A limitation to the wider introduction of personalised dosimetry in theranostics is the relative paucity of imaging radionuclides with suitable physical and chemical properties to be paired with a long-lived therapeutic partner. As most of the betaemitting therapeutic radionuclides emit gamma radiation as well they could potentially be used as the imaging radionuclide as well as the therapeutic radionuclide. However, the downsides are that the beta radiation will deliver a significant radiation dose as part of the treatment planning procedure, and the gamma radiation branching ratio is often quite low. Gallium-67 has been in use in nuclear medicine for over 50 years. However, the tremendous interest in gallium imaging in theranostics in recent times has focused on the PET radionuclide gallium-68. In this article it is suggested that the longer-lived gallium-67, which has desirable characteristics for imaging with the gamma camera and a suitably long half-life to match biological timescales for drug uptake and turnover, has been overlooked, in particular, for treatment planning with radionuclide therapy. Gallium-67 could also allow non-PET facilities to participate in theranostic imaging prior to treatment or for monitoring response after therapy. Gallium-67 could play a niche role in the future development of personalised medicine with theranostics.

Introduction Gallium-67 (67Ga) has been used as a radionuclide for imaging a variety of solid tumors since 1969. Since then use of various gallium-based radiotracers has been reported. Recently, 67Ga-labeled acetylacetate bis(thiosemicarbazones) (67Ga-AATS) complex with significant tumor accumulation and fast blood clearance has been employed. Materials and Methods In this study, the absorbed dose of 67Ga-AATS in each human organ was evaluated and compared with 67Ga-citrate as the most commonly used form of 67Ga in nuclear medicine. 67Ga was produced via 68Zn(p, 2n)67Ga reaction at 30 MeV cyclotron. Moreover, 67Ga-AATS was produced by adding 50 μ l of AATS to absolute ethanol (1 mg/ml) in a gallium-containing vial at 80-90 ° C. The absorbed dose of each human organ was calculated, using RADAR method, based on biodistribution data in Wistar rats. Results According to the results, 67Ga-AATS was produced with radionuclidic and radiochemical purity higher than 99% and 93%, respectively. The highest absorbed dose was reported in the bone surface (0. 401 mGy/MBq), whereas the whole-body absorbed dose was 0. 092 mGy/MBq. Conclusion The absorbed dose of each human organ was comparable with the absorbed dose received by each organ after 67Ga-citrate injection. Considering this interesting finding and the significant tumor uptake, it seems that 67Ga-AATS can be used as an appropriate SPECT tracer.

Among the improvements in cancer management in recent years are impressive advances in the treatment of Hodgkin's disease (HD) and non-Hodgkin's lymphomas (NHL). Most patients with lymphomas can be treated curatively. Accurate diagnosis and proper selection of treatment and early assessment of response to therapy are to obtain the best outcome. So determination of stage of the disease is one of the major prognostic factors, which has important implications on therapeutic strategy and on prognosis. CT scan is considered the standard technique for anatomic localization of nodal disease sites. Unfortunately, the diagnosis of lymph node abnormalities with CT largely depends of lymph node size. Lymph nodes smaller than 10 mm are usually regarded as disease free. However normally sized lymph nodes may be diseased and in contrast, enlarged ones may be free of disease. In addition, sensitivity of CT for  extranodal lymphoma is not optimal, it may miss peripheral sites and the problem of differentiating residual tumor from a residual fibro tic mass is well documented. The Gallium -67 scan has traditionally had a well documented role in lymphoma, for disease staging, assessing treatment response, early detection of recurrent disease and providing prognostic information early during treatment. Ga-67 scan limitations are its low resolution and physiological biodistribution. The overall gallium scan positivity rate for Hodgkin's lymphoma is 85%-95% and for non-Hodgkin's lymphoma is 75%-90%. FDG (fluorodeoxyglucose) has high avidity for most types of lymphoma. Intensity of uptake on pretherapy staging has been reported to correlate with prognosis with higher uptake having poorer prognosis. The advantages of FDG-PET scan are its higher resolution and excellent capability of detecting multiple sites of primary and recurrent disease and differentiating viable lymphoma from a residual fibrotic mass post-treatment.

Breast cancer radioimmunoscintigraphy targeting HER2/neu expression is a growing field of work in nuclear medicine research. In this study, trastuzumab was successively labeled with [67Ga] GaCl3 after conjugation with DOTA-NHS-ester.The conjugates were purified by molecular filtration, the average number of DOTA conjugated per mAb was calculated and total concentration was determined by spectrophotometric method. DOTA-Trastuzumab was labeled with 67Ga. Radiochemical purity, integrity of protein after radiolabeling and stability of 67Ga-DOTA-Trastuzumab were determined followed by biodistribution studies in wild-type rats (30±5.5 mCi, 2, 4 and 24 h p.i.).The radioimmunoconjugate was prepared with a radiochemical purity of higher than 95% (RTLC). The average chelate to antibody ratio (c/a) for the conjugate used in this study was 5.8: 1. The final compound was stable in presence of PBS at 370C and room temperature. The sample was showed to have similar patterns of migration in the gel electrophoresis similar to the native protein. The accumulation of the radiolabeled antibody in liver, spleen, kidney, heart and other tissues demonstrates.67Ga-DOTA-Trastuzumab was prepared as a surrogate for important clinically applicable radionuclides used in SPECT and PET including In-111 and Cu-64 as a model of radiolabeling. It is also a potential compound for molecular imaging of SPECT for diagnosis and treatment studies and follow-up of HER2 expression in oncology.

