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Abstract Background The radiation exposure of nuclear medicine personnel, especially concerning extremity doses, has been a significant focus over the past two decades. This study addresses the evolving practice of NM, particularly with the rise of radionuclide therapy and theranostic procedures, which involve a variety of radionuclides such as 68Ga, 177Lu, and 131I. Traditional studies have concentrated on common radioisotopes like 99mTc, 18F, and 90Y, but there is limited data on these radionuclides, which are more and more frequently used. This study, part of the European SINFONIA project, aims to fill this gap by providing new dosimetry data through a multicenter approach. The research monitors extremity doses to hands, eye lens doses, and whole-body doses in nuclear medicine staff handling 68Ga, 177Lu, and 131I. It examines the type of activities performed and the protective measures used. The study extrapolates measured doses to annual doses, comparing them with annual dose limits, and assesses the contribution of these specific procedures to the overall occupational dose of nuclear medicine personnel. Results Measurements were conducted from November 2020 to August 2023 across nine hospitals. The highest whole-body, eye lens and extremity doses were observed for 68Ga. Average maximum extremity doses, normalized per manipulated activity, were found of 6200 µSv/GBq, 30 µSv/GBq and 260 µSV/GBq for 68Ga, 177Lu and 131I, respectively. Average whole-body doses stayed below 60 µSv/GBq for all 3 isotopes and below 200 µSv/GBq for the eye lens dose. The variation in doses also depends on the task performed. For 68Ga there is a risk of reaching the annual dose limit for skin dose during synthesis and dispensing. Conclusions This study’s measurement campaigns across various European countries have provided new and extensive occupational dosimetry data for nuclear medicine staff handling 68Ga, 177Lu and 131I radiopharmaceuticals. The results indicate that 68Ga contributes significantly to the global occupational dose, despite its relatively low usage compared to other isotopes. Staff working in radiopharmacy hot labs, labeling and dispensing 177Lu contribute less to the finger dose compared to other isotopes.

Background: Despite being essential in patients with acute respiratory distress syndrome (ARDS), mechanical ventilation (MV) may cause lung injury and hemodynamic instability. Mechanical power (MP) may describe the net injurious effects of MV, but whether it reflects the hemodynamic effects of MV is currently unclear. We hypothesized that MP is also associated with cardiac output (CO) and pulmonary blood flow (PBF). Methods: 24 anesthetized pigs with experimental acute lung injury were ventilated for 18 h according to one of three strategies: 1) Open lung approach (OLA), 2) ARDS Network high-PEEP/FIO2 strategy (HighPEEP), or 3) low-PEEP/FIO2 strategy (LowPEEP). Total MP was assessed as the sum of energy dissipated to overcome airway resistance and energy temporarily stored in the elastic lung tissue per minute. The distribution of pulmonary perfusion was determined by positron emission tomography. Regional PBF and MP, assessed in three iso-gravitational regions of interest (ROI) with equal lung mass (ventral, middle, and dorsal ROI), were compared between groups. Results: MP was higher in the LowPEEP than in the OLA group, while CO did not differ between groups. After 18 h, regional PBF did not differ between groups. During LowPEEP, regional MP was higher in the ventral ROI compared to OLA and HighPEEP groups (2.5 ± 0.3 vs. 1.4 ± 0.4 and 1.6 ± 0.3 J/min, respectively, P < 0.001 each), and higher in the middle ROI compared to the OLA group (2.5 ± 0.4 vs. 1.6 ± 0.5 J/min, P = 0.04). MP in the dorsal ROI did not differ between groups (1.4 ± 0.9 vs. 1.4 ± 0.5 vs. 1.3 ± 0.8 J/min, P = 0.916). Total MP was independently associated with CO [0.34 (0.09, 0.59), P = 0.020]. Regional MP was positively associated with PBF irrespective of the regions [0.52 (0.14, 0.76), P = 0.01; 0.49 (0.10, 0.74), P = 0.016; 0.64 (0.32, 0.83), P = 0.001 for ventral, middle, and dorsal ROI, respectively]. Subgroup analysis revealed a significant association of MP and CO only in the OLA group as well as a significant association between MP with regional PBF only in the HighPEEP group. Conclusion: In this model of acute lung injury in pigs ventilated with either open lung approach, high, or low PEEP tables recommended by the ARDS network, MP correlated positively with CO and regional PBF, whereby these clinically relevant lung-protective ventilation strategies influenced the associations. [ABSTRACT FROM AUTHOR]

