The objective of this work is to present commissioning procedures to clinically implement a three-dimensional (3D), image-based, treatment-planning system (TPS) for high-dose-rate (HDR) brachytherapy (BT) for gynecological (GYN) cancer. The physical dimensions of the GYN applicators and their values in the virtual applicator library were varied by 0.4 mm of their nominal values. Reconstruction ...

PURPOSE To investigate how the setting of optimization parameters, fractional dose and tuning structure in tomotherapy treatment planning affects plan dosimetric quality and treatment efficiency. METHODS A digital phantom to simulate head and neck radiotherapy was constructed for this study. Tumor was 10cm long C-shaped with two surrounding parallel normal structures (P-NS) and one serial nor...

In the current era of rapid marketing approval for promising new products in oncology, dose finding and optimization for small-molecule oncology drugs occurs throughout the development cycle and into the postmarketing setting. Many trials that support a regulatory application have high rates of dose reductions and discontinuations, which may result in postmarketing requirements (PMR) to study a...

In inverse planning of lung radiotherapy, techniques are required to ensure dose coverage of target disease in the presence of tumor motion as a result of respiration. A range of published techniques for mitigating motion effects were compared for dose stability across 5 breath cycles of ±2 cm. Techniques included planning target volume (PTV) expansions, internal target volumes with (OITV) and ...

Tilly, D. 2016. Probabilistic treatment planning based on dose coverage. How to quantify and minimize the effects of geometric uncertainties in radiotherapy. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1264. 51 pp. Uppsala: Acta Universitatis Upsaliensis. ISBN 978-91-554-9720-0. Traditionally, uncertainties are handled by expanding the irradiated volume...

We consider the problem of the global convergence of gradient-based optimization algorithms for interstitial high-dose-rate (HDR) brachytherapy dose optimization using variance-based objectives. Possible local minima could lead to only sub-optimal solutions. We perform a configuration space analysis using a representative set of the entire non-dominated solution space. A set of three prostate i...

background: computed tomography (ct) is main contributor of population dose from diagnostic x-ray examinations. children are more radiosensitive than adults, thus optimization of ct examination in these patients is essential. the purpose of this study was to evaluate dose delivered to pediatric patients’ undergoing ct examination of the common examinations and also establishing local diagnostic...

to evaluate the effect of reduced doses of foramsulfuron and nitrogen rates on weed biomass in corn field, an experiment was conducted using split plots arrangement based on randomized complete block design with three replications at research field of ferdowsi university of mashhad, in 2011. main plots were weed control levels comprising three reduced herbicide doses of foramsulfuron (50, 75, a...

background: dose assessment using proper dosimeters is especially important in radiation protection optimization and imaging justification in diagnostic radiology. objective: the aim of this study is to obtain the entrance skin dose (esd) of patients undergoing lumbar spine imaging using two thermoluminescence dosimeters tld-100 (lif: mg, ti) and gr-200 (lif: mg, cu, p) and also to obtain the a...

Optimization of permanent seed implant brachytherapy plans for treatment of prostate cancer should be based on biological effective dose (BED) distributions, since dose does not accurately represent biological effects between different types of sources. Currently, biological optimization for these plans is not feasible due to the amount of time necessary to calculate the BED distribution. This ...