This paper describes a supporting tool for medical doctors, providing the automatic definition of radiation volumes (planning target volume, PTV) for conformal radiotherapy computed on detected tumor areas (gross tumor volume, GTV) within radiographic images. First, the recognized brain tumor is geometrically reconstructed and visualized in three-dimensional space. Then, the respective growth d...

We propose a strategy of individualized image acquisitions and treatment planning for respiratory-gated carbon-ion therapy. We implemented it in clinical treatments for diseases of mobile organs such as lung cancers at the Gunma University Heavy Ion Medical Center in June 2010. Gated computed tomography (CT) scans were used for treatment planning, and four-dimensional (4D) CT scans were used to...

background: in helical tomotherapy (ht), the scaling factor (sf) is the time in seconds that each leaf viewing a target would need to be open to deliver the prescribed dose. the sf is patient-specific and is used to calculate the rotational period of the gantry, and the total treatment time (ttt) of the ht. the sf is generally difficult to estimate. currently, it takes about one hour to fully o...

Introduction: The quality of CT images used for treatment planning of cancer patients is an important issue in accurate outlining of the tumor volume and organs at risk. Different kernels in CT scanner systems are available for improving the image quality. Applying these kernels  on   CT  images  will  change   the   CT  numbers  and  electron   density   of   tissues, conse...

PURPOSE The aim of this study is to ascertain the subsequent radiobiological impact of using a consensus guideline target volume delineation atlas. MATERIALS AND METHODS Using a representative case and target volume delineation instructions derived from a proposed IMRT rectal cancer clinical trial, gross tumor volume (GTV) and clinical/planning target volumes (CTV/PTV) were contoured by 13 ph...

BACKGROUND AND PURPOSE Brachytherapy (BT) plays a crucial role in the management of invasive cervix cancer from stage I to IV. Intracavitary techniques are based on afterloading devices, with different types of applicators. CT and/or MRI compatible applicators allow a sectional image based approach with a better assessment of gross tumour volume (GTV) and definition and delineation of target vo...

BACKGROUND The use of high accuracy dose calculation algorithms, such as Monte Carlo (MC) and Collapsed Cone (CC) determine dose in inhomogeneous tissue more accurately than pencil beam (PB) algorithms. However, prescription protocols based on clinical experience with PB are often used for treatment plans calculated with CC. This may lead to treatment plans with changes in field size (FS) and c...

The purpose was to determine dose-delivery errors resulting from systematic rotational setup errors for fractionated stereotactic radiotherapy using direct simulation in a treatment planning system. Ten patients with brain tumors who received intensity-modulated radiotherapy had dose distributions re-evaluated to assess the impact of systematic rotational setup errors. The dosimetric effect of ...

CyberKnife spinal radiosurgery suffers from a lack of posterior beams due to workspace limitations. This is remedied by a newly available tracking modality for fiducial-free, respiration-compensated spine tracking in prone patient position. We analyzed the potential dosimetric benefit in a planning study. Fourteen exemplary cases were compared in three scenarios: supine (PTV=CTV), prone (PTV=CT...