Adaptive radiotherapy for prostate cancer using kilovoltage cone-beam computed tomography: first clinical results.
Int J Radiat Oncol Biol Phys
; 70(1): 75-82, 2008 Jan 01.
Article
em En
| MEDLINE
| ID: mdl-17869445
ABSTRACT
PURPOSE:
To evaluate the first clinical results of an off-line adaptive radiotherapy (ART) protocol for prostate cancer using kilovoltage cone-beam computed tomography (CBCT) in combination with a diet and mild laxatives. METHODS AND MATERIALS Twenty-three patients began treatment with a planning target volume (PTV) margin of 10 mm. The CBCT scans acquired during the first six fractions were used to generate an average prostate clinical target volume (AV-CTV), and average rectum (AV-Rect). Using these structures, a new treatment plan was generated with a 7-mm PTV margin. Weekly CBCT scans were used to monitor the CTV coverage. A diet and mild laxatives were introduced to improve image quality and reduce prostate motion.RESULTS:
Twenty patients were treated with conform ART protocol. For these patients, 91% of the CBCT scans could be used to calculate the AV-CTV and AV-Rect. In 96% of the follow-up CBCT scans, the CTV was located within the average PTV. In the remaining 4%, the prostate extended the PTV by a maximum of 1 mm. Systematic and random errors for organ motion were reduced by a factor of two compared with historical data without diet and laxatives. An average PTV reduction of 29% was achieved. The volume of the AV-Rect that received >65 Gy was reduced by 19%. The mean dose to the anal wall was reduced on average by 4.8 Gy.CONCLUSIONS:
We safely reduced the high-dose region by 29%. The reduction in irradiated volume led to a significant reduction in the dose to the rectum. The diet and laxatives improved the image quality and tended to reduce prostate motion.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
/
Laxantes
/
Tomografia Computadorizada de Feixe Cônico
Tipo de estudo:
Evaluation_studies
/
Guideline
Limite:
Aged
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Int J Radiat Oncol Biol Phys
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Holanda