Analysis of source dwell position during treatment in brachytherapy using CT scout images.

Purpose: Several cases of inaccurate irradiation in brachytherapy have been reported, occurring similarly to external radiation. Due to a large dose per fraction in brachytherapy, inaccurate irradiation can seriously harm a patient. Although various studies have been conducted, systems that detect inaccurate irradiation in brachytherapy are not as developed as those for external irradiation.

Counting Distinguishable RNA Secondary Structures.

RNA secondary structures are essential abstractions for understanding spacial folding behaviors of those macromolecules. Many secondary structure algorithms involve a common dynamic programming setup to exploit the property that secondary structures can be decomposed into substructures. Dirks et al.

Multi-Institutional Study of End-to-End Dose Delivery Quality Assurance Testing for Image-Guided Brachytherapy Using a Gel Dosimeter.

Purpose: To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of our study is that this is the first multi-institutional end-to-end dose delivery study in the world.

Materials And Methods: The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system.

Development of a broad band AC power amplifier for real time turbulence feedback control experiment in the Saskatchewan Torus-modified (STOR-M) tokamak.

A gated oscillating power amplifier has been developed for high frequency biasing and real time turbulent feedback experiments in the Saskatchewan Torus-modified tokamak. This oscillator is capable of providing a peak to peak oscillating output voltage of around ±60 V with a current around 30 A within the frequency band 1 kHz-50 kHz without any distortions. The overall output power is amplified by a two-stage metal oxide semiconductor field-effect transistor power op-amp as well as nine identical push-pull amplifiers in the final stages.

Incidence of organizing pneumonia after whole-breast radiotherapy for breast cancer, and risk factor analysis.

Radiation-induced organizing pneumonia (OP) reportedly occurs in ~2% of patients who receive whole-breast radiotherapy (WBRT). Though there are several reported risk factors, they remain unclear and controversial. We analyzed the incidence of and risk factors for OP after WBRT at our institution.

[Optimal parameter decision method in VMAT for lung tumors with respiratory motions].

When performing lung cancer treatments using volumetric modulated arc therapy (VMAT) technique, dose error related to respiratory motion of tumors and multi leaf collimator (MLC) movement may occur. The dose error causes daily dose variation in multiple fractionations irradiation. The purpose of this study is to verify the influence of the respiratory motion and the MLC movement on the daily dose variation, and to confirm the feasibility of deciding robust planning parameter against the dose variation.

Incidence of leukoencephalopathy after whole-brain radiation therapy for brain metastases.

Purpose: To evaluate the incidence of leukoencephalopathy after whole-brain radiation therapy (WBRT) in patients with brain metastases.

Methods And Materials: We retrospectively reviewed 111 patients who underwent WBRT for brain metastases from April 2001 through March 2008 and had evaluable computed tomography (CT) and/or magnetic resonance imaging (MRI) at least 1 month after completion of WBRT. We evaluated the leukoencephalopathy according to the Common Terminology Criteria for Adverse Events, version 3.

Management of the baseline shift using a new and simple method for respiratory-gated radiation therapy: detectability and effectiveness of a flexible monitoring system.

Purpose: In respiratory-gated radiation therapy, a baseline shift decreases the accuracy of target coverage and organs at risk (OAR) sparing. The effectiveness of audio-feedback and audio-visual feedback in correcting the baseline shift in the breathing pattern of the patient has been demonstrated previously. However, the baseline shift derived from the intrafraction motion of the patient's body cannot be corrected by these methods.

Causes of photopenic defects in the lower sternum on bone scintigraphy and correlation with multidetector CT.

Purpose: To determine the cause of this photopenia in the lower sternum on bone scintigraphy and its correlation with sternal foramen on multidetector computed tomography (MDCT).

Methods: Between January and December 2008, we studied 1053 patients who underwent bone scintigraphy and CT scanning that included the chest. Bone scintigraphy showed photopenic areas in the lower sternum in 58 of these 1053 patients.

Increased anticoagulant activity of warfarin used in combination with doxifluridine.

Purpose: The purpose of this article is to report the first case of markedly increased anticoagulant activity of warfarin when used in combination with doxifluridine, given as a replacement for capecitabine.

