineated key subtypes; therefore, SCLC is no longer viewed as a homogeneous cancer. Chemoimmunotherapy with PD1 blockade is now the standard of care for advanced disease, and ongoing research efforts are moving this strategy into the limited stage setting. Combination strategies of immunotherapy with radiation are also under active clinical trial in both limited and extensive stage disease. PLAIN LANGUAGE SUMMARY: Small cell lung cancer (SCLC) is a rapidly progressive neuroendocrine carcinoma that, until recently, had a very small armamentarium of effective treatments. Chemoimmunotherapy with immune check point inhibitors is now the standard of care for advanced disease. This comprehensive review provides an overview of current treatment strategies for SCLC, unmet needs in this patient population, and emerging treatment strategies incorporating immunotherapy that will hopefully further improve outcomes for patients.

Oligometastasis: Expansion of Curative Treatments in the Field of Oncology

Oligometastasis is defined as the presence of several limited metastatic lesions and is generally limited to three or fewer than five metastatic lesions. Previously, the treatment of metastatic cancer aimed to alleviate symptoms rather than cure them; however, the use of immunotherapy or targeted therapy has greatly improved patient life expectancy. Additionally, the effectiveness and safety of local treatment have recently been proven for oligometastatic cancers and have significantly improved patient survival and decreased recurrence rates. A few metastatic studies on lung cancer have demonstrated the usefulness of combining radiation therapy and immunotherapy. Recently, local and targeted therapy combinations have shown promising results in treating non-small cell lung cancer, predominantly caused by the epidermal growth factor receptor and anaplastic lymphoma kinase gene mutations, suggesting the potential of these new treatment strategies. It is well known that oligometastasis has better clinical results than polymetastasis; however, research on the biological profile of oligometastasis is still lacking. Studies using circulating tumor DNA and circulating tumor cells are at the initial stages of providing a better understanding of oligometastatic cancers, and the biological characteristics of these cancers may be revealed based on more diverse studies. With the development of these treatments, the prognosis for patients with oligometastatic cancers is steadily improving, and if the biological profile is revealed, customized treatment may be provided.

Safety and efficacy of thoracic radiotherapy combined with chemo-immunotherapy in patients with extensive-stage small cell lung cancer: a multicenter retrospective analysis

Background

Immunotherapy has greatly increased the survival time of patients with extensive-stage small cell lung cancer (ES-SCLC), and is now a standard first-line treatment for these patients. Increasing evidence suggests a possible synergistic effect between immunotherapy and radiotherapy, yet there is a paucity of evidence regarding the efficacy and safety of thoracic radiotherapy (TRT) combined with chemo-immunotherapy for ES-SCLC.

Methods

The medical records of 78 consecutive patients with ES-SCLC who received TRT in combination with chemo-immunotherapy at Jinling Hospital and Jiangsu Cancer Hospital from January 2019 to January 2023 were retrospectively reviewed. The median overall survival (mOS) time and median progression-free survival (mPFS) time were used to evaluate efficacy, and the incidence of adverse events (AEs) was used to evaluate safety.

Results

The median follow-up time was 31.9 months, the objective response rate (ORR) was 59%, and the disease control rate (DCR) was 89.8%. The mOS time was 20.0 months, and the 6-month OS rate was 95%. The mPFS time was 9.2 months, and the 6-month PFS rate was 78%. There were no treatment-related deaths. The incidence of pneumonitis was 23.1%, the incidence of radiation esophagitis was 5.1%, and 2 patients experienced high-grade pneumonitis. Primary liver metastasis was a predictor of poor OS and PFS. Patients who received consolidative TRT after chemo-immunotherapy experienced more benefit than those who received TRT as palliative or salvage treatment for superior vena cava syndrome or disease progression.

Conclusions

TRT is a feasible treatment for patients who receive chemo-immunotherapy for the management of ES-SCLC in consideration of its considerable efficacy and tolerable safety risk. This treatment is especially useful for patients without primary liver metastasis and who receive consolidative TRT after chemo-immunotherapy. Large-scale prospective studies are needed to confirm the efficacy and safety of this treatment modality.

Advances and Challenges in Trials of Local Therapy for Patients With Oligometastatic or Oligoprogressive Disease

The paradigm of oligometastatic disease (OMD), characterized by a limited number of metastases potentially amenable to local therapies, presents unique opportunities and challenges in clinical trial design and implementation. Although local ablative therapies, such as stereotactic body radiation therapy, have shown promise in improving outcomes for patients with OMD, there is a lack of large-scale randomized phase III trials supporting their widespread use. This paper outlines the key challenges in trial design and implementation in the oligometastatic setting, including appropriate patient selection, the definition of the oligometastatic state, trial design considerations, endpoint selection, and logistical considerations related to enrollment and follow-up. We suggest potential strategies to address these challenges, emphasizing the importance of a comprehensive, patient-centric approach, and the integration of multidisciplinary teams in trial design and implementation. The aim is to encourage the design of well-structured clinical trials, ultimately refining best practices and enhancing patient outcomes in the management of OMD.

Radiotherapy for extensive-stage small-cell lung cancer in the immunotherapy era

Currently, chemoimmunotherapy is the first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC). However, only 0.8%-2.5% of the patients presented complete response after chemoimmunotherapy. Considering that ES-SCLC is highly sensitive to radiotherapy, the addition of radiotherapy after first-line treatment for ES-SCLC could further improve local control, which may be beneficial for patients' survival. Prior studies have shown that consolidative thoracic radiotherapy (cTRT) can decrease disease progression and improve overall survival in patients with ES-SCLC who respond well to chemotherapy. However, the efficacy and safety of cTRT in the immunotherapy era remain unclear owing to a lack of prospective studies. Prophylactic cranial irradiation (PCI) has been shown to decrease brain metastasis (BM) and prolong survival in patients with limited-stage SCLC in previous reports. However, according to current guidelines, PCI is not commonly recommended for ES-SCLC. Immunotherapy has the potential to reduce the incidence of BM. Whether PCI can be replaced with regular magnetic resonance imaging surveillance for ES-SCLC in the era of immunotherapy remains controversial. Whole brain radiation therapy (WBRT) is the standard treatment for BM in SCLC patients. Stereotactic radiosurgery (SRS) has shown promise in the treatment of limited BM. Considering the potential of immunotherapy to decrease BM, it is controversial whether SRS can replace WBRT for limited BM in the immunotherapy era. Additionally, with the addition of immunotherapy, the role of palliative radiotherapy may be weakened in patients with asymptomatic metastatic lesions. However, it is still indispensable and urgent for patients with obvious symptoms of metastatic disease, such as spinal cord compression, superior vena cava syndrome, lobar obstruction, and weight-bearing metastases, which may critically damage the quality of life and prognosis. To improve the outcome of ES-SCLC, we discuss the feasibility of radiotherapy, including cTRT, PCI, WBRT/SRS, and palliative radiotherapy with immunotherapy based on existing evidence, which may offer specific prospects for further randomized trials and clinical applications.

