A5008464315- Advanced Radiotherapy Techniques
- Radiation Therapy and Dosimetry
- Radiation Detection and Scintillator Technologies
- Radiation Effects and Dosimetry
- Radiation Effects in Electronics
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Pancreatic and Hepatic Oncology Research
- Hepatocellular Carcinoma Treatment and Prognosis
- Enzyme Structure and Function
- Lung Cancer Diagnosis and Treatment
- Radiation Shielding Materials Analysis
- Phytochemicals and Antioxidant Activities
- Gastric Cancer Management and Outcomes
- Plant Gene Expression Analysis
- Gallbladder and Bile Duct Disorders
- Renal cell carcinoma treatment
- Nuclear Physics and Applications
- Management of metastatic bone disease
- Animal Genetics and Reproduction
- Protein Structure and Dynamics
- Digital Radiography and Breast Imaging
- Cancer Genomics and Diagnostics
- Advanced X-ray Imaging Techniques
- Porphyrin Metabolism and Disorders
The University of Texas MD Anderson Cancer Center
2010-2025
Scripps (United States)
2013-2014
Scripps Institution of Oceanography
2013-2014
German Cancer Research Center
2012
Heidelberg University
2012
Centre hospitalier universitaire de Québec
2011
Universidade de São Paulo
2004-2007
Universidade de Ribeirão Preto
2004
Universidade Estadual de Campinas (UNICAMP)
2002
Brazilian Synchrotron Light Laboratory
1999
The EXTEND trial tested the hypothesis that adding comprehensive metastasis-directed therapy (MDT) to chemotherapy would improve progression-free survival (PFS) over alone among patients with oligometastatic pancreatic ductal adenocarcinoma (PDAC).
Plastic scintillation detectors (PSDs) have many advantages over other in small field dosimetry due to their high spatial resolution, excellent water equivalence and instantaneous readout. However, proton beams, the PSDs undergo a quenching effect which makes signal level reduced significantly when detector is close Bragg peak where linear energy transfer (LET) for protons very high. This study measures correction factor (QCF) PSD clinical passive-scattering beams investigates feasibility of...
EBT-XD model of Gafchromic
The Brazilian National Synchrotron Light Laboratory (LNLS) has a dedicated protein crystallography beamline. optical elements of the beamline include an elastically bent cylindrical mirror and triangular bent-crystal monochromator, which focus synchrotron radiation at position sample in vertical horizontal planes, respectively. monochromatic is tunable between 2.0 1.2 A with optimum wavelengths from 1.3 to 1.6 A, chosen maximize photon flux bending magnets storage ring (1.37 GeV)....
Purpose: The purposes of this study were to validate a discrete spot scanning proton beam nozzle using the Monte Carlo (MC) code MCNPX and use MC validated model investigate effects low‐dose envelope, which surrounds beam's central axis, on measurements integral depth dose (IDD) profiles. Methods: An accurate from University Texas M. D. Anderson Cancer Center (Houston, Texas) was developed basis blueprints provided by manufacturer nozzle. authors performed simulations single pencil beams...
In scanned-beam proton therapy, the beam spot properties, such as lateral and longitudinal size minimum achievable range, are influenced by optics, scattering media drift spaces in treatment unit. Currently available scanning systems offer few options for adjusting these properties. We investigated a method that utilizes downstream plastic pre-absorbers located near water phantom. The adjustment was characterized using Monte Carlo simulations of modified commercial head. Our results revealed...
The dose response for films exposed to clinical x-ray beams is not linear and a calibration curve based on absorbed can be used account this effect. However proton dosimetry the of exhibits an additional dependence because variation energy transfer (LET) as protons penetrate matter. In present study, we hypothesized that EBT2 mathematically described bimolecular chemical reaction. Furthermore, have shown LET effect incorporated in dose–response curve. A set was pristine 161.6 MeV beams. were...
Radiotherapy delivery in the definitive management of lower gastrointestinal (LGI) tract malignancies is associated with substantial risk acute and late (GI), genitourinary, dermatologic, hematologic toxicities. Advanced radiation therapy techniques such as proton beam (PBT) offer optimal dosimetric sparing critical organs at risk, achieving a more favorable therapeutic ratio compared photon therapy. The international Particle Therapy Cooperative Group GI Subcommittee conducted systematic...
Traditional constraints specify that 700 cc of liver should be spared a hepatotoxic dose when delivering liver-directed radiotherapy to reduce the risk inducing failure. We investigated role single-photon emission computed tomography (SPECT) identify and preferentially avoid functional during radiation treatment planning in patients with preserved function but limited volume after receiving prior chemotherapy or surgical resection.
PurposeTo determine the dosimetric limitations of daily online adaptive pancreas stereotactic body radiation treatment by using an automated dose escalation approach.Methods and MaterialsWe collected 108 planning computed tomography (CT) scans from 18 patients (18 × 6 CT scans) who received 5-fraction at MD Anderson Cancer Center. Dose metrics original non-dose-escalated clinical plan (non-DE), dose-escalated created on (DE-ORI), therapy (DE-ART) were analyzed. We developed a dose-escalation...
The type I 3-dehydroquinate dehydratase (DHQase) which catalyses the reversible dehydration of 3-dehydroquinic acid to 3-dehydroshikimic is involved in shikimate pathway for biosynthesis aromatic compounds. absent mammals, makes structural information about DHQase vital rational design antimicrobial drugs and herbicides. crystallographic structure from Salmonella typhi has now been determined native form at 1.78 Å resolution (R = 19.9%; Rfree 24.7%). modified enzyme product covalently bound...
