Pmod software

PET-CT image analysis and quantification were performed using PMOD software (PMOD Technologies, Switzerland). To define the volumes of interest (VOIs), tumors were manually contoured on the CT image. To quantify radioactivity within the tumor corresponding PET uptake values were normalized to the injected radioactivity per body weight (SUV).
The results are represented as the tumor volume for CT and the maximum uptake value of the VOI (SUV_max) for PET. Changes in ¹⁸F-FDG uptake after tumor growth under the different treatment regimens are represented as the percentage difference between SUV_max post-treatment and SUV_max pre-treatment (%ΔSUV_max). Lower %ΔSUV_max denoted lower tumor glucose metabolism in comparisons between treatment regimens.

Image processing and analyses were performed using PMOD software (PMOD Technologies Ltd., Zurich, Switzerland). ¹⁸F-FDG PET images were co-registered to the corresponding T2-weighted MRI images and manually transformed for minor misalignments. Two regions of interest (ROI) were manually drawn over the MRI images (one for the tumor to measure the maximum SUV and the other for the contralateral cortex to measure the mean SUV). The TNR were calculated and the fasting and glucose loading scans were compared.

PET images representing percent injected dose per gram (%ID/g) summed between 0–60 min (the entire scan duration) were analyzed in AMIDE. The distribution volume ratio (DVR’) [11 (link)] for each 60-min scan was estimated using the Logan plot [17 (link)] tool in version 2.6 of the commercial PMOD software (PMOD Technologies, Zurich, Switzerland, www.pmod.com) where the cerebellum, which has few or no D2Rs, was taken as the reference tissue.

List mode data
from PET emission scans of both tracers were normalized and corrected
for decay, scatter, random coincidences, and attenuation. The iterative
reconstruction was performed using Fourier rebinning, an OSEM algorithm
with 4 iterations, and 16 subsets resulting in 21 time frames composed
of 6 × 10, 4 × 30, 2 × 60, 1 × 120, 1 × 180,
4 × 300, and 3 × 600 s of spatial domain information.
The reconstructed [¹¹C]raclopride and [¹¹C]GSK-189254
images were automatically registered by rigid transformation to specific
tracer templates,^{46 (link)} which were spatially
realigned on a T₂-weighted MRI scan of the brain of a Wistar
rat in Paxinos space (Atlas) to enable image processing and further
analysis using PMOD software (version 4.1 PMOD Technologies LLC, Zürich,
Switzerland). Striatum and cerebellum were selected for analyzing
[¹¹C]raclopride data (well-known and validated target and
reference regions for this tracer), while for [¹¹C]GSK-189254
image analysis 12 brain regions (striatum, cerebellum, parietal cortex,
temporal cortex, occipital cortex, frontal cortex, amygdala, hippocampus,
hypothalamus, brainstem, midbrain, thalamus) and a VOI covering the
whole brain were selected from a rat brain atlas.^{46 (link)}

After anesthesia (i.p. injection of ketamine/xyzaline; 1.5 mL/kg, ratio 2:1), mice were injected with 18.5 MBq of ^99mTcO₄⁻ and scanned in a SPECT/CT scanner (Bioscan, Washington DC, USA). SPECT and CT images were acquired with different timing based on specific radioactive levels to obtain 100,000 c.p.s. Images were reconstructed with MEDISO software (Medical Imaging Systems, Budapest, Hungary) and fusion using PMOD software (PMOD Technologies Basel, Switzerland).