The role of thoracic consolidative radiotherapy in the setting of immunotherapy in extensive stage small cell lung cancer

The improvement in treatment strategies and outcomes in small cell lung cancer (SCLC) has lagged behind other cancers. The addition of immune checkpoint inhibitors (ICIs), durvalumab and atezolizumab, to the platinum-based chemotherapy in frontline setting has improved the survival in extensive stage SCLC, (ES-SCLC), albeit modestly, and is now the new standard of care. Prior to advent of immunotherapy into the therapeutic armamentarium in ES-SCLC, consolidative thoracic radiotherapy (TRT) was associated with improved thoracic control and survival outcomes. In the era of ICIs, the role of TRT is not well defined, chiefly because TRT was not incorporated in any immunotherapy trials, secondly due to concerns regarding the increased risks of pneumonitis, and finally uncertain magnitude of benefit with this combined approach. In principle, radiation can increase in the immunogenicity of tumor and hence the activity of immune checkpoint blockade, thereby increasing efficacy both locally and distantly. Such an approach has been promising in non-small cell lung cancer with ICIs improving outcomes after concurrent chemoradiation, but remains unanswered in ES-SCLC. It is, thus, possible that the modest improvement in survival by addition of ICIs to chemotherapy in ES-SCLC can be further improved by the incorporation of consolidative TRT in selected patients. Several early phase trials and retrospective studies have suggested that such an approach may be feasible and safe. Prospective trials are ongoing to answer whether adding radiation therapy to chemoimmunotherapy will improve outcomes in ES-SCLC.

Stereotactic body radiotherapy for extra-cranial oligoprogressive or oligorecurrent small-cell lung cancer

Introduction

The role of local ablative treatments, including stereotactic body radiotherapy (SBRT), is an area of active research in oligometastatic patients. Small cell lung cancer (SCLC) has a poor prognosis, with common diffuse metastatic evolution. We evaluated the outcomes after SBRT in uncommon oligoprogressive/oligorecurrent SCLC presentation.

Methods

Data of SCLC patients who received SBRT for oligoprogressive/oligorecurrent metastatic disease at four centers were retrospectively analyzed. Patients with synchronous oligometastatic disease, SBRT for primary lung tumor and brain radiosurgery were not included. Relapse and survival rates were defined as the time between the date of SBRT and the first event.

Results

Twenty patients (60% with initially limited-disease [LD]) presenting 24 lesions were identified. Oligoprogression and oligorecurrence were observed in 6/20 (30%) and 14/20 (70%) patients, respectively. SBRT was delivered to one (n = 16) to two (n = 4) lesions (median size, 26 mm), mainly to lung [n = 17/24] metastases. At a median follow-up of 2.9 years, no local relapse was observed and 15/20 patients experienced a distant relapse (DR). The median DR and OS were 4.5 months (95 %CI: 2.9-13.7 months) and 17.2 months (95 %CI: 7.5-65.2 months), respectively. The 3-year distant control and OS rates were 25% (95 %CI: 6-44%) and 37% (95 %CI: 15-59%), respectively. Initial LD (vs extensive-disease) was the only prognosis factor associated with a lower risk of post-SBRT DR (HR: 0.3; 95% CI: 0-0.88; p = 0.03). There was no severe observed SBRT-related toxicities.

Conclusion

Prognosis was poor, with DR occurring in most patients. However, local control was excellent and long term response after SBRT may rarely occur in patients with oligoprogressive/oligorecurrent SCLC. Local ablative treatments should be discussed in a multidisciplinary setting on well-selected cases.

Canadian Consensus Recommendations on the Management of Extensive-Stage Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive, neuroendocrine tumour with high relapse rates, and significant morbidity and mortality. Apart from advances in radiation therapy, progress in the systemic treatment of SCLC had been stagnant for over three decades despite multiple attempts to develop alternative therapeutic options that could improve responses and survival. Recent promising developments in first-line and subsequent therapeutic approaches prompted a Canadian Expert Panel to convene to review evidence, discuss practice patterns, and reach a consensus on the treatment of extensive-stage SCLC (ES-SCLC). The literature search included guidelines, systematic reviews, and randomized controlled trials. Regular meetings were held from September 2022 to March 2023 to discuss the available evidence to propose and agree upon specific recommendations. The panel addressed biomarkers and histological features that distinguish SCLC from non-SCLC and other neuroendocrine tumours. Evidence for initial and subsequent systemic therapies was reviewed with consideration for patient performance status, comorbidities, and the involvement and function of other organs. The resulting consensus recommendations herein will help clarify evidence-based management of ES-SCLC in routine practice, help clinician decision-making, and facilitate the best patient outcomes.

Real-World Efficacy and Safety of Thoracic Radiotherapy after First-Line Chemo-Immunotherapy in Extensive-Stage Small-Cell Lung Cancer

(1) Background: At present, the efficacy and safety of thoracic radiotherapy (TRT) after chemo-immunotherapy (CT-IT) in patients with extensive-stage small-cell lung cancer (ES-SCLC) still remain unclear. The purpose of this study was to evaluate the role of TRT after CT-IT in patients with ES-SCLC. (2) Methods: From January 2020 to October 2021, patients with ES-SCLC treated with first-line anti-PD-L1 antibody plus platinum-etoposide chemotherapy were enrolled retrospectively. The survival data and adverse events data of patients treated with or without TRT after CT-IT were collected for analysis. (3) Results: A total of 118 patients with ES-SCLC treated with first-line CT-IT were retrospectively enrolled, with 45 patients with TRT and 73 patients without TRT after CT-IT. The median PFS and OS in the CT-IT + TRT group and CT-IT only group were 8.0 months versus 5.9 months (HR = 0.64, p = 0.025) and 22.7 months versus 14.7 months (HR = 0.52, p = 0.015), respectively. The median PFS and OS in all 118 patients treated with first-line CT-IT were 7.2 and 19.8 months with an ORR of 72.0%. In multivariate analyses, liver metastasis and response to CT-IT were shown to be independent prognostic factors of PFS (p < 0.05), while liver metastasis and bone metastasis were independent predictive factors of OS (p < 0.05). Although TRT was significantly associated with better PFS and OS in univariate analysis, the association of TRT and OS failed to reach statistical significance (HR = 0.564, p = 0.052) in multivariate analysis. There was no significant difference in adverse events (AEs) between two treatment groups (p = 0.58). (4) Conclusions: ES-SCLC patients treated with TRT after first-line CT-IT had prolonged PFS and OS with an acceptable safety profile. Further prospective randomized studies are necessary to explore the efficacy and safety of this treatment modality for ES-SCLC in future.

Role of consolidative thoracic radiation in extensive-stage small-cell lung cancer with first-line chemoimmunotherapy: a retrospective study from a single cancer center

OBJECTIVE

To investigate the role of consolidative thoracic radiation (TRT) in extensive-stage small-cell lung cancer (ES-SCLC) receiving first-line chemo-immunotherapy followed by immunotherapy maintenance.

PATIENTS AND METHODS

Outcomes of patients without disease progression after first-line chemotherapy were retrospectively reviewed (January 2020 to December 2021). Based on TRT or not, patients were allocated to TRT group or non-TRT group. Progression-free survival (PFS), overall survival (OS) and local-recurrence free survival (LRFS) were calculated by the Kaplan-Meier method and compared by log-rank test.

RESULTS

Of 100 patients, 47 received TRT and 53 non-TRT. The median follow-up was 20.3 months. The median PFS and OS in TRT were 9.1 months and 21.8 months, versus 8.8 months (p = 0.93) and 24.3 months (p = 0.63), respectively, in non-TRT. The median LRFS time in TRT was not reached, but significantly longer than 10.8 months in non-TRT (HR = 0.27, p < 0.01). Second-line chemotherapy significantly prolonged survival compared to that with chemo-free patients (mOS: 24.5 vs. 21.4 months, p = 0.026). The subgroup analysis showed a trend of patients with brain metastases benefit from TRT (21.8 versus 13.7 months, HR 0.61, p = 0.38) while liver metastases did not. Of 47 patients with TRT, only 10.6% of patients experienced grade 3 radiation-induced pneumonitis, while no grade 4 or 5 adverse events occurred.

