Cardiac Toxicity of Thoracic Radiotherapy: Existing Evidence and Future Directions

Cardiovascular comorbidities and their prognostic value in small cell lung cancer patients with chemoradiotherapy

BACKGROUND

Small cell lung cancer (SCLC) is an extremely malignant subtype of lung cancer because of its high potential for metastases. Cardiac invasion of SCLC is a serious concern that may lead to systemic embolism or tract obstruction. It has aroused much concern that cardiovascular comorbidities may significantly affect the survival of SCLC patients and their treatment decisions.

METHODS

We consecutively recruited 772 small cell lung cancer (SCLC) patients between January 2011 and December 2018 from 4 cancer specialty hospitals in China. Only newly diagnosed primary cancer inpatients were included. Univariable and multivariable adjusted Cox proportional hazard models were conducted to evaluate the risk factors associated with mortality. Hazard ratios (HRs) for mortality and corresponding 95% confidence intervals (95% CIs) were calculated.

RESULTS

The prevalence of cardiovascular diseases (CVDs) was 34.6% in all SCLC patients. Log-rank analysis presented statistically significant differences in median survival time (MST) between patients with CVD and without CVD in all SCLC patients (9.0 months vs. 15.0 months, P = 0.005) and patients with chemotherapy only (12.0 months vs. 18.0 months, P = 0.048). Pericardial effusion (HR 1.671, 95% CI 1.082-2.580, P = 0.021) and heart failure (HR 1.752, 95% CI 1.290-2.379, P < 0.001) were independent risk factors associated with mortality in all SCLC patients. VTE is related to poorer prognosis in patients with chemotherapy only (HR 5.558, 95% CI 1.335-23.135, P = 0.018) and chemoradiotherapy (HR 3.057, 95% CI 1.270-7.539, P = 0.013).

CONCLUSIONS

Comprehensive management of CVD comorbidities is of vital importance for the long-term prognosis of SCLC patients.

Baseline shift corrections towards the heart: External validation of the impact on survival in early-stage NSCLC patients

PURPOSE

To externally validate Johnson-Hart et al. findings: the association of tumor baseline shifts towards the heart with overall survival (OS) in SBRT for NSCLC. Further analysis included investigating the presence of interfractional heart baseline shifts and the association of OS with heart dose change during treatment.

METHODS

Data from 416 SBRT early-stage NSCLC patients was collected. Pearson's correlations (PCCs) between clinical variables and treatment-averaged tumor shifts towards/away from the heart were explored. Validation of published multivariable Cox model was performed. PCCs between heart and tumor baseline shifts were analyzed. Dose accumulation was performed following daily CBCT-to-pCT deformable registration. Maximum heart dose (D0) was computed for planned and accumulated doses. Differences in OS according to shifts towards/away from the heart or D0 increase/decrease were analyzed. Significant D0 differences between patients with D0 increase/decrease and different tumor locations were explored.

RESULTS

Tumor shifts towards/away from the heart showed no significant association with OS (p = 0.91). Distance between PTV and heart correlated significantly (PCC = 0.18) with shifts to the heart. Cox model did not validate in our cohort. Heart presented baseline shifts positively correlated with tumor baseline shifts in all three directions (PCC ≥ 0.38; p < 0.001). Counterintuitively, patients experiencing increased D0 during treatment showed significantly better OS (p = 0.0077). Upper-lobe tumor patients with increased D0 had lower D0 than those with decreased D0 (right-upper-lobe p ≤ 0.018).

CONCLUSIONS

In our SBRT cohort, the shifts towards the heart were not associated with worse OS. Moderate correlations were found between tumor and heart baseline shifts in each direction. Moreover, the distance between the PTV and the heart showed a significant correlation with shifts to the heart.

Artificial intelligence: The future for multimodality imaging of right ventricle

The crucial pathophysiological and prognostic roles of the right ventricle in various diseases have been well-established. Nonetheless, conventional cardiovascular imaging modalities are frequently associated with intrinsic limitations when evaluating right ventricular (RV) morphology and function. The integration of artificial intelligence (AI) in multimodality imaging presents a promising avenue to circumvent these obstacles, paving the way for future fully automated imaging paradigms. This review aimed to address the current challenges faced by clinicians and researchers in integrating RV imaging and AI technology, to provide a comprehensive overview of the current applications of AI in RV imaging, and to offer insights into future directions, opportunities, and potential challenges in this rapidly advancing field.

Cardiac substructure delineation in radiation therapy - A state-of-the-art review

Delineation of cardiac substructures is crucial for a better understanding of radiation-related cardiotoxicities and to facilitate accurate and precise cardiac dose calculation for developing and applying risk models. This review examines recent advancements in cardiac substructure delineation in the radiation therapy (RT) context, aiming to provide a comprehensive overview of the current level of knowledge, challenges and future directions in this evolving field. Imaging used for RT planning presents challenges in reliably visualising cardiac anatomy. Although cardiac atlases and contouring guidelines aid in standardisation and reduction of variability, significant uncertainties remain in defining cardiac anatomy. Coupled with the inherent complexity of the heart, this necessitates auto-contouring for consistent large-scale data analysis and improved efficiency in prospective applications. Auto-contouring models, developed primarily for breast and lung cancer RT, have demonstrated performance comparable to manual contouring, marking a significant milestone in the evolution of cardiac delineation practices. Nevertheless, several key concerns require further investigation. There is an unmet need for expanding cardiac auto-contouring models to encompass a broader range of cancer sites. A shift in focus is needed from ensuring accuracy to enhancing the robustness and accessibility of auto-contouring models. Addressing these challenges is paramount for the integration of cardiac substructure delineation and associated risk models into routine clinical practice, thereby improving the safety of RT for future cancer patients.

Recommendations for Post-Operative RadioTherapy After Complete Resection of Thymoma-a French DELPHI Consensus Initiative

INTRODUCTION

Thymomas are rare intrathoracic malignancies that can relapse after surgery. Whether or not Post-Operative RadioTherapy (PORT) should be delivered after surgery remains a major issue. RADIORYTHMIC is an ongoing, multicenter, randomized phase 3 trial addressing this question in patients with completely R0 resected Masaoka-Koga stage IIb/III thymoma. Experts in the field met to develop recommendations for PORT.

METHODS

A scientific committee from the RYTHMIC network identified key issues regarding the modalities of PORT in completely resected thymoma. A DELPHI method was used to question 24 national experts, with 115 questions regarding the following: (1) imaging techniques, (2) clinical target volume (CTV) and margins, (3) dose constraints to organs at risk, (4) dose and fractionation, and (5) follow-up and records. Consensus was defined when opinions reached more than or equal to 80% agreement.

RESULTS

We established the following recommendations: preoperative contrast-enhanced computed tomography (CT) scan is recommended (94% agreement); optimization of radiation delivery includes either a four-dimensional CT-based planning (82% agreement), a breath-holding inspiration breath-hold-based planning, or daily control CT imaging (81% agreement); imaging fusion based on cardiovascular structures of preoperative and planning CT scan is recommended (82% agreement); right coronary and left anterior descending coronary arteries should be delineated as cardiac substructures (88% agreement); rotational RCMI/volumetric modulated arc therapy is recommended (88% agreement); total dose is 50 Gy (81% agreement) with 1.8 to 2 Gy per fraction (94% agreement); cardiac evaluation and follow-up for patients with history of cardiovascular disease are recommended (88% agreement) with electrocardiogram and evaluation of left ventricular ejection fraction at 5 years and 10 years.

CONCLUSION

This is the first consensus for PORT in thymoma. Implementation will help to harmonize practices.

A bibliometric analysis of cardiotoxicity in cancer radiotherapy

Background

Radiotherapy, a primary treatment for malignant cancer, presents significant clinical challenges globally due to its associated adverse effects, especially with the increased survival rates of cancer patients. Radiation induced heart disease (RIHD) significantly impacts the long-term survival and quality of life of cancer survivors as one of the most devastating consequences. Quite a few studies have been conducted on preclinical and clinical trials of RIHD, showing promising success to some extent. However, no researchers have performed a comprehensive bibliometric study so far.

Objective

This study attempts to gain a deeper understanding of the focal points and patterns in RIHD research and to pinpoint prospective new research avenues using bibliometrics.

Methods

The study group obtained related 1554 publications between 1990 and 2023 on the Web of Science Core Collection (WOSCC) through a scientific search query. Visualization tools like CiteSpace and VOSviewer were utilized to realize the visual analysis of countries, authors, journals, references and keywords, identifying the hotspots and frontiers in this research field.

