Discovery vct 64

The Vx2 tumors, a squamous carcinoma derived originally from Rous sarcoma virus tumor in rabbits 27 (link), were surgically implanted into New Zealand white rabbits (2.0-2.5 kg) in the right lung proximate to the hilum. Rabbits were fasted 12 h prior to anesthesia. Atropine (0.05 mg/kg) was injected intramuscularly 15 min prior to anesthesia followed by 3% pentobarbital (30 mg/kg) via an indwelling ear vein catheter. Two or three Vx2 tumor fragments (1 mm³ each) were implanted in the hind limb of a donor rabbit, and a tumor grew to a desirable size (~20 mm diameter) in 2 weeks. The tumor was surgically removed from the donor rabbit under general anesthesia (as above) and minced into 1 mm³ fragments. The anesthetized recipient rabbit was positioned supine. The surgical area on the chest was shaved, prepped and draped. Under CT guidance, an 18 ga needle was percutaneously inserted into the right lung and positioned in the right lobe proximal to the hilum. Two fragments of minced Vx2 tumor were implanted through a 20 ga aspiration needle. Following extraction of the needle, the incision point was disinfected and sterile dressings were applied. Rabbits recovered from anesthesia and were allowed food and water ad libitum. Two weeks after tumor implantation, CT (GE Discovery VCT64) was used to confirm tumor development and size.

All images were acquired using a PET/CT scanner [Discovery VCT 64 (GE Healthcare, Milwaukee, Wisconsin, USA)]. Patients were required to fast for at least 6 h and have a blood glucose level of less than 200 mg/dL prior to drug injection. After intravenous ¹⁸F-FDG (4.44 MBq/kg), patients were instructed to rest for 50–60 min before the examination. PET reconstructed images based on CT attenuation correction and ordered subset expectation maximum (OSEM) algorithm.
On an advanced workstation (GE ADW 4.6), CT and PET images were displayed independently and in infusion mode in axial, coronal, and sagittal planes. Abnormal lesions were determined by consensus between two experienced nuclear medicine physicians who were blinded to patient outcomes. PET/CT tumor metabolic parameters were calculated using PETVCAR software (GE ADW 4.6). The boundaries of the tumor were automatically generated using the 41% threshold recommended by the European Association of Nuclear Medicine (25 (link)). SUV_max and MTV were calculated using the software. BVG was defined as the metabolic value of the lesion with the largest volume on ¹⁸F-FDG PET/CT (MTV × SUV_mean of the largest lesion). TLG was the sum of MTV × SUV_mean of all lesions.