On September 18, Joseph M. Reinhardt from the Dept. of Biomedical Engineering, University of Iowa, USA will give a talk.

Date: 18th Sept. 2009, 11:00 am

Place: Lecture hall Q (Van Peperzeelzaal), UMC Utrecht, Heidelberglaan 100, Utrecht (consult www.isi.uu.nl/contact/ on how to get to the adjacent secretarial office)

Title: “Examining radiation-induced changes in pulmonary function by 4D-CT imaging”

Abstract: Present treatment-planning dosimetry constraints for the lung are based on studies that assume lung tissue is homogeneous in its response to toxicity, irrespective of tissue location or underlying function. No human studies have investigated the relationships between local lung function, spatial radiation dose distribution, and radiation-induced lung function changes. We are able to observe radiation-induced changes in lung tissue function using 4DCT and image registration. 4DCT data sets before and after radiation therapy (RT) from two subjects are used in this study. Nonlinear, 3D image registration is applied to register an image acquired near end inspiration to an image acquired near end expiration to calculate local lung expansion. The Jacobian of the image registration transformation serves as an index of regional pulmonary function. We compare regional pulmonary function before and after RT with planned radiation dose at different locations of the lung. The relationships between the radiation dose, position within the lung, and the pulmonary function change suggest that lung tissue function   change is not solely based on radiation dose.