Results

After collecting all the data, a total of 1554 documents were categorized and analyzed using the above tools. The annual number of publications in the field of RIHD shows a continuous growth trend. In 2013, there was a significant rise in the number of linked publications, with the majority of authors being from the USA, according to the statistics. Among all the journals, INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS published the most relevant papers. Cluster analysis of the references showed that research on RIHD has focused on breast cancer, non-small cell lung cancer (NSCLC), and Hodgkin's lymphoma (also among the three main clusters), preclinical research, childhood cancer, heart dose, coronary artery disease, etc, which are also hot topics in the field. High-frequency keywords in the analysis include risk factors, cancer types, heart disease, survival, trials, proton therapy (PT), etc.

Conclusion

Future research on RIHD will mostly focus on thoracic cancer, whose exact cause is yet unknown, with preclinical trials playing an important role. Preventing, consistently monitoring, promptly diagnosing, and timely treating are crucial to decreasing RIHD and extending the life expectancy of cancer survivors.

Dose-dependent changes in cardiac function, strain and remodelling in a preclinical model of heart base irradiation

BACKGROUND AND PURPOSE

Radiation induced cardiotoxicity (RICT) is as an important sequela of radiotherapy to the thorax for patients. In this study, we aim to investigate the dose and fractionation response of RICT. We propose global longitudinal strain (GLS) as an early indicator of RICT and investigate myocardial deformation following irradiation.

METHODS

RICT was investigated in female C57BL/6J mice in which the base of the heart was irradiated under image-guidance using a small animal radiation research platform (SARRP). Mice were randomly assigned to a treatment group: single-fraction dose of 16 Gy or 20 Gy, 3 consecutive fractions of 8.66 Gy, or sham irradiation; biological effective doses (BED) used were 101.3 Gy, 153.3 Gy and 101.3 Gy respectively. Longitudinal transthoracic echocardiography (TTE) was performed from baseline up to 50 weeks post-irradiation to detect structural and functional effects.

RESULTS

Irradiation of the heart base leads to BED-dependent changes in systolic and diastolic function 50 weeks post-irradiation. GLS showed significant decreases in a BED-dependent manner for all irradiated animals, as early as 10 weeks after irradiation. Early changes in GLS indicate late changes in cardiac function. BED-independent increases were observed in the left ventricle (LV) mass and volume and myocardial fibrosis.

CONCLUSIONS

Functional features of RICT displayed a BED dependence in this study. GLS showed an early change at 10 weeks post-irradiation. Cardiac remodelling was observed as increases in mass and volume of the LV, further supporting our hypothesis that dose to the base of the heart drives the global heart toxicity.

IL-33/soluble ST2 axis is associated with radiation-induced cardiac injury

Radiotherapy for treating breast cancer is associated with cardiac damage. This study aimed to investigate the role of the interleukin (IL)-33/soluble receptor ST2 (sST2) axis in radiation-induced cardiac injury. Expressions of IL-33 and sST2 were detected in breast cancer patients following radiotherapy, radiation-induced cardiac damaged mice model, and cardiomyocytes using quantitative real-time PCR (qRT-PCR) and immunohistochemical assay. Cardiac injury was evaluated through an ultrasound imaging system and hematoxylin & eosin staining. The transcriptional factor was assessed using dual-luciferase reporter assay and chromatin immunoprecipitation. The results indicated that IL-33 and sST2 were highly expressed in breast cancer patients, which further elevated post-6 months but reduced after 12 months of radiotherapy. Radiation induces cardiac dysfunction and elevated IL-33 and sST2 levels in a time-dependent manner. However, silencing of IL-33 decreased sST2 expression to alleviate radiation-induced cardiac dysfunction. The IL-33 could be transcriptional activated by TCF7L2 by binding to IL33 promoter sites, which mutation alleviated cardiomyocyte injury caused by radiation. Additionally, radiation treatment resulted in higher levels of TCF7L2, IL-33, and sST2 in cardiomyocytes, and TCF7L2 knockdown reduced IL-33 and sST2 expression. In conclusion, TCF7L2 transcriptional-activated IL-33 mediated sST2 to regulate radiation-induced cardiac damage, providing novel insights into radiotherapy-induced cardiac damage.

Clinical impact of postoperative radiotherapy in pIII-N2 non-small cell lung cancer after complete resection followed by adjuvant chemotherapy: a systematic review and meta-analysis

Background

Theoretically, postoperative radiotherapy (PORT) could reduce the risk of local recurrence and further improve survival outcomes. This study aimed to evaluate the clinical impact of PORT on patients with pIII-N2 non-small cell lung cancer (NSCLC) after complete resection followed by adjuvant chemotherapy.

Methods

A systematic literature search was performed in November 2022 to identify randomized controlled trials (RCTs) that compare PORT with observation in patients with pIII-N2 NSCLC using PubMed, Embase, and the Cochrane Central Register of Controlled Trials. This meta-analysis is in accordance with the recommendations of the PRISMA statement. The main outcomes were overall survival (OS), disease-free survival (DFS), and local recurrence rates, which were compared using hazard ratios (HRs).

Results

Five RCTs involving 1,138 patients were included: 572 patients in the PORT group and 566 patients in the observation group. The methodological quality of the five RCTs was high. Pooled analysis revealed that PORT decreased local recurrence rate [odds ratio =0.53, 95% confidence interval (CI): 0.40-0.70]. However, PORT did not improve median DFS (HR =0.93, 95% CI: 0.80-1.08) and OS (HR =0.94, 95% CI: 0.78-1.14).

Conclusions

Compared to adjuvant chemotherapy alone, additional PORT was significantly associated with a reduced local recurrence rate. However, neither DFS nor OS benefited from PORT in patients with pIII-N2 NSCLC who had undergone complete resection.

Sacubitril/valsartan can improve the cardiac function in heart failure patients with a history of cancer: An observational study

Sacubitril/Valsartan, the combination of angiotensin receptor inhibitor and neprilysin inhibitor, is now becoming the class 1 recommendation for HFrEF. Some studies have shown the positive effect of Sacubitril/Valsartan on HFrEF cancer patients, while there is devoid of evidence about the effect of this drug in aged cancer patients with HFmrEF and HFpEF. By searching the patients with a diagnosis of both cancer and Heart failure (HF) over 65, the patients who had received treatment with Sacubitril/Valsartan were selected as the candidates for Sacubitril/Valsartan group, and the patients who had received conventional HF therapy without Sacubitril/Valsartan were chosen as the control group. Data were collected for up to 9 months. We filtered 38 patients and 50 patients valid for Sacubitril/Valsartan group and control group, respectively. After initiation of heart failure management, our study found a better cardiac condition in Sacubitril/Valsartan group, having better LVEF, LVFS, NT-proBNP in 3rd, 6th, 9th month (P < .05) and better NYHA function classification after the treatment. We also observed fewer cases of deterioration on LAD (P = .029) and LVEDD (P = .023) in Sacubitril/Valsartan group. In subgroup analysis, our study showed that all 3 kinds of HF patients had better LVEF, LVFS, and NT-proBNP in Sacubitril/Valsartan group (P < .05). Our study further indicated that Sacubitril/Valsartan can improve cardiac function and benefit cardiac remolding in aged cancer patients of all 3 kinds of HF. This is the first study to provide new evidence for the use of Sacubitril/Valsartan in aged cancer patients of 3 kinds of HF.

How to contour the different heart subregions for future deep-learning modeling of the heart: A practical pictorial proposal for radiation oncologists

There are currently no accurate rules for manually delineating the subregions of the heart (cavities, vessels, aortic/mitral valves, Planning organ at Risk Volumes for coronary arteries) with the perspective of deep-learning based modeling. Our objective was to present a practical pictorial view for radiation oncologists, based on the RTOG atlas and anatomical complementary considerations for the cases where the RTOG guidelines are missing.

Selective Personalized RadioImmunotherapy for Locally Advanced Non-Small-Cell Lung Cancer Trial (SPRINT)

PURPOSE

Standard therapy for locally advanced non-small-cell lung cancer (LA-NSCLC) is concurrent chemoradiotherapy followed by adjuvant durvalumab. For biomarker-selected patients with LA-NSCLC, we hypothesized that sequential pembrolizumab and risk-adapted radiotherapy, without chemotherapy, would be well-tolerated and effective.

