Learn More
BACKGROUND To determine whether proton radiotherapy has clinical advantages over photon radiotherapy, we modeled the dose characteristics of both to critical normal tissue volumes using data from patients with four types of childhood brain tumors. PROCEDURES Three-dimensional imaging and treatment planning data, including targeted tumor and normal tissues(More)
Inverse treatment planning and intensity-modulated radiation therapy (IMRT) promise advantages in the treatment of tumors of the head and neck region. Currently published studies use IMRT only in the treatment of the primary tumor. In these studies, the lymph nodes of the neck were treated using conventional techniques. The feasibility of an IMRT technique(More)
PURPOSE To evaluate salivary gland function after inversely planned stereotactic intensity-modulated radiotherapy (IMRT) for tumors of the head-and-neck region using quantitative pertechnetate scintigraphy. METHODS AND MATERIALS Since January 2000, 18 patients undergoing IMRT for cancer of the head and neck underwent pre- and posttherapeutic scintigraphy(More)
BACKGROUND The purpose of the study was the clinical implementation of a kV cone beam CT (CBCT) for setup correction in radiotherapy. PATIENTS AND METHODS For evaluation of the setup correction workflow, six tumor patients (lung cancer, sacral chordoma, head-and-neck and paraspinal tumor, and two prostate cancer patients) were selected. All patients were(More)
PURPOSE A study to quantitatively compare the image quality of four different image guided radiotherapy (IGRT) devices based on phantom measurements with respect to the additional dose delivered to the patient. METHODS Images of three different head-sized phantoms (diameter 16-18 cm) were acquired with the following four IGRT-CT solutions: (i) the Siemens(More)
Electromagnetic (EM) tracking allows localization of small EM sensors in a magnetic field of known geometry without line-of-sight. However, this technique requires a cable connection to the tracked object. A wireless alternative based on magnetic fields, referred to as transponder tracking, has been proposed by several authors. Although most of the(More)
UNLABELLED The following question is investigated: How narrow do the leaves of a multileaf collimator have to be such that further reduction of the leaf width does not lead to physical improvements of the dose distribution. Because of the physical principles of interaction between radiation and matter, dose distributions in radiotherapy are generally(More)
One aim of adaptive radiotherapy (ART) is the observation of organ motion followed by a subsequent adaptation of the treatment plan. One way of achieving this goal is a kV x-ray source mounted at a linear accelerator in combination with a flat-panel imager. Two imaging hardware configurations were evaluated for their potential for online tracking and the(More)
BACKGROUND The aim of this treatment planning study was to investigate the potential advantages of intensity-modulated (IM) proton therapy (IMPT) compared with IM photon therapy (IMRT) in nasopharyngeal carcinoma (NPC). METHODS Eight NPC patients were chosen. The dose prescriptions in cobalt Gray equivalent (GyE) for gross tumor volumes of the primary(More)
We have previously developed a tumour tracking system, which adapts the aperture of a Siemens 160 MLC to electromagnetically monitored target motion. In this study, we exploit the use of a novel linac-mounted kilovoltage x-ray imaging system for MLC tracking. The unique in-line geometry of the imaging system allows the detection of target motion(More)