It is well known that in general, an increased oxidative stress is found in cancer cells (e.g. [1, 2]). Low and high LET radiations induce reactive oxidative species and thus increase the oxidative stress even more. Different cancer cells not only do repair the DNA damage differently, they also cope differently with oxidative stress. Increasing the oxidative stress before irradiation might poss...

A therapy-dedicated cyclotron was installed in the National Cancer Center Hospital East (NCCHE) at Kashiwa in 1997. Prior to the start of clinical use, we investigated the biological effectiveness of therapeutic proton beams for cell lethality. The proton beams accelerated up to 235 MeV were horizontally extracted from the cyclotron, and scattered by a bar-ridge filter to produce a Spread-Out-B...

Clinical trials of carbon radiotherapy started at HIMAC in 1994 using three treatment rooms and four beam ports, two horizontal and two vertical. The broad beam method was adopted to make a three-dimensionally uniform field at an isocenter. A spot beam extracted from an accelerator was laterally spread out by using a pair of wobbler magnets and a scatterer. A bar ridge filter modulated the beam...

An increasing number of patients undergoing proton radiotherapy have cardiac implantable electrical devices (CIEDs). We recently encountered a situation in which a high-voltage coil on a lead from an implanted cardiac defibrillator was located within the clinical treatment volume for a patient receiving proton radiotherapy for esophageal cancer. To study the effects of the lead on the dose deli...

Purpose The complex relationship between linear energy transfer (LET) and cellular response to radiation is not yet fully elucidated. To better characterize DNA damage after irradiations with therapeutic protons, we monitored formation disappearance of double-strand breaks (DNA DSB) as a function LET time. Comparisons conventional ?-rays high carbon ions were also performed.Materials Methods In...

PURPOSE To characterize and quantify the distal edge activity fall off, created in a phantom by a proton therapy beam METHOD AND MATERIALS: A 30×30×10cm polymethylmethacrylate phantom was irradiated with a proton therapy beam using different ranges and beams. The irradiation volume is approximated by a right circular cylinder of diameter 7.6cm and varying lengths. After irradiation, the phantom...

The authors attempt to establish the relative biological effectiveness (RBE) calculation for designing therapeutic proton beams on the basis of microdosimetry. The tissue-equivalent proportional counter (TEPC) was used to measure microdosimetric lineal energy spectra for proton beams at various depths in a water phantom. An RBE-weighted absorbed dose is defined as an absorbed dose multiplied by...

BACKGROUND Somatostatin has been used to prevent pancreatitis after endoscopic retrograde cholangiopancreatography but its effect on acute non-biliary pancreatitis is still unclear. AIM The purpose of this study was to evaluate the function of the sphincter of Oddi (SO) and the effect of somatostatin on patients with non-biliary pancreatitis. METHODS Twenty patients (18 males, two females) ...

Background—Somatostatin has been used to prevent pancreatitis after endoscopic retrograde cholangiopancreatography but its eVect on acute non-biliary pancreatitis is still unclear. Aim—The purpose of this study was to evaluate the function of the sphincter of Oddi (SO) and the eVect of somatostatin on patients with non-biliary pancreatitis. Methods—Twenty patients (18 males, two females) with a...

As proton therapy becomes increasingly popular, so does the need for Monte Carlo simulation studies involving accurate beam line modeling of proton treatment units. In this study, the 24 beam configurations of the Mevion S250 proton therapy system installed recently at our institution were modeled using the TOolkit for PArticle Simulation (TOPAS) code. Pristine Bragg peak, spread out Bragg peak...