METHODS

Patients with stage III NSCLC or unresectable stage II NSCLC and an Eastern Cooperative Oncology Group performance status of 0-1 were eligible for this trial. Patients with a PD-L1 tumor proportion score (TPS) of ≥50% received three cycles of induction pembrolizumab (200 mg, once every 21 days), followed by a 20-fraction course of risk-adapted thoracic radiotherapy (55 Gy delivered to tumors or lymph nodes with metabolic volume exceeding 20 cc, 48 Gy delivered to smaller lesions), followed by consolidation pembrolizumab to complete a 1-year treatment course. The primary study end point was 1-year progression-free survival (PFS). Secondary end points included response rates after induction pembrolizumab, overall survival (OS), and adverse events.

RESULTS

Twenty-five patients with a PD-L1 TPS of ≥50% were enrolled. The median age was 71, most patients (88%) had stage IIIA or IIIB disease, and the median PD-L1 TPS was 75%. Two patients developed disease progression during induction pembrolizumab, and two patients discontinued pembrolizumab after one infusion because of immune-related adverse events. Using RECIST criteria, 12 patients (48%) exhibited a partial or complete response after induction pembrolizumab. Twenty-four patients (96%) received definitive thoracic radiotherapy. The 1-year PFS rate is 76%, satisfying our efficacy objective. One- and 2-year OS rates are 92% and 76%, respectively. The most common grade 3 adverse events were colitis (n = 2, 8%) and esophagitis (n = 2, 8%), and no higher-grade treatment-related adverse events have occurred.

CONCLUSION

Pembrolizumab and risk-adapted radiotherapy, without chemotherapy, are a promising treatment approach for patients with LA-NSCLC with a PD-L1 TPS of ≥50%.

Resectable non-stage IV nonsmall cell lung cancer: the surgical perspective

Surgery remains an essential element of the multimodality radical treatment of patients with early-stage nonsmall cell lung cancer. In addition, thoracic surgery is one of the key specialties involved in the lung cancer tumour board. The importance of the surgeon in the setting of a multidisciplinary panel is ever-increasing in light of the crucial concept of resectability, which is at the base of patient selection for neoadjuvant/adjuvant treatments within trials and in real-world practice. This review covers some of the topics which are relevant in the daily practice of a thoracic oncological surgeon and should also be known by the nonsurgical members of the tumour board. It covers the following topics: the pre-operative selection of the surgical candidate in terms of fitness in light of the ever-improving nonsurgical treatment alternatives unfit patients may benefit from; the definition of resectability, which is so important to include patients into trials and to select the most appropriate radical treatment; the impact of surgical access and surgical extension with the evolving role of minimally invasive surgery, sublobar resections and parenchymal-sparing sleeve resections to avoid pneumonectomy.

Sinoatrial Node Dose Is Associated With Worse Survival in Patients Undergoing Definitive Stereotactic Body Radiation Therapy for Central Lung Cancers

PURPOSE

Our purpose was to evaluate the clinical consequences of sinoatrial node (SAN) and atrioventricular node (AVN) irradiation in patients undergoing stereotactic body radiation therapy (SBRT) for central non-small cell lung cancer (NSCLC) tumors.

METHODS AND MATERIALS

A single-institutional retrospective review of patients with primary NSCLC undergoing definitive SBRT for centrally located thoracic tumors from February 2007 to December 2021 was performed. The SAN and AVN were contoured in accordance with a published contouring atlas, and the maximum dose (Dmax) and mean dose (Dmean) for each structure were calculated. Sequential log rank testing between the 50th and 90th percentiles was used to identify potential cutoff values for the corresponding dosimetric parameters and overall survival.

RESULTS

Among 93 eligible patients, the median age was 72.5 years (IQR, 66.6-78.3), and median follow-up was 32.4 months (IQR, 13.0-49.6). The median SAN Dmax and Dmean were 95 cGy (range, 9-5394) and 58 cGy (range, 7-3168), respectively. The median AVN Dmax and Dmean were 45 cGy (range, 4-2121) and 34 cGy (range, 3-1667), respectively. Candidate cutoff values for SAN Dmax and Dmean were 1309 and 836 cGy, respectively. No associations between AVN parameters and survival outcomes were identified. Upon multivariate Cox regression, the SAN Dmax cutoff (hazard ratio [HR], 2.03 [1.09-3.79]; P = .026) and SAN Dmean cutoff (HR, 2.22 [1.20-4.12]; P = .011) were significantly associated with overall survival. For noncancer-associated survival, the SAN Dmax cutoff trended toward significance (HR, 2.02 [0.89-4.57]; P = .092), and the SAN Dmean cutoff remained significantly associated (HR, 2.34 [1.05-5.18]; P = .037).

CONCLUSIONS

For patients undergoing SBRT for NSCLC, SAN Dmax and Dmean were significantly associated with worse overall survival using cut-off values of 1309 and 836 cGy, respectively. Further studies examining the effect of SAN irradiation during SBRT are warranted.

Estimating how contouring differences affect normal tissue complication probability modelling

Background and purpose

Normal tissue complication probability (NTCP) models are developed from large retrospective datasets where automatic contouring is often used to contour the organs at risk. This study proposes a methodology to estimate how discrepancies between two sets of contours are reflected on NTCP model performance. We apply this methodology to heart contours within a dataset of non-small cell lung cancer (NSCLC) patients.

Materials and methods

One of the contour sets is designated the ground truth and a dosimetric parameter derived from it is used to simulate outcomes via a predefined NTCP relationship. For each simulated outcome, the selected dosimetric parameters associated with each contour set are individually used to fit a toxicity model and their performance is compared. Our dataset comprised 605 stage IIA-IIIB NSCLC patients. Manual, deep learning, and atlas-based heart contours were available.

Results

How contour differences were reflected in NTCP model performance depended on the slope of the predefined model, the dosimetric parameter utilized, and the size of the cohort. The impact of contour differences on NTCP model performance increased with steeper NTCP curves. In our dataset, parameters on the low range of the dose-volume histogram were more robust to contour differences.

Conclusions

Our methodology can be used to estimate whether a given contouring model is fit for NTCP model development. For the heart in comparable datasets, average Dice should be at least as high as between our manual and deep learning contours for shallow NTCP relationships (88.5 ± 4.5 %) and higher for steep relationships.

Protective effect of naringin against radiation-induced heart disease in rats via Sirt1/NF-κB signaling pathway and endoplasmic reticulum stress

This study was designed to explore the protective effect and mechanism of naringin (NG) on radiation-induced heart disease (RIHD) in rats. Rats were divided into four x-ray (XR) irradiation groups with different absorbed doses (0/10/15/20 Gy), or into three groups (control, XR, and XR + NG groups). Subsequently, the ultrasonic diagnostic apparatus was adopted to assess and compare the left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular internal diameter at end diastole (LVIDd), and left ventricular internal diameter at end systole (LVIDs) in rats. Hematoxylin-eosin (H&E) staining and Masson staining were applied to detect the pathological damage and fibrosis of heart tissue. Western blot was used to measure the expression levels of myocardial fibrosis-related proteins, endoplasmic reticulum stress-related proteins, and Sirt1 (silent information regulator 1)/NF-κB (nuclear factor kappa-B) signaling pathway-related proteins in cardiac tissues. Additionally, enzyme-linked immunosorbent assay was utilized to detect the activities of pro-inflammatory cytokines, malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) in cardiac tissue. The results showed that NG treatment significantly attenuated the 20 Gy XR-induced decline of LVEF and LVFS and the elevation of LVIDs. Cardiac tissue damage and fibrosis caused by 20 Gy XR were significant improved after NG treatment. Meanwhile, in rats irradiated by XR, marked downregulation was identified in the expressions of fibrosis-related proteins (Col I, collagen type I; α-SMA, α-smooth muscle actin; and TGF-β1, transforming growth factor-beta 1) and endoplasmic reticulum stress-related proteins (GRP78, glucose regulatory protein 78; CHOP, C/EBP homologous protein; ATF6, activating transcription factor 6; and caspase 12) after NG treatment. Moreover, NG treatment also inhibited the production of pro-inflammatory cytokines [interleukin-6, interleukin-1β, and monocyte chemoattractant protein-1 (MCP-1)], reduced the expression of MDA, and promoted the activities of SOD and CAT. Also, NG treatment promoted Sirt1 expression and inhibited p65 phosphorylation. Collectively, XR irradiation induced cardiac injury in rats in a dose-dependent manner. NG could improve the cardiac injury induced by XR irradiation by inhibiting endoplasmic reticulum stress and activating Sirt1/NF-κB signaling pathway.

