A robust lyophilized kit for convenient one-step formulation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 in hospital radiopharmacy for clinical PET imaging.

The present article describes the development of robust lyophilized kit for convenient formulation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 (E = glutamic acid, R = arginine, G = glycine, D = aspartic acid, f = phenylalanine, K = lysine) radiopharmaceutical for clinical use in non-invasive monitoring of malignancies overexpressing integrin αvß3 receptors. Five batches of the kit were prepared with optimized kit contents, all of which showed high 68Ga-radiolabeling yield (>98%). Pre-clinical evaluation of the [68Ga]Ga-radiotracer in SCID mice bearing FTC133 tumour exhibited significant accumulation in the tumor xenograft. Preliminary human clinical investigation carried out in a 60 year old male patient with metastatic lung cancer revealed high radiotracer uptake in the tumor along with satisfactory target to non-target contrast. The developed kit formulation also showed a long shelf-life of at least 12 months on storage at 0 °C. All these results point towards the promising attributes of the developed kit formulation for convenient preparation of [68Ga]Ga-DOTA-E-[c(RGDfK)]2 for routine clinical use.

Empirical 188Re-HDD/lipiodol intra-arterial therapy based on tumor volume, in patients with solitary inoperable hepatocellular carcinoma.

OBJECTIVE: This study aimed to assess the potential benefits and tolerability of an empirical dose of approximately 0.8-1.2 mCi (29.6-44.4 MBq) of Re-4-hexadecyl-1-2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol/lipiodol (Re-HDD/lipiodol) per milliliter of tumor volume, administered after super-selection of the tumor feeding branches of hepatic artery for treatment of inoperable hepatocellular carcinoma (HCC). METHODS: Patients with advanced HCC or classified as inoperable, with no demonstrated extrahepatic disease and no significant comorbidities were eligible. The patients selected for this study had a single tumoral lesion, measuring less than 150 cc. The range of total activity administered was between 30 and 100 mCi (1.2-3.7) GBq Re-HDD/lipiodol, administered in the super selected branches of the hepatic artery supplying the tumor in 42 Patients. Whole-body scintigraphies and single-photon emission computed tomography-computed tomography (SPECT-CT) of the liver including tumor were performed at four-time points after injection. Absorbed doses to the various organs were calculated according to the Medical Internal Radiation Dose formalism. Blood and urine samples were collected at multiple time points until 72 h after injection. Hematological, hepatic and pulmonary toxicity was assessed until 12 weeks after administration using the Common Toxicity Criteria for Adverse Events (version 3.0) scale. Responses were evaluated on contrast enhanced computed tomography (CECT) and by alfa-fetoprotein (AFP) level monitoring. RESULTS: About 40.6 ± 4.8% of the injected activity was excreted in the urine by 72 h after injection. The mean absorbed dose to the liver, lungs, stomach, kidney and intestine was 14.4 ± 1.8, 4.8 ± 0.6, 5.5 ± 1.1, 5.1 ± 0.7, and 6.5 ± 1.0 Gy (mean ± SD), respectively. Up to 6 days after administration, 26 of 44 patients had adverse events consisting of aggravations of preexisting laboratory changes (24 patients), fatigue (5 patients), vomiting (6 patients), fever (2 patients), right hypochondrial pain (8 patients), and pain at site of femoral catheter insertion (8 patients). Toxicity assessment at weeks 6 and 12 revealed two cases of mild worsening of liver function tests and no lung or hematological toxicity noted. Two patients were lost to follow-up after the 6-week visit. The response was assessed on CECT in all the remaining patients and the classification of results was more standardized when using European Association for the Study of the Liver (EASL) criteria rather than response evaluation criteria in solid tumors (RECIST) criteria. According to EASL criteria, 8 patients had a partial response, 28 patients had a complete response, 4 patients had progressive disease and 4 patients with stable disease were reported. Thirty-six patients had a baseline elevated AFP and on follow-up at 6 weeks, 6 of these patients showed stable AFP, progression in 4 patients and 26 showed a reduction. CONCLUSION: After the administration of 1.2-3.7 GBq Re-HDD/lipiodol based on empirical activity calculation of 0.8-1.2 mCi/mL of tumor volume, more than half of the patients in the present study had an objective response on imaging and biochemically. No significant adverse side effects were noted and most of the laboratory markers as well as symptoms returned to normal after 48-72 h post-administration. Selective administration of the radiopharmaceutical into the tumor feeding arteries gives a good anti-tumoral effect with minimal side effects and damage to surrounding normal liver tissue.