Background: The radiation exposure of nuclear medicine personnel, especially concerning extremity doses, has been a significant focus over the past two decades. This study addresses the evolving practice of NM, particularly with the rise of radionuclide therapy and theranostic procedures, which involve a variety of radionuclides such as 68Ga, 177Lu, and 131I. Traditional studies have concentrated on common radioisotopes like 99mTc, 18F, and 90Y, but there is limited data on these radionuclides, which are more and more frequently used. This study, part of the European SINFONIA project, aims to fill this gap by providing new dosimetry data through a multicenter approach. The research monitors extremity doses to hands, eye lens doses, and whole-body doses in nuclear medicine staff handling 68Ga, 177Lu, and 131I. It examines the type of activities performed and the protective measures used. The study extrapolates measured doses to annual doses, comparing them with annual dose limits, and assesses the contribution of these specific procedures to the overall occupational dose of nuclear medicine personnel. Results: Measurements were conducted from November 2020 to August 2023 across nine hospitals. The highest whole-body, eye lens and extremity doses were observed for 68Ga. Average maximum extremity doses, normalized per manipulated activity, were found of 6200 µSv/GBq, 30 µSv/GBq and 260 µSV/GBq for 68Ga, 177Lu and 131I, respectively. Average whole-body doses stayed below 60 µSv/GBq for all 3 isotopes and below 200 µSv/GBq for the eye lens dose. The variation in doses also depends on the task performed. For 68Ga there is a risk of reaching the annual dose limit for skin dose during synthesis and dispensing. Conclusions: This study's measurement campaigns across various European countries have provided new and extensive occupational dosimetry data for nuclear medicine staff handling 68Ga, 177Lu and 131I radiopharmaceuticals. The results indicate that 68Ga contributes significantly to the global occupational dose, despite its relatively low usage compared to other isotopes. Staff working in radiopharmacy hot labs, labeling and dispensing 177Lu contribute less to the finger dose compared to other isotopes. [ABSTRACT FROM AUTHOR]

Background: Despite being essential in patients with acute respiratory distress syndrome (ARDS), mechanical ventilation (MV) may cause lung injury and hemodynamic instability. Mechanical power (MP) may describe the net injurious effects of MV, but whether it reflects the hemodynamic effects of MV is currently unclear. We hypothesized that MP is also associated with cardiac output (CO) and pulmonary blood flow (PBF). Methods: 24 anesthetized pigs with experimental acute lung injury were ventilated for 18 h according to one of three strategies: 1) Open lung approach (OLA), 2) ARDS Network high-PEEP/FIO2 strategy (HighPEEP), or 3) low-PEEP/FIO2 strategy (LowPEEP). Total MP was assessed as the sum of energy dissipated to overcome airway resistance and energy temporarily stored in the elastic lung tissue per minute. The distribution of pulmonary perfusion was determined by positron emission tomography. Regional PBF and MP, assessed in three iso-gravitational regions of interest (ROI) with equal lung mass (ventral, middle, and dorsal ROI), were compared between groups. Results: MP was higher in the LowPEEP than in the OLA group, while CO did not differ between groups. After 18 h, regional PBF did not differ between groups. During LowPEEP, regional MP was higher in the ventral ROI compared to OLA and HighPEEP groups (2. 5 ± 0. 3 vs. 1. 4 ± 0. 4 and 1. 6 ± 0. 3 J/min, respectively, P < 0. 001 each), and higher in the middle ROI compared to the OLA group (2. 5 ± 0. 4 vs. 1. 6 ± 0. 5 J/min, P = 0. 04). MP in the dorsal ROI did not differ between groups (1. 4 ± 0. 9 vs. 1. 4 ± 0. 5 vs. 1. 3 ± 0. 8 J/min, P = 0. 916). Total MP was independently associated with CO [0. 34 (0. 09, 0. 59), P = 0. 020]. Regional MP was positively associated with PBF irrespective of the regions [0. 52 (0. 14, 0. 76), P = 0. 01; 0. 49 (0. 10, 0. 74), P = 0. 016; 0. 64 (0. 32, 0. 83), P = 0. 001 for ventral, middle, and dorsal ROI, respectively]. Subgroup analysis revealed a significant association of MP and CO only in the OLA group as well as a significant association between MP with regional PBF only in the HighPEEP group. Conclusion: In this model of acute lung injury in pigs ventilated with either open lung approach, high, or low PEEP tables recommended by the ARDS network, MP correlated positively with CO and regional PBF, whereby these clinically relevant lung-protective ventilation strategies influenced the associations. [ABSTRACT FROM AUTHOR]

