European Organization for Research and Treatment of Cancer (EORTC) recommendations for planning and delivery of high-dose, high precision radiotherapy for lung cancer

Diagnosis and treatment of radiation induced pneumonitis in patients with lung cancer: An ESTRO clinical practice guideline

The incidence of radiation pneumonitis (RP) has decreased significantly compared to historical series, mainly due to improved radiotherapy techniques and patient selection. Nevertheless, some patients still develop RP. This guideline provides user-friendly flowcharts to address common clinical practice questions regarding RP. We summarize the current state of the art regarding the mechanisms, risk factors, diagnosis and treatment of RP. Dosimetric constraints to minimize the incidence of RP, as well as risk factors for developing RP, such as idiopathic pulmonary fibrosis (IPF) were identified. The combination of radiotherapy and medication as a risk factor for the development of RP was reviewed. RP remains a diagnosis of exclusion, but an algorithm for reaching the diagnosis has been proposed. Finally, practical approaches to the treatment of RP are outlined.

Recommendations for radiotherapy quality assurance in clinical trials

Robust quality assurance (QA) of clinical trials in radiotherapy (RT) is paramount for minimising uncertainties in treatment delivery, thereby strengthening the statistical power of the study and increasing the likelihood of accurately answering the research question. As RT techniques evolve and become more complex, establishing an appropriate QA program for a specific clinical trial becomes increasingly challenging, highlighting the importance of clear and standardised recommendations. This study provide such recommendations for Principal Investigators (PIs) to consider when planning and conducting RT Quality Assurance (RTQA) for clinical trials. They arise from experiences with RTQA in the clinical trials conducted in the Danish Multidisciplinary Cancer Groups (DMCGs). The recommendations include a checklist to guide PIs in developing an effective RTQA program.

Artificial intelligence in automatic image segmentation system for exploring recurrence patterns in small cell carcinoma of the lung

Background

The integration of artificial intelligence (AI) in automatic image segmentation systems offers a novel approach to evaluating the clinical target volume (CTV) in small cell lung cancer (SCLC) patients. Utilizing imaging recurrence data, this study applies a recursive feature elimination algorithm to model and predict patient prognoses, aiming to enhance clinical guidance and prediction accuracy.

Materials and Methods

This research analyzed data from SCLC patients who received curative radiotherapy from January 1, 2010, to December 30, 2021, and had comprehensive follow-up records including pre- and post-treatment imaging. An AI-driven image segmentation system segmented the initial CTV, evaluating 110 clinical parameters. The recursive feature elimination method selected pertinent features, and a random forest-based recursive prediction model was developed to establish a clinically viable recurrence prediction model.

Results

1. Local Control Analysis: A study of 180 patients, with a median follow-up duration of 36 months, revealed that 94 experienced recurrences, while 86 did not. Factors influencing local control rates included gender (male), age (>60 years), T stage, smoking index, and tumor size. Notably, tumor size (≥ 5cm) emerged as an independent factor significantly impacting local control rates, with a Hazard Ratio (HR) of 1.635 (95% CI: 1.055-2.536, p=0.028). 2. Recurrence Analysis: Tumor size (≥ 5cm) was also closely linked to patient local control rates, with a 3-year Local Control Rate Failure (LCRF) contrasting sharply between larger tumors (61.1%) and smaller tumors (86.7%, p=0.004). Upon analyzing recurrence patterns among 94 patients, a total of 170 instances were examined. Recurrence was most prevalent in regions 10R, 10L, 4R, and 7, accounting for 67.65% (115/170) of cases, while regions 2L and 3P showed no recurrences. The initial region of the primary tumor or metastatic lymph nodes was identified as a critical recurrence area, with a 100% recurrence rate in patients whose initial tumor region included 10 specific regions. The recurrence rates for initial tumor regions involving 4R, 7, 11R, and 11L ranged between 41.6% and 45.5%. 3. Development of a recurrence prediction model: utilizing an AI-powered automatic image segmentation system, multidimensional partition parameters, including 110 clinical variables, were analyzed. The recursive feature elimination method facilitated efficient feature selection. From this, a recurrence prediction model for small cell lung cancer was developed using a random forest algorithm, achieving a clinically significant accuracy rate of 77%. This model provides a reliable basis for enhancing the clinical application and decision-making process for medical practitioners.

Conclusion

The utilization of AI-based automatic image segmentation system for delineating the initial CTV has proven pivotal. Analysis and modeling of recurrent images reveal that the initial GTV and GTVnd are critical regions for recurrence. Leveraging partition parameter and variable information, we constructed a clinically viable recurrence prediction model. This model significantly aids in guiding the precise clinical targeting of treatment areas, demonstrating the potential of AI to enhance patient management and treatment outcomes in small cell lung cancer.

Exploring the feasibility of millimeter-wave sensors for non-invasive respiratory motion visualization in diagnostic imaging and therapy

BACKGROUND

Management of respiratory motion during radiation therapy is essential for accurate dose delivery and minimizing the risk to organs. In diagnostic imaging, respiratory monitoring is required for confirmation of breath-hold and four-dimensional computed tomography (CT) reconstruction. Although respiratory monitoring systems are widely used in radiation therapy, they are not often used for diagnostic imaging, where they could improve image quality.

PURPOSE

The purpose of this study was to use a millimeter-wave sensor (MWS) to noninvasively visualize respiratory motion, confirm breath-holding, and explore the potential for clinical implementation of an MWS in diagnostic x-ray imaging, CT, and radiation therapy.

METHODS

A 24 GHz microMWS was used in this study. The MWS directionality was determined using a radio-wave dark-box system. An antenna directionality test evaluated the effective azimuthal and elevational beamwidths. Respiratory waveforms were detected by optimizing the fast Fourier transform threshold and the cutoff frequencies of the bandpass filter. To confirm the reproducibility of the MWS, the detected waveforms were compared with those of a respiratory motion phantom (QUASAR), the amplitude of motion of which could be controlled. The time from valley to peak of the waveforms obtained by normalized MWS and the QUASAR were compared. The MWS was used to acquire respiratory waveforms of 20 healthy volunteers (including an infant and a child) in geometries adopted during chest CT (supine position; anteroposterior view; source-to-surface distance, 400 mm) and chest x-ray imaging (standing position; posteroanterior view; source-to-surface distance, 1800 mm).

RESULTS

The effective azimuthal and elevational beamwidths of the MWS were approximately ± 20° and ± 40°, respectively. By optimizing the acquisition parameters (high-sensitivity setting; with noise cancelling; frequency range, 10-20 min-1), the waveforms detected using the MWS approximately matched those of the respiratory motion phantom at all amplitudes. The MWS was also used to confirm breath-holding in 18 volunteers in both supine (anteroposterior view) and standing (posteroanterior view) positions. In addition, for an infant and a child who were unable to follow the instruction to stop breathing, a visual count of their inhalations matched the number of respiratory cycles measured using the MWS.

CONCLUSION

The 24 GHz MWS successfully monitored respiratory motion and breath-holding during radiographic and CT imaging. With effective directionality and stability, this system holds promise for clinical management of respiratory motion during diagnostic imaging and radiation therapy.

Smart contours: deep learning-driven internal gross tumor volume delineation in non-small cell lung cancer using 4D CT maximum and average intensity projections

BACKGROUND

Delineating the internal gross tumor volume (IGTV) is crucial for the treatment of non-small cell lung cancer (NSCLC). Deep learning (DL) enables the automation of this process; however, current studies focus mainly on multiple phases of four-dimensional (4D) computed tomography (CT), which leads to indirect results. This study proposed a DL-based method for automatic IGTV delineation using maximum and average intensity projections (MIP and AIP, respectively) from 4D CT.

METHODS

We retrospectively enrolled 124 patients with NSCLC and divided them into training (70%, n = 87) and validation (30%, n = 37) cohorts. Four-dimensional CT images were acquired, and the corresponding MIP and AIP images were generated. The IGTVs were contoured on 4D CT and used as the ground truth (GT). The MIP or AIP images, along with the corresponding IGTVs (IGTVMIP-manu and IGTVAIP-manu, respectively), were fed into the DL models for training and validation. We assessed the performance of three segmentation models-U-net, attention U-net, and V-net-using the Dice similarity coefficient (DSC) and the 95th percentile of the Hausdorff distance (HD95) as the primary metrics.

RESULTS

The attention U-net model trained on AIP images presented a mean DSC of 0.871 ± 0.048 and mean HD95 of 2.958 ± 2.266 mm, whereas the model trained on MIP images achieved a mean DSC of 0.852 ± 0.053 and mean HD95 of 3.209 ± 2.136 mm. Among the models, attention U-net and U-net achieved similar results, considerably surpassing V-net.

