Dosimetric impact of contouring and needle reconstruction uncertainties in US-, CT- and MRI-based high-dose-rate prostate brachytherapy treatment planning.
Radiother Oncol
; 123(1): 125-132, 2017 04.
Article
en En
| MEDLINE
| ID: mdl-28284493
ABSTRACT
BACKGROUND AND PURPOSE:
The purpose was to evaluate the dosimetric impact of target contouring and needle reconstruction uncertainties in an US-, CT- and MRI-based HDR prostate BT treatment planning. MATERIAL ANDMETHODS:
US, CT, and MR images were acquired post-needle insertion in 22 HDR-BT procedures for 11 consecutive patients. Dose plans were simulated for an US-, CT- and MRI-based HDR-BT treatment planning procedure. Planning uncertainties in US- and CT-based plans were evaluated using MRI-based planning as reference. Target (CTVProstate) was re-contoured on MRI. Dose results were expressed in total equivalent dose given in 2Gy fractionation dose for EBRT (46Gy) plus 2 HDR-BT fractions.RESULTS:
Uncertainties in US- and CT-based planning caused the planned CTVProstate-D90% to decrease with a mean of 2.9±5.0Gy (p=0.03) and 2.9±2.9Gy (p=0.001), respectively. The intra-observer contouring variation on MRI resulted in a mean variation of 1.6±1.5Gy in CTVProstate-D90%. Reconstruction uncertainties on US resulted in a dose variation of±3Gy to the urethra, whereas data for CT were not available for this.CONCLUSIONS:
Uncertainties related to contouring and reconstruction in US- and CT-based HDR-BT treatment plans resulted in a systematic overestimation of the prescribed target dose. Inter-modality uncertainties (US and CT versus MR) were larger than MR intra-observer uncertainties.Palabras clave
Texto completo:
1
Colección:
01-internacional
Asunto principal:
Neoplasias de la Próstata
/
Planificación de la Radioterapia Asistida por Computador
/
Braquiterapia
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
/
Male
Idioma:
En
Revista:
Radiother Oncol
Año:
2017
Tipo del documento:
Article