CONCLUSION

Consolidative TRT in the period of immunotherapy maintenance followed first-line chemo-immunotherapy did not prolong OS and PFS but associated with improved LRFS in ES-SCLC.

First-line atezolizumab/durvalumab plus platinum-etoposide combined with radiotherapy in extensive-stage small-cell lung cancer

BACKGROUND

Immunotherapy has made significant advances in the treatment of extensive-stage small-cell lung cancer (ES-SCLC), but data in combination with radiotherapy are scarce. This study aims to assess the safety and efficacy of chemoimmunotherapy combined with thoracic radiotherapy in patients with ES-SCLC.

METHODS

This single-center retrospective study analyzed patients with ES-SCLC who received standard platinum-etoposide chemotherapy combined with atezolizumab or durvalumab immunotherapy as induction treatment, followed by consolidative thoracic radiotherapy (CTRT) before disease progression in the first-line setting. Adverse events during radiotherapy with or without maintenance immunotherapy and survival outcomes were assessed.

RESULTS

Between December 2019 and November 2021, 36 patients with ES-SCLC were identified to have received such treatment modality at one hospital. The number of metastatic sites at diagnosis was 1-4. The biological effective dose of CTRT ranged from 52 to 113 Gy. Only two patients (6%) developed grade 3 toxic effect of thrombocytopenia, but none experienced grade 4 or 5 toxicity. Four patients developed immune-related pneumonitis during the induction treatment period but successfully completed later CTRT. The rate of radiation-related pneumonitis was 8% with grades 1-2 and well tolerated. The median progression-free survival (PFS) was 12.8 months, but the median overall survival (OS) was not determined. The estimated 1-year OS was 80.2% and 1-year PFS was 53.4%.

CONCLUSIONS

Immunotherapy combined with CTRT for ES-SCLC is safe and has ample survival benefit.

Use of radiation therapy among patients with Extensive-stage Small-cell lung cancer receiving Immunotherapy: Canadian consensus recommendations

OBJECTIVES

Thoracic radiation therapy (TRT) and prophylactic cranial irradiation (PCI) are commonly used in the management of extensive-stage small-cell lung cancer (ES-SCLC); however, Phase III trials of first-line immunotherapy often excluded these options. Guidance is needed regarding appropriate use of TRT, PCI, and magnetic resonance imaging (MRI) surveillance while new data are awaited.

MATERIALS AND METHODS

In two web-based meetings, a pan-Canadian expert working group of five radiation oncologists and four medical oncologists addressed eight clinical questions regarding use of radiation therapy (RT) and MRI surveillance among patients with ES-SCLC receiving immunotherapy. A targeted literature review was conducted using PubMed and conference proceedings to identify recent (January 2019-April 2022) publications in this setting. Fifteen recommendations were developed; online voting was conducted to gauge agreement with each recommendation.

RESULTS

After considering recently available evidence across lung cancer populations and clinical experience, the experts recommended that all patients with a response to chemo-immunotherapy, good performance status (PS), and limited metastases be considered for consolidation TRT (e.g., 30 Gy in 10 fractions). When considered appropriate after multidisciplinary team discussion, TRT can be initiated during maintenance immunotherapy. All patients who respond to concurrent chemo-immunotherapy should undergo restaging with brain MRI to guide decision-making regarding PCI versus MRI surveillance alone. MRI surveillance should be conducted for two years after response to initial therapy. PCI (e.g., 25 Gy in 10 fractions or 20 Gy in 5 fractions) can be considered for patients without central nervous system involvement who have a response to chemo-immunotherapy and good PS. Concurrent treatment with PCI and immunotherapy or with TRT, PCI, and immunotherapy is appropriate after completion of initial therapy. All recommendations were agreed upon unanimously.

CONCLUSIONS

These consensus recommendations provide practical guidance regarding appropriate use of RT and immunotherapy in ES-SCLC while awaiting new clinical trial data.

Real-world evaluation of atezolizumab and etoposide-carboplatin as a first-line treatment for extensive-stage small cell lung cancer

BACKGROUND/AIMS

Despite the obvious benefits of adding immune checkpoint inhibitors to platinum-etoposide chemotherapy in patients with extensive-stage small-cell lung cancer (ES-SCLC), real-world data remain scarce.

METHODS

This retrospective study included 89 patients with ES-SCLC treated with platinum-etoposide chemotherapy alone (chemo-only group; n = 48) or in combination with atezolizumab (atezolizumab group; n = 41) and compared the survival outcomes between these two groups.

RESULTS

Overall survival (OS) was significantly longer in the atezolizumab group than in the chemo-only group (15.2 months vs. 8.5 months; p = 0.047), whereas the median progression-free survival was almost the same (5.1 months vs. 5.0 months) in both groups (p = 0.754). Subsequent multivariate analysis revealed that thoracic radiation (hazard ratio [HR], 0.223; 95% confidence interval [CI], 0.092-0.537; p = 0.001) and atezolizumab administration (HR, 0.350; 95% CI, 0.184-0.668; p = 0.001) were favorable prognostic factors for OS. In the thoracic radiation subgroup, patients who received atezolizumab demonstrated favorable survival outcomes and no grade 3-4 adverse events (AEs).

CONCLUSION

The addition of atezolizumab to platinum-etoposide resulted in favorable outcomes in this real-world study. Thoracic radiation was associated with improved OS and acceptable AE risk in combination with immunotherapy in patients with ES-SCLC.

Emerging Strategies for the Treatment of Small Cell Lung Cancer: A Review

Importance

Small cell lung cancer (SCLC) is an aggressive disease that is characterized by rapid growth and the early development of metastases. Patients typically respond to initial chemotherapy but quickly experience relapse, resulting in a poor long-term outcome. Therapeutic innovations that substantially improve survival have historically been limited, and reliable, predictive biomarkers are lacking.

Observations

This review examines the biologic characteristics of SCLC, the current treatment landscape, and ongoing efforts to identify novel therapeutic targets. Ongoing research has advanced the understanding of molecular categories and the immunologic microenvironment of SCLC, which in turn has helped improve disease classification and staging. Recently, immunotherapy-based regimens have become available for the management of SCLC, with 2 programmed cell death 1 ligand 1 inhibitors approved in combination with chemotherapy for first-line treatment of extensive-stage disease. For second-line treatment, a novel alkylating agent, lurbinectedin, which inhibits oncogenic transcription, has been approved for use in patients with metastatic SCLC. Furthermore, a wide variety of therapies and innovative combination regimens are being continuously evaluated. Potential therapeutic strategies, including aurora kinase A inhibitors, polyadenosine diphosphate-ribose polymerase inhibitors, ataxia telangiectasia and Rad3-related inhibitors, cyclin-dependent kinase 7 inhibitors, delta-like protein 3 agents, antiganglioside agents, CD47 inhibitors, and lysine-specific histone demethylase 1a inhibitors, are also being examined.

Conclusions and Relevance

Therapeutic optimization of SCLC remains a challenge, but recent trial results and drug approvals are encouraging. Advances in research have revealed critical information regarding biologic characteristics of the disease, which may lead to the identification of vulnerabilities and the development of new therapies. Further research focused on identifying biomarkers and evaluating innovative therapies will be paramount to improving treatment outcomes for patients with SCLC.

The efficacy of thoracic radiotherapy in extensive stage small cell lung cancer with baseline brain metastases: a multi-institutional retrospective cohort study

Background

Thoracic radiotherapy (TRT) had been shown to improve overall survival (OS) in extensive-stage small cell lung cancer (ES-SCLC) patients. However, approximately one fourth of SCLC harbored baseline brain metastases (BMs) and were excluded from previous TRT trials. Thus, the role of TRT in this sub-cohort of ES-SCLC requires elucidation. In this study, we evaluated the efficacy of TRT in ES-SCLC patients with clinically controlled baseline BMs.

Methods

In this retrospective, multi-institutional cohort study, 49 patients fully staged as ES-SCLC with baseline BM, had their disease controlled at all sites with no BM symptoms for three months since treatment initiation were included. The patients were allocated to TRT or no-TRT groups according to whether they received consolidative TRT before progression. Their baseline characteristics were compared using the χ² test. OS was selected as the primary observational endpoint. Survival and the incidence of cumulative progression between the groups were compared using log-rank analysis, and the interaction between TRT and selected factors was assessed via Cox proportional hazard analysis. Subgroup analysis was performed in oligo-metastasis patients (defined as five or fewer metastatic lesions in two or fewer organs).

Results

Seventeen (34.7%) patients received TRT, with a median dose of 54 Gy. The failure pattern analysis revealed initial intrathoracic progression in 31.3% and 66.7% of patients in the TRT no-TRT groups, respectively. Also, the TRT group had a significantly longer OS than the no-TRT group [hazard ratio (HR) 0.426, P=0.011]. Clinical covariates including age, gender, performance status, smoking, metastatic state, response after chemotherapy, and TRT, were included in multivariate regression analysis. TRT remained significantly correlated with better OS (HR 0.430, P=0.029). Twenty-three (46.9%) patients had oligo-metastasis at baseline. Subgroup analyses showed that TRT was significantly correlated with better OS in oligo-metastatic patients but not in non-oligo metastatic patients.

Conclusions

TRT improved the prognosis of select ES-SCLC patients with baseline BMs and should be considered in this sub-cohort, which has not been covered by previous randomized trials.

Thoracic Radiotherapy in Extensive Disease Small Cell Lung Cancer: Multicenter Prospective Observational TRENDS Study

(1) Introduction: Small cell lung cancer (SCLC) is an aggressive tumor type, accounting for about 15% of all lung cancers. Radiotherapy (RT) plays a fundamental role in both early and advanced stages. Currently, in advanced disease, the use of consolidative chest RT should be recommended for patients with good response to platinum-based first-line chemotherapy, but its use has not yet been standardized. The present prospective study aims to evaluate the pattern of care of consolidative chest RT in patients with advanced stage SCLC, and its effectiveness in terms of disease control and tolerability. (2) Materials and methods: This study was a multicenter prospective observational trial, proposed and conducted within the AIRO lung study group to evaluate the pattern of care of consolidative chest RT after first-line chemotherapy in patients with advanced SCLC. The patient and tumor characteristics, doses, fractionation and volumes of thoracic RT and prophylactic cranial irradiation (PCI), as well as the thoracic and extrathoracic response to the treatment, toxicity and clinical outcomes, were collected and analyzed. (3) Results: From January 2017 to December 2019, sixty-four patients were enrolled. Median follow-up was 33 months. The median age was 68 years (range 42-81); 38 patients (59%) were male and 26 (41%) female. Carboplatin + etoposide for 6 cycles was the most commonly used first-line therapeutic scheme (42%). With regard to consolidative chest RT, 56% of patients (35) received 30 Gy in 10 factions and 16 patients (26%) received 45 Gy in 15 sessions. The modulated intensity technique was used in 84.5% of cases, and post-chemotherapy macroscopic residual disease was the target volume in 87.5% of patients. Forty-four patients (69%) also underwent PCI. At the last follow-up, over 60% of patients did not experience chest disease progression, while 67% showed extrathoracic progression. At the first radiological evaluation after RT, complete response and stable disease were recorded in 6% and 46% of the cases, respectively. Two patients had a long-term complete response to the combined treatment. The brain was the first site of extrathoracic progression in 28%. 1y and 2y OS and PFS were 67%, 19%, 28% and 6%, respectively. Consolidative chest RT was well-tolerated in the majority of patients; it was interrupted in three cases (due to G2 pulmonary toxicity, disease progression and clinical decay, respectively). Only 1 patient developed G3 asthenia. (4) Conclusions: Consolidative chest RT has been shown to be useful in reducing the risk of thoracic disease progression and is absolutely well-tolerated in patients with advanced stage SCLC with good response after first-line chemotherapy. Among the Italian centers that participated in this study, there is still variability in the choice of fractionation and target volumes, although the guidelines contain clear recommendations. The aim of future research should be to clarify the role and modalities of chest RT in the era of immunotherapy in advanced-stage SCLC.

An Overview of the Role of Radiotherapy in the Treatment of Small Cell Lung Cancer - A Mainstay of Treatment or a Modality in Decline?

AIMS

Small cell lung cancer (SCLC) accounts for about 15% of all lung cancers. Chemotherapy, immunotherapy and radiotherapy all play important roles in the management of SCLC. The aim of this study was to provide a comprehensive overview of the role and evidence of radiotherapy in the cure and palliation of SCLC.

MATERIALS AND METHODS

The search strategy included a search of the PubMed database, hand searches, reference lists of relevant review articles and relevant published abstracts.

CLINICALTRIALS

gov was also queried for relevant trials.

RESULTS

Thoracic radiotherapy improves overall survival in limited stage SCLC, but the timing and dose remain controversial. The role of thoracic radiotherapy in extensive stage SCLC with immunotherapy is the subject of several ongoing trials. Current evidence supports the use of prophylactic cranial irradiation (PCI) for limited stage SCLC but the evidence is equivocal in extensive stage SCLC. Whole brain radiotherapy is well established for the treatment of brain metastases but evidence is rapidly accumulating for the use of stereotactic radiosurgery. Further studies will define the role of PCI, whole brain radiotherapy and hippocampal avoidant PCI in the immunotherapy era.

CONCLUSION

Radiotherapy is an essential component in the multimodality management of SCLC. Technological advances have allowed safer delivery of radiotherapy with reduced toxicities. Discussion at multidisciplinary team meetings is important to ensure radiotherapy is considered and offered in appropriate patients.

Dissecting Immunotherapy Strategies for Small Cell Lung Cancer: Antibodies, Ionizing Radiation and CAR-T

Small cell lung cancer (SCLC) is a highly aggressive malignancy that accounts for about 14% of all lung cancers. Platinum-based chemotherapy has been the only available treatment for a long time, until the introduction of immune checkpoint inhibitors (ICIs) recently changed first-line standard of care and shed light on the pivotal role of the immune system. Despite improved survival in a subset of patients, a lot of them still do not benefit from first-line chemo-immunotherapy, and several studies are investigating whether different combination strategies (with both systemic and local treatments, such as radiotherapy) may improve patient outcomes. Moreover, research of biomarkers that may be used to predict patients' outcomes is ongoing. In addition to ICIs, immunotherapy offers other different strategies, including naked monoclonal antibodies targeting tumor associated antigens, conjugated antibody, bispecific antibodies and cellular therapies. In this review, we summarize the main evidence available about the use of immunotherapy in SCLC, the rationale behind combination strategies and the studies that are currently ongoing in this setting, in order to give the reader a clear and complete view of this rapidly expanding topic.

