%0 Journal Article
%T Transformation of Physical DVHs to Radiobiologically Equivalent Ones in Hypofractionated Radiotherapy Analyzing Dosimetric and Clinical Parameters: A Practical Approach for Routine Clinical Practice in Radiation Oncology
%A Zoi Thrapsanioti
%A Irene Karanasiou
%A Kalliopi Platoni
%A Efstathios P. Efstathopoulos
%A George Matsopoulos
%A Maria Dilvoi
%A George Patatoukas
%A Demetrios Chaldeopoulos
%A Nikolaos Kelekis
%A Vassilis Kouloulias
%J Computational and Mathematical Methods in Medicine
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/713420
%X Purpose. The purpose of this study was to transform DVHs from physical to radiobiological ones as well as to evaluate their reliability by correlations of dosimetric and clinical parameters for 50 patients with prostate cancer and 50 patients with breast cancer, who were submitted to Hypofractionated Radiotherapy. Methods and Materials. To achieve this transformation, we used both the linear-quadratic model (LQ model) and the Niemierko model. The outcome of radiobiological DVHs was correlated with acute toxicity score according to EORTC/RTOG criteria. Results. Concerning the prostate radiotherapy, there was a significant correlation between RTOG acute rectal toxicity and ( ) and ( ) dosimetric parameters, calculated for £żGy. Moreover, concerning the breast radiotherapy there was a significant correlation between RTOG skin toxicity and dosimetric parameter, calculated for both £żGy ( ) and £żGy ( ). The new tool seems reliable and user-friendly. Conclusions. Our proposed model seems user-friendly. Its reliability in terms of agreement with the presented acute radiation induced toxicity was satisfactory. However, more patients are needed to extract safe conclusions. 1. Introduction Radiotherapy is one of the most commonly used and effective methods for the treatment of cancer. The dose-volume histogram (DVH) has been accepted as a tool for treatment-plan evaluation [1]. In order to have a complete treatment plan, the information about the dose distribution and the anatomic location and its extent should be supplemented by a DVH [2]. The DVH is used ubiquitously and plots delivered dose on the -axis and percent volume of the structure of interest on the -axis. The general shape and area under the DVH curve is essential in determining adequate coverage and homogeneity of dose in the target volume as well as in determining acceptable dose to critical structures. Indeed, the DVH has occupied a central role in modern treatment planning [3]. The Ħ°target volume" referred to in DVH analysis can be a target of radiation treatment or an organ at risk close to the target [4]. The DVH is, therefore, an adequate tool for evaluating a given treatment plan or comparing different treatment plans. Moreover, DVHs are useful for evaluating the uniformity of the irradiation on the target volume and on the normal tissues [5]. Our study is based on the use of the cumulative DVH, the plot of the volume percentage which receives a specified dose as a function of the dose. It has been proved that the cumulative DVH is more useful and preferred than the differential one [2]. A DVH
%U http://www.hindawi.com/journals/cmmm/2013/713420/