Assessment of heart-substructures auto-contouring accuracy for application in heart-sparing radiotherapy for lung cancer

Objectives

We validated an auto-contouring algorithm for heart substructures in lung cancer patients, aiming to establish its accuracy and reliability for radiotherapy (RT) planning. We focus on contouring an amalgamated set of subregions in the base of the heart considered to be a new organ at risk, the cardiac avoidance area (CAA), to enable maximum dose limit implementation in lung RT planning.

Methods

The study validates a deep-learning model specifically adapted for auto-contouring the CAA (which includes the right atrium, aortic valve root, and proximal segments of the left and right coronary arteries). Geometric, dosimetric, quantitative, and qualitative validation measures are reported. Comparison with manual contours, including assessment of interobserver variability, and robustness testing over 198 cases are also conducted.

Results

Geometric validation shows that auto-contouring performance lies within the expected range of manual observer variability despite being slightly poorer than the average of manual observers (mean surface distance for CAA of 1.6 vs 1.2 mm, dice similarity coefficient of 0.86 vs 0.88). Dosimetric validation demonstrates consistency between plans optimized using auto-contours and manual contours. Robustness testing confirms acceptable contours in all cases, with 80% rated as "Good" and the remaining 20% as "Useful."

Conclusions

The auto-contouring algorithm for heart substructures in lung cancer patients demonstrates acceptable and comparable performance to human observers.

Advances in knowledge

Accurate and reliable auto-contouring results for the CAA facilitate the implementation of a maximum dose limit to this region in lung RT planning, which has now been introduced in the routine setting at our institution.

Cardiac Arrhythmias in Patients Treated for Lung Cancer: A Review

Cardio-oncology currently faces one of the greatest challenges in the field of health care. The main goal of this discipline is to ensure that patients treated for cancer do not suffer or die from cardiovascular disease. The number of studies on the mechanisms of heart injury during cancer treatment is constantly increasing. However, there is insufficient data on heart rhythm disorders that may result from this treatment. This issue seems to be particularly important in patients with lung cancer, in whom anticancer therapy, especially radiotherapy, may contribute to the onset of cardiac arrhythmias. The observed relationship between cardiac dosimetry and radiotherapy-induced cardiotoxicity in lung cancer treatment may explain the increased mortality from cardiovascular causes in patients after chest irradiation. Further research is essential to elucidate the role of cardiac arrhythmias in this context. Conversely, recent reports have highlighted the application of stereotactic arrhythmia radioablation (STAR) in the treatment of ventricular tachycardia. This review of available studies on the epidemiology, pathogenesis, diagnosis, and treatment of arrhythmias in patients treated for lung cancer aims to draw attention to the need for regular cardiological monitoring in this group of patients. Improving cardiac care for patients with lung cancer has the potential to enhance their overall therapeutic outcomes.

Refining critical structure contouring in STereotactic Arrhythmia Radioablation (STAR): Benchmark results and consensus guidelines from the STOPSTORM.eu consortium

BACKGROUND AND PURPOSE

In patients with recurrent ventricular tachycardia (VT), STereotactic Arrhythmia Radioablation (STAR) shows promising results. The STOPSTORM.eu consortium was established to investigate and harmonise STAR treatment in Europe. The primary goals of this benchmark study were to standardise contouring of organs at risk (OAR) for STAR, including detailed substructures of the heart, and accredit each participating centre.

MATERIALS AND METHODS

Centres within the STOPSTORM.eu consortium were asked to delineate 31 OAR in three STAR cases. Delineation was reviewed by the consortium expert panel and after a dedicated workshop feedback and accreditation was provided to all participants. Further quantitative analysis was performed by calculating DICE similarity coefficients (DSC), median distance to agreement (MDA), and 95th percentile distance to agreement (HD95).

RESULTS

Twenty centres participated in this study. Based on DSC, MDA and HD95, the delineations of well-known OAR in radiotherapy were similar, such as lungs (median DSC = 0.96, median MDA = 0.1 mm and median HD95 = 1.1 mm) and aorta (median DSC = 0.90, median MDA = 0.1 mm and median HD95 = 1.5 mm). Some centres did not include the gastro-oesophageal junction, leading to differences in stomach and oesophagus delineations. For cardiac substructures, such as chambers (median DSC = 0.83, median MDA = 0.2 mm and median HD95 = 0.5 mm), valves (median DSC = 0.16, median MDA = 4.6 mm and median HD95 = 16.0 mm), coronary arteries (median DSC = 0.4, median MDA = 0.7 mm and median HD95 = 8.3 mm) and the sinoatrial and atrioventricular nodes (median DSC = 0.29, median MDA = 4.4 mm and median HD95 = 11.4 mm), deviations between centres occurred more frequently. After the dedicated workshop all centres were accredited and contouring consensus guidelines for STAR were established.

CONCLUSION

This STOPSTORM multi-centre critical structure contouring benchmark study showed high agreement for standard radiotherapy OAR. However, for cardiac substructures larger disagreement in contouring occurred, which may have significant impact on STAR treatment planning and dosimetry evaluation. To standardize OAR contouring, consensus guidelines for critical structure contouring in STAR were established.

Burden and prognostic impact of cardiovascular disease in patients with cancer

The number of patients at the intersection of cancer and cardiovascular disease (CVD) is increasing, reflecting ageing global populations, rising burden of shared cardiometabolic risk factors, and improved cancer survival. Many cancer treatments carry a risk of cardiotoxicity. Baseline cardiovascular risk assessment is recommended in all patients with cancer and requires consideration of individual patient risk and the cardiotoxicity profile of proposed anticancer therapies. Patients with pre-existing CVD are potentially at high or very high risk of cancer-therapy related cardiovascular toxicity. The detection of pre-existing CVD should prompt cardiac optimisation and planning of surveillance during cancer treatment. In patients with severe CVD, the risk of certain cancer therapies may be prohibitively high. Such decisions require multidisciplinary discussion with consideration of alternative anti-cancer therapies, risk-benefit assessment, and patient preference. Current practice is primarily guided by expert opinion and data from select clinical cohorts. There is need for development of a stronger evidence base to guide clinical practice in cardio-oncology. The establishment of multicentre international registries and national-level healthcare data linkage projects are important steps towards facilitating enrichment of cardio-oncology research programmes. In this narrative review, we consider epidemiological trends of cancer and CVD comorbidities and the impact of their co-occurrence on clinical outcomes, current approach to supporting cancer patients with pre-existing CVD and gaps in existing knowledge.

Current and Future Treatment Options in the Management of Stage III NSCLC

For much of the past two decades, the treatment options for patients with stage III NSCLC were mostly stagnant. In the past 5 years, ongoing innovations have dovetailed alongside advances in biomarker testing, novel therapeutics, precision surgery, and radiotherapy, all of which are leading to an increase in more personalized option for the treatment. This review article will focus on several completed and ongoing initiatives involving treatment of patients with stage III NSCLC. First, it will tackle the progress made in curative treatment of unresectable stage III NSCLC, starting with PACIFIC, and branching out into topics such as concurrent immunotherapy and chemoradiation, intensification of consolidative immunotherapy, dual immunotherapy consolidation, and a reflection on those subpopulations that may not benefit from consolidative immunotherapy. Second, there will be discussion of novel strategies in the setting of resectable stage III disease, most notably neoadjuvant therapy using combined chemoimmunotherapy and immunotherapy alone before surgical resection. Third, it will delve into recent data evaluating adjuvant immunotherapy for resectable stage III NSCLC, including adjuvant targeted therapy (for those harboring driver mutations) and postoperative radiotherapy. Finally, a look to future trials/initiatives will be interspersed throughout the review, to reveal the ongoing efforts being made to continue to improve outcomes in this group of patients.

Reflecting on the cardiac toxicity in non-small cell lung cancer in the era of immune checkpoint inhibitors therapy combined with thoracic radiotherapy

In recent years, immune checkpoint inhibitors (ICIs) have become a widely used treatment for non-small cell lung cancer (NSCLC), and the combination with traditional radiotherapy (RT) has shown significant potential in prolonging patient survival. However, both thoracic RT and ICIs can lead to cardiac toxicity, including radiation-induced heart damage (RIHD) and immunotherapy-related heart damage (IRHD). It still remains uncertain whether the combination of thoracic RT and immunotherapy will exacerbate acute or late cardiovascular (CV) toxicity and incidence. In this review, we summarize safety data from relevant clinical studies regarding CV toxicity for the combination therapy in NSCLC patients, explore the underlying synergetic mechanisms and common risk factors, and proposed treatment and management strategies. We hope to increase emphasis on the long-term assessment of CV toxicity risks associated with the combination therapy, and reduce the incidence of CV deaths resulting from such regimens.

