Symbia truepoint

A 62-year-old man (weight 60 kg; height 168 cm) diagnosed with advanced plantar malignant melanoma was enrolled in this study (Ethics Committee: Protocol No. 2023-MN02). The trial was approved based on the microdose concept and proof-of-concept studies. In addition, the ethical standards of the INCan Hospital based on the Declaration of Helsinki regarding human experimentation and the GMP certificate granted to ININ by the Mexican Ministry of Health were taken into account. The patient signed an informed consent form after receiving detailed information about the purpose of the study, which could help decide on treatment and monitor disease progression. The patient underwent SPECT/CT (Symbia TruePoint, Siemens) 2 h after intravenous administration of [^99mTc]Tc-iPD-L1 (740 MBq) and had a previous [¹⁸F]FDG PET/CT (Excel 20; Siemens Medical Solutions) scan 5 days earlier.

^99mTc-CXCR4-L images in volunteers were obtained with a Symbia TruePoint dual-head gamma camera (SPECT/CT, Siemens), with high-resolution and low-energy collimators. The established parameters were velocity: 12 cm/min; matrix size: 256 × 1024 pixels; window: 20% symmetric at 140 keV; and scatter corrections: dual-energy window with simultaneous acquisition at 119 keV (20% width). Transmission factors to obtain the body (abdomen and chest) attenuation were calculated by using the I/I₀ counting rate, with (I) and without (I₀) the patient of a ^99mTc-filled flood source (555 MBq). Anterior and posterior scintigraphy of the whole body was obtained at 0.3, 1, 2, 4, 6, and 24 h after radiopharmaceutical administration.
In patients, preoperative (15 ± 5 d before surgery) cerebral SPECT (Siemens E. Cam Signature double detector) images were acquired at 3 h after ^99mTc-CXCR4-L (0.74 GBq) administration using a 128 × 128 matrix, window centered on 140 keV, with scattering correction, 360-degree rotation, 128 images of 20 s, and a total duration of approximately 21 min.

V/Q scans were performed with a one-day protocol (13 (link)). The V SPECT images were obtained before the Q scan. A 12-15 millicurie (444-555 megabecquerel) technetium‑99m (Tc-99m)-Technegas generated by the “TechnegasPlus” generator device (Cyclomedica Australia Pty Ltd., Australia) was used for the V phase. SPECT images of patients using a 180° dual head detector on SPECT/CT (Siemens Symbia TruePoint, Siemens Medical Solutions, USA) were acquired. Afterward, a Q SPECT with low dose CT scans was immediately obtained on the same table. After a slow (within 20-30 s) injection of 4-5 millicurie (148-185 megabecquerel). Tc-99m-macro aggregated albumin, (TechneScan LyoMAA; Mallinckrodt Medical) containing 100,000-200,000 particles, SPECT/CT was taken on the same device using similar SPECT parameters as those used for the V phase (low-energy high-resolution collimator, 128x128 matrix, 64 projections of 10 s, 1.00 zoom factor, and 140±10% keV energy window) and 13-25 mAs, 130 kV, and slice width of 5 mm for CT. Raw data of SPECT images processed with the “Tomo Reconstruction v.8.2.26.4” (Syngo‑Siemens AG) application and reconstruction was conducted with ordered subset expectation maximization method.