Planning study to compare dynamic and rapid arc techniques for postprostatectomy radiotherapy of prostate cancer.
Strahlenther Onkol
; 190(6): 569-74, 2014 Jun.
Article
en En
| MEDLINE
| ID: mdl-24557057
ABSTRACT
PURPOSE:
To compare our standard technique for postprostatectomy radiotherapy of prostate cancer, i.e. using two lateral conformal dynamic arcs with volumetric-modulated arc therapy (VMAT) performed with the RapidArc(®) (Varian Medical Systems, Palo Alto, CA, USA). The plans were referred to as DA and RA, respectively. MATERIALS ANDMETHODS:
The treatment plans of 44 patients receiving adjuvant/salvage radiotherapy in the first months of 2010 were compared. In all cases, the prescribed total dose was 66-68.2 Gy (2.2 Gy per fraction). Both DA and RA plans were optimized in terms of dose coverage and constraints.RESULTS:
Small differences between the techniques were observed for planning target volume (PTV) dose distribution, whereas significant differences in sparing of organs at risk (OARs) were recorded (p < 0.0001). The OAR values (median; 95 % confidence interval, CI) were rectum D30 % = 60.7 Gy (59.40-62.04 Gy) and 48.2 Gy (46.40-52.72 Gy), D60 % = 34.1 Gy (28.50-38.92 Gy) and 27.7 Gy (21.80-31.51 Gy); bladder D30 % = 57.3 Gy (45.83-64.53 Gy) and 46.4 Gy (33.23-61.48 Gy), D50 % = 16.4 Gy (11.89-42.38 Gy) and 17.2 Gy (10.97-27.90 Gy), for DA and RA, respectively. Treatment times were very similar, whereas the monitor units (MU) were 550 ± 29 versus 277 ± 3 for RA and DA, respectively.CONCLUSION:
Dose-volume histograms (DVHs) show improvements in OAR sparing with RA. However, the RA technique is associated with almost double the number of MUs compared to DA. Regarding the PTV, DA is slightly superior in terms of D2 % and dose homogeneity. On the whole, the results suggest that RA be the favorable technique.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Prostatectomía
/
Neoplasias de la Próstata
/
Planificación de la Radioterapia Asistida por Computador
/
Radioterapia Adyuvante
Tipo de estudio:
Etiology_studies
Límite:
Aged
/
Aged80
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Strahlenther Onkol
Asunto de la revista:
NEOPLASIAS
/
RADIOTERAPIA
Año:
2014
Tipo del documento:
Article