Background: The timing of imaging for 68gallium (68Ga)-PSMA and 68Ga-DOTATOC are stated to be around 60 min post-injection (p.i.). In some lesions, late imaging (3–4 h p.i.) showed advantages. The aim of our evaluation was to demonstrate the relevance of an "early" late acquisition. Methods: We retrospectively evaluated 112 patients who underwent 68Ga-DOTATOC-PET/CT and 82 patients who underwent 68Ga-PSMA-PET/CT. The first scan was acquired 60 min (±15 min) after application. In cases of diagnostic ambiguity, a second scan was performed 30–60 min later. Pathological lesions were analyzed. Results: Almost half of all 68Ga-DOTATOC cases and about one-third of all 68Ga-PSMA examinations showed a change in findings due to the second acquisition. In total, 45.5% of neuroendocrine tumor (NET) patients and 66.7% of prostate cancer (PCa) patients showed relevant TNM classification changes. For 68Ga-PSMA, there were significant increases in sensitivity and specificity from 81.8% to 95.7% and from 66.7% to 100%, respectively. Statistically significant improvements in sensitivity (from 53.3% to 93.3%) and specificity (from 54.6% to 86.4%) were demonstrated for NET patients. Conclusion: Early second images can improve diagnostics with 68Ga-DOTATOC and 68Ga-PSMA PET/CT. [ABSTRACT FROM AUTHOR]

Prostate specific membrane antigen (PSMA) scanning is a sensitive method of prostate cancer detection. In a 71 y.o. man with a PSA of 49 (6%F), 4 negative MRI studies and 6 negative biopsies over an 8 year interval, a 68Ga-PSMA PET/CT scan showed a PSMA-avid spot in the prostate. Using image fusion technology, the lesion was target-biopsied and Gleason 3 + 4 = 7 (cancer core length of 12 mm) was identified. This case may herald a new application for PSMA scanning and prostate cancer imaging.

Background: The timing of imaging for 68gallium (68Ga)-PSMA and 68Ga-DOTATOC are stated to be around 60 min post-injection (p.i.). In some lesions, late imaging (3–4 h p.i.) showed advantages. The aim of our evaluation was to demonstrate the relevance of an “early” late acquisition. Methods: We retrospectively evaluated 112 patients who underwent 68Ga-DOTATOC-PET/CT and 82 patients who underwent 68Ga-PSMA-PET/CT. The first scan was acquired 60 min (±15 min) after application. In cases of diagnostic ambiguity, a second scan was performed 30–60 min later. Pathological lesions were analyzed. Results: Almost half of all 68Ga-DOTATOC cases and about one-third of all 68Ga-PSMA examinations showed a change in findings due to the second acquisition. In total, 45.5% of neuroendocrine tumor (NET) patients and 66.7% of prostate cancer (PCa) patients showed relevant TNM classification changes. For 68Ga-PSMA, there were significant increases in sensitivity and specificity from 81.8% to 95.7% and from 66.7% to 100%, respectively. Statistically significant improvements in sensitivity (from 53.3% to 93.3%) and specificity (from 54.6% to 86.4%) were demonstrated for NET patients. Conclusion: Early second images can improve diagnostics with 68Ga-DOTATOC and 68Ga-PSMA PET/CT.

The biochemical relapse of prostate cancer is diagnostically challenging but of high clinical impact for subsequent patient treatment. PET/CT with radiolabeled PSMA ligands outperforms conventional diagnostic methods in the detection of tumor recurrence. Several radiopharmaceuticals were and are available for use. The aim of this study was to investigate whether the routinely applied [68Ga]Ga-PSMA ligands PSMA-617, -I&T and -11 (HBED-CC) differ in physiological and pathological distribution, or in tumor detection rate. A retrospective evaluation of 190 patients (39 patients received PSMA-617, 68 patients PSMA-I&T and 83 patients PSMA-11) showed significant differences in tracer accumulation within all organs examined. The low retention within the compartments blood pool, bone and muscle tissue is a theoretical advantage of PSMA-11. Evaluation of tumor lesion uptake and detection rate did not reveal superiority of one of the three radiopharmaceuticals, neither in the whole population, nor in particularly challenging subgroups like patients with very low PSA levels. We conclude that all three [68Ga]Ga-PSMA ligands are equally feasible in this clinically important scenario, and may replace each other in case of unavailability or production restrictions.

Nano chitosan was extracted from shrimp wastes. Biotin, as a tumor-targeting agent, and curcumin, as potential carriers of 68Ga, were immobilized on the nano chitosan, and a novel bio-nanocomposite was designed. It was characterized by FT-IR, SEM, TEM, XRD, TGA, and elemental analysis. It seems that the chitosan has a fibril shape with an average size of 70 nm, and the biotin and curcumin are evenly distributed as obtained SEM images. While, the size of Chit/Cur@Biot bio-nanocomposite was between 10 and 20 nm according to the TEM images. Cell cytotoxicity assay, cellular uptake, and fluorescence spectroscopy on A549 lung cancer cells were performed to show the potential applications of this bio-nanocomposite. The obtained results were demonstrated that Chit/Cur and Chit/Cur@Biot bio-nanocomposite exhibit antitumor activity, while, the Chit/Cur@Biot bio-nanocomposite is more effective than Chit/Cur against cancer cell lines at high concentrations. The results of fluoresce microscopy show that fluoresce of Chit/Cur@Biot was much stronger than Chit/Cur in the A549 cell lines. Moreover, the cellular uptake of Chit/Cur@Biot was enhanced when compared with the control group. The potentials of this bio-nanocomposite as anticancer and cancer-detecting agent in nuclear medicine were confirmed. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the effect of combined 68Ga and 18F-FDG PET/CT on treatment management for patients with pancreatic neuroendocrine tumor (PNET). Methods: Between January 2012 and April 2014, 49 consecutive patients with a cytologically and/or histologically proven diagnosis of PNET underwent combined 68Ga and 18FDG PET/CT on the same day. Results: The study group consisted of 21 males and 28 females with a median age of 59 years. Disease detection was achieved in 48 out of the 49 cases with 68Ga imaging, and in 36 of the 49 cases with 18FDG PET/CT. These results corresponded to sensitivities of 98% for 68Ga versus 73% for 18FDG PET/CT. Patients with NET-G1/NET-G2 had a positive 68Ga and negative 18FDG PET/CT in 13 cases, whereas both 68Ga and 18FDG PET/CT were positive in 27 cases. Patients with NEC-G3 were positive by both 68Ga and 18FDG PET/CT in 7 cases and positive only by 18FDG in 1 case. Another NEC-G3 patient was only positive by 68Ga PET/CT. The median Ki67 was 7% for 68Ga PET/CT-positive tumors and 10% for tumors with both 68Ga and 18FDG PET/CT positivity (p = 0.130). Half of the patients with a prevalent uptake of 18FDG (n = 7) had an NEC-G3 compared with 12% of patients with a prevalent uptake of 68Ga (p = 0.012). There were no significant differences between patients with positive 68Ga and those with positive 18FDG with regards to treatment choice. Conclusions: The association of 18FDG slightly increases sensitivity of 68Ga PET/CT alone in the diagnosis of PNET. A combined dual tracer PET/CT does not influence the choice of treatment strategy. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Detection of neuroendocrine tumor (NET) disease progression is a key issue in determining management. Currently, assessment is by imaging (MRI/CT and Octreoscan®) and plasma Chromogranin A (CgA) measurement. Case presentation: We report use of a NET-specific multigene PCR-derived blood transcript signature (NET Index) to assess disease and correlated CgA and gene transcripts with MRI, CT, Octreoscan®, 11C-5HTP-PET/CT and 68Ga-DOTA-PET/CT in a patient with NET. Conclusions: Our results identify limitations in evaluating disease status by CgA and identify that a PCR-based test is more sensitive. Alteration in NET blood gene transcript levels prior to image-based tumor confirmation suggests this parameter may also have utility as an index of therapeutic efficacy. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Human antimicrobial peptides are of interest for the development of positron emission tomography (PET) tracers as they exhibit desirable characteristics that make them good candidates for targeting vectors. Due to their natural role in the innate immune system they selectively bind to pathogenic bacteria and yeast, whilst remaining minimally immunogenic and cytotoxic to humans. Research into ubiquicidin (UBI)-based tracers has focused on 99mTc as a radionuclide, however, the use of bi-functional chelators such as 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), in combination with 68Ga as a radionuclide, allows for a simple radiolabeling procedure which is preferable in a clinical setting using PET/CT. Methods: The peptides fragments UBI29-41, UBI30-41 were synthesized by standard microwave Fmoc/tert-butyl (tBu)-solid phase synthetic protocols. Characterizations were performed using analytical HPLC and LC/MS. Both NOTA-conjugated peptides were exposed to natGa3+; their complexed form was quantified by direct LC/MS injection. This complexation was utilized to testify bacterial and mammalian cell binding potential of fluorophore-linked NOTA-UBI29-41/30-41. 68Ga labeled NOTA-UBI fragments were also tested for competitive interaction to Staphylococcus aureus to proof the binding target. 68Ga was eluted from SnO2- and TiO2-based 68Ge/68Ga generators using fractionated elution and anion exchanged-based post-procession. NOTA-peptide radiolabeling was carried out including optimization of buffer molarity, NOTA-peptide concentration(s), incubation temperature and –duration as well as considering various SPE purification cartridges. Results: Pure UBI29-41, UBI30-41 and NOTA-UBI30-41 were successfully characterized. Both, NOTA-UBI fragments exhibited complexation rates to natGa3+ ≥99%. The percentage binding was significantly higher to Staphylococcus aureus bacilli over Mt4 human leucocytes (P>0.05) for NOTA-UBI29-41[Lys(Abz)]0.03) after pre-incubation with excess unlabeled NOTA-UBI. Reproducible 68Ga radiolabeling ranged for 51–85% and 46–78% for NOTA-UBI29-41 and NOTA-UBI30-41, respectively. Conclusion: Aside from successful peptide syntheses the first ever 68Ga-radiolabeling method is reported for NOTA-UBI fragments. The NOTA-conjugation didn’t compromise the selective and specific interaction with bacterial cells in vitro. Both tracers are warranting prospective imaging of infection with PET/CT. [Copyright &y& Elsevier]

Introduction: Expression of vascular adhesion protein-1 (VAP-1) is induced at the sites of inflammation where extravasation of leukocytes from blood to the peripheral tissue occurs. VAP-1 is a potential target for anti-inflammatory therapy and for in vivo imaging of inflammation. Purpose of this study was to preliminarily evaluate a novel VAP-1-targeting peptide as a potential PET imaging agent. Methods: Cyclic 17-amino-acid peptide selected from phage display libraries was 1,4,7,10-tetraazacyclododecane-N,N′,N′′,N′′′-tetraacetic acid (DOTA) conjugated via 8-amino-3,6-diooxaoctanoyl linker (polyethylene glycol, PEG derivative) and labelled with 68Ga (68Ga-DOTAVAP-PEG-P2). In vitro stability of 68Ga-DOTAVAP-PEG-P2 was determined in saline, rat plasma and human plasma by radio-HLPC. Lipophilicity was measured by calculating octanol-water partition coefficient (log P). Whole-body distribution kinetics and stability after intravenous injection in healthy rats was studied in vivo by PET imaging, ex vivo by measuring radioactivity of excised tissues, and by radio-HPLC. Results: In vitro the 68Ga-DOTAVAP-PEG-P2 remained stable >4 h in saline and rat plasma, but degraded slowly in human plasma after 2 h of incubation. The log P value of 68Ga-DOTAVAP-PEG-P2 was −1·3. In rats, 68Ga-radioactivity cleared rapidly from blood circulation and excreted quickly in urine. At 120 min after injection the fraction of intact 68Ga-DOTAVAP-PEG-P2 were 77 ± 6·0% and 99 ± 1·0% in rat plasma and urine, respectively. Conclusions: These basic and essential in vitro and in vivo studies of the new VAP-1 targeting peptide revealed promising properties for an imaging agent. Further investigations to clarify in vivo VAP-1 targeting are warranted. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Vascular adhesion protein-1 (VAP-1) is an infection/inflammation-inducible endothelial glycoprotein. Based on our previous studies, the most VAP-1-selective peptide (VAP-P1) was 1,4,7,10-tetraazacyclododecane-N′,N″,N‴,N⁗-tetraacetic acid (DOTA)-conjugated, 68gallium (68Ga)-labeled (named [68Ga]DOTAVAP-P1) and evaluated preliminarily. Methods: Targeting was evaluated by using VAP-1-transfected cells. Biodistribution of [68Ga]DOTAVAP-P1 was studied by positron emission tomography imaging of healthy rats and rats with bone inflammation caused by Staphylococcus aureus infection. Uptake of [68Ga]DOTAVAP-P1 in osteomyelitis was compared with negative control peptide and competition with an excess of unlabeled DOTAVAP-P1. Results: [68Ga]DOTAVAP-P1 bound more efficiently to VAP-1-transfected cells than to controls. In rats, [68Ga]DOTAVAP-P1 cleared rapidly from blood circulation, excreted quickly in urine and showed an in vivo half-life of 26±2.3 min. Imaging of osteomyelitis demonstrated modest target-to-background ratio. Studies with the negative control peptide and competitors revealed a significantly lower uptake at the infection site compared to [68Ga]DOTAVAP-P1. Conclusions: The results represent a proof-of-concept that infection-induced VAP-1 can be targeted by [68Ga]DOTA peptide. [68Ga]DOTAVAP-P1 is just the first candidate peptide and an essential opening for developing VAP-1-specific imaging agents. [Copyright &y& Elsevier]