CONCLUSIONS

DL models can automate IGTV delineation using MIP and AIP images, streamline contouring, and enhance the accuracy and consistency of lung cancer radiotherapy planning to improve patient outcomes.

Efficacy and Failure Patterns Following Target Volume and Dose Reduction After Neoadjuvant Therapy in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

BACKGROUND

In this study, we aimed to analyze the efficacy and failure patterns of contouring target volume based on the residual tumor and decreasing the dose to the area of tumor regression after neoadjuvant therapy in locoregionally advanced head and neck squamous cell carcinoma (HNSCC).

METHODS

We retrospectively analyzed the patients with locoregionally advanced HNSCC treated by our group from May 2011 to June 2023. All patients received neoadjuvant therapy followed by intensity-modulated radiation therapy. Gross tumor volumes for the primary tumor and metastatic lymph nodes were delineated according to postneoadjuvant extension. The tumor shrinkage after neoadjuvant therapy was included in the high-risk clinical target volume (CTV1) and prescribed a dose of 60 Gy. Kaplan-Meier analysis was employed to calculate local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS), overall survival (OS), and distant metastasis-free survival (DMFS). Failure patterns were analyzed by mapping the location and extent of locoregional recurrence onto pretreatment planning CT.

RESULTS

This study included a total of 114 patients, with a median follow-up of 34 months. The 5-year LRFS, RRFS, OS, and DMFS rates were 70.2%, 70.7%, 74.8%, and 73.8%, respectively. Among the 14 patients with recurrences, there were 5 local failures, 6 regional recurrences, and 3 both local and regional recurrences. All local recurrences occurred within the 95% isodose line, classified as in-field failures. Only one regional recurrence was marginal failure. No out-of-field failure was observed.

CONCLUSION

Reduction of target volume after neoadjuvant therapy and distribution of 60 Gy of dose to the tumor regression area may be feasible.

Impact of tumor position displacement during end-exhalation breath-hold condition on tumor dose in lung stereotactic body radiation therapy using volumetric modulated arc therapy

Background and purpose

In lung stereotactic body radiation therapy (SBRT) using a breath-holding technique, displacement of tumor during breath-holding is rarely considered. This study used four-dimensional (4D) dose calculation with cine computed tomography (CT) to evaluate the impact of unexpected tumor position displacement during breath-holding on the target dose of lung volumetric modulated arc therapy (VMAT)-SBRT.

Materials and methods

This study included 20 cases for which tumor position displacement during end-exhalation breath-holding (range: 0.5-12.6 mm) was evaluated on cine CT. VMAT-SBRT plans (3D dose) were generated using treatment planning CT images (reference CT) acquired during end-exhalation breath-hold. For each plan, the 4D dose was calculated using deformable image registration of the cine CT images and was accumulated onto the reference CT. Dose metrics and the mean biologically effective dose at α / β  = 10 (BED10) for the gross tumor volume (GTV) were compared between 3D and 4D doses.

Results

In the 17 cases where the tumor was within the planning target volume (PTV) during breath-holding, the difference between the 3D and 4D doses was within 3 % for each dose metric. However, in 3 cases where the tumor position during breath-holding included displacement outside the PTV, both the D98% and mean BED10 of the GTV were reduced by 6.9-20.0 % and 2.1-13.8 %, respectively, in 4D doses compared to 3D doses.

Conclusion

Our study showed that tumor position displacements during breath-holding may lead to substantial tumor dose reduction.

Advances of PET/CT in Target Delineation of Lung Cancer Before Radiation Therapy

In the clinical management of lung cancer, radiotherapy remains a cornerstone of multimodal treatment strategies, often used alongside surgery or in combination with systemic therapies such as chemotherapy, tyrosine kinase inhibitors, and immune checkpoint inhibitors. While conventional imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) continue to play a central role in staging, response assessment, and radiotherapy planning, advanced imaging techniques, particularly [18F]FDG PET/CT, are being increasingly integrated into routine clinical practice. These advanced techniques address the limitations of standard imaging by providing insight into molecular and metabolic tumor characteristics, enabling precise tumor visualization, accurate target volume delineation, and early treatment response assessment. This review examines the role of radiotherapy in the multidisciplinary management of lung cancer, detailing current concepts of morphological and functional imaging for staging and treatment planning. It also highlights the growing importance of PET-based radiotherapy planning, emphasizing its contributions to target volume definition and predictive value for treatment outcomes. Recent methodological advances, including the integration of artificial intelligence (AI), radiomics, technical innovations, and novel PET ligands, are discussed, highlighting their potential to improve the precision, efficacy, and personalization of lung cancer radiotherapy planning.

Adaptive treatment margins to reduce organs at risk dose in patients with no or minimal anatomical changes in radiotherapy of non-small cell lung cancer

Background and purpose

In non-small cell lung cancer (NSCLC) a significant portion of the planning target volume (PTV) margin accommodates for anatomical changes during treatment. Patients with no or minimal anatomical changes might therefore benefit from a reduced PTV margin, resulting in lower organ at risk (OAR) doses. We evaluated a plan of the day approach using different PTV margins to quantify its effect on OAR and clinical target volume (CTV) dose.

Materials and methods

Twenty NSCLC patients were included in this retrospective study. CBCTs of all fractions were evaluated using an image-guided radiotherapy (IGRT) protocol to classify fractions into two groups: no or minimal anatomical changes to which reduced PTV margin plans (5 or 2 mm) were assigned, or with anatomical changes that received the reference treatment plan (8 mm PTV margin). OAR doses were investigated and CTV coverage was evaluated using CBCT dose recalculations.

Results

All plans showed decreased OAR dose when the PTV margin was reduced from 8 mm to 5 mm or 2 mm. The IGRT protocol selected 254/600 fractions in 19/20 patients, that could be treated with a smaller margin. CTV V95% remained ≥95% in 94% of the 5 mm plans and 87% of the 2 mm plans, compared to 98% of the reference 8 mm plans.

Conclusion

The IGRT protocol could identify fractions with no or minimal anatomical changes allowing a plan of the day approach to reduce PTV margins. Target coverage remained adequate in the majority of patients, while reducing OAR doses.

Prediction of new-onset atrial fibrillation in patients with non-small cell lung cancer treated with curative-intent conventional radiotherapy

BACKGROUND

Atrial fibrillation (AF) is an important side effect of thoracic Radiotherapy (RT), which may impair quality of life and survival. This study aimed to develop a prediction model for new-onset AF in patients with Non-Small Cell Lung Cancer (NSCLC) receiving RT alone or as a part of their multi-modal treatment.

PATIENTS AND METHODS

Patients with stage I-IV NSCLC treated with curative-intent conventional photon RT were included. The baseline electrocardiogram (ECG) was compared with follow-up ECGs to identify the occurrence of new-onset AF. A wide range of potential clinical predictors and dose-volume measures on the whole heart and six automatically contoured cardiac substructures, including chambers and conduction nodes, were considered for statistical modeling. Internal validation with optimism-correction was performed. A nomogram was made.

RESULTS

374 patients (mean age 69 ± 10 years, 57 % male) were included. At baseline, 9.1 % of patients had AF, and 42 (11.2 %) patients developed new-onset AF. The following parameters were predictive: older age (OR=1.04, 95 % CI: 1.013-1.068), being overweight or obese (OR=1.791, 95 % CI: 1.139-2.816), alcohol use (OR=4.052, 95 % CI: 2.445-6.715), history of cardiac procedures (OR=2.329, 95 % CI: 1.287-4.215), tumor located in the upper lobe (OR=2.571, 95 % CI: 1.518-4.355), higher forced expiratory volume in 1 s (OR=0.989, 95 % CI: 0.979-0.999), higher creatinine (OR=1.008, 95 % CI: 1.002-1.014), concurrent chemotherapy (OR=3.266, 95 % CI: 1.757 to 6.07) and left atrium Dmax (OR=1.022, 95 % CI: 1.012-1.032). The model showed good discrimination (area under the curve = 0.80, 95 % CI: 0.76-0.84), calibration and positive net benefits.

CONCLUSION

This prediction model employs readily available predictors to identify patients at high risk of new-onset AF who could potentially benefit from active screening and timely management of post-RT AF.

Correlation between glucose metabolism and body mass index in tumor lesions of patients with lung cancer

OBJECTIVE

Lung cancer, along with various other cancers, is characterized by increased glucose metabolism. The maximum standardized uptake value (SUVmax), derived from positron emission tomography-computed tomography (PET-CT), serves as an indicator of glucose metabolic activity in tumor lesions. This study aimed to evaluate the correlation between body mass index (BMI) and SUVmax in individuals with lung cancer.

METHODS

This study included 41 patients with lung cancer, who were divided into two groups: Group 1 (n = 21), with a BMI greater than 22.4, and Group 2 (n = 20), with a BMI less than 22.4. All participants underwent 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) imaging. The SUVmax was calculated by manually delineating the regions of interest. A t-test was performed to assess whether the differences in SUVmax between the two groups were statistically significant.

RESULTS

The mean SUVmax for Group 1 was 11.20 ± 5.45, while for Group 2 it was 10.65 ± 5.96. Although the mean SUVmax was higher in Group 1 compared to Group 2, the difference between the groups was not statistically significant (P = 0.757).

CONCLUSION

The findings indicate a non-significant difference in glucose metabolism in lung cancer lesions between patients with different BMI levels. These results offer valuable insights into the metabolic characteristics of lung cancer and contribute to a deeper understanding of its pathophysiology.

Esophagitis and Pneumonitis Related to Concurrent Chemoradiation ± Durvalumab Consolidation in Unresectable Stage III Non-Small-Cell Lung Cancer: Risk Assessment and Management Recommendations Based on a Modified Delphi Process

The addition of durvalumab consolidation to concurrent chemoradiation therapy (cCRT) has fundamentally changed the standard of care for patients with unresectable stage III non-small-cell lung cancer (NSCLC). Nevertheless, concerns related to esophagitis and pneumonitis potentially impact the broad application of all regimen components. A Canadian expert working group (EWG) was convened to provide guidance to healthcare professionals (HCPs) managing these adverse events (AEs) and to help optimize the patient experience. Integrating literature review findings and real-world clinical experience, the EWG used a modified Delphi process to develop 12 clinical questions, 30 recommendations, and a risk-stratification guide. The recommendations address risk factors associated with developing esophagitis and pneumonitis, approaches to risk mitigation and optimal management, and considerations related to initiation and re-initiation of durvalumab consolidation therapy. For both AEs, the EWG emphasized the importance of upfront risk assessment to inform the treatment approach, integration of preventative measures, and prompt initiation of suitable therapy in alignment with AE grade. The EWG also underscored the need for timely, effective communication between multidisciplinary team members and clarity on responsibilities. These recommendations will help support HCP decision-making related to esophagitis and pneumonitis arising from cCRT ± durvalumab and improve outcomes for patients with unresectable stage III NSCLC.

Pathogenic mechanisms and latest therapeutic approaches for radiation-induced lung injury: A narrative review

The treatment of thoracic tumors with ionizing radiation can cause radiation-induced lung injury (RILI), which includes radiation pneumonitis and radiation-induced pulmonary fibrosis. Preventing RILI is crucial for controlling tumor growth and improving quality of life. However, the serious adverse effects of traditional RILI treatment methods remain a major obstacle, necessitating the development of novel treatment options that are both safe and effective. This review summarizes the molecular mechanisms of RILI and explores novel treatment options, including natural compounds, gene therapy, nanomaterials, and mesenchymal stem cells. These recent experimental approaches show potential as effective prevention and treatment options for RILI in clinical practice.

Adaptive intensity modulated proton therapy using 4D robust planning: a proof-of-concept for the application of dose mimicking approach

Objective.A four-dimensional robust optimisation (4DRO) is usually employed when the tumour respiratory motion needs to be addressed. However, it is computationally demanding, and an automated method is preferable for adaptive planning to avoid manual trial-and-error. This study proposes a 4DRO technique based on dose mimicking for automated adaptive planning.Approach.Initial plans for 4DRO intensity modulated proton therapy were created on an average CT for four patients with clinical target volume (CTV) in the lung, oesophagus, or pancreas, respectively. These plans were robustly optimised using three phases of four-dimensional computed tomography (4DCT) and accounting for setup and density uncertainties. Weekly 4DCTs were used for adaptive replanning, using a constant relative biological effectiveness (cRBE) of 1.1. Two methods were used: (1) template-based adaptive (TA) planning and (2) dose-mimicking-based adaptive (MA) planning. The plans were evaluated using variable RBE (vRBE) weighted doses and biologically consistent dose accumulation (BCDA).Main results.MA and TA plans had comparable CTV coverage except for one patient where the MA plan had a higher D98 and lower D2 but with an increased D2 in few organs at risk (OARs). CTV D98 deviations in non-adaptive plans from the initial plans were up to -7.2 percentage points (p.p.) in individual cases and -1.8 p.p. when using BCDA. For the OARs, MA plans showed a reduced mean dose and D2 compared to the TA plans, with few exceptions. The vRBE-weighted accumulated doses had a mean dose and D2 difference of up to 0.3 Gy and 0.5 Gy, respectively, in the OARs with respect to cRBE-weighted doses.Significance.MA plans indicate better performance in target coverage and OAR dose sparing compared to the TA plans in 4DRO adaptive planning. Moreover, MA method is capable of handling both forms of anatomical variation, namely, changes in density and relative shifts in the position of OARs.

Dosimetric comparison of nodal clinical target volume for locally advanced non‑small cell lung cancer: Options for geometric expansion vs. lymph node stations

The purpose of the present retrospective study was to evaluate whether dosimetric differences existed in nodal clinical target volume (CTV) using options for geometric expansion and lymph node (LN) stations based on the European Society for Radiotherapy and Oncology guideline for locally advanced non-small cell lung cancer (NSCLC). In the treatment planning computed tomographic images of 17 patients with cT4N2M0 NSCLC, nodal CTVs were contoured based on the guideline options of: i) Geometric expansion, with CTV including the nodal gross tumor volume plus 5 mm margin; and ii) LN stations, with CTV including the affected LN stations. Treatment planning of 60 Gy in 30 fractions was performed using volumetric modulated arc therapy; Dmean was the mean irradiated dose to the structure; and VnGy was the volume of the structure receiving ≥n Gy. Dose-volume parameters were compared between the two options. Consequently, the option of geometric expansion was associated with a significantly lower V60Gy and Dmean of the esophagus, V20Gy, V5Gy and Dmean of the lungs, and Dmean of the heart than the option of LN stations in all patients (P=0.017, P<0.001, P<0.001, P<0.001, P<0.001 and P=0.029, respectively). For the V20Gy of the lungs, the 8 patients (47%) with LN metastases in stations 2 or 3 had significantly larger differences in the values between the two options than the 9 patients (53%) without those metastases; the median values of the difference of V20Gy of the lungs between the two options were 2.8% (range, 0.2 to 9.6%) with LN metastases in stations 2 or 3 and 0.5% (range, -0.2 to 5.0%) without these metastases (P=0.027). In conclusion, using the option for geometric expansion might help reduce the V60Gy and Dmean of the esophagus, V20Gy, V5Gy and Dmean of the lungs, and Dmean of the heart in all patients, and the V20Gy of the lungs in patients with LN metastases in stations 2 or 3.

Can prediction models for hospital readmission be improved by incorporating patient-reported outcome measures? A systematic review and narrative synthesis

PURPOSE

To investigate the roles, challenges, and implications of using patient-reported outcome measures (PROMs) in predicting the risk of hospital readmissions.

METHODS

We systematically searched four bibliometric databases for peer-reviewed studies published in English between 1 January 2000 and 15 June 2023 and used validated PROMs to predict readmission risks for adult populations. Reported studies were analysed and narratively synthesised in accordance with the CHARMS and PRISMA guidelines.

RESULTS

Of the 2858 abstracts reviewed, 23 studies met predefined eligibility criteria, representing diverse geographic regions and medical specialties. Among those, 19 identified the positive contributions of PROMs in predicting readmission risks. Seven studies utilised generic PROMs exclusively, eleven used generic and condition-specific PROMs, while 5 focussed solely on condition-specific PROMs. Logistic regression was the most used modelling approach, with 13 studies aiming at predicting 30-day all-cause readmission risks. The c-statistic, ranging from 0.54 to 0.84, was reported in 22/23 studies as a measure of model discrimination. Nine studies reported model calibration in addition to c-statistic. Thirteen studies detailed their approaches to dealing with missing data.

