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Information concerning radiation-induced malignancies comes from the A-bomb survivors and from medically exposed individuals, including second cancers in radiation therapy patients. The A-bomb survivors show an excess incidence of carcinomas in tissues such as the gastrointestinal tract, breast, thyroid, and bladder, which is linear with dose up to about(More)
PURPOSE Urinary retention requiring catheterization is a known complication among prostate cancer patients treated with permanent interstitial radioactive seed implantation. However, the factors associated with this complication are not well known. This study was conducted to determine these factors. METHODS AND MATERIALS Ninety-one consecutive prostate(More)
Preclinical studies for boron neutron capture therapy (BNCT) using epithermal neutrons are ongoing at several laboratories. The absorbed dose in tumor cells is a function of the thermal neutron flux at depth, the microscopic boron concentration, and the size of the cell. Dosimetry is therefore complicated by the admixture of thermal, epithermal, and fast(More)
Cell progression through the mitotic cycle during low dose rate irradiation may alter notably the survival probability, particularly when a fraction of the dose is delivered during a sensitive phase of the cycle. In this paper we indicate that the consequences of this phenomenon, commonly believed to lead to an "inverse dose rate effect", may be(More)
Microdosimetric measurements were made with tissue-equivalent plastic (TEP), C-, Mg-, and Fe-walled proportional counters filled with propane-based tissue equivalent (TE) gas and Ar gas and irradiated with 14.7-MeV neutrons. A theoretical model was used for the analysis of energy deposition in spherical detectors. An effective average mass stopping-power(More)
Angioplasty balloons inflated with a solution of the beta-emitter Re-188 have been used for intravascular brachytherapy to prevent restenosis. Coronary stents are in extensive clinical use for the treatment of de novo atherosclerotic stenoses. In this study, the effect of an interposed stent on the dose distribution has been measured for Re-188 balloon(More)
An integer linear programming model is proposed as a framework for optimizing seed placement and dose distribution in brachytherapy treatment planning. The basic model involves using 0/1 indicator variables to describe the placement or non-placement of seeds in a prespecified three-dimensional grid of potential locations. The dose delivered to each point in(More)
PURPOSE Portal dose images acquired with an amorphous silicon electronic portal imaging device (EPID) suffer from artifacts related to backscattered radiation. The backscatter signal varies as a function of field size (FS) and location on the EPID. Most current portal dosimetry algorithms fail to account for the FS dependence. The ramifications of this(More)
PURPOSE We hypothesized that intraoperative preplanning for transperineal interstitial permanent prostate brachytherapy may yield better prostate cancer control than preoperative preplanning. We tested this hypothesis by comparing treatment outcomes of patients who underwent implantation using these two preplanning methods. PATIENTS AND METHODS We(More)
PURPOSE To describe our approach to intraoperative preplanning (INTRA-OP) for prostate implants and compare it to our standard method using a pre-implant volume study (STAND). METHODS AND MATERIALS Twenty patients (10 STAND, 10 INTRA-OP) were evaluated. Time required for each step of the INTRA-OP procedure was recorded. Overall procedure times and(More)