A new homogeneity index based on statistical analysis of the dose-volume histogram.
The goal of the present study was to develop a new dose-volume histogram (DVH)- based homogeneity index for effectively evaluating the dose homogeneity of intensity-modulated radiotherapy plans. The new index, called the sigma-index ("S-index") is defined as the standard deviation of the normalized differential DVH curve. In a study of 16 patients with brain tumors at our institution, the S-index was found to vary from 0.80 to 3.15. Our results showed that the S-index provides a more reliable and accurate measure of dose homogeneity than that given by conventional methods. A guideline for evaluating the dose homogeneity of treatment plans based on the S-index and its relation to equivalent uniform dose is discussed.
Yoon
Myonggeun
M
Research Institute and Hospital, National Cancer Center, Goyang, Korea. mxy131@ncc.re.kr
Park
Sung Yong
SY
Shin
Dongho
D
Lee
Se Byeong
SB
Pyo
Hong Ryull
HR
Kim
Dae Yong
DY
Cho
Kwan Ho
KH
D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D011874:Radiometry / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity