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


METHODS
During 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.


RESULTS
An 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.


CONCLUSIONS
IMRT 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.
Kataria
Tejinder
T
Department of Radiation Oncology, Rajiv Gandhi Cancer Institute and Research Center, N. Delhi, India. t_kataria@rediffmail.com
Rawat
Sheh
S
Sinha
S N
SN
Garg
C
C
Bhalla
N K
NK
Negi
P S
PS
D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D008168:Lung / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D013899:Thoracic Neoplasms / Q000532:radiotherapy*; D016896:Treatment Outcome