Volumetric image-guidance: does routine usage prompt adaptive re-planning? An institutional review.
Acta Oncol
; 47(7): 1444-53, 2008.
Article
em En
| MEDLINE
| ID: mdl-18661434
ABSTRACT
PURPOSE:
To investigate how the use of volumetric image-guidance using an on-board cone-beam computed tomography (CBCT) system impacts on the frequency of adaptive re-planning. MATERIAL ANDMETHODS:
Treatment courses of 146 patients who have undergone a course of external beam radiation therapy (EBRT) using volumetric CBCT image-guidance were analyzed. Target locations included the brain, head and neck, chest, abdomen, as well as prostate and non-prostate pelvis. The majority of patients (57.5%) were treated with hypo-fractionated treatment regimens (three to 15 fraction courses). The frequency of image-guidance ranged from daily (87.7%) to weekly or twice weekly. The underlying medical necessity for adaptive re-planning as well as frequency and consequences of plan adaptation to dose-volume parameters was assessed.RESULTS:
Radiation plans of 34 patients (23.3%) were adapted at least once (up to six time) during their course of EBRT as a result of image-guidance CBCT review. Most common causes for adaptive planning were tumor change (mostly shrinkage 10 patients; four patients more than one re-plan), change in abdominal girth (systematic change in hollow organ filling; n=7, two patients more than one re-plan), weight loss (n=5), and systematic target setup deviation from simulation (n=5). Adaptive re-plan was required mostly for conventionally fractionated courses; only 5 patient plans undergoing hypo-fractionated treatment were adjusted. In over 91% of adapted plans, the dose-volume parameters did deviate from the prescribed plan parameters by more than 5% for at least 10% of the target volume, or organs-at-risk in close proximity to the target volume.DISCUSSION:
Routine use of volumetric image-guidance has in our practice increased the demand for adaptive re-planning. Volumetric CBCT image-guidance provides sufficient imaging information to reliably predict the need for dose adjustment. In the vast majority of cases evaluated, the initial and adapted dose-volume parameters differed to a degree that was considered clinically significant.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Planejamento da Radioterapia Assistida por Computador
/
Tomografia Computadorizada de Feixe Cônico
Tipo de estudo:
Guideline
/
Prognostic_studies
Limite:
Humans
/
Male
Idioma:
En
Revista:
Acta Oncol
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos