Title :

Development of CBCT-based prostate setup correction strategies and impact of rectal distension

Author(s) :

Boydev, Christine [Auteur]
Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 [LAMIH]
Tahleb Ahmed, Abdelmalik [Auteur]
Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 [LAMIH]
Derraz, Foued [Auteur]
Unité de traitement des signaux Biomédicaux [UTSB]
Peyrodie, Laurent [Auteur]
LAGIS-SI
Thiran, Jean-Philippe [Auteur]
Laboratoire de Traitement du signal [EPFL] / Signal Processing Laboratories [SP Lab]
Pasquier, David [Auteur]
Méthodes et Outils pour la Conception Intégrée de Systèmes [MOCIS]

Journal title :

Radiation Oncology

Pages :

83

Publisher :

BioMed Central

Publication date :

2015

ISSN :

1748-717X

English keyword(s) :

Image registration
Cone-beam computed tomography
Image-guided radiotherapy
Prostate cancer

HAL domain(s) :

Sciences du Vivant [q-bio]/Cancer
Sciences du Vivant [q-bio]/Médecine humaine et pathologie/Urologie et Néphrologie
Sciences du Vivant [q-bio]/Ingénierie biomédicale/Imagerie

English abstract : [en]

Background: Cone-beam computed tomography (CBCT) image-guided radiotherapy (IGRT) systems are widely used tools to verify and correct the target position before each fraction, allowing to maximize treatment accuracy and ...
Show more >Background: Cone-beam computed tomography (CBCT) image-guided radiotherapy (IGRT) systems are widely used tools to verify and correct the target position before each fraction, allowing to maximize treatment accuracy and precision. In this study, we evaluate automatic three-dimensional intensity-based rigid registration (RR) methods for prostate setup correction using CBCT scans and study the impact of rectal distension on registration quality.Methods: We retrospectively analyzed 115 CBCT scans of 10 prostate patients. CT-to-CBCT registration was performed using (a) global RR, (b) bony RR, or (c) bony RR refined by a local prostate RR using the CT clinical target volume (CTV) expanded with 1-to-20-mm varying margins. After propagation of the manual CT contours, automatic CBCT contours were generated. For evaluation, a radiation oncologist manually delineated the CTV on the CBCT scans. The propagated and manual CBCT contours were compared using the Dice similarity and a measure based on the bidirectional local distance (BLD). We also conducted a blind visual assessment of the quality of the propagated segmentations. Moreover, we automatically quantified rectal distension between the CT and CBCT scans without using the manual CBCT contours and we investigated its correlation with the registration failures. To improve the registration quality, the air in the rectum was replaced with soft tissue using a filter. The results with and without filtering were compared.Results: The statistical analysis of the Dice coefficients and the BLD values resulted in highly significant differences (p<10−6) for the 5-mm and 8-mm local RRs vs the global, bony and 1-mm local RRs. The 8-mm local RR provided the best compromise between accuracy and robustness (Dice median of 0.814 and 97% of success with filtering the air in the rectum). We observed that all failures were due to high rectal distension. Moreover, the visual assessment confirmed the superiority of the 8-mm local RR over the bony RR.Conclusion: The most successful CT-to-CBCT RR method proved to be the 8-mm local RR. We have shown the correlation between its registration failures and rectal distension. Furthermore, we have provided a simple (easily applicable in routine) and automatic method to quantify rectal distension and to predict registration failure using only the manual CT contours.Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Centre de Recherche en Informatique, Signal et Automatique de Lille (CRIStAL) - UMR 9189

Source :

Harvested from HAL