Validation of an automatic contour propagation method for lung cancer 4D adaptive radiation therapy

• Published in: 2009 IEEE International Symposium on Biomedical Imaging: From Nano to Macro pp. 1071 - 1074
• Main Authors: Peroni, M., Spadea, M.F., Riboldi, M., Baroni, G., Chen, G.T.Y., Sharp, G.C.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2009
• Subjects: 4D Treatment Planning; Adaptive Radiation Therapy; Anthropomorphism; Biomedical applications of radiation; Cancer; Computed tomography; Contour Propagation; Deformable Registration; Imaging phantoms; Lesions; Lungs; Medical treatment; Oncology; Re-planning; Spline
• ISBN: 1424439310; 9781424439317
• ISSN: 1945-7928
• DOI: 10.1109/ISBI.2009.5193241

The objective of this work is to validate a fast and reliable 4D-based adaptive treatment planning procedure for the Radiation Oncology clinic. A non-rigid B-Spline based registration is performed between CT scans at different respiratory phases. Radiotherapy contours drawn on a reference phase are than propagated to the target phase. We present results from two novel validation methods: a validation study using a 4D anthropomorphic computational phantom, and a patient data analysis comparing auto-rater versus inter-rater variability. For the phantom study, the overlap was greater than 90%, while the diameter variation was 5.1% at exhale and 3.4% at inhale. For the patient dataset, pairwise auto-rater Dice coefficient values exceeded inter-rater values for 9 of 15 structures. Though subject to inaccuracies caused by residual motion artifacts, and manual contouring variations, the reliability of the method suggests it could be soon introduced in the clinical practice.