BrachyView, A novel inbody imaging system for HDR prostate brachytherapy: Design and Monte Carlo feasibility study

Abstract

. (2013). BrachyView, A novel inbody imaging system for HDR prostate brachytherapy: Design and Monte Carlo feasibility study. Medical Physics, 40 (7), 071715-1-071715-10.BrachyView, A novel inbody imaging system for HDR prostate brachytherapy: Design and Monte Carlo feasibility study AbstractPurpose: High dose rate (HDR) brachytherapy is a form of radiation therapy for treating prostate cancer whereby a high activity radiation source is moved between predefined positions inside applicators inserted within the treatment volume. Accurate positioning of the source is essential in delivering the desired dose to the target area while avoiding radiation injury to the surrounding tissue. In this paper, HDR BrachyView, a novel inbody dosimetric imaging system for real time monitoring and verification of the radioactive seed position in HDR prostate brachytherapy treatment is introduced. The current prototype consists of a 15 × 60 mm2 silicon pixel detector with a multipinhole tungsten collimator placed 6.5 mm above the detector. Seven identical pinholes allow full imaging coverage of the entire treatment volume. The combined pinhole and pixel sensor arrangement is geometrically designed to be able to resolve the three-dimensional location of the source. The probe may be rotated to keep the whole prostate within the transverse plane. The purpose of this paper is to demonstrate the efficacy of the design through computer simulation, and to estimate the accuracy in resolving the source position (in detector plane and in 3D space) as part of the feasibility study for the BrachyView project. Methods: Monte Carlo simulations were performed using the GEANT4 radiation transport model, with a 192Ir source placed in different locations within a prostate phantom. A geometrically accurate model of the detector and collimator were constructed. Simulations were conducted with a single pinhole to evaluate the pinhole design and the signal to background ratio obtained. Second, a pair of adjacent pinholes were simulated to evaluate the error in calculated source location. Results: Simulation results show that accurate determination of the true source position is easily obtainable within the typical one second source dwell time. The maximum error in the estimated projection position was found to be 0.95 mm in the imaging (detector) plane, resulting in a maximum source positioning estimation error of 1.48 mm. Conclusions: HDR BrachyView is a feasible design for real-time source tracking in HDR prostate brachytherapy. It is capable of resolving the source position within a subsecond dwell time. In combination with anatomical information obtained from transrectal ultrasound imaging, HDR BrachyView adds a significant quality assurance capability to HDR brachytherapy treatment systems. © 2013 American Association of Physicists in Medicine.Keywords brachytherapy, design, monte, carlo, feasibility, study, prostate, hdr, brachyview, system, imaging, inbody, novel Purpose: High dose rate (HDR) brachytherapy is a form of radiation therapy for trea...

Preliminary Monte Carlo Investigation of Using Ir-192 as the Source for Real Time Imaging Purpose

“…Safavi-Naeini et al . designed a BrachyView in vivo imaging device for brachytherapy [15] [16] [17], which can achieve sub-millimeter accuracy with an equivalent acquisition time of 0.5 s and their results support the use of the Ir-192 source as an imaging source. However, since BrachyView is an in-body device, its application is limited in other treatment sites, such as with breast HDR.…”

“…Safavi-Naeini el al . developed a BrachyView in-body imaging system for HDR prostate brachytherapy in 2013 and 2015 [15] [16] [17], which was capable of providing imaging, localization and dose validation. However, due to physical space limitations, the device may not be suitable for all types of HDR treatment.…”

Body composition patterns and breast cancer risk in Chinese women with breast diseases: A latent class analysis

“…The operation of the analyzer is simple and non‐invasive and the process of measurement involves standing on a metal platform and holding onto two handles for about one minute. It has been generally recognized in current researches (Okamoto et al, ; Ogawa et al, ; Bandera et al, ; Safavi‐Naeini et al, ; Finn, Saint‐Maurice, Karsai, Ihasz, & Csanyi ; Salacinski, Howell, Hill, ).…”

Radiation dose enhancement at tissue-tungsten interfaces in HDR brachytherapy

“…Two probe geometries (planar and cylindrical) and an 192 Ir HDR brachytherapy source were simulated using the Geant4 toolkit. The source model used throughout the simulations was based on a Nucletron microSelectron HDR 192 Ir source (also known as the mHDR-v2), as shown in figure 1 (Daskalov et al 1998, Borg and Rogers 1998, Perez-Calatayud et al 2012, Safavi-Naeini et al 2013. The core consists of a pure iridium metal cylinder (3.6 mm long and 0.6 mm in diameter) with 192 Ir uniformly distributed through its core volume, surrounded by a steel shell (4.5 mm in length with an outer diameter of 0.9 mm), connected to a short steel wire (2 mm long and and 0.7 mm in diameter).…”