Methods: International normalized ratio (INR) of a 73-year-old female patient receiving warfarin was increased after starting chemotherapy using oral fluoropyrimidines (capecitabine or doxifluridine). Since the concomitant use of warfarin and the oral fluoropyrimidines was unavoidable in this case, the warfarin dosage was adjusted to keep INR within goal range (1.

Cardiac-sparing radiotherapy for the left breast cancer with deep breath-holding.

Purpose: The aim of this study was to evaluate the effect of decreasing the irradiated cardiac volume in breast-conserving therapy (BCT) using breath-adapted radiation therapy (BART).

Materials And Methods: The radiation therapy (RT)-computed tomography (CT) of 21 patients with left breast cancer during free breathing (FB), end-inspiration gating (IG) with audio-prompting, and deep inspiration breath-hold (DIBH) were subjected to BART planning analysis. Respiratory movement was monitored during CT scanning with the respiratory-gating system.

Possible application of flow cytometry for evaluation of the structure and functional status of WASP in peripheral blood mononuclear cells.

The Wiskott-Aldrich syndrome protein (WASP), which is defective in Wiskott-Aldrich syndrome (WAS) patients, is an intracellular protein expressed in non-erythroid hematopoietic cells. Previously, we have established methods to detect intracellular WASP expression in peripheral blood mononuclear cells (PBMNCs) using flow cytometric analysis (FCM-WASP) and have revealed that WAS patients showed absent or very low level intracellular WASP expression in lymphocytes and monocytes, while a significant amount of WASP was detected in those of normal individuals. We applied these methods for diagnostic screening of WAS patients and WAS carriers, as well as to the evaluation of mixed chimera in WAS patients who had previously undergone hematopoietic stem cell transplantation.

[Examination of formula for enhanced dynamic wedge factors in symmetric and asymmetric fields].

We proposed a formula for the enhanced dynamic wedge (EDW) factor in the half-field (HF) that combined the formula proposed by Liu et al. in 1998 and their formula in 2003. When the EDW was used for irradiation to the tangent line of the HF breast, the values calculated by our formula and the measured values were consistent within 0.

[Polarity effects of commercial plane-parallel ionization chamber in therapeutic electron dosimetry-Results with C-134A ionization chamber.].

Plane-parallel ionization chambers that exhibit polar effects with low energy electron beams are recommended for therapeutic electron dosimetry. In this study, the polarity effects of a C-134A ionization chamber, a major commercially available plane-parallel ionization chamber in Japan, were characterized as a function of mean energy at various depths. Polarity effects were measured at representative depths along depth dose curves of nominal 4, 6, 9, 12 and 15 MeV electron beams, and were compared with previously reported results.

[Absorbed dose measurement of photon beam with Farmer-type ionization chambers in Japanese dosimetry protocols].

The Japan Society of Medical Physics (JSMP) has published a new dosimetry protocol "JSMP-01" (standard dosimetry of absorbed dose in external beam radiotherapy) which conforms to the recommendations of the International Atomic Energy Agency (IAEA TRS-398) and the American Association of Physicists in Medicine (AAPM TG-51) protocols for the calibration of radiotherapy beams. Since the new protocol offers the physical data for the Famer-type ionization chambers of the various wall materials, the user can measure the absorbed dose at reference point (D(r)) using most of the commercially available Famer-type ionization chambers. In this paper, the six Famer-type ionization chambers of the various wall materials are examined for photon beam by two ways.

Confirming or excluding the diagnosis of Wiskott-Aldrich syndrome in children with thrombocytopenia of an unknown etiology.

Early diagnosis is an important factor in a better prognosis in patients with Wiskott-Aldrich syndrome (WAS), but it is not always easy to distinguish between WAS and immune thrombocytopenic purpura on clinical grounds. To confirm or to exclude a WAS diagnosis promptly for children with thrombocytopenia, the authors performed flow cytometric screening of Wiskott-Aldrich syndrome protein (WASP) for 10 children with thrombocytopenia of an unknown etiology. Five children were diagnosed with WAS, and the remaining 5 were diagnosed as having non-WAS causes of thrombocytopenia.