Radiation-induced skin and heart toxicity in patients with breast cancer treated with adjuvant proton radiotherapy: a comparison with photon radiotherapy

This study aimed to investigate the dose parameters and incidence of radiotherapy (RT)-associated toxicity in patients with left breast cancer (LBC) treated with proton-RT, compared with photon-RT. We collected data from 111 patients with LBC who received adjuvant RT in our department between August 2021 and March 2023. Among these patients, 24 underwent proton-RT and 87 underwent photon-RT. In addition to the dosimetric analysis for organs at risk (OARs), we measured NT-proBNP levels before and after RT. Our data showed that proton-RT improved dose conformity and reduced doses to the heart and lungs and was associated with a lower rate of increased NT-proBNP than did photon-RT. Regarding skin toxicity, the Dmax for 1 c.c. and 10 c.c. and the average dose to the skin-OAR had predictive roles in the risk of developing radiation-induced dermatitis. Although pencil beam proton-RT with skin optimization had a dose similar to that of skin-OAR compared with photon-RT, proton-RT still had a higher rate of radiation dermatitis (29%) than did photon RT (11%). Using mice 16 days after irradiation, we demonstrated that proton-RT induced a greater increase in interleukin 6 and transforming growth factor-β1 levels than did photon-RT. Furthermore, topical steroid ointment reduced the inflammatory response and severity of dermatitis induced by RT. In conclusion, we suggest that proton-RT with skin optimization spares high doses to OARs with acceptable skin toxicity. Furthermore, prophylactic topical steroid treatment may decrease radiation dermatitis by alleviating proton-induced inflammatory responses in vivo.

[Prevention, Diagnosis, Therapy, and Follow-up of Lung Cancer - Interdisciplinary Guideline of the German Respiratory Society and the German Cancer Society - Abridged Version]

The current S3 Lung Cancer Guidelines are edited with fundamental changes to the previous edition based on the dynamic influx of information to this field:The recommendations include de novo a mandatory case presentation for all patients with lung cancer in a multidisciplinary tumor board before initiation of treatment, furthermore CT-Screening for asymptomatic patients at risk (after federal approval), recommendations for incidental lung nodule management , molecular testing of all NSCLC independent of subtypes, EGFR-mutations in resectable early stage lung cancer in relapsed or recurrent disease, adjuvant TKI-therapy in the presence of common EGFR-mutations, adjuvant consolidation treatment with checkpoint inhibitors in resected lung cancer with PD-L1 ≥ 50%, obligatory evaluation of PD-L1-status, consolidation treatment with checkpoint inhibition after radiochemotherapy in patients with PD-L1-pos. tumor, adjuvant consolidation treatment with checkpoint inhibition in patients withPD-L1 ≥ 50% stage IIIA and treatment options in PD-L1 ≥ 50% tumors independent of PD-L1status and targeted therapy and treatment option immune chemotherapy in first line SCLC patients.Based on the current dynamic status of information in this field and the turnaround time required to implement new options, a transformation to a "living guideline" was proposed.

Development of a comprehensive cardiac atlas on a 1.5 Tesla Magnetic Resonance Linear Accelerator

Background and purpose

The 1.5 Tesla (T) Magnetic Resonance Linear Accelerator (MRL) provides an innovative modality for improved cardiac imaging when planning radiation treatment. No MRL based cardiac atlases currently exist, thus, we sought to comprehensively characterize cardiac substructures, including the conduction system, from cardiac images acquired using a 1.5 T MRL and provide contouring guidelines.

Materials and methods

Five volunteers were enrolled in a prospective protocol (NCT03500081) and were imaged on the 1.5 T MRL with Half Fourier Single-Shot Turbo Spin-Echo (HASTE) and 3D Balanced Steady-State Free Precession (bSSFP) sequences in axial, short axis, and vertical long axis. Cardiac anatomy was contoured by (AS) and confirmed by a board certified cardiologist (JR) with expertise in cardiac MR imaging.

Results

A total of five volunteers had images acquired with the HASTE sequence, with 21 contours created on each image. One of these volunteers had additional images obtained with 3D bSSFP sequences in the axial plane and additional images obtained with HASTE sequences in the key cardiac planes. Contouring guidelines were created and outlined. 15-16 contours were made for the short axis and vertical long axis. The cardiac conduction system was demonstrated with eleven representative contours. There was reasonable variation of contour volume across volunteers, with structures more clearly delineated on the 3D bSSFP sequence.

Conclusions

We present a comprehensive cardiac atlas using novel images acquired prospectively on a 1.5 T MRL. This cardiac atlas provides a novel resource for radiation oncologists in delineating cardiac structures for treatment with radiotherapy, with special focus on the cardiac conduction system.

ATP protects anti-PD-1/radiation-induced cardiac dysfunction by inhibiting anti-PD-1 exacerbated cardiomyocyte apoptosis, and improving autophagic flux

The synergy between radiotherapy and immunotherapy in treating thoracic cancers presents a potent therapeutic advantage, yet it also carries potential risks. The extent and nature of cumulative cardiac toxicity remain uncertain, prompting the need to discern its mechanisms and devise effective mitigation strategies. Radiation alone or in combination with an anti- Programmed cell death protein1 (PD-1) antibody significantly reduced cardiac function in C57BL/6J mice, and this pathologic effect was aggravated by anti-PD-1 (anti-PD-1 + radiation). To examine the cellular mechanism that causes the detrimental effect of anti-PD-1 upon cardiac function after radiation, AC16 human cardiomyocytes were used to study cardiac apoptosis and cardiac autophagy. Radiation-induced cardiomyocyte apoptosis was significantly promoted by anti-PD-1 treatment, while anti-PD-1 combined radiation administration blocked the cardiac autophagic flux. Adenosine 5'-triphosphate (ATP) (a molecule that promotes lysosomal acidification) not only improved autophagic flux in AC16 human cardiomyocytes, but also attenuated apoptosis induced by radiation and anti-PD-1 treatment. Finally, ATP administration in vivo significantly reduced radiation-induced and anti-PD-1-exacerbated cardiac dysfunction. We demonstrated for the first time that anti-PD-1 can aggravate radiation-induced cardiac dysfunction via promoting cardiomyocyte apoptosis without affecting radiation-arrested autophagic flux. ATP enhanced cardiomyocyte autophagic flux and inhibited apoptosis, improving cardiac function in anti-PD-1/radiation combination-treated animals.

Comparison of photon intensity modulated, hybrid and volumetric modulated arc radiation treatment techniques in locally advanced non-small cell lung cancer

Background and purpose

There is no consensus on the best photon radiation technique for non-small cell lung cancer (NSCLC). This study quantified the differences between commonly used treatment techniques in NSCLC to find the optimal technique.

Materials and methods

Treatment plans were retrospectively generated according to clinical guidelines for 26 stage III NSCLC patients using intensity modulated radiation therapy (IMRT), hybrid, and volumetric modulated arc therapy (VMATC, and VMATV5 optimized for lower lung and heart dose). Plans were evaluated for target coverage, organs at risk dose (including heart substructures) and normal tissue complication probabilities (NTCP).

Results

The comparison showed significant and largest median differences (>1 Gy or >5%) in favor of IMRT for the mediastinal envelope and heart (maximum dose), in favor of the hybrid technique for the lungs (V5Gy of the total lungs and V5Gy of the contralateral lung) and in favor of VMATC for the heart (Dmean), most of the substructures of the heart, and the spinal cord (maximum dose). The VMATV5 technique had significantly lower heart dose compared to the hybrid technique and significantly lower lung dose compared to the VMATC, combining both advantages in one technique. The mean ΔNTCP did not exceed the 2 percent point (pp) for grade 5 (mortality), and 10 pp for grade ≥2 toxicities (radiation pneumonitis and acute esophageal toxicity), but ΔNTCP was mostly in favor of VMATC/V5 for individual patients.

Conclusion

This planning study showed that VMATV5 was preferred as it achieved low lung and heart doses, as well as low NTCPs, simultaneously.

