Dosimetric differences in intensity modulated radiation therapy based on EUD and DV optimizations in lung cancer / 中国辐射卫生

ABSTRACT

Objective To compare the dosimetric difference between the biological function based on equivalent uniform dose (EUD) and the physical function based on dose volume (DV) in the intensity modulated radiotherapy for stage Ⅲ non-small cell lung cancer. Methods Four different radiotherapy plans were designed for 15 stage Ⅲ non-small cell lung cancer patients Group A, physical function optimization (DV + DV) was used for target area and organs at risk; GroupB, in the target region, biological function optimization conditions were added on the basis of physical function optimization, and physical function optimization of organs at risk (DV－EUD + DV) was added. Group C, biological function optimization (EUD + EUD) was used for target area and organs at risk. Group D, in the target area, physical function optimization conditions were added on the basis of biological function optimization, and biological function optimization of organs at risk (EUD－DV + DV) was added. The differences in dosimetric parameters of the four plans were compared. Results Target area PTV D2%, D98%, D50%, D105% and Dmax values of group C (P < 0.05) is the highest while group B and group D were relatively small (P > 0.05); The homogeneity index the results of the group B and the group D were better than those of the other two groups (P < 0.05). conformity index The results of the four groups were similar (P>0.05). Organ at risk lung tissue mean dose (MLD), V5, V10, V20, V30 and heart V30, V40, Dmean dose parameters were similar (P > 0.05). Spinalcord Group C and group D D1% were better than the other two groups (P < 0.05). There was no statistical difference in the number ofmonitor unit (MU) among the four groups (P > 0.05). Conclusion The optimization method combining physical and biological function optimization in the target area can improve the conformity of the target area on the premise of ensuring the treatment. The Spinalcord load would be significantly reduced when using biological function optimization or the combination of biological function and physical function optimization.