Supine craniospinal irradiation in pediatric patients by proton pencil beam scanning.
Radiother Oncol
; 123(1): 112-118, 2017 04.
Article
en En
| MEDLINE
| ID: mdl-28283192
ABSTRACT
BACKGROUND AND PURPOSE:
Proton therapy is the emerging treatment modality for craniospinal irradiation (CSI) in pediatric patients. Herein, special methods adopted for CSI at proton Therapy Center of Trento by pencil beam scanning (PBS) are comprehensively described. MATERIALS ANDMETHODS:
Twelve pediatric patients were treated by proton PBS using two/three isocenters. Special methods refer to (i) patient positioning in supine position on immobilization devices crossed by the beams; (ii) planning field-junctions via the ancillary-beam technique; (iii) achieving lens-sparing by three-beams whole-brain-irradiation; (iv) applying a movable-snout and beam-splitting technique to reduce the lateral penumbra. Patient-specific quality assurance (QA) program was performed using two-dimensional ion chamber array and γ-analysis. Daily kilovoltage alignment was performed.RESULTS:
PBS allowed to obtain optimal target coverage (mean D98%>98%) with reduced dose to organs-at-risk. Lens sparing was obtained (mean D1â¼730cGyE). Reducing lateral penumbra decreased the dose to the kidneys (mean Dmean<600cGyE). After kilovoltage alignment, potential dose deviations in the upper and lower junctions were small (average 0.8% and 1.2% respectively). Due to imperfect modeling of range shifter, QA showed better agreements between measurements and calculations at depths >4cm (mean γ>95%) than at depths<4cm.CONCLUSIONS:
The reported methods allowed to effectively perform proton PBS CSI.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Posicionamiento del Paciente
/
Irradiación Craneoespinal
/
Terapia de Protones
Tipo de estudio:
Etiology_studies
Límite:
Adolescent
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Radiother Oncol
Año:
2017
Tipo del documento:
Article