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The effect on esophagus after different radiotherapy techniques for early stage Hodgkin's lymphoma

Introduction. The cure rate of early stage Hodgkin's lymphoma (HL) is excellent; investigating the late effects of treatment is thus important. Esophageal toxicity is a known side effect in patients receiving radiotherapy (RT) to the mediastinum, although little is known of this in HL survivors. This study investigates the dose to the esophagus in the treatment of early stage HL using different RT

Spatially varying Riemannian elasticity regularization : Application to thoracic CT registration in image-guided radiotherapy

For deformable registration of computed tomography (CT) scans in image guided radiation therapy (IGRT) we apply Riemannian elasticity regularization. We explore the use of spatially varying elasticity parameters to encourage bone rigidity and local tissue volume change only in the gross tumor volume (GTV) and the lungs. We evaluate the method on the point-validated 4DCT breathing thorax POPI-model

Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume o

Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer

Background: PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. Objective: To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans used for radiation therapy planning in children with cancer, and compare to the risks attributable to t

Artifacts in conventional computed tomography (CT) and free breathing four-dimensional CT induce uncertainty in gross tumor volume determination

Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumo

A Retrospective Evaluation of the Benefit of Referring Pediatric Cancer Patients to an External Proton Therapy Center

Background: Pediatric cancer patients requiring radiation therapy (RT) have been routinely assessed and referred to proton therapy (PT) at an external institution. The benefit of the delivered PT compared to the state-of-the-art intensity modulated x-ray RT (XT) at the home institution was evaluated. Procedure: Twenty-four consecutive children referred for PT during 2010–2013 for craniospinal (CSI

Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking

Purpose. The purpose of this study was to compare treatment plans generated using fixed beam Intensity Modulated photon Radiation Therapy (IMRT), inversely optimized arc therapy (RapidArc(R), RA) with spot-scanned Intensity Modulated Proton Therapy (IMPT) for high-grade glioma patients. Plans were compared with respect to target coverage and sparing of organs at risk (OARs), with special attention

Stability of percutaneously implanted markers for lung stereotactic radiotherapy

The purpose of this study was to evaluate the stability of complex markers implanted into lung tumors throughout a course of stereotactic body radiotherapy (SBRT). Fifteen patients referred for lung SBRT were prospectively included. Radio-opaque markers were implanted percutaneously, guided by computed tomography (CT). Deep inspiration breath-hold CT scans (BHCT) were acquired at planning and on t

Risk of developing cardiovascular disease after involved node radiotherapy versus mantle field for Hodgkin lymphoma

Purpose: Hodgkin lymphoma (HL) survivors are known to have increased cardiac mortality and morbidity. The risk of developing cardiovascular disease after involved node radiotherapy (INRT) is currently unresolved, inasmuch as present clinical data are derived from patients treated with the outdated mantle field (MF) technique. Methods and Materials: We included all adolescents and young adults with

The prognostic value of FET PET at radiotherapy planning in newly diagnosed glioblastoma

Background: Glioblastoma patients show a great variability in progression free survival (PFS) and overall survival (OS). To gain additional pretherapeutic information, we explored the potential of O-(2-18F-fluoroethyl)-L-tyrosine (FET) PET as an independent prognostic biomarker. Methods: We retrospectively analyzed 146 consecutively treated, newly diagnosed glioblastoma patients. All patients were

Quantification and comparison of visibility and image artifacts of a new liquid fiducial marker in a lung phantom for image-guided radiation therapy

Purpose: A new biodegradable liquid fiducial marker was devised to allow for easy insertion in lung tumors using thin needles. The purpose of this study was to evaluate the visibility of the liquid fiducial markers for image-guided radiation therapy and compare to existing solid fiducial markers and to one existing liquid fiducial marker currently commercially available. Methods: Fiducial marker v

Dose escalation to high-risk sub-volumes based on non-invasive imaging of hypoxia and glycolytic activity in canine solid tumors : A feasibility study

Introduction: Glycolytic activity and hypoxia are associated with poor prognosis and radiation resistance. Including both the tumor uptake of 2-deoxy-2-[18 F]-fluorodeoxyglucose (FDG) and the proposed hypoxia tracer copper(II)diacetyl-bis(N4)-methylsemithio-carbazone (Cu-ATSM) in targeted therapy planning may therefore lead to improved tumor control. In this study we analyzed the overlap between s

The dosimetric impact of inversely optimized arc radiotherapy plan modulation for real-time dynamic MLC tracking delivery

Purpose: Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced by using a leaf position constraint (LPC) that reduces the difference in the position of adjacent MLC lea

The MCNP Monte Carlo Program

Monte Carlo N-Particle (MCNP) is a Monte Carlo code package allowing coupled neutron, photon, and electron transport calculations. Also, the possibility of performing heavy charged particle transport calculations was recently introduced with the twin MCNPX code package. An arbitrary three-dimensional problem can be formulated through the use of surfaces defining building blocks (“cells” that are a

Patient QA systems for rotational radiation therapy : A comparative experimental study with intentional errors

Purpose: The purpose of the present study was to investigate the ability of commercial patient quality assurance (QA) systems to detect linear accelerator-related errors. Methods: Four measuring systems (Delta 4®, OCTAVIUS®, COMPASS, and Epiqa™) designed for patient specific quality assurance for rotational radiation therapy were compared by measuring four clinical rotational intensity modulated r

Long term safety and visibility of a novel liquid fiducial marker for use in image guided radiotherapy of non-small cell lung cancer

Safety and clinical feasibility of injecting a novel liquid fiducial marker for use in image guided radiotherapy in 15 patients with non-small cell lung cancer are reported. No major safety or toxicity issues were encountered. Markers present at start of radiotherapy remained visible in cone beam computed tomography and fluoroscopy images throughout the treatment course and on computed tomography

The clinical commissioning of beams for neutron capture therapy

The clinical commissioning of beams for neutron capture therapy involves the measurement and analysis of a large amount of data in various geometries and using various detectors. The process as such is akin to that in the conventional photon and electron radiotherapy field, while the tools, methods and considerations in the field of neutron capture therapy are different. This chapter provides an i

A treatment planning study of the potential of geometrical tracking for intensity modulated proton therapy of lung cancer

Background. Proton therapy of lung cancer holds the potential for a reduction of the volume of irradiated normal lung tissue. In this work we investigate the robustness of intensity modulated proton therapy (IMPT) plans to motion, and evaluate a geometrical tumour tracking method to compensate for tumour motion. Material and methods. Seven patients with a nine targets with 4DCT scans were selected

Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-tr

Deviations in delineated GTV caused by artefacts in 4DCT

Background and purpose: Four-dimensional computed tomography (4DCT) is used for breathing-adapted radiotherapy planning. Irregular breathing, large tumour motion or interpolation of images can cause artefacts in the 4DCT. This study evaluates the impact of artefacts on gross tumour volume (GTV) size. Material and methods: In 19 4DCT scans of patients with peripheral lung tumours, GTV was delineate