The biochemical relapse of prostate cancer is diagnostically challenging but of high clinical impact for subsequent patient treatment. PET/CT with radiolabeled PSMA ligands outperforms conventional diagnostic methods in the detection of tumor recurrence. Several radiopharmaceuticals were and are available for use. The aim of this study was to investigate whether the routinely applied [68Ga]Ga-PSMA ligands PSMA-617, -I&T and -11 (HBED-CC) differ in physiological and pathological distribution, or in tumor detection rate. A retrospective evaluation of 190 patients (39 patients received PSMA-617, 68 patients PSMA-I&T and 83 patients PSMA-11) showed significant differences in tracer accumulation within all organs examined. The low retention within the compartments blood pool, bone and muscle tissue is a theoretical advantage of PSMA-11. Evaluation of tumor lesion uptake and detection rate did not reveal superiority of one of the three radiopharmaceuticals, neither in the whole population, nor in particularly challenging subgroups like patients with very low PSA levels. We conclude that all three [68Ga]Ga-PSMA ligands are equally feasible in this clinically important scenario, and may replace each other in case of unavailability or production restrictions. [ABSTRACT FROM AUTHOR]

The interest in (68)Gallium labeled PET probes continues to increase around the world. Widespread use in Europe and Asia has led to great interest for use at numerous sites in the US. One barrier to entry is the cost of the automated synthesis units for relatively simple labeling procedures. We describe the construction and testing of a relatively low-cost automated (68)Ga-labeling unit for human-use. We provide a guide for construction, including part lists and synthesis timelists to facilitate local implementation. Such inexpensive systems could help increase use around the globe and in the US in particular by removing one of the barriers to greater widespread availability. The developed automated synthesis unit reproducibly synthesized (68)Ga-DOTATOC with average yield of 71 ± 8% and a radiochemical purity ≥ 95% in a synthesis time of 25 ± 1 minutes. Automated product yields are comparable to that of manual synthesis. We demonstrate in-house construction and use of a low-cost automated synthesis unit for labeling of DOTATOC and similar peptides with (68)Gallium.

Over the past several years, Positron Emission Tomography (PET) imaging agents labeled with ;68Gallium (68Ga) have undergone a significant increase in clinical utilization. 68Ga is conveniently produced from a germanium-68/gallium-68 (68Ge/68Ga) generator. Because of the compact size and ease of use of the generator, 68Ga labeled compounds may be more cost-effective than PET radioisotopes that are cyclotron-produced. The convenient half-life of 68Ga (T1/2=68 min) provides sufficient radioactivity for various PET imaging applications, while delivering acceptable radiation doses to patients. This chapter summarizes the emerging clinical utilization of 68Ga-based radiotracers in medical imaging., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)