Background: In order to obtain an anti-CD2O conjugate to be used in future therapeutic studies with therapeutic radioisotopes, 67Ga-labeled antibody wasprepared as a model of metal chelated immunoconjugate for preliminary dosimetric and biodistribution studies. Materials and Methods: Rituximab was labeled with [67Ga]-gallium chloride after residulation with freshly prepared cyclic DTPAdianhydride. The best results of the conjugation were obtained by the addition of 1 ml of a rituximab pharmaceutical solution (5 mg/ml, in phosphate buffer, pH=8) to a glass tube pre-coated with DTPA- dianhydride (0.01 mg) at 25oC with continuous mild stirring for 30 min. The final isotonic 67Ga-DTPArituximab complex was checked by gel electrophoresis for radiolysis/chemolysis control. Radio-TLC was performed to ensure the formation of only one species. Preliminary in vivo studies in normal rat model were performed to determine the biodistribution of the radioimmunoconjugate up to 6 hours. Results: Radio-thin layer chromatography showed an overall radiochemical purity of 96-99% at optimized conditions (specific activity =300-500 MBq/mg, labeling efficiency 77%). Gel electrophoresis showed no protein cleavage after radiolabeling. Conclusion: Preliminary in vivo studies in normal rat model showed [67Ga]-DTPA-rituximab is a good probe for bio-dosimetry of therapeutic rituximab conjugates.

Introduction: The aim of this work is Optimization of 67Ga-Oxine preparation in order to diagnostic purposes and cell labeling. The incorporation of Gallium-67 into 8-hydroxyquinoline was targeted for cell labeling due to interesting physical properties and wide availability of this nuclide as a single photon emission computed tomography (SPECT) radionuclide.Methods: Gallium-67 is a bioisoester of ferric iron with physical half-life of 3.3 days (78 hr) and biological half-life of 2-3 weeks. In this study, 67Ga was produced at a 30 MeV cyclotron (IBA-Cyclone 30) via the 68Zn (p, n) 67Ga reaction. Oxine has been labeled with this radionuclide in the form of [67Ga] gallium chloride for its possible diagnostic properties and the reaction conditions were optimized for time, temperature and reactant concentrations. In vitro white blood cell (WBC) labeling was also performed.Results: The [67Ga] oxine complex was obtained at pH=5.5 in acetate buffer medium at 25°C in 2 hours.Radio-TLC showed a radiochemical purity of more than 95 ± 2%. The chemical stability of the complex was checked in vitro with a specific activity of 1432 GBq/mmol. The labeled compound was used in WBC labeling. The cell uptake ratio was 0.12 after 120 min.Conclusion: [67Ga] (III) oxinate used in this study is a widely available agent for use in WBC labeling studies in biology, medicine and various other research areas.

This study reports the labeling of Gallium-Bleomycin (67Ga-BLM) complex as a radiopharmaceutical and optimization of its labeling conditions; pH, reaction time, temperature, concentration of bleomycin and its biodistribution in normal Bulb C mice. The biodistribution of the complex was compared with 67Ga-Cl3 in 11 selected organs including blood, liver, lung, spleen, muscle, skin, heart, kidney, colon, colon content, and bladder at five selected times of 1, 2, 4, 24 and 48 hours after injection. Cyclotron produced 67Gallium was labeled with bleomycin under Thakur method. The optimized pH condition was found 2 at temperature of 90 C for reaction temperature of 30 minutes when 0.5 mg of bleomycin was mixed with 1 mCi of 67Ga-Cl3. Pharmacokinetic data indicated higher uptakes of 67Ga-BLM in all 11 tissues except blood, liver and spleen in comparison with 67Ga-Cl3. The average of total uptakes from 67Ga-BLM and 67Ga-Cl3 radiopharmaceuticals at one hour after injection were 73.35% and 53.55% then reduced to 14.55% and 25.2% after 48 hours respectively. The blood uptake of 67Ga-Cl3 was higher than 67Ga-BLM in all time intervals. Bladder uptake of 67Ga-BLM was highest among 11 tissues at all time intervals but the uptake of 67Ga-Cl3 was only highest at first hour after the injection. The results indicated the high stability of the complex both in-vitro and in-vivo, and yet excreted faster than carrier free 67Gallium. The effective half life of 67Ga-BLM complex was found 48.15 hours.

Introduction: Cardiovascular disease is the major cause of morbidity and mortality in developing and developed countries. Rapid diagnosis of the thrombosis can be an essential step in management of thestroke.Methods: In this work a recently developed radiolabeled streptokinase (STP) tracer was evaluated in an animal thrombotic model using SPECT imaging and biodistribution studies. Locally labeled [67Ga]- Streptokinase was checked by ITLC, HPLC and SDS-PAGE experiments to check the tracer integrity and purity. The biodistribution studies were performed in thrombotic femoral vein of rats using tissue counting and preliminary SPECT studies, respectively (up to 2 h).Results: [67Ga]-Streptokinase prepared with suitable radiochemical purity (HPLC >95%, ITLC >99%) was administered to FeCl3 induced thrombotic rats and the percentage of injected dose per gram of tissue (ID/g%) as well as the SPECT images demonstrated the good specific binding of the tracer in thrombotic clots located in heart and aorta 2 hours post injection.Conclusion: [67Ga]-DTPA-STP can be a suitable probe for imaging of thrombosis in cardiovascular diseases. Ga-68 labeled STP has the potential to be an alternative superior labeled compound due to positron emission properties for PET studies as well as appropriate physical half life.