CONCLUSION

Our study highlights the potential of PROMs to enhance predictive accuracy in readmission models, while acknowledging the diversity in data collection methods, readmission definitions, and model evaluation approaches. Recognizing that PROMs serve various purposes beyond readmission reduction, our study supports routine data collection and strategic integration of PROMs in healthcare practices to improve patient outcomes. To facilitate comparative analysis and broaden the use of PROMs in the prediction framework, it is imperative to consider the methodological aspects involved.

Chest wall pain after single-fraction thoracic stereotactic ablative Radiotherapy: Dosimetric analysis from the iSABR trial

BACKGROUND AND PURPOSE

Concerns over chest wall toxicity has led to debates on treating tumors adjacent to the chest wall with single-fraction stereotactic ablative radiotherapy (SABR). We performed a secondary analysis of patients treated on the prospective iSABR trial to determine the incidence and grade of chest wall pain and modeled dose-response to guide radiation planning and estimate risk.

MATERIALS AND METHODS

This analysis included 99 tumors in 92 patients that were treated with 25 Gy in one fraction on the iSABR trial which individualized dose by tumor size and location. Toxicity events were prospectively collected and graded based on the CTCAE version 4. Dose-response modeling was performed using a logistic model with maximum likelihood method utilized for parameter fitting.

RESULTS

There were 22 grade 1 or higher chest wall pain events, including five grade 2 events and zero grade 3 or higher events. The volume receiving at least 11 Gy (V11Gy) and the minimum dose to the hottest 2 cc (D2cc) were most highly correlated with toxicity. When dichotomized by an estimated incidence of ≥ 20 % toxicity, the D2cc > 17 Gy (36.6 % vs. 3.7 %, p < 0.01) and V11Gy > 28 cc (40.0 % vs. 8.1 %, p < 0.01) constraints were predictive of chest wall pain, including among a subset of patients with tumors abutting or adjacent to the chest wall.

CONCLUSION

For small, peripheral tumors, single-fraction SABR is associated with modest rates of low-grade chest wall pain. Proximity to the chest wall may not contraindicate single fractionation when using highly conformal, image-guided techniques with sharp dose gradients.

And Yet It Moves: Clinical Outcomes and Motion Management in Stereotactic Body Radiation Therapy (SBRT) of Centrally Located Non-Small Cell Lung Cancer (NSCLC): Shedding Light on the Internal Organ at Risk Volume (IRV) Concept

The internal organ at risk volume (IRV) concept might improve toxicity profiles in stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC). We studied (1) clinical aspects in central vs. peripheral tumors, (2) the IRV concept in central tumors, (3) organ motion, and (4) associated normal tissue complication probabilities (NTCPs). We analyzed patients who received SBRT for NSCLC (clinical aspects, n = 78; motion management, n = 35). We found lower biologically effective doses, larger planning target volume sizes, higher lung doses, and worse locoregional control for central vs. peripheral tumors. Organ motion was greater in males and tall patients (bronchial tree), whereas volume changes were lower in patients with a high body mass index (BMI) (esophagus). Applying the IRV concept (retrospectively, without new optimization), we found an absolute increase of >10% in NTCPs for the bronchial tree in three patients. This study emphasizes the need to optimize methods to balance dose escalation with toxicities in central tumors. There is evidence that organ motion/volume changes could be more pronounced in males and tall patients, and less pronounced in patients with higher BMI. Since recent studies have made efforts to further subclassify central tumors to refine treatment, the IRV concept should be considered for optimal risk assessment.

Targeted treatment for unresectable EGFR mutation-positive stage III non-small cell lung cancer: Emerging evidence and future perspectives

Epidermal growth factor receptor (EGFR) mutations are detected in up to one third of patients with unresectable stage III non-small cell lung cancer (NSCLC). The current standard of care for unresectable stage III NSCLC is consolidation durvalumab for patients who have not progressed following concurrent chemoradiotherapy (the 'PACIFIC regimen'). However, the benefit of immunotherapy, specifically in patients with EGFR mutation-positive (EGFRm) tumors, is not well characterized, and this treatment approach is not recommended in these patients, based on a recent ESMO consensus statement. EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated significant improvements in patient outcomes in EGFRm metastatic NSCLC. The benefits of these agents have also translated to patients with EGFRm early-stage resectable disease as adjuvant therapy. The role of EGFR-TKIs has yet to be prospectively characterized in the unresectable setting. Preliminary efficacy signals for EGFR-TKIs in unresectable EGFRm stage III NSCLC have been reported from a limited number of subgroup and retrospective studies. Several clinical trials are ongoing assessing the safety and efficacy of EGFR-TKIs in this patient population. Here, we review the current management of unresectable EGFRm stage III NSCLC. We outline the rationale for investigating EGFR-TKI strategies in this setting and discuss ongoing studies. Finally, we discuss the evidence gaps and future challenges for treating patients with unresectable EGFRm stage III NSCLC.

[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.

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.

Impact of radiation on host immune system in patients treated with chemoradiotherapy and durvalumab consolidation for unresectable locally advanced non-small cell lung cancer

Background

The optimal modalities of radiotherapy when combining concurrent chemoradiation (CCRT) and immunotherapy (IO) for locally advanced non-small cell lung cancer (LA-NSCLC) remain to be determined. The aim of this study was to investigate the impact of radiation on different immune structures and immune cells in patients treated with CCRT followed by durvalumab.

Material and methods

Clinicopathologic data, pre- and post-treatment blood counts, and dosimetric data were collected in patients treated with CCRT and durvalumab consolidation for LA-NSCLC. Patients were divided into two groups according to the inclusion (NILN-R+) or not (NILN-R-) of at least one non-involved tumor-draining lymph node (NITDLN) in the clinical target volume (CTV). Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method.

Results

Fifty patients were included with a median follow-up of 23.2 months (95% CI 18.3-35.2). Two-year PFS and 2-year OS were 52.2% (95% CI 35.8-66.3) and 66.2% (95% CI 46.5-80.1), respectively. In univariable analysis, NILN-R+ (hazard ratio (HR) 2.60, p = 0.028), estimated dose of radiation to immune cells (EDRIC) >6.3 Gy (HR 3.19, p = 0.049), and lymphopenia ≤ 500/mm³ at IO initiation (HR 2.69, p = 0.021) were correlated with poorer PFS; lymphopenia ≤ 500/mm³ was also associated with poorer OS (HR 3.46, p = 0.024). In multivariable analysis, NILN-R+ was the strongest factor associated with PFS (HR 3.15, p = 0.017).

Conclusion

The inclusion of at least one NITDLN station within the CTV was an independent factor for poorer PFS in the context of CCRT and durvalumab for LA-NSCLC. The optimal sparing of immune structures might help in achieving better synergy between radiotherapy and immunotherapy in this indication.

Tackling the current dilemma of immunotherapy in extensive-stage small cell lung cancer: A promising strategy of combining with radiotherapy

Progress in the treatment of small cell lung cancer (SCLC) has been modest over the past decades until the advent of immune checkpoint inhibitors, which have redefined the standard first-line treatment for extensive-stage SCLC (ES-SCLC). However, despite the positive results of several clinical trials, the limited survival benefit achieved suggests that the priming and sustaining of immunotherapeutic efficacy are poor and further investigation is urgently needed. In this review, we aim to summarize the potential mechanisms underlying the limited efficacy of immunotherapy and intrinsic resistance in ES-SCLC, including impaired antigen presentation and limited T cell infiltration. Moreover, to tackle the current dilemma, given the synergistic effects of radiotherapy on immunotherapy, especially the unique advantages of low-dose radiotherapy (LDRT), such as less immunosuppression and lower radiation toxicity, we propose radiotherapy as a booster to enhance the immunotherapeutic efficacy by overcoming the poor priming effect. Recent clinical trials, including ours, have also focused on adding radiotherapy, including LDRT, to first-line treatment of ES-SCLC. Additionally, we also suggest combination strategies to sustain the immunostimulatory effect of radiotherapy, as well as the cancer-immunity cycle, and further improve survival outcomes.

Polyphenols as Potential Protectors against Radiation-Induced Adverse Effects in Patients with Thoracic Cancer

Radiotherapy is one of the standard treatment approaches used against thoracic cancers, occasionally combined with chemotherapy, immunotherapy and molecular targeted therapy. However, these cancers are often not highly sensitive to standard of care treatments, making the use of high dose radiotherapy necessary, which is linked with high rates of radiation-induced adverse effects in healthy tissues of the thorax. These tissues remain therefore dose-limiting factors in radiation oncology despite recent technological advances in treatment planning and delivery of irradiation. Polyphenols are metabolites found in plants that have been suggested to improve the therapeutic window by sensitizing the tumor to radiotherapy, while simultaneously protecting normal cells from therapy-induced damage by preventing DNA damage, as well as having anti-oxidant, anti-inflammatory or immunomodulatory properties. This review focuses on the radioprotective effect of polyphenols and the molecular mechanisms underlying these effects in the normal tissue, especially in the lung, heart and esophagus.

