An automatic contour propagation method to follow parotid gland deformation during head-and-neck cancer tomotherapy

E. Faggiano, C. Fiorino, E. Scalco, S. Broggi, M. Cattaneo, E. Maggiulli, I. Dell'oca, N. Di Muzio, R. Calandrino, G. Rizzo

Research output: Contribution to journalArticlepeer-review


We developed an efficient technique to auto-propagate parotid gland contours from planning kVCT to daily MVCT images of head-and-neck cancer patients treated with helical tomotherapy. The method deformed a 3D surface mesh constructed from manual kVCT contours by B-spline free-form deformation to generate optimal and smooth contours. Deformation was calculated by elastic image registration between kVCT and MVCT images. Data from ten head-and-neck cancer patients were considered and manual contours by three observers were included in both kVCT and MVCT images. A preliminary inter-observer variability analysis demonstrated the importance of contour propagation in tomotherapy application: a high variability was reported in MVCT parotid volume estimation (p = 0.0176, ANOVA test) and a larger uncertainty of MVCT contouring compared with kVCT was demonstrated by DICE and volume variability indices (Wilcoxon signed rank test, p <10-4 for both indices). The performance analysis of our method showed no significant differences between automatic and manual contours in terms of volumes (p > 0.05, in a multiple comparison Tukey test), center-of-mass distances (p = 0.3043, ANOVA test), DICE values (p = 0.1672, Wilcoxon signed rank test) and average and maximum symmetric distances (p = 0.2043, p = 0.8228 Wilcoxon signed rank tests). Results suggested that our contour propagation method could successfully substitute human contouring on MVCT images.

Original languageEnglish
Pages (from-to)775-791
Number of pages17
JournalPhysics in Medicine and Biology
Issue number3
Publication statusPublished - Feb 7 2011

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology


Dive into the research topics of 'An automatic contour propagation method to follow parotid gland deformation during head-and-neck cancer tomotherapy'. Together they form a unique fingerprint.

Cite this