Mitochondrial dysfunction at the crossroad of cardiovascular diseases and cancer

A large body of evidence indicates the existence of a complex pathophysiological relationship between cardiovascular diseases and cancer. Mitochondria are crucial organelles whose optimal activity is determined by quality control systems, which regulate critical cellular events, ranging from intermediary metabolism and calcium signaling to mitochondrial dynamics, cell death and mitophagy. Emerging data indicate that impaired mitochondrial quality control drives myocardial dysfunction occurring in several heart diseases, including cardiac hypertrophy, myocardial infarction, ischaemia/reperfusion damage and metabolic cardiomyopathies. On the other hand, diverse human cancers also dysregulate mitochondrial quality control to promote their initiation and progression, suggesting that modulating mitochondrial homeostasis may represent a promising therapeutic strategy both in cardiology and oncology. In this review, first we briefly introduce the physiological mechanisms underlying the mitochondrial quality control system, and then summarize the current understanding about the impact of dysregulated mitochondrial functions in cardiovascular diseases and cancer. We also discuss key mitochondrial mechanisms underlying the increased risk of cardiovascular complications secondary to the main current anticancer strategies, highlighting the potential of strategies aimed at alleviating mitochondrial impairment-related cardiac dysfunction and tumorigenesis. It is hoped that this summary can provide novel insights into precision medicine approaches to reduce cardiovascular and cancer morbidities and mortalities.

The American Association for Thoracic Surgery (AATS) 2023 Expert Consensus Document: Staging and multidisciplinary management of patients with early-stage non-small cell lung cancer

Novel targeted therapy and immunotherapy drugs have recently been approved for use in patients with surgically resectable lung cancer. Accurate staging, early molecular testing, and knowledge of recent trials are critical to optimize oncologic outcomes in these patients.

Association between statin therapy dose intensity and radiation cardiotoxicity in non-small cell lung cancer: Results from the NI-HEART study

INTRODUCTION

Radiation cardiotoxicity is a dose-limiting toxicity and major survivorship issue for patients with non-small cell lung cancer (NSCLC) completing curative-intent radiotherapy, however patients' cardiovascular baseline is not routinely optimised prior to treatment. In this study we examined the impact of statin therapy on overall survival and post-radiotherapy cardiac events.

METHODS

Patients treated between 2015-2020 at a regional center were identified. Clinical notes were interrogated for baseline patient, tumor and cardiac details, and both follow-up cancer control and cardiac events. Three cardiologists verified cardiac events. Radiotherapy planning scans were retrieved for application of validated deep learning-based autosegmentation. Pre-specified Cox regression analyses were generated with varying degrees of adjustment for overall survival. Fine and Gray regression for the risk of cardiac events, accounting for the competing risk of death and cardiac covariables was undertaken.

RESULTS

Statin therapy was prescribed to 59% of the 478 included patients. The majority (88%) of patients not prescribed a statin had at least one indication for statin therapy according to cardiovascular guidelines. In total, 340 patients (71%) died and 79 patients (17%) experienced a cardiac event. High-intensity (HR 0.68, 95%CI 0.50-0.91, p = 0.012) and medium-intensity (HR 0.70, 95%CI 0.51-0.97, p = 0.033) statin therapy were associated with improved overall survival after adjustment for patient, cancer, treatment, response and cardiovascular clinical factors. There were no consistent differences in the rate or grade of cardiac events according to statin intensity.

CONCLUSIONS

Statin therapy is associated with improved overall survival in patients receiving curative-intent radiotherapy for NSCLC, and there is evidence of a dose-response relationship. This study highlights the importance of a pre-treatment cardiovascular risk assessment in this cohort. Further studies are needed to examine if statin therapy is cardioprotective in patients undergoing treatment for NSCLC with considerable incidental cardiac radiation dose and a low baseline cardiac risk.

Radiation therapy in the thoracic region: Radio-induced cardiovascular disease, cardiac delineation and sparing, cardiac dose constraints, and cardiac implantable electronic devices

Radiation therapy in the thoracic region may deliver incidental ionizing radiation to the surrounding healthy structures, including the heart. Radio-induced heart toxicity has long been a concern in breast cancer and Hodgkin's lymphoma and was deemed a long-term event. However, recent data highlight the need to limit the dose to the heart in less favorable thoracic cancers too, such as lung and esophageal cancers in which incidental irradiation led to increased mortality. This article will summarize available cardiac dose constraints in various clinical settings and the types of radio-induced cardiovascular diseases encountered as well as delineation of cardiac subheadings and management of cardiac devices. Although still not completely deciphered, heart dose constraints remain intensively investigated and the mean dose to the heart is no longer the only dosimetric parameter to consider since the left anterior descending artery as well as the left ventricle should also be part of dosimetry constraints.

External validation of ardiac disease, ypertension, and ogarithmic eft anterior descending coronary artery radiation dose for predicting major adverse cardiac events after lung cancer radiotherapy

Background and purpose

Major adverse cardiac events(MACE) are prevalent in patients with locally advanced-non-small cell lung cancer(LA-NSCLC) following radiotherapy(RT). The CHyLL model, incorporating coronary heart disease(CHD),Hypertension(HTN),Logarithmic LADV15 was developed and internally-validated to predict MACE among LA-NSCLC patients. We sought to externally validate CHyLL to predict MACE in an independent LA-NSCLC cohort.

Patients and methods

Patients with LA-NSCLC treated with RT were included. CHyLL score was calculated:5.51CHD + 1.28HTN + 1.48ln(LADV15 + 1)-1.36CHD*ln(LADV15 + 1). CHyLL performance in predicting MACE was assessed and compared to mean heart dose(MHD) using Cox-proportional hazard(PH) analyses and Harrel's concordance(C)-indices. MACE and overall survival(OS) among low-vs high-risk groups(CHyLL < 5 vs ≥ 5) were compared.

Results

In the external validation cohort(N = 102), the median age was 71 years and 55% were females. Most(n = 74,73%), had clinical Stage III disease and 35(34%) underwent surgery. CHyLL demonstrated good MACE prediction with C-index of 0.73(95% Confidence Interval(CI):0.58-0.89), while MHD did not (C-index = 0.46 (95% CI:0.30-0.62)). Per CHyLL, 32(31%) and 70(69%) patients were considered low-and high-risk for MACE, respectively. CHyLL consistently identified lower MACE rates in the low-vs high-risk group(log-rank p = 0.108):0 vs 8%(12 months),5 vs 16%(24 months),5 vs 16%(36 months),and 5 vs 19%(48 months) post-RT. In the pooled internal and external validation cohort(N = 303), MACE rates in low-vs high-risk groups were statistically significantly different(log-rank p = 0.01):1 vs 6%(12 months),3 vs 12%(24 months),6 vs 19%(36 months),and 6 vs 21%(48 months).

Conclusions

CHyLL was externally validated and superior to MHD in predicting MACE. CHyLL has the potential to identify high-risk patients who may benefit from cardio-oncology optimization and to estimate personalized LADV15 constraints based on cardiac risk factors and acceptable MACE thresholds.

Cardiac Substructure Radiation Dose and Risk of Late Cardiac Disease in Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

PURPOSE

Radiation-associated cardiac disease is a major cause of morbidity/mortality among childhood cancer survivors. Radiation dose-response relationships for cardiac substructures and cardiac diseases remain unestablished.

METHODS

Using the 25,481 5-year survivors of childhood cancer treated from 1970 to 1999 in the Childhood Cancer Survivor Study, we evaluated coronary artery disease (CAD), heart failure (HF), valvular disease (VD), and arrhythmia. We reconstructed radiation doses for each survivor to the coronary arteries, chambers, valves, and whole heart. Excess relative rate (ERR) models and piecewise exponential models evaluated dose-response relationships.

RESULTS

The cumulative incidence 35 years from diagnosis was 3.9% (95% CI, 3.4 to 4.3) for CAD, 3.8% (95% CI, 3.4 to 4.2) for HF, 1.2% (95% CI, 1.0 to 1.5) for VD, and 1.4% (95% CI, 1.1 to 1.6) for arrhythmia. A total of 12,288 survivors (48.2%) were exposed to radiotherapy. Quadratic ERR models improved fit compared with linear ERR models for the dose-response relationship between mean whole heart and CAD, HF, and arrhythmia, suggesting a potential threshold dose; however, such departure from linearity was not observed for most cardiac substructure end point dose-response relationships. Mean doses of 5-9.9 Gy to the whole heart did not increase the risk of any cardiac diseases. Mean doses of 5-9.9 Gy to the right coronary artery (rate ratio [RR], 2.6 [95% CI, 1.6 to 4.1]) and left ventricle (RR, 2.2 [95% CI, 1.3 to 3.7]) increased risk of CAD, and to the tricuspid valve (RR, 5.5 [95% CI, 2.0 to 15.1]) and right ventricle (RR, 8.4 [95% CI, 3.7 to 19.0]) increased risk of VD.

