3D-segmentation of the 18F-choline PET signal for target volume definition in radiation therapy of the prostate.
Technol Cancer Res Treat
; 6(1): 23-30, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17241097
ABSTRACT
Volumetric assessment of PET signals becomes increasingly relevant for radiotherapy (RT) planning. Here, we investigate the utility of 18F-choline PET signals to serve as a structure for semi-automatic segmentation for forward treatment planning of prostate cancer. 18F-choline PET and CT scans of ten patients with histologically proven prostate cancer without extracapsular growth were acquired using a combined PET/CT scanner. Target volumes were manually delineated on CT images using standard software. Volumes were also obtained from 18F-choline PET images using an asymmetrical segmentation algorithm. PTVs were derived from CT 18F-choline PET based clinical target volumes (CTVs) by automatic expansion and comparative planning was performed. As a read-out for dose given to non-target structures, dose to the rectal wall was assessed. Planning target volumes (PTVs) derived from CT and 18F-choline PET yielded comparable results. Optimal matching of CT and 18F-choline PET derived volumes in the lateral and cranial-caudal directions was obtained using a background-subtracted signal thresholds of 23.0+/-2.6%. In antero-posterior direction, where adaptation compensating for rectal signal overflow was required, optimal matching was achieved with a threshold of 49.5+/-4.6%. 3D-conformal planning with CT or 18F-choline PET resulted in comparable doses to the rectal wall. Choline PET signals of the prostate provide adequate spatial information amendable to standardized asymmetrical region growing algorithms for PET-based target volume definition for external beam RT.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Próstata
/
Neoplasias da Próstata
/
Planejamento da Radioterapia Assistida por Computador
/
Colina
/
Tomografia por Emissão de Pósitrons
Limite:
Humans
/
Male
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article