Impact of palliative radiotherapy with or without lung irradiation in patients with interstitial lung disease

BACKGROUND AND PURPOSE

Acute exacerbations or acute lung injury, including radiation pneumonitis (AE-ALI/RP) of interstitial lung disease (ILD), has a fatal prognosis. We evaluated the risk of palliative-intent radiotherapy (RT), with or without lung irradiation, for AE-ALI/RP of ILD.

MATERIALS AND METHODS

The data of patients with ILD who received palliative-intent RT between January 2011 and January 2022 were retrospectively reviewed. Factors associated with AE-ALI/RP grade ≥3 were assessed using univariate and multivariate analyses.

RESULTS

One hundred and three patients were examined, with median imaging and survival follow-up times of 88 (2-1440) and 144 (8-1441) days. The median time to onset of AE-ALI/RP grade ≥3 was 72 (5-206) days. In multivariate analysis, a higher pulmonary fibrosis score (PFS ≥ 3) (hazard ratio, HR: 2.16; 95% confidence interval, CI: 1.36-3.43; p < 0.01) and lung irradiation (lung-RT) (HR: 3.82; 95% CI: 1.01-15.73; p = 0.04) were significant factors for AE-ALI/RP grade ≥3. In patients who received lung-RT, the 100-day survival rate and cumulative incidence of AE-ALI/RP grade ≥3 were 56.8% and 13.7%, respectively. In patients with PFS ≥3 and who underwent lung-RT, the 100-day cumulative incidence of AE-ALI/RP grade ≥3 was 37.5%; all patients with AE-ALI/RP grade ≥3 had grade 5. In patients with PFS ≥3 without lung-RT, the 100-day cumulative incidence of AE-ALI/RP grade ≥3 was 4.8%.

CONCLUSION

High PFS and lung-RT are significant risk factors for AE-ALI/RP grade ≥3. Even with relatively low doses, palliative-intent lung-RT carries an extremely high risk of AE-ALI/RP when PFS is high.

Patient and therapeutic radiographer experiences of comfort during the radiotherapy pathway: A qualitative study

INTRODUCTION

There is little research regarding the experiences of patient comfort and how it is best managed in radiotherapy. The aim of this study was to explore the experiences of patient and therapeutic radiographer views of comfort during radiotherapy.

METHODS

This qualitative study involved semi-structured interviews, with cancer patients (n = 25) and therapeutic radiographers (n = 25), conducted between January-July 2019. Patients were recruited from one radiotherapy clinic and therapeutic radiographers were recruited from across the United Kingdom via specialist interest groups and social media. Interviews were audio-recorded and transcribed verbatim. Thematic analysis was used to analyse the data separately between both groups and shared themes were identified.

RESULTS

Four themes were identified of which two themes were shared among both the patients and therapeutic radiographer. Emotional Health was a shared theme highlighting experiences such as stress, vulnerability and privacy. The second shared theme, Positioning and Immobilisation Experiences, concerned how patients' experience being physically positioned and using immobilisation for accurate radiotherapy. The theme Information and Communication Experience was derived from patients highlighting concerns over sharing and provision of information and ways of communication. The last theme, Environmental Experience, emerged from the patient interviews and related to the first impressions of the radiotherapy environment such as reception or treatment rooms and how this effects the overall feelings of comfort.

CONCLUSION

This qualitative study has provided the shared voice of patients and therapeutic radiographers and their experiences of comfort during radiotherapy. These shared experiences emphasise the importance of considering comfort holistically and not just from a physical context. This information can be used by therapeutic radiographers to better understand their patients experiences and needs to provide better comfort during radiotherapy to improve patients' outcomes.

IMPLICATIONS FOR PRACTICE

The clinical implications of our study can encourage Therapeutic Radiographers to provide holistic care for their patients throughout the pathway and specifically to comfort patients while they are having treatment. In the short term this could be via simple adaptions to practice while in the long term, research is needed to develop comfort interventions for patients receiving radiotherapy.

Feasibility of omitting the clinical target volume under PET-CT guidance in unresectable stage III non-small-cell lung cancer: A phase II clinical trial

BACKGROUND

This clinical trial aims at investigate the feasibility of CTV-omitted, positron-emission tomography computed tomography (PET-CT) combined with intensity-modulated radiation therapy (IMRT) for unresectable stage III NSCLC.

METHODS AND MATERIALS

This was a single-center, phase II clinical trial initiated in July 2016. Patients with unresectable stage III NSCLC undergoing routine IMRT were randomly enrolled into the study group (CTV-omitted under PET-CT guidance) and the control group (CTV-delineated). Patients received platinum-based dual-drug concurrent chemoradio therapy. In the study group, the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions; in the control group, the PCTV dose was 54 Gy given in 30 daily 1.8 Gy fractions, and the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions. The primary endpoint was the incidence of radiation respiratory events or esophagitis with grade 3 or higher. The secondary endpoints included objective response rate (ORR), locate control rate, progression-free survival (PFS), failure pattern and overall survival (OS).

RESULTS

A total of 90 patients were enrolled between July 2016 and March 2019. The incidence of radiation respiratory events or esophagitis with grade 3 or higher was 11.1 % in the study group, significantly lower than the rate of 28.9 % in the control group (P = 0.035), basically due to the reduced irradiated volumes of the lungs and esophagus in the study group. The median PFS was 9.0 months versus 10.0 months (P = 0.597), and the median OS 31.0 months versus 26.0 months (P = 0.489) in the study group and the control group, respectively. The failure pattern was not significantly different between the two groups (P = 0.826).

CONCLUSION

Omitting the CTV under PET-CT guidance has high feasibility to reduce severe radiation associated toxicity in IMRT for unresectable stage III NSCLC, without compromising the efficacy.

Diagnosis and management of patients with stage III non‑small cell lung cancer: A joint statement by the Lebanese Society of Medical Oncology and the Lebanese Pulmonary Society (Review)

Proper management of stage III non-small cell lung cancer (NSCLC) might result in a cure or patient long-term survival. Management should therefore be preceded by adequate and accurate diagnosis and staging, which will inform therapeutic decisions. A panel of oncologists, surgeons and pulmonologists in Lebanon convened to establish a set of recommendations to guide and unify clinical practice, in alignment with international standards of care. Whilst chest computerized tomography (CT) scanning remains a cornerstone in the discovery of a lung lesion, a positron-emission tomography (PET)/CT scan and a tumor biopsy allows for staging of the cancer and defining the resectability of the tumor(s). A multidisciplinary discussion meeting is currently widely advised for evaluating patients on a case-by-case basis, and should include at least the treating oncologist, a thoracic surgeon, a radiation oncologist and a pulmonologist, in addition to physicians from other specialties as needed. The standard of care for unresectable stage III NSCLC is concurrent chemotherapy and radiation therapy, followed by consolidation therapy with durvalumab, which should be initiated within 42 days of the last radiation dose; for resectable tumors, neoadjuvant therapy followed by surgical resection is recommended. This joint statement is based on the expertise of the physician panel, available literature and evidence governing the treatment, management and follow-up of patients with stage III NSCLC.

[The role of endoscopy in exploration of the mediastinum, indications and results]

Since 2005, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a standard pulmonological tool. The procedure is safe and well tolerated by patients, with minimal morbidity and almost no mortality. A previous review on the technique was published in 2012. However, over the last ten years, a number of new studies have been published on "benign" (sarcoidosis, tuberculosis…) as well as "malignant" diseases (lung cancer, metastases of extra-thoracic cancers, search for mutations and specific oncogenic markers…). These developments have led to expanded indications for EBUS-TBNA, with which it is indispensable to be familiar, in terms of "staging" as well as "diagnosis". In view of optimizing lymph node sampling, several publications have described and discussed EBUS exploration by means of newly available tools (biopsy forceps, larger needles…), and proposed interpretation of the images thereby produced. Given the ongoing evolution of linear EBUS, it seemed indispensable that information on this marvelous tool be updated. This review is aimed at summarizing the novel elements we have found the most important.

Real-World Patterns and Decision Drivers of Radiotherapy for Lung Cancer Patients in Romania: RADIO-NET Study Results

Radiotherapy (RT) plays a crucial role in all stages of lung cancer. Data on recent real-world RT patterns and main drivers of RT decisions in lung cancer in Romania is scarce; we aimed to address these knowledge gaps through this physician-led medical chart review in 16 RT centers across the country. Consecutive patients with lung cancer receiving RT as part of their disease management between May-October 2019 (pre-COVID-19 pandemic) were included. Descriptive statistics were generated for all variables. This cohort included 422 patients: median age 63 years, males 76%, stages I-II 6%, III 43%, IV 50%, mostly adeno- and squamous cell carcinoma (76%), ECOG 0-1 50% at the time of RT. Curative intent RT was used in 36% of cases, palliative RT in 64%. Delays were reported in 13% of patients, mostly due to machine breakdown (67%). Most acute reported RT toxicity was esophagitis (19%). Multiple disease-, patient-, physician- and context-related drivers counted in the decision-making process. This is the first detailed analysis of RT use in lung cancer in Romania. Palliative RT still dominates the landscape. Earlier diagnosis, coordinated multidisciplinary strategies, and the true impact of the multimodal treatments on survival are strongly needed to improve lung cancer outcomes.

CArdiac and REspiratory adaptive Computed Tomography (CARE-CT): a proof-of-concept digital phantom study

Current respiratory 4DCT imaging for high-dose rate thoracic radiotherapy treatments are negatively affected by the complex interaction of cardiac and respiratory motion. We propose an imaging method to reduce artifacts caused by thoracic motion, CArdiac and REspiratory adaptive CT (CARE-CT), that monitors respiratory motion and ECG signals in real-time, triggering CT acquisition during combined cardiac and respiratory bins. Using a digital phantom, conventional 4DCT and CARE-CT acquisitions for nineteen patient-measured physiological traces were simulated. Ten respiratory bins were acquired for conventional 4DCT scans and ten respiratory bins during cardiac diastole were acquired for CARE-CT scans. Image artifacts were quantified for 10 common thoracic organs at risk (OAR) substructures using the differential normalized cross correlation between axial slices (ΔNCC), mean squared error (MSE) and sensitivity. For all images, on average, CARE-CT improved the ΔNCC for 18/19 and the MSE and sensitivity for all patient traces. The ΔNCC was reduced for all cardiac OARs (mean reduction 21%). The MSE was reduced for all OARs (mean reduction 36%). In the digital phantom study, the average scan time was increased from 1.8 ± 0.4 min to 7.5 ± 2.2 min with a reduction in average beam on time from 98 ± 28 s to 45 s using CARE-CT compared to conventional 4DCT. The proof-of-concept study indicates the potential for CARE-CT to image the thorax in real-time during the cardiac and respiratory cycle simultaneously, to reduce image artifacts for common thoracic OARs.

PET/CT for Target Delineation of Lung Cancer Before Radiation Therapy

In clinical routine of patients suffering from lung cancer, radiotherapy/radiation oncology represents one of the therapeutic hallmarks in the multimodal treatment besides or in combination with other local treatments such as surgery, but also systemic treatments such as chemotherapy, tyrosine kinase, and immune check-point inhibitors. Conventional morphological imagings such as CT or MR are commonly used for staging, response assessment, but also for radiotherapy planning. However, advanced imaging techniques such as PET do continuously get increasing access to clinical routine overcoming limitations of standard imaging techniques by visualizing and quantifying molecular processes such as glucose metabolism, which is also of relevance for radiotherapy planning. This review article summarizes the current place of radiotherapy within the treatment regimens of patients with lung cancer and elucidates current concepts of standard morphological imaging for staging and radiotherapy planning. Moreover, the place of PET-based radiotherapy planning in a clinical context is presented and current methodological/technical advances that do comprise a potential role for radiotherapy planning in lung cancer patients are discussed.

Prediction of malignant lymph nodes in NSCLC by machine-learning classifiers using EBUS-TBNA and PET/CT

Accurate determination of lymph-node (LN) metastases is a prerequisite for high precision radiotherapy. The primary aim is to characterise the performance of PET/CT-based machine-learning classifiers to predict LN-involvement by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in stage-III NSCLC. Prediction models for LN-positivity based on [¹⁸F]FDG-PET/CT features were built using logistic regression and machine-learning models random forest (RF) and multilayer perceptron neural network (MLP) for stage-III NSCLC before radiochemotherapy. A total of 675 LN-stations were sampled in 180 patients. The logistic and RF models identified SUV_max, the short-axis LN-diameter and the echelon of the considered LN among the most important parameters for EBUS-positivity. Adjusting the sensitivity of machine-learning classifiers to that of the expert-rater of 94.5%, MLP (P = 0.0061) and RF models (P = 0.038) showed lower misclassification rates (MCR) than the standard-report, weighting false positives and false negatives equally. Increasing the sensitivity of classifiers from 94.5 to 99.3% resulted in increase of MCR from 13.3/14.5 to 29.8/34.2% for MLP/RF, respectively. PET/CT-based machine-learning classifiers can achieve a high sensitivity (94.5%) to detect EBUS-positive LNs at a low misclassification rate. As the specificity decreases rapidly above that level, a combined test of a PET/CT-based MLP/RF classifier and EBUS-TBNA is recommended for radiation target volume definition.

Dose-Response Analysis Describes Particularly Rapid Repopulation of Non-Small Cell Lung Cancer during Concurrent Chemoradiotherapy

(1) Purpose: We analysed overall survival (OS) rates following radiotherapy (RT) and chemo-RT of locally-advanced non-small cell lung cancer (LA-NSCLC) to investigate whether tumour repopulation varies with treatment-type, and to further characterise the low α/β ratio found in a previous study. (2) Materials and methods: Our dataset comprised 2-year OS rates for 4866 NSCLC patients (90.5% stage IIIA/B) belonging to 51 cohorts treated with definitive RT, sequential chemo-RT (sCRT) or concurrent chemo-RT (cCRT) given in doses-per-fraction ≤3 Gy over 16-60 days. Progressively more detailed dose-response models were fitted, beginning with a probit model, adding chemotherapy effects and survival-limiting toxicity, and allowing tumour repopulation and α/β to vary with treatment-type and stage. Models were fitted using the maximum-likelihood technique, then assessed via the Akaike information criterion and cross-validation. (3) Results: The most detailed model performed best, with repopulation offsetting 1.47 Gy/day (95% confidence interval, CI: 0.36, 2.57 Gy/day) for cCRT but only 0.30 Gy/day (95% CI: 0.18, 0.47 Gy/day) for RT/sCRT. The overall fitted tumour α/β ratio was 3.0 Gy (95% CI: 1.6, 5.6 Gy). (4) Conclusion: The fitted repopulation rates indicate that cCRT schedule durations should be shortened to the minimum in which prescribed doses can be tolerated. The low α/β ratio suggests hypofractionation should be efficacious.

[68Ga]FAPI-PET/CT for radiation therapy planning in biliary tract, pancreatic ductal adeno-, and adenoidcystic carcinomas

Biliary-tract-carcinomas (BTC), pancreatic-ductal-adenocarcinomas (PDAC) and adenoidcystic-carcinomas (AC) have in common that they are traditionally treated with large clinical-target-volumes (CTV). The aim of this study is to examine the impact of pretreatment-[⁶⁸Ga]FAPI-PET/CT on target-volume-definition and posttreatment-[⁶⁸Ga]FAPI-PET/CT-response-assessment for BTC-, PDAC- and AC-patients referred to radiation-therapy. All consecutive BTC-, PDAC-, and AC-patients who received pretreatment-[⁶⁸Ga]FAPI-PET/CT±[¹⁸F]FDG-PET/CT were included from 01.01.2020 to 01.03.2022. MTV and SUV_max were separately generated based on [⁶⁸Ga]FAPI- and [¹⁸F]FDG-PET/CT-images. A [⁶⁸Ga]FAPI- and [¹⁸F]FDG-based-CTV was defined. Treatment-plans were compared. Treatment-response was reassessed by a second [⁶⁸Ga]FAPI-PET/CT and [¹⁸F]FDG-PET/CT after treatment-completion. Intermodality comparison of lesion-to-background-ratios [SUV_{max_lesion}/SUV_{mean_background}] for individual timepoints t₁ and t₂ revealed significant higher values for [⁶⁸Ga]FAPI compared to [¹⁸F]FDG (t₁, p = 0.008; t₂, p = 0.005). Intermodality comparison of radiation-therapy-plans showed that [⁶⁸Ga]FAPI-based planning resulted in D100% = 97.2% and V95% = 98.8% for the [¹⁸F]FDG-MTV. [¹⁸F]FDG-based-planning resulted in D100% = 35.9% and V95% = 78.1% for [⁶⁸Ga]FAPI-MTV. [¹⁸F]FDG-based-planning resulted only in 2 patients in V95% > 95% for [⁶⁸Ga]FAPI-MTV, and in 1 patient in D100% > 97% for [⁶⁸Ga]FAPI-MTV. GTV-coverage in terms of V95% was 76.4% by [¹⁸F]FDG-based-planning and 99.5% by [⁶⁸Ga]FAPI-based-planning. Pretreatment [⁶⁸Ga]FAPI-PET/CT enhances radiation-treatment-planning in this particular group of patients. While perilesional and tumoral follow-up [¹⁸F]FDG-uptake behaved uniformly, perilesional and tumoral reaction may differ in follow-up [⁶⁸Ga]FAPI-imaging. Complementary [⁶⁸Ga]FAPI- and [¹⁸F]FDG-imaging enhance treatment-response-assessment.

