%0 Journal Article
%T Influence of photon energy on the quality of prostate intensity modulated radiation therapy plans based on analysis of physical indices
%A Thangavelu Sundaram
%A Jayakumar S
%A Govindarajan K
%A Supe Sanjay
%J Journal of Medical Physics
%D 2011
%I Medknow Publications
%X The goal of the present study was to study the effects of low- and high-energy intensity-modulated photon beams on the planning of target volume and the critical organs in cases of localized prostate tumors in a cohort of 8 patients. To ensure that the difference between the plans is due to energy alone, all other parameters were kept constant. A mean dose volume histogram (DVH) for each value of energy and for each contoured structure was created and was considered as completely representative for all patients. To facilitate comparison between 6-MV and 15-MV beams, the DVH-s were normalized. The different parameters that were compared for 6-MV and 15-MV beams included mean DVH, different homogeneity indices, conformity index, etc. Analysis of several indices depicts more homogeneous dose for 15-MV beam and more conformity for 6-MV beam. Comparison of all these parameters showed that there was little difference between the 6-MV and 15-MV beams. For rectum, 2 to 4 % more volume received high dose with the 6-MV beam in comparison with the 15-MV beam, which was not clinically significant, since in practice much tighter constraints are maintained, such that Normal Tissue Complication Probability (NTCP) is kept within 5 %. Such tighter constraints might increase the dose to other regions and other critical organs but are unlikely to increase their complication probabilities. Hence the slight advantages of 15-MV beam in providing benefits of better normal-tissue sparing and better coverage cannot be considered to outweigh its well-known risk of non-negligible neutron production.
%K Energy
%K H-index
%K HI-index
%K normal tissue complication probability
%K prostate intensity-modulated radiation therapy
%K Sigma-index
%K tumor control probability
%U http://www.jmp.org.in/article.asp?issn=0971-6203;year=2011;volume=36;issue=1;spage=29;epage=34;aulast=Thangavelu