Integrated systems combining functional (single-photon emission computed tomography; SPECT) imaging with anatomic (computed tomography; CT) imaging have the potential to greatly improve the accuracy of dose estimation in radionuclide therapy. In this article, we present the methodology for highly patient-specific tumor dosimetry by utilizing such a system and apply it to a pilot study of 4 foll...

The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden) are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR) 192Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm). The user ...

Protein X-ray structures are determined with ionizing radiation that damages the protein at high X-ray doses. As a result, diffraction patterns deteriorate with the increased absorbed dose. Several strategies such as sample freezing or scavenging of X-ray-generated free radicals are currently employed to minimize this damage. However, little is known about how the absorbed X-ray dose affects ti...

Measurements of the skylight polarized radiance distribution were performed at different measurement sites, atmospheric conditions, and three wavelengths with our newly developed Polarization Radiance Distribution Camera System (RADS-IIP), an analyzer-type Stokes polarimeter. Three Stokes parameters of skylight (I, Q, U), the degree of polarization, and the plane of polarization are presented i...

When CV-1 mammalian cells were X-irradiated before infection with ultraviolet (UV)-irradiated herpes simplex virus, an increase in survival of this virus was observed. X-ray reactivation is proposed as the name of this phenomenon by analogy with UV reactivation. The amount of survival enhancement was about the same as that found for UV reactivation in the same virus-host system. The enhancement...

An in vivo transplantation technique has been developed which can be utilized to determine the reproductive survival of parenchymal hepatocytes exposed either in vitro or in vivo to both physical and chemical genotoxic agents. We have used this assay system to determine the survival of liver cells exposed to sparsely ionizing radiation. The D0 value of the survival curve was 249 rads and the ex...

In using hyperthermia in the clinic, thermal dosimetry is essen tial and is discussed in terms of equating time-temperature relationships for an isoeffect to an equivalent time at a reference temperature, 43° for example. In applying time-temperatureequivalence, the sequence between heat and radiation and be tween two heat treatments, radiation dose rate, linear energy transfer, and physiologi...

Patients with metastatic differentiated thyroid cancer (DTC) may be prepared using either thyroid-stimulating hormone withdrawal (THW) or recombinant human thyroid-stimulating hormone (rhTSH) injections before 131I administration for treatment. The objective of this study was to compare the absorbed dose to the critical organs and tumors determined by 124I PET/CT-based dosimetry for 131I therap...

Histological preparations of ultrasonically produced lesions in cat brain, at 3 and 4 MHz, have been studied microscopically. The relationship of the delivered acoustic intensity at the lesion site, the energy absorbed per unit volume of the lesion, and the lesion volume is exhibited. It is suggested that universal responses to ultrasonic exposure may exist for different tissues.

background: the presence of small intestine in the radiation field during pelvic cancers treatment causes an interruption in radiotherapy. a non-invasive method was developed to exclude small intestine during conventional radiotherapy. materials and methods: the incidence of the radiation therapy interruption is highly dependent upon the area of the small intestine included in the portals and i...