CONCLUSION

Among children with cancer, there may be no threshold dose below which radiation to the cardiac substructures does not increase the risk of cardiac diseases. This emphasizes their importance in modern treatment planning.

Accelerated Atherosclerosis and Cardiovascular Toxicity Induced by Radiotherapy in Breast Cancer

The number of patients diagnosed with breast cancer and cardiovascular disease is continuously rising. Treatment options for breast cancer have greatly evolved, but radiotherapy (RT) still has a key role in it. Despite many advances in RT techniques, cardiotoxicity is one of the most important side effects. The new cardio-oncology guidelines recommend a baseline evaluation, risk stratification and follow-up of these patients. Cardiotoxicity induced by RT can be represented by almost all forms of cardiovascular disease, with atherosclerosis being the most frequent. An interdisciplinary team should manage these patients, in order to have maximum therapeutic effect and minimum cardiovascular toxicity. This review will summarize the current incidence, risk factors, mechanisms and follow-up of RT-induced cardiovascular toxicity.

Higher Lung and Heart Doses Decrease Early and Long-Term Survival, Respectively, in Patients With Non-Small Cell Lung Cancer Undergoing Postoperative Radiation

Purpose

Cardiopulmonary toxic effects may reduce the efficacy of postoperative radiation therapy (PORT) in patients with non-small cell lung cancer (NSCLC). However, few studies have examined whether the heart and lung doses affect overall survival (OS). We investigated the correlation of heart and lung doses with OS in patients with NSCLC undergoing PORT.

Methods and Materials

This retrospective analysis included 307 patients with NSCLC undergoing PORT. The total dose was 50 Gy. Landmark analyses were performed at 36 months, with hazard ratios (HRs) calculated separately for events occurring up to 36 months (early survival) and after 36 months (long-term survival). Stabilized inverse probability of treatment weighting (sIPTW) was performed to balance the characteristics of the high- and low-dose groups. We performed sensitivity analyses at 24 and 48 months.

Results

The median follow-up period was 67.42 months. Heart doses were significantly correlated with long-term survival (HR, 1.14; P = .015) but not with early survival (HR, 0.97; P = .41) or whole survival (HR, 1.02; P = .58). Lung doses were marginally significantly correlated with early survival (HR, 1.03; P = .07) but not with long-term survival (HR, 1.00; P = .85) or whole survival (HR, 1.02; P = .12). Higher heart and lung doses were associated with decreased long-term and early survival, respectively, before and after sIPTW. Landmark analyses at 24 and 48 months showed consistent results.

Conclusions

For patients with NSCLC undergoing PORT, a higher heart dose was associated with decreased long-term survival, whereas a higher lung dose was associated with decreased early survival.

Exploring causes and consequences of early discontinuation of durvalumab after chemoradiotherapy for non-small cell lung cancer

Introduction

For most locally advanced non-small cell lung cancer (LA-NSCLC) patients who complete definitive chemoradiotherapy (CRT) and do not experience disease progression, one year of adjuvant durvalumab is recommended. Here, we explore causes and consequences of early durvalumab discontinuation.

Materials and Methods

We reviewed patients treated for LA-NSCLC with definitive CRT who began adjuvant durvalumab between 2017 and 2021. Duration of durvalumab receipt and causes for early discontinuation were tabulated. Logistic regression models were utilized to evaluate predictors of early durvalumab discontinuation. Landmark analyses were performed to explore associations between early durvalumab discontinuation and clinical outcomes (progression-free survival (PFS), overall survival (OS)).

Results

Fifty-nine patients were included. Forty-one patients (69%) discontinued durvalumab early, most commonly for disease progression (n = 14) or lung toxicity (n = 10). Multivariable analysis revealed mean heart radiotherapy dose (MHD) was associated with risk of durvalumab discontinuation from progression (HR = 2.34 per 10 Gy, p = 0.052), and there was a trend suggesting an association between MHD and risk of durvalumab discontinuation from lung toxicity (HR = 2.16 per 10 Gy, p = 0.126). Median PFS duration following durvalumab initiation was 14 months, and median OS duration was 32 months. Landmark analyses that excluded patients with progression or death within one year of durvalumab initiation demonstrated improved outcomes for patients who completed one year of durvalumab (2-year PFS 100% v. 40%, p < 0.001; 2-year OS 100% v. 67%, p = 0.862). Improved outcomes were observed for patients who received MHD below the cohort median (9.3 Gy) compared to patients with higher MHD (median PFS 32 months v. 8 months, p < 0.001; 2-year OS 69% v. 44%, p = 0.088).

Conclusion

For LA-NSCLC patients treated with CRT followed by immunotherapy, extent of cardiac irradiation may be a risk factor for immunotherapy discontinuation, disease recurrence, and death.

Cardiovascular Complications of Pan-Cancer Therapies: The Need for Cardio-Oncology

It is more likely that a long-term survivor will have both cardiovascular disease and cancer on account of the progress in cancer therapy. Cardiotoxicity is a well-recognized and highly concerning adverse effect of cancer therapies. This side effect can manifest in a proportion of cancer patients and may lead to the discontinuation of potentially life-saving anticancer treatment regimens. Consequently, this discontinuation may adversely affect the patient's survival prognosis. There are various underlying mechanisms by which each anticancer treatment affects the cardiovascular system. Similarly, the incidence of cardiovascular events varies with different protocols for malignant tumors. In the future, comprehensive cardiovascular risk assessment and clinical monitoring should be considered for cancer treatments. Baseline cardiovascular evaluation risk should be emphasized prior to initiating clinical therapy in patients. Additionally, we highlight that there is a need for cardio-oncology to avoid or prevent cardiovascular side effects. Cardio-oncology service is based on identifying cardiotoxicity, developing strategies to reduce these toxicities, and minimizing long-term cardiotoxic effects.

Treatment Decisions for Resectable Non-Small-Cell Lung Cancer: Balancing Less With More?

For patients with non-small-cell lung cancer (NSCLC), the outcomes for patients with resectable disease are historically poor compared with other solid organ malignancies. In recent years, there have been significant advances in multidisciplinary care, which have resulted in improved outcomes. Innovations in surgical oncology include the use of limited resection and minimally invasive techniques. Recent data in radiation oncology have suggested refinements in pre- and postoperative radiation therapy, resulting in optimization of techniques in the curative setting. Finally, the success of immune checkpoint inhibitors and targeted therapies in the advanced setting has paved the way for inclusion in the adjuvant and neoadjuvant settings, resulting in recent regulatory approvals for four regimens (CheckMate-816, IMpower010, PEARLS, ADAURA). In this review, we will provide an overview of the seminal studies informing advancements in optimal surgical resection, radiation treatment, and systemic therapy for resectable NSCLC. We will summarize the key data on survival outcomes, biomarker analyses, and future directions for perioperative studies.

Demystifying the Results of RTOG 0617: Identification of Dose Sensitive Cardiac Subregions Associated With Overall Survival

INTRODUCTION

The RTOG 0617 trial presented a worse survival for patients with lung cancer treated in the high-dose (74 Gy) arm. In multivariable models, radiation level and whole-heart volumetric dose parameters were associated with survival. In this work, we consider heart subregions to explain the observed survival difference between radiation levels.

METHODS

Voxel-based analysis identified anatomical regions where the dose was associated with survival. Bootstrapping clinical and dosimetric variables into an elastic net model selected variables associated with survival. Multivariable Cox regression survival models assessed the significance of dose to the heart subregion, compared with whole heart v5 and v30. Finally, the trial outcome was assessed after propensity score matching of patients on lung dose, heart subregion dose, and tumor volume.

RESULTS

A total of 458 patients were eligible for voxel-based analysis. A region of significance (p < 0.001) was identified in the base of the heart. Bootstrapping selected mean lung dose, radiation level, log tumor volume, and heart region dose. The multivariable Cox model exhibited dose to the heart region (p = 0.02), and tumor volume (p = 0.03) were significantly associated with survival, and radiation level was not significant (p = 0.07). The models exhibited that whole heart v5 and v30 were not associated with survival, with radiation level being significant (p < 0.05). In the matched cohort, no significant survival difference was seen between radiation levels.

