Vue point fx

The studies were acquired in RT treatment position on either a Philips Gemini-GXL-PET-CT (n = 48) or a GE Discovery-710 PET-CT (n = 24). Patients received between 4.1 (for GE) and 5.18 (for Philips) MBq/kg of FDG after at least 4 hours of fasting. The average blood sugar level was 5.7 ± 1.2 mmol/L (range: 3.3-9.6 mmol/L). The staging and all sequential post-treatment scans were performed on the same scanner with the same acquisition and reconstruction protocols.
The PET studies were acquired in three-dimensional (3D) mode for a total acquisition time of 1.5 – 2.5 min per bed position adjusted according to the patient weight, from vertex to proximal femora at about 1-hour post injection. Transmission scans and attenuation corrections were obtained by using CT: a Philips Brilliance 6-slice CT or a 64-slice GE CT, using helical mode without the use of a contrast medium. CT images were acquired at 3.75 to 5 mm slice thickness and reconstructed to a transaxial matrix size of 512 × 512. The current (30–40 mAs) and voltage (120–140 kV) were varied according to the patient weight. The PET images were reconstructed using a Philips Line of Response-Row Action Maximum Likelihood Algorithm (LOR-RAMLA) or GE VUE Point FX (Time of Flight) algorithm into a 144 × 144 (for Philips) or 256 × 256 (for GE) matrix size with a slice thickness of 3.75 to 4.0 mm.

¹⁸F-DCPyL for both centres was sourced from Cyclotek (Melbourne, Australia and Wellington, New Zealand) produced by the same method described previously [14 ].
PRC: Patients were required to drink 1–2L of water prior to their appointment and void immediately prior to scanning. No diuretics were administered. Patients were imaged on a GE Discovery 690 (General Electric Medical Systems, Milwaukee WI, USA). Low-dose attenuation correction CT images were acquired and reconstructed to 3.75 mm slice thickness with an increment of 3.27 mm using iterative reconstruction (50% ASiR). All patients at both centres were administered 250 MBq (± 50 MBq) of 18F-DCFPyL intravenously in accordance with reference standards outlined by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) [15 ]. Imaging was performed at 120 min (± 10 min) after injection. PET images were acquired at 3.5 min/bed through the pelvis and 3.0 min/bed to the lung apices. Images were reconstructed from time of flight emission data using VUE Point FX and Q-Clear™ “GE Healthcare” iterative technique with a β value of 400. Sharp IR function was applied with no Z-axis filter. PET images were reconstructed on a 256 matrix.
STV: Patients were imaged on a GE Discovery 710 PET/CT (General Electric Medical Systems, Milwaukee WI, USA). Otherwise the scanning protocol matched that described above.