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Definition of the clinical target volume (CTV) is one of the weakest links in the radiation therapy chain. In particular, inability to account for uncertainties is a severe limitation in the traditional CTV delineation approach. Here, we…

Medical Physics · Physics 2018-08-15 Nadya Shusharina , David Craft , Yen-Lin Chen , Helen Shih , Thomas Bortfeld

Inter-observer variation is a significant problem in clinical target volume(CTV) segmentation in postoperative settings, where there is no gross tumor present. In this scenario, the CTV is not an anatomically established structure, but one…

Treatment planning uncertainties are typically managed using margin-based or robust optimization. Margin-based methods expand the clinical target volume (CTV) to a planning target volume, generally unsuited for proton therapy. Robust…

Purpose: In this modelling study we pursued two main goals. The first was to establish a new CTV-to-PTV expansion which considers the closest and most critical organ at risk (OAR). The second goal was to investigate the impact of the…

Medical Physics · Physics 2023-03-21 Stephan Radonic , Jürgen Besserer , Carla Rohrer Bley , Uwe Schneider , Valeria Meier

Objective: The overarching objective is to make the definition of the clinical target volume (CTV) in radiation oncology less subjective and more scientifically based. The specific objective of this study is to investigate similarities and…

Medical Physics · Physics 2022-07-27 Thomas Bortfeld , Gregory Buti

In post-operative radiotherapy for prostate cancer, the cancerous prostate gland has been surgically removed, so the clinical target volume (CTV) to be irradiated encompasses the microscopic spread of tumor cells, which cannot be visualized…

Gross tumor volume (GTV) delineation on tomography medical imaging is crucial for radiotherapy planning and cancer diagnosis. Convolutional neural networks (CNNs) has been predominated on automatic 3D medical segmentation tasks, including…

Image and Video Processing · Electrical Eng. & Systems 2020-12-15 Chun-Hung Chao , Hsien-Tzu Cheng , Tsung-Ying Ho , Le Lu , Min Sun

Dose volume histograms are a useful tool in state-of-the-art radiotherapy planning, and it is essential to be aware of their limitations. Dose distributions computed by treatment planning systems are affected by several sources of…

Medical Physics · Physics 2007-06-13 Francisco Cutanda-Henriquez , Silvia Vargas-Castrillon

Rotational setup errors are usually neglected in most clinical centers. An analytical formula is developed to determine the extra margin between clinical target volume (CTV) and planning target volume (PTV) to account for setup errors. The…

Medical Physics · Physics 2014-11-18 Qinghui Zhang , Weijun Xiong , M. Chan , Y. Song , C. Burman

We present a method of directly optimizing on deviations in clinical goal values in radiation therapy treatment planning. Using a new mathematical framework in which metrics derived from the dose-volume histogram are regarded as functionals…

Medical Physics · Physics 2021-09-07 Tianfang Zhang , Rasmus Bokrantz , Jimmy Olsson

The Radiotherapy treatment planning optimization process based on a quasi-Newton algorithm with an object function containing dose-volume constraints is not guaranteed to converge when the dose value in the dose-volume constraint is a…

Classical Analysis and ODEs · Mathematics 2008-12-02 I. Hoveijn

The goal of radiation therapy for cancer is to deliver prescribed radiation dose to the tumor while minimizing dose to the surrounding healthy tissues. To evaluate treatment plans, the dose distribution to healthy organs is commonly…

Methodology · Statistics 2024-05-24 Thai-Son Tang , Zhihui Liu , Ali Hosni , John Kim , Olli Saarela

This paper deals with the classic radiotherapy dose fractionation problem for cancer tumors concerning the following goals: a) To maximize the effect of radiation on the tumor, restricting the effect produced to the organs at risk (healing…

Optimization and Control · Mathematics 2021-02-17 Luis Alberto Fernández , Lucía Fernández

Objective: Large irradiated volumes are a major contributor to severe side-effects in patients with head and neck cancer undergoing curatively intended radiotherapy. We propose a data-driven approach for defining the elective clinical…

Large variability between cell lines brings a difficult optimization problem of drug selection for cancer therapy. Standard approaches use prediction of value for this purpose, corresponding e.g. to expected value of their distribution.…

Quantitative Methods · Quantitative Biology 2022-09-15 Jarek Duda

We consider the effects of parameter uncertainty on the optimal radiation schedule in the context of the linear-quadratic model. Our interest arises from the observation that if inter-patient variations in OAR and tumor sensitivities to…

Tissues and Organs · Quantitative Biology 2015-06-05 Hamidreza Badri , Yoichi Watanabe , Kevin Leder

A mathematical model for time development of metastases and their distribution in size and carrying capacity is presented. The model is used to theoretically investigate anti-cancer therapies such as surgery and chemical treatments…

Tissues and Organs · Quantitative Biology 2013-06-21 Sebastien Benzekry , Dominique Barbolosi , Assia Benabdallah , Florence Hubert , Philip Hahnfeldt

This paper proposes a novel criterion for the allocation of patients in Phase~I dose-escalation clinical trials aiming to find the maximum tolerated dose (MTD). Conventionally, using a model-based approach the next patient is allocated to…

Methodology · Statistics 2018-07-17 Pavel Mozgunov , Thomas Jaki

Radiotherapy planning is a critical aspect of cancer treatment, where the optimal selection of beam directions and dose distributions significantly impacts treatment efficacy and patient outcomes. Traditionally, this process involves…

Medical Physics · Physics 2023-12-05 Keshav Kumar K. , NVSL Narasimham , A. Ramakrishna Prasad

Although optimal control theory has been used for the theoretical study of anti-cancerous drugs scheduling optimization, with the aim of reducing the primary tumor volume, the effect on metastases is often ignored. Here, we use a previously…

Tissues and Organs · Quantitative Biology 2013-06-21 Sebastien Benzekry , Philip Hahnfeldt
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