Journal of Medical Physics
ORIGINAL ARTICLE
Year
: 2012  |  Volume : 37  |  Issue : 1  |  Page : 27--31

Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source


Barlanka Ravikumar1, S Lakshminarayana2 
1 Department of Radiotherapy, Government General Hospital, Kakinada, Andhra Pradesh, India
2 Department of Nuclear Physics, Andhra University, Visakhapatnam, Andhra Pradesh, India

Correspondence Address:
Barlanka Ravikumar
Department of Radiotherapy, Government General Hospital, Kakinada - 53 3001, Andhra Pradesh
India

In Brachytherapy treatment planning, the effects of tissue heterogeneities are commonly neglected due to lack of accurate, general and fast three-dimensional (3D) dose-computational algorithms. In performing dose calculations, it is assumed that the tumor and surrounding tissues constitute a uniform, homogeneous medium equivalent to water. In the recent past, three-dimensional computed tomography (3D-CT) based treatment planning for Brachytherapy applications has been popularly adopted. However, most of the current commercially available planning systems do not provide the heterogeneity corrections for Brachytherapy dosimetry. In the present study, we have measured and quantified the impact of inhomogeneity caused by different tissues with a 0.015 cc ion chamber. Measurements were carried out in wax phantom which was employed to measure the heterogeneity. Iridium-192 (192 Ir) source from high dose rate (HDR) Brachytherapy machine was used as the radiation source. The reduction of dose due to tissue inhomogeneity was measured as the ratio of dose measured with different types of inhomogeneity (bone, spleen, liver, muscle and lung) to dose measured with homogeneous medium for different distances. It was observed that different tissues attenuate differently, with bone tissue showing maximum attenuation value and lung tissue resulting minimum value and rest of the tissues giving values lying in between those of bone and lung. It was also found that inhomogeneity at short distance is considerably more than that at larger distances.


How to cite this article:
Ravikumar B, Lakshminarayana S. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source.J Med Phys 2012;37:27-31


How to cite this URL:
Ravikumar B, Lakshminarayana S. Determination of the tissue inhomogeneity correction in high dose rate Brachytherapy for Iridium-192 source. J Med Phys [serial online] 2012 [cited 2020 Oct 26 ];37:27-31
Available from: https://www.jmp.org.in/article.asp?issn=0971-6203;year=2012;volume=37;issue=1;spage=27;epage=31;aulast=Ravikumar;type=0