Basic Radiation Oncology

Beyzadeoğlu, Murat; Özyiğit, Gökhan; Ebruli, Cuneyt

doi:10.1007/978-3-642-11666-7

Cited by 80 publications

(65 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Despite its high incidence, it is only the seventh cancer-related mortality cause thanks to early diagnosis and treatment (Polyzos et al, 2006;Beyzadeoglu et al, 2010). Some subgroup of patients with early stage EC may have a higher likelihood for progression or recurrence.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Treatment Outcomes of Early-Stage Endometrial Cancer Radiotherapy: A Single Center Experience

Demiral

Beyzadeoğlu²,

Sager³

et al. 2014

Asian Pacific Journal of Cancer Prevention

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Evaluation of Treatment Outcomes of Early-Stage Endometrial Cancer Radiotherapy: A Single Center Experience

Demiral

Beyzadeoğlu²,

Sager³

et al. 2014

Asian Pacific Journal of Cancer Prevention

View full text Add to dashboard Cite

“…Эти процессы отражены в модели параметрами α и β. Параметр α отражает радиочувствительность клеток, это натуральный логарифм числа клеток, которые погибают на каж-дый Гр излучения из-за неспособности восстановиться после облучения. Параметр β отражает способность к восстановлению, это натуральный логарифм числа пораженных клеток с неле-тальными повреждениями [23]. Значения этих параметров опре-деляются по кривым выживаемости стволовых клеток.…”

Section: Doi: 1017116/onkolog20165688-96unclassified

Radiobiological models and clinical radiation oncology

Stolbovoy¹,

Zalyalov²

2016

Onkol. Z. im. P.A. Gercena

View full text Add to dashboard Cite

medical Academy of Postgraduate Education, ministry of Health of the Russian Federation, moscow, RussiaThe paper presents basic radiobiological models in radiation oncology as the theories that predict the effect in normal tissues and in tumors during their ionizing radiation. It shows their mathematical basis leaning upon an event in a certain cell, as well as they are applied to the practice of radiation therapy to calculate the dose of radiation and the number of fractions per treatment cycle in order to adjust the dose sufficient for tumor destruction, by preserving the viability or physiological function of normal tissues and organs. The paper considers how the radiobiological models allow one to compare the biological effect of irradiation in a variety of dose adjustment over time, i.e. during different fractionation modes and how they are used to represent physical quantities (e.g. an absorbed dose) as clinical indicators, such as a biologically effective dose, tumor control probability, and normal tissue complication probability, which are used to optimize radiation plans. It gives the history of radiobiological models and the current view on their role in the practice of radiotherapy.

show abstract

“…For photon-radiation and β-particles on the other hand the indirect effect is the most significant. 9 Damage due to the direct effects means that the radiation causes ionisation directly in the atoms of the DNA. The electrons that leave the atoms cause bonds to be broken, which can break the DNA strand.…”

Section: How Radiation Damages the Cellmentioning

confidence: 99%

Mathematical Optimization of HDR Brachytherapy

Holm¹

2013

View full text Add to dashboard Cite

One out of eight deaths throughout the world is due to cancer. Developing new treatments and improving existing treatments is hence of major importance. In this thesis we have studied how mathematical optimization can be used to improve an existing treatment method: high-dose-rate (HDR) brachytherapy.HDR brachytherapy is a radiation modality used to treat tumours of for example the cervix, prostate, breasts, and skin. In HDR brachytherapy catheters are implanted into or close to the tumour volume. A radioactive source is moved through the catheters, and by adjusting where the catheters are placed, called catheter positioning, and how the source is moved through the catheters, called the dwelling time pattern, the dose distribution can be controlled.By constructing an individualized catheter positioning and dwelling time pattern, called dose plan, based on each patient's anatomy, it is possible to improve the treatment result. Mathematical optimization has during the last decade been used to aid in creating individualized dose plans. The dominating optimization model for this purpose is a linear penalty model. This model only considers the dwelling time pattern within already implanted catheters, and minimizes a weighted deviation from dose intervals prescribed by a physician.In this thesis we show that the distribution of the basic variables in the linear penalty model implies that only dwelling time patterns that have certain characteristics can be optimal. These characteristics cause troublesome inhomogeneities in the plans, and although various measures for mitigating these are already available, it is of fundamental interest to understand their cause.We have also shown that the relationship between the objective function of the linear penalty model and the measures commonly used for evaluating the quality of the dose distribution is weak. This implies that even if the model is solved to optimality there is no guarantee that the generated plan is optimal with respect to clinically relevant objectives, or even near-optimal. We have therefore constructed a new model for optimizing the dwelling time pattern. This model approximates the quality measures by the concept conditional value-at-risk, and we show that the relationship between our new model and the quality measures is strong. Furthermore, the new model generates dwelling time patterns that yield high-quality dose distributions.Combining optimization of the dwelling time pattern with optimization of the catheter positioning yields a problem for which it is rarely possible to find a proven optimal solution within a reasonable time frame. We have therefore developed a variable neighbourhood search heuristic that outperforms a state-of-the-art optimization software (CPLEX). We have also developed a tailored branch-and-bound algorithm that is better at improving the dual bound than a general branch-and-bound algorithm. This is a step towards the development of a method that can find proven optimal solutions to the combined problem within a reasonable ...

show abstract

Basic Radiation Oncology

Cited by 80 publications

References 3 publications

Evaluation of Treatment Outcomes of Early-Stage Endometrial Cancer Radiotherapy: A Single Center Experience

Evaluation of Treatment Outcomes of Early-Stage Endometrial Cancer Radiotherapy: A Single Center Experience

Radiobiological models and clinical radiation oncology

Mathematical Optimization of HDR Brachytherapy

Contact Info

Product

Resources

About