Role of Local Treatment for Oligometastasis: A Comparability-Based Meta-Analysis

PURPOSE

We intend to investigate the oncological efficacy and feasibility of local consolidative therapy (LCT) through a meta-analysis method.

MATERIALS AND METHODS

Four databases including PubMed, MEDLINE, Embase, and Cochrane library were searched. Target studies are controlled trials comparing outcomes of LCT versus a control group. Primary endpoints are overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 54 studies involving 7,242 patients were included. Pooled analyses showed that the LCT arm could achieve improved OS with pooled odds ratio of 2.896 (95% confidence interval [CI], 2.377 to 3.528; p < 0.001). Regarding PFS, pooled analyses showed pooled odds ratio of 3.045 (95% CI, 2.356 to 3.937; p < 0.001) in favor of the LCT arm. In the subgroup analyses including the studies with reliable comparability (e.g. randomized studies or intentionally matched studies without significant favorable prognosticator in LCT arms), pooled odds ratio was 2.548 (95% CI, 1.808 to 3.591; p < 0.001) favoring the LCT arm regarding OS. Regarding PFS, pooled OR was 2.656 (95% CI, 1.713 to 4.120; p < 0.001) which also favored the LCT arm. Subgroup analyses limited to the randomized controlled trials (RCT) were also performed and pooled odds ratios on OS and PFS were 1.535 (95% CI, 1.082 to 2.177; p=0.016) and 1.668 (95% CI, 1.187 to 2.344; p=0.003). The rates of grade ≥ 3 complications related to LCT was mostly low (< 10%) and not significantly higher compared to the control arm.

CONCLUSION

Pooled analyses results of all included studies, selected studies with reliable comparability, and RCT's demonstrated the survival benefit of LCT. These consistent results suggest that LCT was beneficial to the patients with oligometastasis.

Protocol of the TREASURE study: Thoracic RadiothErapy with Atezolizumab in Small cell lUng canceR Extensive disease – a randomized, open-label, multicenter phase II trial

Background

Recently, the combination of the programmed death-ligand 1 (PD-L1) inhibitor atezolizumab with first-line chemotherapy has demonstrated to improve outcome for patients with advanced small cell lung cancer (SCLC), leading to approval of this regimen. At the same time, accumulating (pre-)clinical data suggest synergisms of radiotherapy and immunotherapy via the radiation-mediated induction of anti-tumor immunogenicity. Combining the recent findings, the TREASURE trial aims at further enhancing response to upfront chemo-immunotherapy by the addition of thoracic radiotherapy (TRT).

Methods/design

The TREASURE trial is a randomized, multicenter, phase II clinical trial (ClinicalTrials.gov identifier, NCT04462276). One hundred four patients suffering from extensive disease (ED) SCLC, with any response to the standard of care induction chemo-immunotherapy will be randomized to receive atezolizumab maintenance therapy with or without TRT. The primary endpoint of this study is overall survival (OS). Secondary endpoints include further measures of efficacy, safety, and the collection of biomarker samples. A safety interim analysis will take place after n = 23 patients receiving TRT have been observed for three months after the end of TRT.

Discussion

This trial will investigate whether treatment efficacy can be improved by adding TRT to atezolizumab maintenance therapy in ED SCLC patients with any response after chemo-immunotherapy. Safety and feasibility of such a regimen will be evaluated, and biomaterials for a translational research project will be collected. Together, the results of this trial will deepen our comprehension of how checkpoint inhibition and radiotherapy interact and contribute to the evolving landscape of SCLC therapy.

Trial registration

Clinicaltrials.gov identifier: NCT04462276 (Date of initial registration: 8th July 2020), https://clinicaltrials.gov/ct2/show/NCT04462276

Eudra-CT Number: 2019-003916-29 (Date of initial registration: 30th March 2020), https://www.clinicaltrialsregister.eu/ctr-search/trial/2019-003916-29/DE

Risk Factors for Brain Metastases in Patients With Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

The use of prophylactic cranial irradiation (PCI) for small cell lung cancer (SCLC) patients is controversial. Risk factors for brain metastasis (BM) development are largely lacking, hampering personalized treatment strategies. This study aimed to identify the possible risk factors for BM in SCLC.We systematically searched the Pubmed database (1 January 1995 to 18 January 2021) according to the PRISMA guidelines. Eligibility criteria: studies reporting detailed BM data with an adequate sample size (randomized clinical trials [RCTs]: N ≥50; non-RCTs: N ≥100) in patients with SCLC. We summarized the reported risk factors and performed meta-analysis to estimate the pooled hazard ratios (HR) if enough qualified data (i.e., two or more studies; the same study type; the same analysis method; and HRs retrievable) were available. In total, 61/536 records were eligible (18 RCTs and 39 non-RCTs comprising 13,188 patients), in which 57 factors were reported. Ten factors qualified BM data for meta-analysis: Limited stage disease (LD) (HR = 0.34, 95% CI: 0.17-0.67; P = 0.002) and older age (≥65) (HR = 0.70, 95% CI: 0.54-0.92; P = 0.01) were associated with less BM; A higher T stage (≥T3) (HR = 1.72, 95% CI: 1.16-2.56; P = 0.007) was a significant risk factor for BM. Male sex (HR = 1.24, 95% CI: 0.99-1.54; P = 0.06) tended to be a risk factor, and better PS (0-1) (HR = 0.66, 95% CI: 0.42-1.02; P = 0.06) tended to have less BM. Smoking, thoracic radiotherapy dose were not significant (P >0.05). PCI significantly decreased BM (P <0.001), but did not improve OS in ED-SCLC (P = 0.81). A higher PCI dose did not improve OS (P = 0.11). The impact on BM was conflicting between Cox regression data (HR = 0.59, 95% CI: 0.26-1.31; P = 0.20) and competing risk regression data (HR = 0.74, 95% CI: 0.55-0.99; P = 0.04). Compared to M0-M1a, M1b was a risk factor for OS (P = 0.01) in ED-SCLC, but not for BM (P = 0.19). As regular brain imaging is rarely performed, high-quality data is lacking. Other factors such as N-stage and blood biomarkers had no qualified data to perform meta-analysis. In conclusion, younger age, higher T stage, and ED are risk factors for BM, suggesting that PCI should be especially discussed in such cases. Individual patient data (IPD) meta-analysis and well-designed RCTs are needed to better identify more risk factors and further confirm our findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021228391, identifier CRD42021228391.

Radiation therapy for extensive-stage small-cell lung cancer in the era of immunotherapy

Unlike non-small-cell lung cancer (NSCLC), the progression of small-cell lung cancer (SCLC) is slow. Extensive-stage SCLC (ES-SCLC) is a serious threat to human health, with a 5-year survival rate of <7%. Chemotherapy has been the first-line treatment for the past 30 years. The anti-PD-L1 checkpoint blockades durvalumab and atezolizumab have greatly prolonged overall survival and have become the standard first-line therapy for ES-SCLC since the CASPIAN and IMpower133 trials. In the era of chemotherapy, radiation therapy (RT), including thoracic radiation therapy (TRT) and brain radiation therapy (BRT), has shown clinical effects in randomized and retrospective studies on ES-SCLC. RT-immunotherapy has shown exciting synergistic effects in NSCLC. For ES-SCLC, the clinical effects of combining TRT/BRT with immunotherapy have not yet been systematically explored. In this review, we found that studies on RT-immunotherapy in ES-SCLC are relatively few and limited to early phase studies focusing on toxicity. The efficacy and safety profiles of early phase studies encourage prospective clinical trials. In this review, we discuss the best population, optimum TRT dose, proper TRT time, and strategies for reducing radiation-induced neurotoxicity. Furthermore, we suggest that biomarkers and patient performance status should be fully assessed before RT-immunotherapy treatment. Prospective trials are needed to provide more evidence for RT-immunotherapy applications in ES-SCLC.

