Dose reduction to normal tissues as compared to the gross tumor by using intensity modulated radiotherapy in thoracic malignancies.

C Garg,SN Sinha,PS Negi,NK Bhalla,Sheh Rawat,Tejinder Kataria

doi:10.1186/1748-717x-1-31

Abstract

Background and purposeIntensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities.The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies.Materials and methodsDuring the period January 2002 to March 2004, 12 patients of various sites of malignancies in the thoracic region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms.ResultsAn average dose reduction of the mean values by 73% to the heart, 69% to the right lung and 74% to the left lung, with respect to the GTV could be achieved with IMRT.The 2 year disease free survival was 59% and 2 year overall survival was 59%. The average number of IMRT fields used was 6.ConclusionIMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs.

Highlights

Background and purposeIntensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities.The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies
We present our initial experience with the designing, implementation and dosimetric aspects of IMRT plans of patients
Pulmonary fibrosis occurs in almost 100% of patients receiving high doses of irradiation [15,16,17] but may not be of clinical significance if the volume is small enough

Summary

Introduction

Background and purposeIntensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities.The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for thoracic malignancies. Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities. Curative doses of radiation in many instances may lead to a good disease control but cause radiation induced chronic morbidities such as interstitial capillary injury of the myocardium leading to an increased incidence of coronary artery disease, cardiomyopathy and pulmonary interstitial fibrosis. These toxicities are dose related and different structures have varying tolerance to radiation

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