Ge lightspeed 16 slice ct scanner

All patients were immobilized using the Body Pro‐Lok^TM platform (CIVCO system, Orange City, IA) in the supine position with their arms up. A Knee cushion was used to immobilize the knees. Patients were instructed to present for CT simulation and treatment with a comfortably full bladder and empty rectum. To ensure a relatively empty rectum, patients were instructed to use metamucil beginning 3‐day prior to simulation and daily throughout the course of treatment. A free‐breathing planning 3D‐CT scan was acquired on a GE Lightspeed 16 slice CT scanner (General Electric Medical Systems, Waukesha, WI) with 512 × 512 pixels at 2.5‐mm slice thickness in the axial helical mode. The planning 3D‐CT images were imported into Eclipse treatment planning system (TPS, Version 15.6, Varian Medical Systems, Palo Alto, CA) for contouring the entire prostate capsule as a clinical target volume (CTV) and the OAR. The planning target volume (PTV) was generated by adding a 3 mm symmetric margin around the prostate capsule per RTOG‐0938 recommendation.¹² The average PTV size was 117.0 ± 34.0 cc (range, 73.0 to 186.0 cc), corresponding to an average PTV diameter of 6.0 ± 0.6 cm (range, 5.2 to 7.1 cm). OAR contours included rectum, bladder, penile bulb, femoral heads, skin, and urethra per RTOG‐0938 requirement. In addition, small bowel and sigmoid were also contoured for dose reporting.

Lateral radiographs were performed after implantation and before sacrifice to determine whether any gas accumulation or intervertebral space subsidence occurred. The disc space height (DSH) was defined as the average of the measured height of the anterior, midpoint, and posterior disc space (Figure 1(c)). A high-resolution CT scan was conducted at the end of the observation period to evaluate the interbody fusion. With a sagittal reconstruction of the CT images, the interbody fusion could be evaluated based on a scoring system reported by Goldschlager et al. [22 (link)]. The criteria for CT scoring were as follows: 0, no new bone formation; 1, new bone formation but not continuous between C2/3 and C4/5; 2, continuous bridging new bone but comprises <30% of fusion area; and 3, continuous bridging new bone but comprises >30% of fusion area.
All the CT scans were performed using a GE LightSpeed 16 Slice CT Scanner (GE Healthcare, Milwaukee, WI, USA) with the 0.63 mm slice thickness and 0.63 mm interval.

In this study, all the patients underwent a non-contrast CT of the chest by the performance of a Siemens SOMATOM Sensation 64-Slice CT Scanner (Siemens, Forchheim, Germany) or a GE LightSpeed 16-Slice CT scanner (GE Healthcare, Beijing, China). CT related parameters were as follows: routine section thickness1.0, 1.25, or 1.5 mm; section thickness after reconstruction: 0.625–1.25 mm; filtered back-projection reconstruction method; 80–120 kV; 200–280 mAs; and a B70f kernel. The data of these 677 patient’s chest CT were procured from picture archiving and communication system (PACS).