Combined radio-immunotherapy: An opportunity to increase the therapeutic ratio of oligometastasis-directed radiotherapy

The utility of radiotherapy as a means of palliating symptoms due to metastatic cancer is well-accepted. A growing body of literature suggests that radiotherapy may play a role beyond palliation in some patients with low-burden metastatic disease. Recent data suggest that oligometastasis-directed radiotherapy may improve progression-free and even overall survival in select patients. Immunotherapy also has a growing role in the management of patients with metastatic cancer and, like radiotherapy, appears to be most effective in the setting of low-volume disease. Thus, the addition of immunotherapy may be a feasible means of increasing the therapeutic ratio of metastasis-directed radiotherapy, particularly among patients with oligometastatic cancer.

Pooled analysis on image-guided moderately hypofractionated thoracic irradiation in inoperable node-positive/recurrent patients with non-small cell lung cancer with poor prognostic factors and severely limited pulmonary function and reserve

BACKGROUND

The objective of this study was to investigate the feasibility and efficacy of image-guided moderately hypofractionated thoracic radiotherapy (hypo-IGRT) in patients with non-small cell lung cancer (NSCLC) with poor performance status and severely limited pulmonary function and reserve.

METHODS

Consecutive inoperable patients who had node-positive, stage IIB-IIIC (TNM, 8th edition) or recurrent NSCLC, had an Eastern Cooperative Oncology Group performance status ≥1, and had a forced expiratory volume in 1 second (FEV₁ ) ≤1.0 L, had a single-breath diffusing capacity of the lung for carbon monoxide (DLCO-SB) ≤40% and/or on long-term oxygen therapy were analyzed. All patients received hypofractionated IGRT to a total dose of 42.0 to 49.0 Gy/13 to 16 fractions (2.8-3.5 Gy/fraction) (equivalent dose in 2-Gy fractions/biologically effective dose [α/β = 10] = 45.5-55.1 Gy/54.6-66.2 Gy) alone. Patients were monitored closely for nonhematological toxicity, which was classified per National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

Between 2014 and 2021, 47 consecutive patients with a median age of 72 years (range, 52.2-88 years) were treated. At baseline, the median FEV₁ , vital capacity, and DLCO-SB were 1.17 L (range, 0.69-2.84 L), 2.34 L (range, 1.23-3.74 L), and 35% predicted (range, 13.3%-69.0%), respectively. The mean and median planning target volumes were 410.8 cc (SD, 267.1 cc) and 315.4 cc (range, 83.4-1174.1 cc). With a median follow-up of 28.9 months (range, 0.5-90.6 months) after RT, the median progression-free survival (PFS)/overall survival (OS) and 6- and 12-month PFS/OS rates were 10.4 months (95% CI, 7-13.8 months)/18.3 months (95% CI, 9.2-27.4 months), 70%/89.4%, and 38.8%/66%, respectively. Treatment was well tolerated with only 1 case each of grade 3 pneumonitis and esophagitis. No toxicity greater than grade 3 was observed.

CONCLUSIONS

Patients with inoperable node-positive NSCLC, a poor performance status, and severely limited lung function can be safely and effectively treated with individualized moderately hypofractionated IGRT. The achieved survival rates for this highly multimorbid group of patients were encouraging.

Bombesin-drug conjugates in targeted therapy for small cell lung cancer

Small cell lung cancer (SCLC) is a aggressive form of primary lung neoplasm that often presents in elderly smokers. While stage I SCLC can be managed with surgery, extensive-stage disease is managed with chemotherapy using etoposide and cisplatin among other agents, and often complemented by radiation therapy to the chest and cranium. Recent advances in pharmacological research have yielded novel antibody and peptide-conjugated adjunctive chemotherapy, of which bombesin and bombesin receptors have played an important role due to their overexpression in SCLC and other lung cancers. Chemotherapy agents conjugated to bombesin or bombesin-like peptides often demonstrate higher therapeutic efficacy, greater treatment specificity, as well as improved cytotoxicity towards SCLC cells that demonstrate drug resistance. Further modifications to the bombesin-drug conjugate, such as liposomal preparation, have further enhanced bio-availability and half-life of the compound. Additionally, bombesin-radioisotope conjugates can be used for early detection of SCLC using positron emission tomography, as well as subsequent targeted adjuvant radiotherapy to help minimize radiation-induced fibrosis of healthy tissue. Ultimately, further studies are imperative to capitalize on the various applications of bombesin conjugates in both the diagnosis and management of SCLC.

Consolidative Thoracic Radiation Therapy After First-Line Chemotherapy and Immunotherapy in Extensive-Stage Small Cell Lung Cancer: A Multi-Institutional Case Series

Purpose

Survival for patients with extensive-stage small cell lung cancer (ES-SCLC) remains poor. Consolidative thoracic radiation therapy (cTRT) and upfront immunotherapy with chemotherapy have each incrementally improved patient outcomes, but have not yet been combined in clinical trials. We sought to characterize outcomes and toxicities after first-line chemotherapy and immunotherapy followed by cTRT.

Methods and Materials

Patients with ES-SCLC who were treated with first-line chemotherapy and immunotherapy followed by cTRT were identified at 2 institutions. Patient outcomes including overall survival (OS), progression-free survival, local progression-free survival, distant progression free-survival, and toxicity were assessed.

Results

Twenty patients were included in our data set treated from 2018 to 2021 with a median follow-up of 12 months. Median OS in this cohort was 16 months with 6-month OS of 94.7% and 12-month OS of 77.5% (comparable to historical controls). There were also low rates of toxicity, including 0% grade 3+ toxicity, 0% grade 2 pneumonitis, and 5% grade 2 esophagitis.

Conclusions

Treatment of ES-SCLC with first-line chemoimmunotherapy followed by cTRT appears to be safe and to have outcomes comparable to published modern clinical trials. Further studies are warranted to determine the therapeutic effect of cTRT after chemoimmunotherapy.

Radiotherapy for primary lung cancer

Herein are presented the recommendations from the Société française de radiothérapie oncologique regarding indications and modalities of lung cancer radiotherapy. The recommendations for delineation of the target volumes and organs at risk are detailed.

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.

Revisiting a Null Hypothesis: Exploring the Parameters of Oligometastasis Treatment

PURPOSE

In the treatment of patients with metastatic cancer, the current paradigm states that metastasis-directed therapy does not prolong life. This paradigm forms the basis of clinical trial null hypotheses, where trials are built to test the null hypothesis that patients garner no overall survival benefit from targeting metastatic lesions. However, with advancing imaging technology and increasingly precise techniques for targeting lesions, a much larger proportion of metastatic disease can be treated. As a result, the life-extending benefit of targeting metastatic disease is becoming increasingly clear.

METHODS AND MATERIALS

In this work, we suggest shifting this qualitative null hypothesis and describe a mathematical model that can be used to frame a new, quantitative null. We begin with a very simple formulation of tumor growth, an exponential function, and illustrate how the same intervention (removing a given number of cells from the tumor) at different times affects survival. Additionally, we postulate where recent clinical trials fit into this parameter space and discuss the implications of clinical trial design in changing these quantitative parameters.