Former studies have shown that in homogeneities the path of therapeutic proton beams can lead to a degradation distal edge Bragg peak. These mostly investigated bone-air interfaces. This study focuses on caused by finely structured soft tissue - air interfaces, which be found lung tissue.A randomly filled voxelized lung-like phantom was designed and produced using rapid prototyping methods. The results transmission measurements this were used validate Monte Carlo (MC) calculations, then as...
The knowledge of a radioactive beam energy or quality is important in radiotherapy once it correlated with the type, size, and localization tumor. One indicative radiation half-value-layer (HVL), material thickness which reduces intensity to half. analysis treatment spectrum can be inferred through its homogeneity coefficient (HC, ratio between first second HVL) that for values ≥ 0.7 has indication adequate treatments. Another indicator mass absorption (cm2/g), related photons energies...
In this work we present a Monte Carlo study of proton irradiation lung parenchyma phantoms for particle energies that are typically used therapy, ranging from 150 to 200 MeV. The Bragg peaks the beams were scored in water phantom distal voxelized slabs material. A detailed was modeled and converted into structure, with resolution similar obtained by computed tomography, differences dose deposited caused merging small structures larger voxels. results show peak can vary up 11%, edge...
Stereotactic body radiation therapy (SBRT) for abdominal targets faces a variety of challenges, including motion caused by the respiration and digestion relatively poor level contrast between tumor surrounding tissues. Breath-hold treatments with computed tomography-on-rails (CTOR) image guidance is one way addressing these allowing both normal tissues to be well-visualized. Using isodose lines (IDLs) from CT simulations as guide, anatomical information can used shift alignment or trigger...
Advancements in radiotherapy technology now enable the delivery of ablative doses to targets upper urinary tract, including primary renal cell carcinoma (RCC) or tract urothelial carcinomas (UTUC), and secondary involvement by other histologies. Magnetic resonance imaging-guided linear accelerators (MR-Linacs) have shown promise further improve precision adaptability stereotactic body (SBRT).
The Kunitz-type trypsin inhibitor from seeds of Flamboyant ( Delonix regia ) has been purified to homogeneity and plate-like crystals suitable for X-ray analysis have grown by the hanging-drop method using PEG 6000 as a precipitant. belong space group P 2 1 with unit-cell parameters = 32.15, b 69.39, c 72.54 Å. diffraction data collected 2.95 Å resolution. structure solved molecular replacement known structures inhibitors Erythrina caffra (PDB code 1tie) soya beans Glycine max ; PDB 1ba7)...
Purpose: To illustrate patient QA results for the first 10 patients treated at Scripps Proton Center by comparing point dose measurement using an ion chamber and in‐house developed secondary MU program, of 2D distribution array. Methods: At time writing, plans were approved treatment Varian ProBeam pencil beam scanning system Eclipse planning software. We used IBA CC04 0.04 cm3 PTW Unidos E electrometer in a small water tank (Sun Nuclear 1D scanner). independent check software based on...
Purpose: To quantitatively evaluate dosimetric consequence of spot size variations and validate beam-matching criteria for commissioning a pencil beam model multiple treatment rooms. Methods: A planning study was first conducted by simulating to systematically impact in selected cases, which used establish the in-air tolerance matching specifications. system created using profiles acquired one room. These were also from another room assessing actual between two We twenty five test plans with...
Purpose: To determine the correlation between Relative Biological Effectiveness (RBE)‐weighted dose and radiation pneumonitis (RP) incidence in cancer patients treated with proton therapy. Methods: The Monte Carlo calculation system MC2 based on MCNPX was used to recalculate treatment plans taken from clinical planning (TPS) compute dose‐averaged LET each voxel of CT patient model. linear scaling model (LSM) for RBE biological coefficients RP variable RBE‐weighted distributions. These were...
Purpose: To evaluate the absolute dose accuracy of PTW Octavius 729 XDR 2D ion chamber array at a high rate pencil beam scanning proton therapy facility. Methods: A set 18 plans were created in our treatment planning system, each which comprising unique combination field sizes (FS), length spread out Bragg peaks (SOBP) and depths. The parameters used were: FS 5×5cm2, 10×10cm2 15×15cm2; flat SOBP 5cm 10cm; isocenter depths 10cm, 15cm 20cm, coincides with center SOBP. detector was positioned...
Purpose: An automated system, MC2, was developed to convert DICOM proton therapy treatment plans into a sequence MCNPX input files, and submit these computing cluster. MC2 converts the results format, any planning system can import data for comparison vs. conventional dose predictions. This work describes efforts made validate against measured profiles how calibrated predict correct number of monitor units (MUs) deliver prescribed dose. Methods: A set simulated lateral longitudinal compared...
Purpose: To evaluate the differences between relative biological effectiveness (RBE)‐weighted doses calculated with either linear quadratic (LQ) or repair‐misrepair‐fixation (RMF) RBE model for intensity modulated proton therapy (IMPT) treatment plans. Methods: The commercial planning system (TPS) used at MD Anderson Cancer Center (MDACC) does not provide LET information necessary in order to utilize variable models calculate RBE‐weighted dose obtain this Monte Carlo code MCNPX was...