The purpose of this study is to investigate the interplay effect between dynamic MLC movement and tumor respiratory motion in volumetric-modulated arc therapy (VMAT)-based lung SBRT treatment delivered by the flattening filter-free (FFF) beam of a Varian TrueBeam machine. Six lung cancer patients with tumor motions ranging between 0.5-1.6 cm were recruited in this study. All patients underwent ...

PURPOSE To evaluate an algorithm for real-time 3D tumor localization from a single x-ray projection image for lung cancer radiotherapy. METHODS Recently, we have developed an algorithm for reconstructing volumetric images and extracting 3D tumor motion information from a single x-ray projection [Li et al., Med. Phys. 37, 2822-2826 (2010)]. We have demonstrated its feasibility using a digital ...

PURPOSE To develop a three-dimensional (3-D) volumetric registration algorithm to estimate the intra-fractional lung tumor motion between respiratory phases for improving the accuracy of radiotherapy treatment. METHODS The 3-D thoracic CT volumes (512×512×160 voxels, with dimensions 0.97×0.97×2.5 mm3 ) in different respiratory phases were acquired on a General Electric Optima T580 scanner in ...

Background: Inclusion of inhomogeneity corrections in intensity modulated small fields always makes conformal irradiation of lung tumor very complicated in accurate dose delivery.Objective: In the present study, the performance of five algorithms via Monte Carlo, Pencil Beam, Convolution, Fast Superposition and Superposition were evaluated in lung cancer Intensity Modulated Radiotherapy plannin...

The interest of PET complementary information for the delineation of the target volume in radiotherapy of lung cancer is increasing. However, respiratory motion requires the determination of a functional internal target volume (ITV) on PET images for which several strategies have been proposed. The purpose of this study was the comparison of these strategies for taking into account respiratory ...

the brain is a rare site for metastasis in most extracranial pediatric solid tumors, including wilm’s tumor. outcome for these patients are generally dismal. very few cases have been reported to have good survival even after therapy. this paper reports a case of stage iv wilm’s tumor with lung metastases in a patient who developed a solitary brain metastasis five months after completion of chem...

In this work we develop techniques that can derive the tumor position from external respiratory surrogates (abdominal surface motion) through periodically updated internal/external correlation. A simple linear function is used to express the correlation between the tumor and surrogate motion. The function parameters are established during a patient setup session with the tumor and surrogate pos...

PURPOSE The objectives of this study are (1) to measure concordance of tumor position on breath-hold (BH) computed tomography (CT) scans relative to the natural tumor path during free breathing (FB) and (2) to evaluate the benefits of the breathing monitoring device Abches (Apex Medical, Tokyo) for stereotactic ablative radiotherapy (SABR) treatment planning. METHODS In 53 lung cancer patient...

INTRODUCTION Although radiation therapy (RT) is an effective treatment for malignant atelectasis, its accurate delivery is challenging because of difficulty differentiating between tumor and atelectatic lung. Furthermore, reexpansion of lung during treatment repositions tumor and normal structures necessitating replanning to ensure treatment accuracy. Facilitating lung reexpansion before initia...

multipotent mesenchymal stem cells (mscs) are recently found to alter the tumor condition. however their exact role in tumor development is not yet fully unraveled. mscs were established to perform many of their actions through paracrine effect. thus investigation of msc secretome interaction with tumor cells may provide important information for scientists who are attempting to apply stem cell...