Xie K, Sun H, Lin T, Gao L, Sui J, Ni X. IMRT dose verification considering passing rate and respiratory motion.
Oncol Lett 2018;
16:963-969. [PMID:
29963170 PMCID:
PMC6019885 DOI:
10.3892/ol.2018.8724]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 03/28/2018] [Indexed: 12/02/2022] Open
Abstract
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 cm3, respectively. The simulated A values were set at 0, 5, 10, 15, 20 and 25 mm. The T values were 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.
Collapse