IMRT dose verification considering passing rate and respiratory motion

Kai Xie, Hongfei Sun, Tao Lin, Liugang Gao, Jianfeng Sui, Xinye Ni
2018 Oncology Letters  
The aim of the present study was to investigate the association between the dynamic intensity-modulated radiation therapy planned γ analysis passing rate and respiratory amplitude (A) and period (T) for different tumor volumes. A total of 30 patients with malignant lung tumors were divided into three groups: A; B; and C. The average tumor volumes (V) in the A, B and C groups were 635, 402 and 213 cm 3 , respectively. The simulated A values were set at 0, 5, 10, 15, 20 and 25 mm. The T values
more » ... e set at 4, 5 and 6 sec. The γ analysis passing rate was calculated under different conditions (dose difference, 3%; distance difference, 3 mm). Compared with the γ analysis passing rate in the A group (A=0, static; T=4, 5, 6 sec), the γ analysis passing rate deviation (A=5 mm) was <3.3%. However, this difference was not statistically significant (P>0.05). With a gradual increase in A value, the passing rate decreased. The deviation between the 3 groups was <2.5% at the same A value (T=4, 5 and 6 sec). A descending trend of passing rate with increased A value was revealed. At the same A and T values, the passing rate decreased with decreased tumor volume. At the same tumor volume, the passing rate decreased when the A value increased. The respiratory cycle was not demonstrated to be associated with the passing rate. Overall, these results suggest that the A value should be controlled in clinical radiotherapy.
doi:10.3892/ol.2018.8724 pmid:29963170 pmcid:PMC6019885 fatcat:no4qyeavkvettcauq6wh4boqua