The authors developed a fast and clinically feasible patient-specific collision detection program for proton therapy based on a ray casting algorithm. If incorporated during the treatment planning phase it may lead to improved clinical efficiency. This methodology could also be applied to patient collision detection in photon therapy.

BackgroundOur purpose was to report acute gastrointestinal (GI) and genitourinary (GU) toxicity rates for prostate cancer patients undergoing image-guided intensity modulated radiation therapy (IG-IMRT) with a daily endorectal water-filled balloon (ERBH2O), and assess associations with planning parameters and pretreatment clinical characteristics.MethodsThe first 100 patients undergoing prostate and proximal seminal vesicle IG-IMRT with indexed-lumen 100 cc ERBH2O to 79.2 Gy in 1.8 Gy fractions at our institution from 12/2008- 12/2010 were assessed. Pretreatment characteristics, organ-at-risk dose volume histograms, and maximum GU and GI toxicities (CTCAE 3.0) were evaluated. Logistic regression models evaluated univariate association between toxicities and dosimetric parameters, and uni- and multivariate association between toxicities and pretreatment characteristics.ResultsMean age was 68 (range 51–88). Thirty-two, 49, and 19 patients were low, intermediate, and high-risk, respectively; 40 received concurrent androgen deprivation. No grade 3 or greater toxicities were recorded. Maximum GI toxicity was grade 0, 1, and 2 in 69%, 23%, and 8%, respectively. Infield (defined as 1 cm above/below the CTV) rectal mean/median doses, D75, V30, and V40 and hemorrhoid history were associated with grade 2 GI toxicity (Ps < 0.05). Maximum acute GU toxicity was grade 0, 1, and 2 for 17%, 41%, and 42% of patients, respectively. Infield bladder V20 (P = 0.03) and pretreatment International Prostate Symptom Scale (IPSS) (P = 0.003) were associated with grade 2 GU toxicity.ConclusionProstate IG-IMRT using a daily ERBH2O shows low rates of acute GI toxicity compared to previous reports of air-filled ERB IMRT when using stringent infield rectum constraints and comparable GU toxicities.

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Laure-Line ROUVE (3) , Nicolas LE BIHAN (2) , Jean-Louis COULOMB (1)(3) (1) LEG-UMR 5529-INPG/UJF-CNRS-ENSIEG-BP 46-38402 Grenoble-France (2) LIS-UMR 5083-INPG/UJF-CNRS-ENSIEG-BP 46-38402 Grenoble-France (3) LMN-INPG-ENSIEG-BP 46-38402 Grenoble-France Abstract-This paper shows the reliability of fault detection on electrical machines by analysis of the low frequency magnetic stray field. It is based on our own experience about magnetic discretion of naval electrical propulsion machine. We try to apply the techniques developed in previous works on the subject to faults detection. In this paper we focus on rotor defaults in a synchronous generator (eccentricity and short-circuit in rotor). Two kinds of study are performed. The first one is numerical. Firstly, an adapted Finite Elements Method is used to compute the stray field around the device. However, this approach is difficult to apply to fault detection and not well-adapted. A new model, simpler and faster, is developed. Results are compared for both modelling. The second one is experimental and is driven thanks to a laboratory machine representative of a real high power generator and to fluxgate magnetometers located around the device. Both studies show good agreement and demonstate the reliability of the approach.

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This paper presents a new computational method of magnetic field in the air created by the known current density distribution in coils or solid conductor. The method consists of decoupling three components of the vector field 0 . The method is faster and requires less memory than the classical approach, used in the magnetostatic and magnetodynamic finite-element formulations.Index Terms-Finite-element method, magnetic scalar potential, nodal interpolation, source field.

Wave-based analog computing is a new computing paradigm heralded as a potentially superior alternative to existing digital computers. Currently, there are optical and low-frequency acoustic analog Fourier transformers. However, the former suffers from phase retrieval issues, and the latter is too physically bulky for integration into CMOS-compatible chips. This paper presents a solution to these problems: the Ultrasonic Fourier Transform Analog Computing System (UFT-ACS), a metalens-based analog computer that utilizes ultrasonic waves to perform Fourier transform calculations. Through wave propagation simulations on MATLAB, the UFT-ACS has been shown to calculate the Fourier transform of various input functions with a high degree of accuracy. Moreover, the optimal selection of parameters through sufficient zero padding and appropriate truncation and bandlimiting to minimize errors is also discussed.

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