Automated radiosynthesis, quality control, and biodistribution of Ga-68 pentixafor: First Indian experience

Abstract

Background: Chemokine receptor CXCR4 is overexpressed in more than 27 different human tumors that make it a promising target in oncology. Ga-68 Pentixafor is the most promising positron emission tomography tracer for imaging CXCR4 receptors; hence, the present study was carried out to optimize the radiosynthesis of Ga-68-Pentixafor using fully automated method and the quality control (QC) checks were performed before being used as a clinical product. We also studied the normal biodistribution pattern of Ga-68-pentixafor intended for the use in variety of malignancies. Materials and Methods: We optimized the automated radio-synthesis of Ga-68 Pentixafor under good manufacturing practice conditions. A total of 62 productions were carried out in a span of 4 years. Extensive QC tests were performed to check for potency, identity, efficacy, and stability of the tracer. Biodistribution of Ga-68 Pentixafor was investigated in a healthy volunteer to determine normal range of standardized uptake value maximum (SUV max ) values in various organs. Results: The radiotracer was prepared successfully in 57/62 productions with radiochemical purity of >99%. Mean radiolabelling efficiency of 73.1% ± 7.7% ( n = 57) was obtained with synthesis time approximatively of 34 min. The radiolabeled complex showed no signs of dissociation up to 4 h at the room temperature. Ga-68 Pentixafor upon incubation with human serum was found to be stable at 37°C for 4 h. The highest normal organ uptake was seen in urinary bladder (SUV mean = 146.0), spleen (SUV mean = 6.80) followed by kidneys (SUV mean = 4.99). Conclusion: Using the automated radiosynthesis, Ga-68 Pentixafor exhibited good radiolabelling efficiency with excellent in vitro and in vivo stability and favorable biodistribution showing clinical applicability of the tracer.

68Ga-Pentixafor PET/CT for In Vivo Imaging of CXCR4 Receptors in Glioma Demonstrating a Potential for Response Assessment to Radiochemotherapy: Preliminary Results

“…Amino acid-based PET imaging using 18 F-FET and 10 Cmethonine tracers is often used in suspected recurrent or residual disease on MRI in GBM patients in the posttreatment follow-up pe-In clinical practice, FET and MET PET are reported to have a similar sensitivity and specificity. [24][25][26] The clinical utility of 18 F-FET PET/CT imaging has been reported for treatment and response assessment to radiation therapy.…”

“…Amino acid-based PET imaging using 18 F-FET and 10 Cmethonine tracers is often used in suspected recurrent or residual disease on MRI in GBM patients in the posttreatment follow-up pe-In clinical practice, FET and MET PET are reported to have a similar sensitivity and specificity. [24][25][26] The clinical utility of 18 F-FET PET/CT imaging has been reported for treatment and response assessment to radiation therapy. 27 Furthermore, 18 F-FET PET/CT imaging utility in delineating the biological tumor volume in GBM patients before initiating chemo/radiation treatment has been reported to be a strong prognostic factor for predicting PFS and OS.…”

“…[24][25][26] The clinical utility of 18 F-FET PET/CT imaging has been reported for treatment and response assessment to radiation therapy. 27 Furthermore, 18 F-FET PET/CT imaging utility in delineating the biological tumor volume in GBM patients before initiating chemo/radiation treatment has been reported to be a strong prognostic factor for predicting PFS and OS. 28 They further suggested that patients harboring resectable GBM might benefit from maximal FET PET-guided tumor resection.…”

“…The detailed method of labelling procedure had been reported previously. 18 Imaging was done on a dedicated GE Discovery 710 PET/CT scanner (GE Healthcare, Milwaukee, WI) approximately 45 minutes after the IV administration of approximately 111.0-148.0 MBq of 68 Ga-pentixafor. After CT acquisition (tube current 250-350 mAs, voltage 140 kVp), 3D PET acquisition of the brain in each patient was done in a single bed position for 5 minutes.…”

68Ga-Pentixafor PET/CT for in-vivo mapping of CXCR4 receptors as potential radiotheranostic targets in soft tissue and bone sarcoma: preliminary results

“…The labelling of 68 Ga with Pentixafor peptide was done under GMP conditions in a fully automated synthesiser (Scintomics, Munich, Germany), The radiolabelling was done using the standard procedure as has been reported previously [33].…”