Registration of portal images for online correction of positioning errors during radiation therapy of prostate cancer

Julia Vlad; Sebastian Eulenstein; Waldemar Wlodarczyk; Peter Wust; Roland Felix

doi:10.1117/12.428102

28 May 2001 Registration of portal images for online correction of positioning errors during radiation therapy of prostate cancer

Julia Vlad, Sebastian Eulenstein, Waldemar Wlodarczyk, Peter Wust, Roland Felix

Author Affiliations +

Proceedings Volume 4319, Medical Imaging 2001: Visualization, Display, and Image-Guided Procedures; (2001) https://doi.org/10.1117/12.428102
Event: Medical Imaging 2001, 2001, San Diego, CA, United States

Abstract

Radiation therapy of prostate cancer requires a high geometric accuracy of dose delivery. Unfortunately, this accuracy can be hardly obtained because of imperfect patients repositioning throughout the preparation and execution of the treatment. In order to correct for such errors we developed methods for online registration of portal images (PI) and digitally reconstructed radiographs (DRR). To improve the preconditions for registration of the Pis and DRRs image preprocessing, such as contrast-limited adaptive histogram equalization (CLAHE) of the Pis, noise and edge filtering of the Pis and the DRRs, has been performed. Then, similarity measures as mean square error, cross correlation and mutual information were investigated. A fully automatic bony-based registration method has been developed. As a reference method a semi-automatic stereometric fiducial-based registration has also been developed. This method uses gold seeds implanted into the prostate as internal fiducial markers for assessment of the similarity measures. Small lead spheres as well were adhered as external fiducial markers on the Alderson phantom. This method was also used for the verification of the automatic bony-based registration. The registration of repositioning was then performed fully automatically in less than 30 s with the Alderson phantom and with the patient data. At the present stage, there remains a registration error of less than 2 mm.

Citation Download Citation

Julia Vlad, Sebastian Eulenstein, Waldemar Wlodarczyk, Peter Wust, and Roland Felix "Registration of portal images for online correction of positioning errors during radiation therapy of prostate cancer", Proc. SPIE 4319, Medical Imaging 2001: Visualization, Display, and Image-Guided Procedures, (28 May 2001); https://doi.org/10.1117/12.428102

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available