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Peter Manser Daniel Frauchiger Daniel Frei Werner Volken Dario Terribilini Michael K. Fix 《Zeitschrift für medizinische Physik》2019,29(1):31-38
Purpose
Using volumetric modulated arc therapy (VMAT) delivery technique gantry position, multi-leaf collimator (MLC) as well as dose rate change dynamically during the application. However, additional components can be dynamically altered throughout the dose delivery such as the collimator or the couch. Thus, the degrees of freedom increase allowing almost arbitrary dynamic trajectories for the beam. While the dose delivery of such dynamic trajectories for linear accelerators is technically possible, there is currently no dose calculation and validation tool available. Thus, the aim of this work is to develop a dose calculation and verification tool for dynamic trajectories using Monte Carlo (MC) methods.Methods
The dose calculation for dynamic trajectories is implemented in the previously developed Swiss Monte Carlo Plan (SMCP). SMCP interfaces the treatment planning system Eclipse with a MC dose calculation algorithm and is already able to handle dynamic MLC and gantry rotations. Hence, the additional dynamic components, namely the collimator and the couch, are described similarly to the dynamic MLC by defining data pairs of positions of the dynamic component and the corresponding MU-fractions. For validation purposes, measurements are performed with the Delta4 phantom and film measurements using the developer mode on a TrueBeam linear accelerator. These measured dose distributions are then compared with the corresponding calculations using SMCP. First, simple academic cases applying one-dimensional movements are investigated and second, more complex dynamic trajectories with several simultaneously moving components are compared considering academic cases as well as a clinically motivated prostate case.Results
The dose calculation for dynamic trajectories is successfully implemented into SMCP. The comparisons between the measured and calculated dose distributions for the simple as well as for the more complex situations show an agreement which is generally within 3% of the maximum dose or 3 mm. The required computation time for the dose calculation remains the same when the additional dynamic moving components are included.Conclusion
The results obtained for the dose comparisons for simple and complex situations suggest that the extended SMCP is an accurate dose calculation and efficient verification tool for dynamic trajectory radiotherapy. This work was supported by Varian Medical Systems. 相似文献4.
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Greco Silvia Giambelluca Dario Pecoraro Giusy Salvaggio Giuseppe 《Abdominal imaging》2020,45(1):241-242
Abdominal Radiology - 相似文献
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Filippo Pietrantonio Fotios Loupakis Giovanni Randon Alessandra Raimondi Massimiliano Salati Dario Trapani Filippo Pagani Ilaria Depetris Giulia Maddalena Federica Morano Salvatore Corallo Michele Prisciandaro Francesca Corti Vincenzo Guarini Alessandro Bocconi Antonio Marra Carmen Belli Andrea Spallanzani Matteo Fassan Sara Lonardi Giuseppe Curigliano Giovanni Fucà Maria Di Bartolomeo Filippo de Braud 《The oncologist》2020,25(9):803-809
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Davide Campobasso Pietro Granelli Umberto Maestroni Dario Cerasi Stefania Ferretti Pietro Cortellini 《The Indian journal of surgery》2015,77(3):222-225
Nephroenteric fistulas can be secondary to different etiologies, the most common of which are pyelocolic fistulas. The absence of pathognomonic symptoms and the heterogeneity of presentation can sometimes result in a delay in diagnosis. We report on three cases: a pyelo-duodenal fistula secondary to kidney stones and subsequent pyonephrosis, a pyelocolic fistula due to inveterate ureteral stones with hydropyonephrosis, and a rare case of posttraumatic pyelocolic fistula. All patients were treated with radical nephrectomy and resection of the involved intestinal tract. Fistulas of the kidney with the gastrointestinal tract are complex not only for the surgical treatment, which is mandatory in the majority of cases, but also for clinical and instrumental diagnosis. Severe infection is a major concern due to the admixture of the enteric bacterial flora with the urinary tract. Nephroenteric fistulas require skilled surgical procedures, close control of the septic risk, management of patient''s overall medical condition, and balance between invasive and conservative approach. 相似文献