Background: The International Commission on Radiation Units and Measurements (ICRU) report 38 recommends reporting of total reference air kerma (TRAK) and reference ICRU isodose volumes during intracavitary brachytherapy (ICBT) in cancer of the cervix. The present study attempts to estimate the volumes enclosed by isodose surfaces from TRAK and evaluate its utility to represent doses to organs of interest.
Material And Methods: Volumes encompassed by isodose surfaces of 3 Gy, 6 Gy, 9 Gy, and 12 Gy were obtained for 90 high-dose rate (HDR) ICBT procedures. These were used to derive a relation between isodose volumes, TRAK/dose (K/D), and rectal and bladder doses.
Results: Actual volumes (V) encompassed by isodose surfaces were reflected as a quadratic function of K/D (r(2)=0.998) and the expression, V=-23.09+1295.99(K/D)+5661.65(K/D)(2) gave the best estimates for various volumes. No correlation was observed between TRAK and bladder (r(2)=0.086) or rectal doses (r(2)=0.082).
Conclusions: Estimates of volumes encompassed by different dose levels from TRAK could be derived with reasonable certainty. However, TRAK fails to correlate with rectal and bladder doses.
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http://dx.doi.org/10.1016/S1538-4721(03)00096-5 | DOI Listing |
Brachytherapy
December 2024
Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada; Lawson Health Research Institute, London, Ontario, Canada; Department of Oncology, Western University, London, Ontario, Canada; London Regional Cancer Program, London, Ontario, Canada. Electronic address:
Background: Poor needle placement in prostate high-dose-rate brachytherapy (HDR-BT) results in sub-optimal dosimetry and mentally predicting these effects during HDR-BT is difficult, creating a barrier to widespread availability of high-quality prostate HDR-BT.
Purpose: To provide earlier feedback on needle implantation quality, we trained machine learning models to predict 2D dosimetry for prostate HDR-BT on axial TRUS images.
Methods And Materials: Clinical treatment plans from 248 prostate HDR-BT patients were retrospectively collected and randomly split 80/20 for training/testing.
J Appl Clin Med Phys
November 2024
Advanced Oncology Solutions, Varian Medical Systems, Hixson, Tennessee, USA.
Purpose: Minimizing intermediate dose spill in stereotactic radiosurgery (SRS) for brain treatment is crucial. Intermediate dose spill correlates with the exposure of normal brain tissue to high doses, which increases the risk of radionecrosis. R50%, defined as the volume of the 50% of prescription isodose cloud/planning target volume, is one metric for intermediate dose spill.
View Article and Find Full Text PDFJ Med Phys
September 2024
Department of Physics, Jawaharlal Nehru Technological University Anantapur, Ananthapuramu, Andhra Pradesh, India.
Purpose: The purpose of this study was to systematically examine the normal tissue objective (NTO) function by comparing its variations for planning solitary brain metastasis with intensity-modulated and volumetric-modulated arc radiosurgery techniques.
Materials And Methods: Twenty-two cases were retrospectively planned with two NTO parameter sets named A and B using intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques. The Type A set used slope, k = 0.
Phys Med Biol
October 2024
Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia, United States of America.
With advancements in high-dose rate brachytherapy, the clinical translation of intensity modulated brachytherapy (IMBT) innovations necessitates utilization of model-based dose calculation algorithms (MBDCA) for accurate and rapid dose calculations. This study uniquely benchmarks a commercial MBDCA, BrachyVision ACUROS(BVA), against Monte Carlo (MC) simulations, evaluating dose distributions for a novel IMBT applicator, termed as theDirection Modulated Brachytherapy (DMBT) tandem, expanding beyond previous focus on partially shielded vaginal cylinder applicators, through a novel methodology.The DMBT tandem applicator, made of a tungsten alloy with six evenly spaced grooves, was simulated using the GEANT4 MC code.
View Article and Find Full Text PDFPhotobiomodul Photomed Laser Surg
November 2024
Poorsina Hospital, Neuroscience Research Center, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
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