Dosimetric effects of respiratory motion during stereotactic body radiation therapy of lung tumors

BACKGROUND

Respiratory-induced lung tumor motion may affect the delivered dose in stereotactic body radiation therapy (SBRT). Previous studies are often based on phantom studies for one specific treatment technique. In this study, the dosimetric effect of tumor motion was quantified in real patient geometries for different modulated treatments and tumor motion amplitudes for lung-SBRT.

MATERIAL AND METHODS

A simulation method using deformable image registrations and 4-dimensional computed tomographies (4DCT) was developed to assess the dosimetric effects of tumor motion. The method was evaluated with ionization chamber and Gafchromic film measurements in a thorax phantom and used to simulate the effect for 15 patients with lung tumors moving 7.3-27.4 mm. Four treatment plans with different complexities were created for each patient and the motion-induced dosimetric effect to the gross tumor volume (GTV) was simulated. The difference between the planned dose to the static tumor and the simulated delivered dose to the moving tumor was quantified for the near minimum (D_98%), near maximum (D_2%) and mean dose (D_mean) to the GTV as well as the largest observed local difference within the GTV (Max_diff).

RESULTS

No correlation was found between the dose differences and the tumor motion amplitude or plan complexity. However, the largest deviations were observed for tumors moving >15.0 mm. The simulated delivered dose was within 2.5% from the planned dose for D_98% (tumors moving <15 mm) and within 3.3% (tumors moving >15 mm). The corresponding values were 1.7% vs. 6.4% (D_2%); 1.7% vs. 2.4% (D_mean) and 8.9% vs. 35.2% (Max_diff). Using less complex treatment techniques minimized Max_diff for tumors moving >15.0 mm.

CONCLUSION

The dosimetric effects of respiratory-induced motion during lung SBRT are patient and plan specific. The magnitude of the dosimetric effect cannot be assessed solely based upon tumor motion amplitude or plan complexity.

Novel Harmonization Method for Multi-Centric Radiomic Studies in Non-Small Cell Lung Cancer

The purpose of this multi-centric work was to investigate the relationship between radiomic features extracted from pre-treatment computed tomography (CT), positron emission tomography (PET) imaging, and clinical outcomes for stereotactic body radiation therapy (SBRT) in early-stage non-small cell lung cancer (NSCLC). One-hundred and seventeen patients who received SBRT for early-stage NSCLC were retrospectively identified from seven Italian centers. The tumor was identified on pre-treatment free-breathing CT and PET images, from which we extracted 3004 quantitative radiomic features. The primary outcome was 24-month progression-free-survival (PFS) based on cancer recurrence (local/non-local) following SBRT. A harmonization technique was proposed for CT features considering lesion and contralateral healthy lung tissues using the LASSO algorithm as a feature selector. Models with harmonized CT features (B models) demonstrated better performances compared to the ones using only original CT features (C models). A linear support vector machine (SVM) with harmonized CT and PET features (A1 model) showed an area under the curve (AUC) of 0.77 (0.63–0.85) for predicting the primary outcome in an external validation cohort. The addition of clinical features did not enhance the model performance. This study provided the basis for validating our novel CT data harmonization strategy, involving delta radiomics. The harmonized radiomic models demonstrated the capability to properly predict patient prognosis.

Exposure of the heart in lung cancer radiation therapy: A systematic review of heart doses published during 2013 to 2020

BACKGROUND AND PURPOSE

Lung cancer radiotherapy increases the risk of cardiotoxicity and heart radiation dose is an independent predictor of poor survival. This study describes heart doses and strategies aiming to reduce exposure.

MATERIALS AND METHODS

A systematic review of lung cancer dosimetry studies reporting heart doses published 2013-2020 was undertaken. Doses were compared according to laterality, region irradiated, treatment modality (stereotactic ablative body radiotherapy (SABR) and non-SABR), planning technique, and respiratory motion management.

RESULTS

For 392 non-SABR regimens in 105 studies, the average MHD was 10.3 Gy (0.0-48.4) and was not significantly different between left and right-sided tumours. It was similar between IMRT and 3DCRT (10.9 Gy versus 10.6 Gy) and lower with particle beam therapy (proton 7.0 Gy; carbon-ion 1.9 Gy). Active respiratory motion management reduced exposure (7.4 Gy versus 9.3 Gy). For 168 SABR regimens in 35 studies, MHD was 4.0 Gy (0.0-32.4). Exposure was higher in central and lower lobe lesions (6.3 and 5.8 Gy respectively). MHD was lowest for carbon ions (0.5 Gy) compared to other techniques. Active respiratory motion management reduced exposure (2.4 Gy versus 5.0 Gy). Delineation guidelines and Dose Volume Constraints for the heart varied substantially.

CONCLUSIONS

There is scope to reduce heart radiation dose in lung cancer radiotherapy. Consensus on planning objectives, contouring and DVCs for the heart may lead to reduced heart doses in the future. For IMRT, more stringent optimisation objectives may reduce heart dose. Active respiratory motion management or particle therapy may be considered in situations where cardiac dose is high.

Respiratory gated multistatic PET reconstructions to delineate radiotherapy target volume in patients with mobile lung tumors

BACKGROUND

PET-CT with ¹⁸F-FDG or other radiopharmaceuticals is a recommended tool to help the delineation of lung cancers candidate to radiotherapy. The motion artifacts caused by respiratory movements are reduced by 4D acquisitions. We introduced an extended reconstruction algorithm (multiple reconstruct register and average [multi-RRA]) which requires much shorter acquisition times than standard 4D PET-CT. Our aim was to evaluate the interest on multi-RRA images as an alternative of 3D and 4D PET-CT for the delineation of lung lesion.

METHODS

PET acquisitions synchronized to the respiratory signal were obtained in 18 patients with mobile lung tumors. We compared the tumor volumes delineated on Multi-RRA images to 3D and 4D PET-CT, considering the 4D CT as a reference. The tumor volumes were delineated and compared with topologic similarity indexes (Dice, Jaccard and overlap).

RESULTS

Twenty tumors were delineated. The volumes delineated with multi-RRA and 4D PET were not significantly different (mean difference of 0.2±0.7 mL). Comparison by pairs (Tukey-Kramer test) showed that 3D-PET volumes were significantly smaller than 4D-PET and multi-RRA volumes (P<0.001). Topologic similarity indexes with 4D-PET were slightly statistically higher with multi-RRA than with 3D-PET (Dice and Jaccard) or 4D-CT (Dice, Jaccard and Overlap).

CONCLUSIONS

The tumor volumes delineated on multi-RRA are similar to the volumes obtained with 4D PET, with shorter acquisition time.

Lung cancer in patients with fibrosing interstitial lung diseases – An overview of current knowledge and challenges

Patients with progressive fibrosing interstitial lung diseases (fILD) have increased morbidity and mortality. Lung fibrosis can be associated with lung cancer. The pathogenesis of both diseases shows similarities, although not all mechanisms are understood. The combination of the diseases is challenging, due to the amplified risk of mortality, and also because lung cancer treatment carries additional risks in patients with underlying lung fibrosis. Acute exacerbations in fILD patients are linked to increased mortality, and the risk of acute exacerbations is increased after lung cancer treatment with surgery, chemotherapy or radiotherapy. Careful selection of treatment modalities is crucial to improve survival while maintaining acceptable quality of life in patients with combined lung cancer and fILD. This overview of epidemiology, pathogenesis, treatment and a possible role for antifibrotic drugs in patients with lung cancer and fILD is the summary of a session presented during the virtual European Respiratory Society Congress in 2021. The review summarises current knowledge and identifies areas of uncertainty. Most current data relate to patients with combined idiopathic pulmonary fibrosis and lung cancer. There is a pressing need for additional prospective studies, required for the formulation of a consensus statement or guideline on the optimal care of patients with lung cancer and fILD.