Clinical utility of 188Rhenium-hydroxyethylidene-1,1-diphosphonate as a bone pain palliative in multiple malignancies.

188Rhenium-hydroxyethylidene-1,1-diphosphonate (188Re-HEDP) is a clinically established radiopharmaceutical for bone pain palliation of patients with metastatic bone cancer. Herein, the effectiveness of 188Re-HEDP for the palliation of painful bone metastases was investigated in an uncontrolled initial trial in 48 patients with different types of advanced cancers. A group of 48 patients with painful bone metastases of lung, prostate, breast, renal, and bladder cancer was treated with 2.96-4.44 GBq of 188Re-HEDP. The overall response rate in this group of patients was 89.5%, and their mean visual analog scale score showed a reduction from 9.1 to 5.3 (P < 0.003) after 1 week posttherapy. The patients did not report serious adverse effects either during intravenous administration or within 24 h postadministration of 188Re-HEDP. Flare reaction was observed in 54.2% of patients between day 1 and day 3. There was no correlation between flare reaction and response to therapy (P < 0.05). Although bone marrow suppression was observed in patients receiving higher doses of 188Re-HEDP, it did not result in any significant clinical problems. The present study confirmed the clinical utility and cost-effectiveness of 188Re-HEDP for palliation of painful bone metastases from various types of cancer in developing countries.

68Ga-NOTA-ubiquicidin fragment for PET imaging of infection: From bench to bedside.

This study explores the possibility of formulation of a cold kit for fast and easy preparation of a PET radiopharmaceutical, 68Ga-NOTA-UBI (29-41) for clinical translation. In this study, Circular dichroism (CD) spectroscopy to study conformation of NOTA-UBI (29-41) and its comparison with conformation of UBI (29-41) was done. Pharmaceutical grade cold kits of NOTA-UBI (29-41) were formulated for radiolabeling with 68Ga and necessary quality control tests were carried out. 68Ga-NOTA-UBI (29-41) could be prepared in >90% radiochemical yield and radiochemical purity using cold kits of NOTA-UBI (29-41). In vitro and in vivo evaluation of 68Ga-NOTA-UBI (29-41) was done to demonstrate specificity of the agent for imaging infection. Kits were utilized for preparation of patient dose of 68Ga-NOTA-UBI (29-41). Simple instant thin layer chromatography (ITLC) method for estimating radiolabeling yield of 68Ga-NOTA-UBI (29-41) at hospital radiopharmacy was demonstrated. Clinical evaluation was done in patients with suspected infection. 148-185 MBq of 68Ga-NOTA-UBI (29-41) was injected intravenously in three patients. 68Ga-NOTA-UBI (29-41) uptake could clearly delineate infection foci from non target normal tissues. This is the first report on formulation of a cold kit of NOTA-UBI (29-41) for preparation of 68Ga labeled NOTA-UBI(29-41) at hospital radiopharmacy for infection imaging. Initial clinical evaluation reveal it to be a prospective agent for imaging infection.

A "mix-and-use" approach for formulation of human clinical doses of 177 Lu-DOTMP at hospital radiopharmacy for management of pain arising from skeletal metastases.

Use of bone-seeking radiopharmaceuticals is an established modality in the palliative care of pain due to skeletal metastases. 177 Lu-DOTMP is a promising radiopharmaceutical for this application owing to the ideally suited decay properties of 177 Lu and excellent thermodynamic stability and kinetic rigidity of the macrocyclic complex. The aim of the present study is to develop a robust and easily adaptable protocol for formulation of clinical doses of 177 Lu-DOTMP at hospital radiopharmacy. After extensive radiochemical studies, an optimized strategy for formulation of clinical doses of 177 Lu-DOTMP was developed, which involves simple mixing of approximately 3.7 GBq of 177 Lu activity as 177 LuCl3 solution to an aqueous solution containing 5 mg of DOTMP and 8 mg of NaHCO3 . The proposed protocol yielded 177 Lu-DOTMP with >98% radiochemical purity, and the resultant formulation showed excellent in vitro stability and desired pharmacokinetic properties in animal model. Preliminary clinical investigations in 5 patients showed specific skeletal accumulation with preferential localization in the osteoblastic lesion sites and almost no uptake in soft tissue or any other major nontarget organ. The developed "mix-and-use" strategy would be useful for large number of nuclear medicine centers having access to 177 Lu activity and would thereby accelerate the clinical translation of 177 Lu-DOTMP.

Preliminary PET/CT Imaging with Somatostatin Analogs [68Ga]DOTAGA-TATE and [68Ga]DOTAGA-TOC.

