OBJECTIVE Passive scattering proton beam (PSPB) radiotherapy for accelerated partial-breast irradiation (APBI) provides superior dosimetry for APBI three-dimensional conformal photon radiotherapy (3DCRT). Here we examine the potential incremental benefit of intensity-modulated proton radiotherapy (IMPT) for APBI and compare its dosimetry with PSPB and 3DCRT. METHODS Two theoretical IMPT plans...

A radiation test plan for thin-film photovoltaic technologies focused on a MEO flight experiment is outlined. The proton and electron radiation response of thin film, amorphous Si solar cells and CuInGaSe2 solar cells, with and without space coatings, is presented. The degradation of the photovoltaic output under penetrating and junction-damaging proton irradiation, and 0.6 MeV and 1 MeV electr...

In proton radiotherapy, a proton generates secondary neutrons and photons in a patient’s body. This leads to irradiation of the area in proximity to the target region with incidental doses caused by secondary radiation in addition to the therapeutic dose. However in current treatment planning of proton radiotherapy, conventional dose estimation algorithms like the pencil beam method can not est...

AIMS To assess the cellular proliferation using the monoclonal antibody Ki-67, in paraffin embedded uveal melanomas irradiated by proton beam, as well as in non-irradiated uveal melanomas. METHODS 30 enucleated eyes were included for histopathological study and Ki-67 immunostaining. Patients were enucleated between 1991 and 1996 for uveal melanoma, 14 after proton beam irradiation and 16 with...

Abstract--The effects of 63MeV proton irradiation on SiGe:C HBTs are reported for the first time. The dc characteristics and neutral base recombination of these SiGe:C HBTs are investigated for proton fluences up to 5×10 p/cm. A comparison is made with SiGe HBTs fabricated in the same technology. Despite the fact that these SiGe:C HBTs degrade significantly during proton exposure, there is no i...

The purpose of this work was to compare the risk of developing a second cancer after craniospinal irradiation using photon versus proton radiotherapy by means of simulation studies designed to account for the effects of neutron exposures. Craniospinal irradiation of a male phantom was calculated for passively-scattered and scanned-beam proton treatment units. Organ doses were estimated from tre...

AlGaN/GaN high electron mobility transistors (HEMTs) were exposed to 3 MeV protons at fluences of 6 10, 4 10 and 1 10 protons/cm. The drain saturation currents decreased by 20% and the maximum transconductance decreased by 5% at the highest fluence. As the fluence increased, the threshold voltage shifted more positive values. After proton irradiation, the gate leakage current increased. The Sch...

UNLABELLED The aim of this study was to examine the induction of oxidative stress and apoptosis-associated gene expression profiles in retina after proton irradiation exposure at 0.5 to 4 Gy. MATERIALS AND METHODS One eye of each Sprague-Dawley rat (6 per group) was irradiated with a conformal proton beam to total doses of 0, 0.5, 1 and 4 Gy. Retinal tissues were isolated for characterization...

Overall Program Goals for Year One Year one of this project had three major goals. First, to specify, order and install a new high current ion source for more rapid and stable proton irradiation. Second, to assess the use of chromium pre-enrichment and hardening by combining cold-work and irradiation in an effort to isolate a radiation damage microstructure in stainless steel without the effect...

BACKGROUND Laser acceleration of protons and heavy ions may in the future be used in radiation therapy. Laser-driven particle beams are pulsed and ultra high dose rates of >10⁹ Gy s⁻¹ may be achieved. Here we compare the radiobiological effects of pulsed and continuous proton beams. METHODS The ion microbeam SNAKE at the Munich tandem accelerator was used to directly compare a pulsed and a co...