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.

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.

Bronchial Stenosis in Central Pulmonary Tumors Treated With Stereotactic Body Radiation Therapy.

Purpose: Stereotactic body radiation therapy (SBRT) in lung tumors has an excellent local control due to the high delivered dose. Proximity of the proximal bronchial tree (PBT) to the high dose area may result in pulmonary toxicity. Bronchial stenosis is an adverse event that can occur after high dose to the PBT.

Deep learning model for automatic contouring of cardiovascular substructures on radiotherapy planning CT images: Dosimetric validation and reader study based clinical acceptability testing.

Background And Purpose: Large radiotherapy (RT) planning imaging datasets with consistently contoured cardiovascular structures are essential for robust cardiac radiotoxicity research in thoracic cancers. This study aims to develop and validate a highly accurate automatic contouring model for the heart, cardiac chambers, and great vessels for RT planning computed tomography (CT) images that can be used for dose-volume parameter estimation.

Materials And Methods: A neural network model was trained using a dataset of 127 expertly contoured planning CT images from RT treatment of locally advanced non-small-cell lung cancer (NSCLC) patients.

Delivered dose-effect analysis of radiation induced rib fractures after thoracic SBRT.

Background And Purpose: Anatomical changes during the stereotactic body radiation therapy (SBRT) of early stage non-small cell lung cancer (NSCLC) may cause the delivered dose to deviate from the planned dose. We investigate if normal tissue complication probability (NTCP) models based on the delivered dose predict radiation-induced rib fractures better than models based on the planned dose.

Material And Methods: 437 NSCLC patients treated to a median dose of 3x18 Gy were included.

The prognostic value of volumetric changes of the primary tumor measured on Cone Beam-CT during radiotherapy for concurrent chemoradiation in NSCLC patients.

Introduction: The aim of this study was to identify subgroups of locally advanced NSCLC patients with a distinct treatment response during concurrent chemoradiotherapy (CCRT). Subsequently, we investigated the association of subgroup membership with treatment outcomes.

Methods: 394 NSCLC-patients treated with CCRT between 2007 and 2013 were included.

Quantification of Esophageal Tumor Motion and Investigation of Different Image-Guided Correction Strategies.

Purpose: To accurately quantify esophageal tumor position variability and to optimize image guided correction strategies.

Material And Methods: Esophageal cancer patients receiving chemoradiotherapy (41.4-50.

Safety and efficacy of reduced dose and margins to involved lymph node metastases in locally advanced NSCLC patients.

Background And Purpose: (Chemo)Radiotherapy for locally advanced non-small lung cancer (LA-NSCLC) causes severe dysphagia due to the radiation dose to the mediastinal lymphadenopathy. Reducing the dose to the mediastinum and the margins to the planning target volume (PTV) might reduce severe toxicity rates. The results of both adaptations in LA-NSCLC patients receiving (chemo)radiotherapy were analysed.

Subgroup Survival Analysis in Stage I-II NSCLC Patients With a Central Tumor Partly Treated With Risk-Adapted SBRT.

Purpose: Stereotactic body radiation therapy has been associated with increased toxicity when delivered to patients with early-stage non-small cell lung cancer with a tumor within 2 cm of the proximal bronchial tree (PBT). We investigated noncancer deaths for these patients as related to gross tumor volume (GTV) proximity to the PBT, compared with peripheral tumors.

Methods And Materials: We included 765 patients with early-stage non-small cell lung cancer who were treated with stereotactic body radiation therapy to a median of 3 × 18 Gy.

Heart dose associated with overall survival in locally advanced NSCLC patients treated with hypofractionated chemoradiotherapy.

Association of heart dose and overall survival was investigated in a cohort including 469 locally-advanced NSCLC patients receiving daily low-dose hypofractionated chemo-radiotherapy. Significant associations were found over a range of dose parameters. Multivariate analysis showed significant associations of heart_V:HR=1.

Dose to heart substructures is associated with non-cancer death after SBRT in stage I-II NSCLC patients.

Background And Purpose: To investigate potential associations between dose to heart (sub)structures and non-cancer death, in early stage non-small cell lung cancer (NSCLC) patients treated with stereotactic body radiation therapy (SBRT).

Methods: 803 patients with early stage NSCLC received SBRT with predominant schedules of 3×18Gy (59%) or 4×12Gy (19%). All patients were registered to an average anatomy, their planned dose deformed accordingly, and dosimetric parameters for heart substructures were obtained.

Dose-effect analysis of radiation induced rib fractures after thoracic SBRT.

Background And Purpose: To determine a dose-effect relation for radiation induced rib fractures after stereotactic body radiation therapy (SBRT) in early stage non-small cell lung cancer (NSCLC). Automatic rib delineation has enabled the analysis of a large patient group.

Material And Methods: Four-hundred and sixty-six patients with stage I/II NSCLC received SBRT with a median of 54Gy in 3 fractions.

Validation of automatic segmentation of ribs for NTCP modeling.

Background And Purpose: Determination of a dose-effect relation for rib fractures in a large patient group has been limited by the time consuming manual delineation of ribs. Automatic segmentation could facilitate such an analysis. We determine the accuracy of automatic rib segmentation in the context of normal tissue complication probability modeling (NTCP).

How the blood pool properties at onset affect the temporal behavior of simulated bruises.

The influence of initial blood pool properties on the temporal behavior of bruises is currently unknown. We addressed this important issue by utilizing three typical classes of bruises in our three-layered finite compartment model. We simulated the effects of their initial shapes, regularity of boundaries and initial blood concentration distributions (gaussian vs.

Can color inhomogeneity of bruises be used to establish their age?

Bruises become spatially inhomogeneous during the healing process; a smaller red-blue core area, caused by hemoglobin, is surrounded by a larger yellow area, caused by bilirubin, which is enzymatically formed from hemoglobin. These two areas develop at different rates and hence carry information about the age of the bruise. We present a proof of principle demonstration that the age of bruises can be determined via an inverse procedure using a mathematical model and daily measurements of these two areas using a hyperspectral imaging system.

3D finite compartment modeling of formation and healing of bruises may identify methods for age determination of bruises.

Simulating the spatial and temporal behavior of bruises may identify methods that allow accurate age determination of bruises to assess child abuse. We developed a numerical 3D model to simulate the spatial kinetics of hemoglobin and bilirubin during the formation and healing of bruises. Using this model, we studied how skin thickness, bruise diameter and diffusivities affect the formation and healing of circular symmetric bruises and compared a simulated bruise with a natural inhomogeneous bruise.