A semiautomatic tool for prostate segmentation in radiotherapy treatment planning

BMC Medical Imaging

Fred Godtliebsen¹  Kirsten Marienhagen³  Veronika Kristine Tømmerås³  Stein Olav Skrøvseth²  Jörn Schulz¹ 

[1] Department of Mathematics and Statistics, University of Tromsø, 9037 Tromsø, Norway;Norwegian Centre for Integrated Care and Telemedicine, University Hospital of North Norway, 9038 Tromsø, Norway;Department of Oncology, University Hospital of North Norway, 9038 Tromsø, Norway

关键词: Statistical shape analysis;    Radiotherapy treatment planning;    Prostate;    Empirical Bayes;    Ellipse model;    Delineation;   

Others  :  849158
DOI  :  10.1186/1471-2342-14-4

 received in 2013-07-01, accepted in 2014-01-15,  发布年份 2014

【 摘 要 】

Background

Delineation of the target volume is a time-consuming task in radiotherapy treatment planning, yet essential for a successful treatment of cancers such as prostate cancer. To facilitate the delineation procedure, the paper proposes an intuitive approach for 3D modeling of the prostate by slice-wise best fitting ellipses.

Methods

The proposed estimate is initialized by the definition of a few control points in a new patient. The method is not restricted to particular image modalities but assumes a smooth shape with elliptic cross sections of the object. A training data set of 23 patients was used to calculate a prior shape model. The mean shape model was evaluated based on the manual contour of 10 test patients. The patient records of training and test data are based on axial T1-weighted 3D fast-field echo (FFE) sequences. The manual contours were considered as the reference model. Volume overlap (Vo), accuracy (Ac) (both ratio, range 0-1, optimal value 1) and Hausdorff distance (HD) (mm, optimal value 0) were calculated as evaluation parameters.

Results

The median and median absolute deviation (MAD) between manual delineation and deformed mean best fitting ellipses (MBFE) was Vo (0.9 ± 0.02), Ac (0.81 ± 0.03) and HD (4.05 ± 1.3)mm and between manual delineation and best fitting ellipses (BFE) was Vo (0.96 ± 0.01), Ac (0.92 ± 0.01) and HD (1.6 ± 0.27)mm. Additional results show a moderate improvement of the MBFE results after Monte Carlo Markov Chain (MCMC) method.

Conclusions

The results emphasize the potential of the proposed method of modeling the prostate by best fitting ellipses. It shows the robustness and reproducibility of the model. A small sample test on 8 patients suggest possible time saving using the model.

【 授权许可】

   
2014 Schulz et al.; licensee BioMed Central Ltd.

【 图 表 】

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