Evaluation of a commercial Monte Carlo dose calculation algorithm for electron treatment planning.

Evaluation of a commercial Monte Carlo dose calculation algorithm for electron treatment planning. J Appl Clin Med Phys. 2019 May 23;: Authors: Huang JY, Dunkerley D, Smilowitz JB Abstract The RayStation treatment planning system implements a Monte Carlo (MC) algorithm for electron dose calculations. For a TrueBeam accelerator, beam modeling was performed for four electron energies (6, 9, 12, and 15 MeV), and the dose calculation accuracy was tested for a range of geometries. The suite of validation tests included those tests recommended by AAPM's Medical Physics Practice Guideline 5.a, but extended beyond these tests in order to validate the MC algorithm in more challenging geometries. For MPPG 5.a testing, calculation accuracy was evaluated for square cutouts of various sizes, two custom cutout shapes, oblique incidence, and heterogenous media (cork). In general, agreement between ion chamber measurements and RayStation dose calculations was excellent and well within suggested tolerance limits. However, this testing did reveal calculation errors for the output of small cutouts. Of the 312 output factors evaluated for square cutouts, 20 (6.4%) were outside of 3% and 5 (1.6%) were outside of 5%, with these larger errors generally being for the smallest cutout sizes within a given applicator. Adjustment of beam modeling parameters did not fix these calculation errors, nor does the planning software allow the user to input correction factors as a func...
Source: Journal of Applied Clinical Medical Physics - Category: Physics Authors: Tags: J Appl Clin Med Phys Source Type: research

Related Links:

This study compared treatment failures between patients treated exclusively with IV antibiotics and those transitioned from IV to oral antibiotics for bacteraemia secondary to UTI.MethodsThis single-centre, retrospective cohort study included hospitalised, non-critically ill adult patients treated with culture-susceptible antibiotic therapy for 7–21 days. Patients were divided into two cohorts based on the route of definitive antibiotic administration. Treatment failure was a composite outcome of death and recurrence of the index micro-organism within 21 days following negative blood cultures.Results and discussionAm...
Source: Journal of Global Antimicrobial Resistance - Category: Infectious Diseases Source Type: research
Source: Annals of Hematology - Category: Hematology Source Type: research
Source: Annals of Hematology - Category: Hematology Source Type: research
Source: Annals of Hematology - Category: Hematology Source Type: research
Source: Annals of Hematology - Category: Hematology Source Type: research
AbstractAplastic anemia (AA) has been reported to be associated with inflammatory bowel disease (IBD), but mostly with ulcerative colitis (UC). Little is known about the associations between AA and Crohn ’s disease (CD). We aim to determine the portraits of patients with AA-CD. Among a total of 657 patients with CD registered in Xijing Hospital of Digestive Diseases IBD center from January 2008 to October 2018, the patients diagnosed with concurrent AA were reviewed. Clinical presentation, medical history, endoscopic features, response to treatment, and prognosis in this set of patients were collected. Six male patie...
Source: Annals of Hematology - Category: Hematology Source Type: research
AbstractNodal peripheral T cell lymphomas (nPTCL) present aggressive clinical course, and its heterogeneous nature and poor prognosis with current therapeutic strategies make it a target for the development of new prognostic markers. Thus, we investigated tumor-associated macrophages (TAM) according to the number of cells expressing CD68 in biopsies and the absolute monocyte count (AMC) in peripheral blood of 87 patients with nPTCL. The median overall survival (OS) was 3  years (95% CI 1.3–8.4 years) and estimate 5 years OS of 43.3% (95% CI 32.5–53.7%). The median progression-free survival (PFS) ...
Source: Annals of Hematology - Category: Hematology Source Type: research
AbstractIncidence and outcome of microbiologically documented bacterial/viral infections and invasive fungal disease (IFD) in children and adults after hematopoietic cell transplantation (HCT) were compared in 650 children and 3200 adults in multicenter cross-sectional nationwide study. Infections were diagnosed in 60.8% children and 35.0% adults, including respectively 69.1% and 63.5% allo-HCT, and 33.1% and 20.8% auto-HCT patients. The incidence of bacterial infections was higher in children (36.0% vs 27.6%;p 
Source: Annals of Hematology - Category: Hematology Source Type: research
In conclusion, efficacy data, the reassuring safety profile, and the novel mechanism of action of plitidepsin suggest that this combination can be an alternative option in patients with relapsed/refractory multiple myeloma after at least three prior therapy lines.
Source: Annals of Hematology - Category: Hematology Source Type: research
Source: Annals of Hematology - Category: Hematology Source Type: research
More News: Physics