PURPOSE Mathematical models are used in Industrial & Systems Engineering to analyze complex integrated operational systems. Adapting this approach to radiation therapy can help quantify the precision and accuracy necessary to achieve optimal outcome of radiation treatment. The purpose of this work is to develop such a model using clinical data and assess the effect uncertainties have on treatme...

PURPOSE To calculate the normal tissue complication probability (NTCP) of late radiation effects on the rectum and bladder from repetitive CT scans during fractionated high-dose-rate brachytherapy (HDRB) and external beam radiotherapy (EBRT) of the uterine cervix and compare the NTCP with the clinical frequency of late effects. METHODS AND MATERIALS Fourteen patients with cancer of the uterin...

background: tangential irradiation of intact breast is one of the most common procedures performed in any radiotherapy center. this method is performed by using 2d and 3d treatment planning. the aim of this study was to compare 2d with 3d plans in breast conserving radiotherapy. homogeneity of isodose, and lung received dose were compared. materials and methods: twenty patients with breast canc...

IMRT treatment planning with commercial treatment planning systems is a trial-and-error process, based on a series of subjective human decisions. Therefore the quality of the IMRT treatment plans may not be consistent among patients, planners or institutions with different experience. Different plan quality assurance (QA) models have been proposed recently, that could flag suboptimal plans that...

Radiobiological metrics such as tumor control probability (TCP) and normal tissue complication probability (NTCP) help in assessing the quality of brachytherapy plans. Application of such metrics in clinics as well as research is still inadequate. This study presents the implementation of two indigenously designed plan evaluation modules: Brachy_TCP and Brachy_NTCP. Evaluation tools were constr...

BACKGROUND The purpose of this study was to investigate the potential dose reduction to the heart, left anterior descending (LAD) coronary artery and the ipsilateral lung for patients treated with tangential and locoregional radiotherapy for left-sided breast cancer with enhanced inspiration gating (EIG) compared to free breathing (FB) using the AAA algorithm. The radiobiological implication of...

Background: In order to improve the evaluation of possible rectal toxicity based on the rectal normal tissue complication probability (NTCP), we consider the fractional dependence of the NTCP on the wall thickness (tW) and rectal displacement (RM). Materials and Methods: The two-dimensional NTCP model (NTCP2D) was developed using radiotherapy plans of ten randomly selected patients with prostat...

 Background: To analyze the dosimetric and radio biologic advantages between intensity modulated radiotherapy (IMRT) and 3 dimensional conformal radiotherapy (3DCRT) and selection of optimal photon energy for IMRT treatments. Material and methods: 24 patients with localized prostate carcinoma were planned for 3DCRT and IMRT techniques. Radiation dose of 54 Gy with 2 Gy/fraction, was planned to ...

Introduction: Due to the effect of radiation on both the tumor and the surrounding normal tissues, the side effects of radiation in normal tissues are expected. One of the important complications in the head and neck radiotherapy is the doses reached to the larynx and spinal cord of patients with non-laryngeal head and neck tumors.   Materials and Methods: ...