Timothy Cullip

Learn More
Seven years of experience in compensator intensity-modulated radiotherapy (IMRT) clinical implementation are presented. An inverse planning dose optimization algorithm was used to generate intensity modulation maps, which were delivered via either the compensator or segmental multileaf collimator (MLC) IMRT techniques. The in-house developed(More)
PURPOSE Several intensity modulation (IM) treatment techniques for tangential breast irradiation were evaluated in terms of dose uniformity in the treated breast volume, contralateral breast dose, and treatment irradiation time. METHODS AND MATERIALS Contralateral breast dose was measured via TLD chips, and the dose uniformity was calculated on two(More)
Three-dimensional visualization is an important tool in the evaluation and demonstration of injury. Creating convincing graphics, however, requires strict distinction between illustrative and reconstructive visualizations and a method of validation. We present a case in which we used a radiation-planning tool to provide a 3-dimensional illustrative(More)
PURPOSE We believe that a three-dimensional (3D) registration of nonplanning (diagnostic) imaging data with the planning computed tomography (CT) offers a substantial improvement in tumor target identification for many radiation therapy patients. The purpose of this article is to review and discuss our experience to date. METHODS AND MATERIALS We reviewed(More)
The production of off-focus x rays in the head of a 6 MV linac has been investigated using the EGS4 Monte Carlo code. The purpose of the study was to identify the sources of off-focus radiation and the relative contribution for each source. Even though a particular energy and linac were modeled, the broad conclusions are expected to be general since the(More)
Radiation oncology is an ever-advancing, complex, technologically based specialty that has been thrust into the public spotlight because of recent reports of serious treatment delivery errors that have impacted the quality of patient care. Although quality assurance (QA) initiatives are already common place in radiation oncology, the continued complex(More)
PURPOSE To develop an automated beam-orientation selection procedure for intensity-modulated radiotherapy (IMRT), and to determine if a small number of beams picked by this automated procedure can yield results comparable to a large number of manually placed orientations. METHODS AND MATERIALS The automated beam selection procedure maximizes an(More)
PURPOSE In clinical practice, physicians are constantly comparing multiple images taken at various times during the patient's treatment course. One goal of such a comparison is to accurately define the gross tumor volume (GTV). The introduction of three-dimensional treatment planning has greatly enhanced the ability to define the GTV, but there are times(More)