CONCLUSIONS

Dose to the base of the heart is associated with overall survival, partly removing the radiation level effect, and explaining that worse survival in the high-dose arm is owing, in part, to the heart subregion dose. By defining a heart avoidance region, future dose escalation trials may be feasible.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Radiation Treatment Mechanisms of Cardiotoxicity: A Systematic Review

Radiotherapy may be used alone or in combination with chemotherapy for cancer treatment. There are many mechanisms of radiation treatment exposure to toxicities. Our aim was to summarize the literature about known mechanisms of radiation-induced cardiac toxicities. We performed a systematic review of the literature on the PubMed database until October 2022 about cardiovascular toxicities and radiation therapy exposure. Only systematic reviews, meta-analyses, and reviews were selected. Out of 1429 publications screened, 43 papers met inclusion criteria and were selected for the umbrella review process. Microvascular and macrovascular complications could lead to adverse cardiac effects. Many radiotherapy-associated risk factors were responsible, such as the site of radiation treatment, beam proximity to heart tissues, total dosage, the number of radiotherapy sessions, adjuvant chemotherapeutic agents used, and patient traditional cardiovascular risk factors, patient age, and gender. Moreover, important dosage cutoff values could increase the incidence of cardiac toxicities. Finally, the time from radiation exposure to cardiac side effects was assessed. Our report highlighted mechanisms, radiation dosage values, and the timeline of cardiovascular toxicities after radiation therapy. All of the above may be used for the assessment of cardiovascular risk factors and the development of screening programs for cancer patients.

Open-source, fully-automated hybrid cardiac substructure segmentation: development and optimisation

Radiotherapy for thoracic and breast tumours is associated with a range of cardiotoxicities. Emerging evidence suggests cardiac substructure doses may be more predictive of specific outcomes, however, quantitative data necessary to develop clinical planning constraints is lacking. Retrospective analysis of patient data is required, which relies on accurate segmentation of cardiac substructures. In this study, a novel model was designed to deliver reliable, accurate, and anatomically consistent segmentation of 18 cardiac substructures on computed tomography (CT) scans. Thirty manually contoured CT scans were included. The proposed multi-stage method leverages deep learning (DL), multi-atlas mapping, and geometric modelling to automatically segment the whole heart, cardiac chambers, great vessels, heart valves, coronary arteries, and conduction nodes. Segmentation performance was evaluated using the Dice similarity coefficient (DSC), mean distance to agreement (MDA), Hausdorff distance (HD), and volume ratio. Performance was reliable, with no errors observed and acceptable variation in accuracy between cases, including in challenging cases with imaging artefacts and atypical patient anatomy. The median DSC range was 0.81-0.93 for whole heart and cardiac chambers, 0.43-0.76 for great vessels and conduction nodes, and 0.22-0.53 for heart valves. For all structures the median MDA was below 6 mm, median HD ranged 7.7-19.7 mm, and median volume ratio was close to one (0.95-1.49) for all structures except the left main coronary artery (2.07). The fully automatic algorithm takes between 9 and 23 min per case. The proposed fully-automatic method accurately delineates cardiac substructures on radiotherapy planning CT scans. Robust and anatomically consistent segmentations, particularly for smaller structures, represents a major advantage of the proposed segmentation approach. The open-source software will facilitate more precise evaluation of cardiac doses and risks from available clinical datasets.

Platelet membrane camouflaged AIEgen-mediated photodynamic therapy improves the effectiveness of anti-PD-L1 immunotherapy in large-burden tumors

Although immunotherapy has achieved recent clinical success in antitumor therapy, it is less effective for solid tumors with large burdens. To overcome this challenge, herein, we report a new strategy based on platelet membrane-camouflaged aggregation-induced emission (AIE) luminogen (Plt-M@P) combined with the anti-programmed death ligand 1 (anti-PD-L1) for tumoral photodynamic-immunotherapy. Plt-M@P is prepared by using poly lactic-co-glycolic acid (PLGA)/PF3-PPh₃ complex as a nanocore, and then by co-extrusion with platelet membranes. PF3-PPh₃ is an AIE-active conjugated polyelectrolyte with photosensitizing capability for photodynamic therapy (PDT). Plt-M@P exhibits superior tumor targeting capacity in vivo. When applied in small tumor-bearing (~40 mm³) mice, Plt-M@P-mediated PDT significantly inhibits tumor growth. In tumor models with large burdens (~200 mm³), using Plt-M@P-mediated PDT or anti-PD-L1 alone is less effective, but the combination of both is effective in inhibiting tumor growth. Importantly, this combination therapy has good biocompatibility, as demonstrated by the absence of damage to the major organs, especially the reproductive system. In conclusion, we show that Plt-M@P-mediated PDT can improve anti-PD-L1 immunotherapy by enhancing antitumor effects, providing a promising strategy for the treatment of tumors with large burdens.

Impact of delineation errors on the estimated organ at risk dose and of dose errors on the normal tissue complication probability model

BACKGROUND

Normal tissue complication probability (NTCP) models are often based on doses retrieved from delineated volumes. For retrospective dose-response studies focusing on organs that have not been delineated historically, automatic segmentation might be considered. However, automatic segmentation risks generating considerable delineation errors and knowledge regarding how these errors impact the estimated organ dose is important. Furthermore, organ-at-risk (OAR) dose uncertainties cannot be eliminated and might affect the resulting NTCP model. Therefore, it is also of interest to study how OAR dose errors impact the NTCP modeling results.

PURPOSE

To investigate how random delineation errors of the proximal bronchial tree, heart, and esophagus impact the estimated OAR dose, and to investigate how random errors in the doses used for dose-response modeling affect the estimated NTCPs.

METHODS

We investigated the impact of random delineation errors on the estimated OAR dose using the treatment plans of 39 patients treated with conventionally fractionated radiation therapy of non-small-cell lung cancer. Study-specific reference structures were defined by manually contouring the proximal bronchial tree, heart and esophagus. For each patient and organ, 120 reshaped structures were created by introducing random shifts and margins to the entire reference structure. The mean and near-maximum dose to the reference and reshaped structures were compared. In a separate investigation, the impact of random dose errors on the NTCP model was studied performing dose-response modeling with study sets containing treatment outcomes and OAR doses with and without introduced errors. Universal patient populations with defined population risks, dose-response relationships and distributions of OAR doses were used as ground truth. From such a universal population, we randomly sampled data sets consisting of OAR dose and treatment outcome into reference populations. Study sets of different sizes were created by repeatedly introducing errors to the OAR doses of each reference population. The NTCP models generated with dose errors were compared to the reference NTCP model of the corresponding reference population.

RESULTS

A total of 14 040 reshaped structures with random delineation errors were created. The delineation errors resulted in systematic mean dose errors of less than 1% of the prescribed dose (PD). Mean dose differences above 15% of PD and near-maximum doses differences above 25% of PD were observed for 211 and 457 reshaped structures, respectively. Introducing random errors to OAR doses used for dose-response modeling resulted in systematic underestimations of the median NTCP. For all investigated scenarios, the median differences in NTCP were within 0.1 percentage points (p.p.) when comparing different study sizes.

CONCLUSIONS

Introducing random delineation errors to the proximal bronchial tree, heart and esophagus resulted in mean dose and near-maximum dose differences above 15% and 25% of PD, respectively. We did not observe an association between the dose level and the magnitude of the dose errors. For the scenarios investigated in this study, introducing random errors to OAR doses used for dose-response modeling resulted in systematic underestimations of the median NTCP for reference risks higher than the universal population risk. The median NTCP underestimation was similar for different study sizes, all within 0.1 p.p.

Cardiovascular Toxicity and Risk Mitigation with Lung Cancer Treatment

PURPOSE OF REVIEW

Patients with lung cancer often have concomitant cardiovascular comorbidities and receive potentially cardiotoxic therapies. As oncologic outcomes improve, the relative impact of cardiovascular disease on lung cancer survivors is expected to increase. This review summarizes cardiovascular toxicities observed after treatment for lung cancer, as well as recommended risk mitigation strategies.

RECENT FINDINGS

A variety of cardiovascular events may be observed after surgery, radiation therapy (RT), and systemic therapy. The risk of cardiovascular events after radiation therapy (RT) is higher than previously appreciated (23-32%), and RT dose to the heart is a modifiable risk factor. Targeted agents and immune checkpoint inhibitors have been associated with cardiovascular toxicities distinct from those of cytotoxic agents; these are rare but can be severe and require prompt intervention. Optimization of cardiovascular risk factors is important at all phases of cancer therapy and survivorship. Recommended practices for baseline risk assessment, preventive measures, and appropriate monitoring are discussed herein.