Comparison of dosiology between three dimensional

Authors: Hong Ma Jun Han Tao Zhang Yang Ke

Publish Date: 2013/10/20

Volume: 33, Issue: 5, Pages: 759-764

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Abstract

The purpose of this study was to compare the dose distribution of intensitymodulated radiotherapy IMRT in 7 and 5 fields as well as 3D conformal radiotherapy 3DCRT plans for gastric cancer using dosimetric analysis In 15 patients with gastric cancer after D1 resection dosimetric parameters for IMRT 7 and 5 fields and 3DCRT were calculated with a total dose of 45 Gy 18 Gy/day These parameters included the conformal index CI homogeneity index HI maximum dose spot for the planned target volume PTV dosevolume histogram DVH and dose distribution in the organs at risk OAR mean dose Dmean maximal dose Dmax in the spinal cord percentage of the normal liver volume receiving more than 30 Gy V30 and percentage of the normal kidney volume receiving more than 20 Gy V20 IMRT 7 and 5 fields and 3DCRT achieved the PTV coverage However IMRT presented significantly higher CI and HI values and lower maximum dose spot distribution than 3DCRT P=0001 For dose distribution of OAR IMRT had a significantly lower Dmean and Dmax in spinal cord than 3DCRT P=0009 There was no obvious difference in V30 of liver and V20 of kidney between IMRT and 3DCRT but 5field IMRT showed lower Dmean in the normal liver than other two plans P=0001 IMRT revealed favorable tumor coverage as compared to 3DCRT and IMRT plans Specifically 5field IMRT plan was superior to 3DCRT in protecting the spinal cord and liver but this superiority was not observed in the kidney Further studies are needed to compare differences among the three approaches

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