*2.3. 68Ga-Nitroimidazole PET/CT Imaging Procedure*

There was no specific patient preparation applied for the 68Ga-Nitroimidazole scan.

The injected activity of 68Ga-Nitroimidazole was weight based (1.8–2.2 MBq) and ranged between 111–185 MBq. We obtained a pelvic image at 30 min. post tracer injection. This was followed by a whole body (vertex to mid-thigh) PET/CT image at 60 min post tracer injection. Lasix was administered at the time of tracer injection. Patients were catheterized prior to the 60-min image to reduce bladder activity. PET imaging was acquired in 3D mode at 3 min per bed position. We used CT data for attenuation correction and for anatomic delineation of lesions. We performed image reconstruction using ordered subset expectation maximization iterative reconstruction algorithm (four iterations, eight subsets) followed by post reconstruction filtering with a Gaussian filter applied at 5.0 mm FWHM.
