Somatom sensation open 40 slice ct scanner

A Somatom Sensation Open 40-slice CT scanner (Siemens AG, Erlangen, Germany) was used for preoperative CT scanning. The imaging workstation was from Siemens AG. syngo image-processing software (Siemens AG) was used for image analysis (Fig. 1).Fig. 1

a: Anterior, median, and posterior vertebral wall heights. b Local kyphosis angle. c Distances of the posterior vertebral edge of the injured vertebrae from the upper and lower adjacent posterior vertebral walls. d Median vertebral canal sagittal diameter. e Cross-sectional area of the vertebral canal

All patients were immobilized with custom-made thermoplastic mask and underwent computed tomography (CT) scan with slice thickness of 3 mm (for head and neck patients) or 5 mm (for thoracic, abdominal and pelvic patients ) using the Siemens Somatom Sensation Open 40 slice CT scanner (Siemens, Forchheim, Germany). The targets and OARs were contoured slice by slice on the treatment planning CT images. Relevant organs were delineated for different anatomic regions. The body was segmented automatically by the Eclipse (Versions 11.0) Treatment Planning System (TPS) (Varian Medical Systems, Palo Alto, CA). Isotropic margins of 3 mm (for head and neck patients) or 5 mm (for thoracic, abdomen and pelvic patients) were created around the clinical target volume (CTV) and gross tumor volume (GTV) to generate the planning target volume (PTV) and planning gross tumor volume (PGTV), respectively.

This study was approved by the Institutional Review Board of our hospital, and written informed consents were obtained from the patients before treatment. Six adults (Four females, Two males) were treated with 6MV photon (Table 2). Patients were in supine position, immobilized in a BodyFIX® vacuum cushion from head to hip (Elekta AB, Stockholm, Sweden) with a headrest, a knee support, and a thermoplastic mask. The planning CT scan was acquired using a Siemens Somatom® Sensation Open 40-slice CT scanner (Siemens Medical Solutions, Forchheim, Germany). The slice thickness of CT images was 3 mm. The image set was exported to a Monaco Treatment Planning System (Monaco version 3.2, Elekta AB, Stockholm, Sweden) for planning.Table 2

Patient characteristics, treatment plan design and quality assurance

Patients
Age (years)	31–53
Positioning	Supine
Fixation	Thermoplastic mask, vacuum bag and knee support
Patient’s height (cm)	152–175.6
Plans
Length of target (cm)	68.1–80.7
Height of target (cm)	13.1–15.6
Width of target (cm)	14.2–15.8
The number of isocenters	2
Distance between isocenters (cm)	35–41
Total dose prescription (Gy)/Fraction	36/20
Quality assurance
Device	MatriXX plus MultiCube (IBA inc.) EBT2 film (International Special Products inc.)
Image guidance	Cone-beam CT, daily