RESULTS

Our model shows that although any amount of cell kill will extend survival, in many cases the extent is so small as to be unnoticeable in a clinical context or is outweighed by factors related to toxicity and treatment time.

CONCLUSIONS

Recasting the null in these quantitative terms will allow trialists to design trials specifically to increase understanding of the circumstances (patient selection, disease burden, tumor growth kinetics) that can lead to improved overall survival when targeting metastatic lesions, rather than whether targeting metastases extends survival for patients with (oligo-) metastatic disease.

Role of radiation in extensive stage small cell lung cancer: a National Cancer Database registry analysis

The role of prophylactic cranial irradiation (PCI) and thoracic radiation therapy (TRT) in extensive-stage small cell lung cancer remains controversial. The authors examined the National Cancer Database and identified patients with extensive-stage small cell lung cancer with no brain metastasis. Patients were excluded if they died 30 days from diagnosis, did not receive polychemotherapy, had other palliative radiation or had missing information. A propensity score-matched analysis was also performed. A total of 21,019 patients were identified. The majority of patients did not receive radiation (69%), whereas 10% received PCI and 21% received TRT. The addition of PCI and TRT improved median survival and survival at 1 and 2 years (p ≤ 0.05). The propensity score-matched analysis confirmed the same overall survival benefit with both PCI and TRT. This registry-based analysis of >1500 accredited cancer programs shows that PCI and TRT are not commonly utilized for extensive-stage small cell lung cancer patients who are treated with multiagent chemotherapy. The addition of PCI and TRT significantly improves overall survival in this otherwise poor prognostic group. Further research is needed to confirm the role of PCI and TRT, especially in the era of improved systemic therapy.

Prognostic factor analysis of patients with small cell lung cancer: Real-world data from 988 patients

Background

Small cell lung cancer (SCLC) is characterized by aggressive spread and poor prognosis, but has limited treatment options. Results of prognostic factors from randomized trials on treatment arrangement are conflicting and large‐scale real‐world analysis is lacking.

Methods

Patients diagnosed SCLC between 2008 and 2018 in Peking University Cancer Hospital were included in this study. Kaplan–Meier methods were adopted, and univariate analysis and multivariate Cox regression models were constructed to analyze prognostic factors.

Results

Among 1045 patients who presented to our center, 988 eligible patients were identified. Median overall survival (OS) was 16.0 months for the whole group, 24.0 months and 11.0 months for limited stage small cell lung cancer (LS‐SCLC) and extensive stage small cell lung cancer (ES‐SCLC), separately. Limited‐stage, good performance status (PS) (ECOG 0–1), response to primary systemic treatment, and patients who received initiative irradiation and three or more lines of chemotherapy were predicted to have better OS in the whole group. Only response to first‐line systemic therapy and prophylactic cranial irradiation (PCI) were independent prognostic factors of survival in LS‐SCLC; while good PS (ECOG 0–1), without liver, bone, or subcutaneous metastases, response to first‐line therapy, initial local irradiation, and three or more lines of systemic therapy predicted a favorable prognosis in ES‐SCLC.

Conclusions

The present study retrieved from large real–world data suggested that response to primary systemic therapy and aggressive radiotherapy are independent prognostic factors for SCLC. PCI and initiative irradiation for original or metastatic sites improved the OS in LS‐SCLC and ES‐SCLC, respectively.

Development and validation of a nomogram for assessing survival in extensive-stage small-cell lung cancer patients with superior vena cava syndrome referred for thoracic radiotherapy: a comparison of upfront vs. consolidative approaches

PURPOSE

This study sought to design and validate a nomogram capable of predicting outcomes in extensive-stage small-cell lung cancer (ES-SCLC) patients with superior vena cava syndrome (SVCS) based upon the timing of their radiotherapy treatment.

METHODS

We retrospectively analyzed data from 175 ES-SCLC patients with SCVS, comparing outcomes between those that underwent upfront thoracic radiotherapy (initial radiotherapy with simultaneous chemotherapy) and those that underwent consolidative thoracic radiotherapy (following 4-6 cycles of chemotherapy). Significant predictors of patient outcomes were identified using a Cox proportional hazard model and were used to construct our nomogram. This model was subsequently validated using receiver operating characteristic (ROC) curves, concordance index (C-index) values, and a risk classification system in order to evaluate its discriminative and predictive accuracy.

RESULTS

The overall survival (OS) of ES-SCLC patients with SVCS that underwent chemotherapy (CT), consolidative thoracic radiotherapy (cc-TRT), and upfront thoracic radiotherapy (cu-TRT) was 8.2, 11.7, and 14.9 months, respectively (p < 0.001), with respective progression-free survival (PFS) durations of 3.3, 5.0, and 7.3 months (p < 0.001). A multivariate regression analysis revealed age, gender, ECOG performance status, sites of tumor metastasis, and treatment approach to all be independent predictors of survival outcomes. A nomogram was therefore developed incorporating these factors. C‑index values upon internal and external validation of this nomogram were 0.7625 and 0.7959, respectively, and ROC and calibration curves revealed this model to be accurate and consistent.

CONCLUSIONS

We found that upfront thoracic radiotherapy in combination with chemotherapy may be associated with a positive impact on outcomes in ES-SCLC patients with SVCS.

Thoracic radiotherapy in small cell lung cancer-a narrative review

Small-cell lung cancer (SCLC) represents 10–15% of all lung cancers and has a poor prognosis. Thoracic radiotherapy plays a central role in current SCLC management. Concurrent chemoradiotherapy (CTRT) is the standard of care for localised disease (stage I−III, limited-stage, LS). Definitive thoracic radiotherapy may be offered in metastatic patients (stage IV, extensive stage, ES-SCLC) after chemotherapy. For LS-SCLC, the gold standard is early accelerated hyperfractionated twice-daily CTRT (4 cycles of cisplatin etoposide, starting with the first or second chemotherapy cycle). Modern radiation techniques should be used with involved-field radiotherapy based on baseline CT and PET/CT scans. In ES-SCLC, thoracic radiotherapy should be discussed in cases of initial bulky mediastinal disease/residual thoracic disease not progressing after induction chemotherapy. This strategy was however not assessed in recent trials establishing chemo-immunotherapy as the standard first line treatment in ES-SCLC. Future developments include technical radiotherapy advances and the incorporation of new drugs. Thoracic irradiation is delivered more precisely given technical developments (IMRT, image-guided radiotherapy, stereotactic radiotherapy), reducing the risks of severe adverse events. Stereotactic ablative radiotherapy may be discussed in rare early stage (T1 to 2, N0) inoperable patients. A number of current clinical trials are investigating immunoradiotherapy. In this review, we highlight the current role of thoracic radiotherapy and describe ongoing research in the integration of biological surrogate markers, advanced radiotherapy technologies and novel drugs in SCLC patients.

