4DCT-based measurement of changes in pulmonary function following a course of radiation therapy

摘要: Purpose: Radiation therapy (RT) for lung cancer is commonly limited to subtherapeutic doses due unintended toxicity normal tissue. Reducing the frequency of occurrence and magnitude function loss may benefit from treatment plans that incorporate regional radiation dose information. In this article, authors propose a method quantitatively measures changes in tissue following course by using 4DCT image registration techniques. Methods: data sets before after RT two subjects are used study. Nonlinear 3D applied register an acquired near end inspiration expiration estimate pulmonary function. The Jacobian transformation, indicating local expansion or contraction, serves as index Approximately 120 annotated vascular bifurcation points landmarks evaluate accuracy. compare planned at different locations lung. Results: all pairs, average landmark distances on order 1 mm. change indicated ranges −0.15 0.1 contralateral −0.22 0.23 ipsilateral subject A, −0.4 0.39 −0.25 0.5 B. Both show larger range increase than lung. For regions receiving 24 Gy, decrease was observed. smaller either relationship between varies locations. Conclusions: With use techniques, prior can be measured. preliminary application approach subjects, were observed with weak correlation change. certain sections lung, detected locally compromised have resulted injury.