68Ga-NOTA-UBI 29-41: A specific radiopharmaceutical for diagnosis of bacterial infection by PET/CT in hip prosthesis
Objectives: UBI 29-41 is an antimicrobial peptide derived from Ubiquicidin that binds specifically to S. aureus and B. subtilis according to the results obtained in preclinical studies. The high thermodynamic and kinetic stability of 68Ga-NOTA-UBI 29-41, associated with the fact that 68Ga is obtaine...
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| Published in: | The Journal of nuclear medicine (1978) Vol. 60 |
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| Main Authors: | , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
New York
Society of Nuclear Medicine
01-05-2019
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | Objectives: UBI 29-41 is an antimicrobial peptide derived from Ubiquicidin that binds specifically to S. aureus and B. subtilis according to the results obtained in preclinical studies. The high thermodynamic and kinetic stability of 68Ga-NOTA-UBI 29-41, associated with the fact that 68Ga is obtained from a 68Ge/ 68Ga generator (β+, T1/2 = 68 minutes) allows a rapid production with high efficiency. Our aim was to evaluate the capability to discriminate between septic and aseptic loosening of hip prosthesis in patients using 68Ga-NOTA-UBI 29-41 produced under GMP conditions. Methods: The radiopharmaceutical was produced in a synthesis module (ITG) with a 68Ga/68Ge generator. Twenty one patients (44-86 years old) with hip prosthesis (Ethics Committee approval), with evidence of aseptic loosening or prosthesis joint infection (PJI), from X-ray, serological, and /or clinical signs (e.g. pain, joint swelling, fever) were studied for differential diagnosis, within a postoperative period of at least 1 year. Two PET /CT studies were performed on separate days: 68Ga-NOTA-UBI 29-41 (up to 4 MBq/kg) and 18F-FDG (4.07 MBq/kg) and subsequently a bacteriological study was done. The pattern of uptake was classified, for different locations around the prosthesis into major, minor and no uptake, according the SUV values. Results: 68Ga-NOTA-UBI 29-41 was produced with high yield, the radiochemical purity was higher than 95%. Specific activity was higher than 17.5±5.4 MBq/nmol. Seventeen patients showed major 18F-FDG uptake with 14 true positive and 3 false positive respect to the microbiological test. Minor uptake was observed in the other 4 patients with 3 true negative and 1 false negative. Sensitivity was 93% and specificity was 50%. For 68Ga-NOTA-UBI 29-41, 14 patients showed major uptake with 14 true positive and 7 patients showed minor uptake with 6 true negatives and 1 false negative result. Sensitivity was 93 % and specificity was 100%. 68Ga-NOTA-UBI 29-41 show high renal excretion and high uptake at the infection site at 45 min post injection. Image analysis of the 14 patients true positive for 68Ga-NOTA-UBI 29-41, show increased tracer uptake along the interface between bone and prosthesis. A definitive diagnosis of infection or aseptic loosening was made from the evaluation of intraoperative specimens (tissues and/or prosthesis) obtained, or from clinical/serological evaluation. These samples were evaluated by histopathological examination and/or microbiological culture. Conclusions: This new radiopharmaceutical 68Ga-NOTA-UBI 29 41, was developed with a high standard of quality and is highly promising for use in clinical trials in patients. Further studies to increase the number of patients are in course. |
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| ISSN: | 0161-5505 1535-5667 |