GOECP/SEOR radiotherapy guidelines for small-cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 20% of all lung cancers. The main treatment is chemotherapy (Ch). However, the addition of radiotherapy significantly improves overall survival (OS) in patients with non-metastatic SCLC and in those with metastatic SCLC who respond to Ch. Prophylactic cranial irradiation reduces the risk of brain metastases and improves OS in both metastatic and non-metastatic patients. The 5-year OS rate in patients with limited-stage disease (non-metastatic) is slightly higher than 30%, but less than 5% in patients with extensive-stage disease (metastatic). The present clinical guidelines were developed by Spanish radiation oncologists on behalf of the Oncologic Group for the Study of Lung Cancer/Spanish Society of Radiation Oncology to provide a current review of the diagnosis, planning, and treatment of SCLC. These guidelines emphasise treatment fields, radiation techniques, fractionation, concomitant treatment, and the optimal timing of Ch and radiotherapy. Finally, we discuss the main indications for reirradiation in local recurrence.

Role of thoracic radiation in extensive stage small cell lung cancer: a NCDB analysis

Prognosis of extensive stage small cell lung cancer (ES-SCLC) remains poor. Previous randomized trials suggested consolidation chest radiation (CXRT) has a modest survival benefit; however, its role in subgroups of ES-SCLC, especially ipsilateral pleural effusion (IPE), is unknown. Using National Cancer Database (NCDB), 283,347 ES-SCLC cases diagnosed between 2004 and 2017 were screened. Eligible cases must have been staged with 7th edition of staging system and have information about clinical T and N stage, and minimum follow-up of one month. Role of CXRT was examined in M1a, M1b, and IPE subgroups. Surveillance, Epidemiology, and End Results Program (SEER) was analyzed as independent validation. Univariate, multivariate analyses were conducted with cox proportional hazard model. A P value < 0.05 was considered as statistically significant. A total of 36,762 were analyzed. In both M1a and IPE groups, use of CXRT was significantly associated with younger age, female sex, non-academic institution, and clinical T stage. Both univariate and multivariate analyses showed that use of CXRT demonstrated significantly longer overall survival in all the groups, with lower hazard ratios in M1a and IPE groups than M1b (univariate hazard ratio 0.62, 0.56, and 0.72, respectively). Propensity score analysis of IPE group showed the survival advantage with hazard ratio of 0.54. Use of SEER data validated its survival advantage of CXRT in IPE group. This retrospective database analysis suggests M1a and IPE subgroups have more survival benefit of CXRT than M1b subgroup. Further studies are warranted to confirm the hypothesis.

Radiation Therapy for Small-Cell Lung Cancer: ASCO Guideline Endorsement of an ASTRO Guideline

PURPOSE

The American Society for Radiation Oncology (ASTRO) produced an evidence-based guideline on radiation therapy (RT) for small-cell lung cancer (SCLC). Because of the relevance of this topic to ASCO membership, ASCO reviewed the guideline, applying a set of procedures and policies used to critically examine guidelines developed by other organizations.

METHODS

The ASTRO guideline on RT for SCLC was reviewed for developmental rigor by methodologists. Then, an ASCO Expert Panel reviewed the content and the recommendations.

RESULTS

The ASCO Expert Panel determined that the recommendations from ASTRO guideline on RT for SCLC, published in June 2020, are clear, thorough, and based upon the most relevant scientific evidence. ASCO endorsed ASTRO guideline on RT for SCLC with a few discussion points.

RECOMMENDATIONS

Recommendations addressed thoracic radiotherapy for limited-stage SCLC, role of stereotactic body radiotherapy in stage I or II node-negative SCLC, prophylactic cranial radiotherapy, and thoracic consolidation for extensive-stage SCLC. Additional information is available at www.asco.org/thoracic-cancer-guidelines .

Clinical outcomes of extensive-stage small cell lung cancer patients treated with thoracic radiotherapy at different times and fractionations

Objective

The purpose of this study was to assess whether thoracic radiotherapy (TRT) combined with chemotherapy (CHT) showed promising anti-tumour activity in extensive-stage small cell lung cancer (ES-SCLC), to explore practice patterns for the radiation time and dose/fractionation and to identify prognostic factors for patients who would benefit from CHT/TRT.

Methods

A total of 492 ES-SCLC patients were included from January 2010 to March 2019, 244 of whom received CHT/TRT. Propensity score matching was performed to minimize bias between the CHT/TRT and CHT-alone groups. Patients in the CHT/TRT group were categorized into four subgroups based on the number of induction CHT cycles. For effective dose fractionation calculations, we introduced the time-adjusted biological effective dose (tBED). Categorical variables were analysed with chi-square tests and Fisher’s exact tests. Kaplan–Meier curves were generated to estimate survival rates using the R-project. Multivariate prognostic analysis was performed with Cox proportional hazards models.

Results

Patients who received CHT/TRT experienced improved overall survival (OS) (18.1 vs 10.8 months), progression-free survival (PFS) (9.3 vs 6.0 months) and local recurrence-free survival (LRFS) (12.0 vs 6.6 months) before matching, with similar results after matching. In the CHT/TRT group, the median LRFS times for the groups based on the radiation time were 12.7, 12.0, 12.0, and 9.0 months, respectively. Early TRT had a tendency to prolong PFS (median 10.6 vs 9.8 vs 9.0 vs 7.7 months, respectively, p = 0.091) but not OS (median 17.6 vs 19.5 vs 17.2 vs 19.0 months, respectively, p = 0.622). Notably, patients who received TRT within 6 cycles of CHT experienced prolonged LRFS (p = 0.001). Regarding the radiation dose, patients in the high-dose group (tBED > 50 Gy) who achieved complete response and partial response (CR and PR) to systemic therapy had relatively short OS (median 27.1 vs 22.7, p = 0.026) and PFS (median 11.4 vs 11.2, p = 0.032), but the abovementioned results were not obtained after the exclusion of patients who received hyperfractionated radiotherapy (all p > 0.05).

Conclusion

CHT/TRT could improve survival for ES-SCLC patients. TRT performed within 6 cycles of CHT and hyperfractionated radiotherapy (45 Gy in 30 fractions) may be a feasible treatment scheme for ES-SCLC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01773-x.

New Therapies and Biomarkers: Are We Ready for Personalized Treatment in Small Cell Lung Cancer?

Small cell lung cancer (SCLC) is an aggressive form of lung cancer with a 5-year survival rate of less than 7%. In contrast to non-small cell lung cancer, SCLC has long been treated as a homogeneous disease without personalized treatment options. In recent years, the incorporation of immunotherapy into the treatment paradigm has brought moderate benefit to patients with SCLC; however, more effective therapies are urgently needed. In this article, we describe the current treatment standards and emerging therapeutic approaches for the treatment of SCLC. We also discuss promising biomarkers in SCLC and the recently discovered four subtypes of SCLC, each with its unique therapeutic vulnerability. Lastly, we discuss the advances in radiation therapy for the treatment of SCLC.

X-change symposium: status and future of modern radiation oncology-from technology to biology

Future radiation oncology encompasses a broad spectrum of topics ranging from modern clinical trial design to treatment and imaging technology and biology. In more detail, the application of hybrid MRI devices in modern image-guided radiotherapy; the emerging field of radiomics; the role of molecular imaging using positron emission tomography and its integration into clinical routine; radiation biology with its future perspectives, the role of molecular signatures in prognostic modelling; as well as special treatment modalities such as brachytherapy or proton beam therapy are areas of rapid development. More clinically, radiation oncology will certainly find an important role in the management of oligometastasis. The treatment spectrum will also be widened by the rational integration of modern systemic targeted or immune therapies into multimodal treatment strategies. All these developments will require a concise rethinking of clinical trial design. This article reviews the current status and the potential developments in the field of radiation oncology as discussed by a panel of European and international experts sharing their vision during the "X-Change" symposium, held in July 2019 in Munich (Germany).