Lung fibrosis can be associated with lung cancer. More and better-designed studies are needed to determine the true incidence/prevalence of lung cancer in fILD. Optimal treatment strategies urgently need to be defined and evaluated.https://bit.ly/37CzTMu

Unmet needs in the management of unresectable stage III non-small cell lung cancer: a review after the 'Radio Talk' webinars

INTRODUCTION

Stage III non-small cell lung cancer (NSCLC) is a variable entity, encompassing bulky primary tumors, nodal involvement or both. Multidisciplinary evaluation is essential to discuss multiple treatment options, to outline optimal management and to examine the main debated topics and critical issues not addressed by current trials and guidelines that influence daily clinical practice.

AREAS COVERED

From March to May 2021, 5 meetings were scheduled in a webinar format titled 'Radio Talk' due to the COVID-19 pandemic; the faculty was composed of 6 radiation oncologists from 6 different Institutions of Italy, all of them were the referring radiation oncologist for lung cancer treatment at their respective departments and were or had been members of AIRO (Italian Association of Radiation Oncology) Thoracic Oncology Study Group. The topics covered included: pulmonary toxicity, cardiac toxicity, radiotherapy dose, fractionation and volumes, unfit/elderly patients, multidisciplinary management.

EXPERT OPINION

The debate was focused on the unmet needs triggered by case reports, personal experiences and questions; the answers were often not univocal, however, the exchange of opinion and the contribution of different centers confirmed the role of multidisciplinary management and the necessity that the most critical issues should be investigated in clinical trials.

Open issues in the therapeutic management of unresectable stage III NSCLC in the immunotherapy era

Treatment of stage III non-small cell lung cancer (NSCLC) has traditionally been controversial and challenging: multidisciplinary approach is mandatory and defining resectability is a critical issue; furthermore, patients are often frail due to age or comorbidities. After PACIFIC trial publication, a new therapeutic path has been defined for patients with unresectable NSCLC, with a prominent prognostic advantage. A trimodality treatment, with chemo-radiotherapy followed by maintenance durvalumab is now the standard of care, recommended by international guidelines. However, despite an impressive activity, the use of consolidative immunotherapy after concurrent chemoradiotherapy is highly debated in some clinically-relevant situations, including patients harboring EGFR mutations, older and/or frail patients not suitable for combined treatment, PD-L1 tumor expression. Here we report an expert virtual Italian meeting summary, where six medical oncologists and six radiation oncologists discussed all these aspects trying to underline the critical aspects and to find the possible clinical solutions.

Stereotactic radiotherapy for oligometastases in the lymph nodes

Even though systemic therapy is standard treatment for lymph node metastases, metastasis-directed stereotactic radiotherapy (SRT ) seems to be a valid option in oligometastatic patients with a low disease burden.

Positron emission tomography-computed tomography (PET-CT ) is the gold standard for assessing metastases to the lymph nodes; co-registration of PET-CT images and planning CT images are the basis for gross tumor volume (GTV ) delineation. Appropriate techniques are needed to overcome target motion. SRT schedules depend on the irradiation site, target volume and dose constraints to the organs at risk (OARs) of toxicity. Although several fractionation schemes were reported, total doses of 48–60 Gy in 4–8 fractions were proposed for mediastinal lymph node SRT, with the spinal cord, esophagus, heart and proximal bronchial tree being the dose limiting OAR s. Total doses ranged from 30 to 45 Gy, with daily fractions of 7–12 Gy for abdominal lymph nodes, with dose limiting OARs being the liver, kidneys, bowel and bladder. SRT on lymph node metastases is safe; late side effects, particularly severe, are rare.

Radiotherapy Patterns of Care for Locally-advanced Non-small Cell Lung Cancer in the Pre- and Post-durvalumab Era: A Region-wide Survey in a Japanese Prefecture

The promising results of the PACIFIC study led to the approval of consolidation durvalumab for coverage by the National Health Insurance (NHI) in 2018 for patients with locally-advanced unresectable non-small cell lung carcinoma (NSCLC) treated with definitive concurrent chemoradiotherapy (CCRT). However, the effect of NHI coverage on the patterns of care for this population remains unclear. Here, we conducted a questionnaire-based survey to determine the patterns of care for patients with stage II-III NSCLC treated with definitive radiotherapy in 2017 (pre-durvalumab era) or in 2019 (post-durvalumab era). Data were obtained from 11 radiotherapy facilities in Gunma prefecture, which has a population of 1.94 million. We identified 80 and 83 patients with stage II-III NSCLC who received definitive radiotherapy in Gunma in 2017 and 2019, respectively. At a given facility, CCRT was the treatment of choice in a significantly greater proportion of patients in 2019 than in 2017 (66% ± 20% vs 51% ± 29%, P = 0.041). Intensity-modulated radiotherapy (IMRT) was more frequent in 2019 than in 2017 (24% vs 1.2%). Carboplatin plus paclitaxel was used for CCRT at higher rate in 2019 than in 2017 (73% vs 44%). Consolidation durvalumab was performed in 73% (40/55) of CCRT-treated patients in 2019, and the treatment was performed for the planned 12 months in 45% (18/40) of patients. These data indicate that NHI coverage of durvalumab might be a possible reason for choosing CCRT in patients with stage II-III NSCLC in the real-world setting.

A Comparison of Isotoxic Dose-escalated Radiotherapy in Lung Cancer with Moderate Deep Inspiration Breath Hold, Mid-ventilation and Internal Target Volume Techniques

AIMS

With interest in normal tissue sparing and dose-escalated radiotherapy in the treatment of inoperable locally advanced non-small cell lung cancer, this study investigated the impact of motion-managed moderate deep inspiration breath hold (mDIBH) on normal tissue sparing and dose-escalation potential and compared this to planning with a four-dimensional motion-encompassing internal target volume or motion-compensating mid-ventilation approach.

MATERIALS AND METHODS

Twenty-one patients underwent four-dimensional and mDIBH planning computed tomography scans. Internal and mid-ventilation target volumes were generated on the four-dimensional scan, with mDIBH target volumes generated on the mDIBH scan. Isotoxic target dose-escalation guidelines were used to generate six plans per patient: three with a target dose cap and three without. Target dose-escalation potential, normal tissue complication probability and differences in pre-specified dose-volume metrics were evaluated for the three motion-management techniques.

RESULTS

The mean total lung volume was significantly greater with mDIBH compared with four-dimensional scans. Lung dose (mean and V21 Gy) and mean heart dose were significantly reduced with mDIBH in comparison with four-dimensional-based approaches, and this translated to a significant reduction in heart and lung normal tissue complication probability with mDIBH. In 20/21 patients, the trial target prescription dose cap of 79.2 Gy was achievable with all motion-management techniques.

CONCLUSION

mDIBH aids lung and heart dose sparing in isotoxic dose-escalated radiotherapy compared with four-dimensional planning techniques. Given concerns about lung and cardiac toxicity, particularly in an era of consolidation immunotherapy, reduced normal tissue doses may be advantageous for treatment tolerance and outcome.

Joint EANM/SNMMI/ESTRO practice recommendations for the use of 2-[18F]FDG PET/CT external beam radiation treatment planning in lung cancer V1.0

PURPOSE

2-[18F]FDG PET/CT is of utmost importance for radiation treatment (RT) planning and response monitoring in lung cancer patients, in both non-small and small cell lung cancer (NSCLC and SCLC). This topic has been addressed in guidelines composed by experts within the field of radiation oncology. However, up to present, there is no procedural guideline on this subject, with involvement of the nuclear medicine societies.

METHODS

A literature review was performed, followed by a discussion between a multidisciplinary team of experts in the different fields involved in the RT planning of lung cancer, in order to guide clinical management. The project was led by experts of the two nuclear medicine societies (EANM and SNMMI) and radiation oncology (ESTRO).

RESULTS AND CONCLUSION

This guideline results from a joint and dynamic collaboration between the relevant disciplines for this topic. It provides a worldwide, state of the art, and multidisciplinary guide to 2-[18F]FDG PET/CT RT planning in NSCLC and SCLC. These practical recommendations describe applicable updates for existing clinical practices, highlight potential flaws, and provide solutions to overcome these as well. Finally, the recent developments considered for future application are also reviewed.