PURPOSE: Somatostatin receptor positron emission tomography/X-ray computed tomography (SSTR-PET/CT) is a well-established technique for staging and detection of neuroendocrine tumors (NETs). Ga-68-labeled DOTA-conjugated octreotide analogs are the privileged radiotracers for diagnosis and therapeutic monitoring of NETs. Hence, we were interested in assessing the influence of promising, newer variant DOTAGA on the hydrophilicity, pharmacokinetics, and lesion pick-up of somatostatin analogs. Herein, the potential of ([68Ga]DOTAGA, Tyr3, Thr8) octreotide ([68Ga]DOTAGA-TATE) and ([68Ga]DOTAGA, Tyr3) octreotide ([68Ga]DOTAGA-TOC) as NET imaging agents has been investigated. PROCEDURES: Amenability of [68Ga]DOTAGA-(TATE/TOC) to kit-type formulation has been demonstrated. Biodistribution studies were carried out in normal rats at 1 h post-injection (p.i.). [68Ga]DOTAGA-(TATE/TOC) PET/CT scans were carried out in patients (70-170 MBq, 1 h p.i.) with histologically confirmed well-differentiated NETs. RESULTS: [68Ga]DOTAGA-TATE exhibited hydrophilicity similar to [68Ga]DOTA-TATE (log P = -3.51 vs -3.69) whereas [68Ga]DOTAGA-TOC was more hydrophilic than [68Ga]DOTA-TOC (log P = -3.27 vs -2.93). [68Ga]DOTAGA-TATE and [68Ga]DOTA-TATE showed almost identical blood and kidney uptake in normal rats whereas significantly fast clearance (p < 0.05) of [68Ga]DOTAGA-TATE was observed from other non-specific organs (liver, lungs, spleen, intestine). [68Ga]DOTAGA-TOC also demonstrated rapid clearance from blood and kidneys (p < 0.05) in comparison to [68Ga]DOTA-TOC. The metastatic lesions in NET patients were well identified by [68Ga]DOTAGA-TATE and [68Ga]DOTAGA-TOC. CONCLUSION: The phenomenal analogy was observed between [68Ga]DOTAGA-TATE and [68Ga]DOTA-TATE as well as between [68Ga]DOTAGA-TOC and [68Ga]DOTA-TOC in biodistribution studies in rats. The good lesion detection ability of the two radiotracers indicates their potential as NET imaging radiotracers.

Convenient Preparation of [(68)Ga]DKFZ-PSMA-11 Using a Robust Single-Vial Kit and Demonstration of Its Clinical Efficacy.

PURPOSE: [(68)Ga]DKFZ-PSMA-11 has proved to be an important diagnostic radiotracer for targeting prostate-specific membrane antigen (PSMA) overexpression in both recurrent prostate cancer (PC) and relevant metastatic sites. However, the widespread, routine clinical use of such a potential radiopharmaceutical demands availability of a ready-to-use kit formulation to enable convenient radiopharmaceutical preparation. Herein, we report the development of a freeze-dried kit vial for the formulation of [(68)Ga]DKFZ-PSMA-11 and its clinical use in patients using a "shake-bake-inject" methodology. PROCEDURES: The freeze-dried kit vial was developed after optimization of ligand content (PSMA-11) and pH conditions. The kit was formulated using (68)Ga from two different commercially available generators. Positron emission tomography/X-ray computed tomography (PET/CT) images of PC patients were obtained using the kit-formulated radiotracer. RESULTS: [(68)Ga]DKFZ-PSMA-11 was prepared in >98 % radiochemical yield and purity using the freeze-dried kit vials. Kits were optimized for the preparation of four patient doses. The clinical utility was evaluated in patients with histologically confirmed prostate cancer, and the images were of good quality as well as conforming to tumor marker and clinical expectations. CONCLUSION: The development of a simple and ready-to-use freeze-dried DKFZ-PSMA-11 kit for the preparation of Ga-68-based radiotracers constitutes a major step towards the expedition of the widespread and economical screening of PC patients.

Utility of (99m)Tc-Hynic-TOC in 131I Whole-Body Scan Negative Thyroid Cancer Patients with Elevated Serum Thyroglobulin Levels.

Several studies have reported on the expression of somatostatin receptors (SSTRs) in patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the imaging abilities of a recently developed Technetium-99m labeled somatostatin analog, (99m)Tc-Hynic-TOC, in terms of precise localization of the disease. The study population consisted of 28 patients (16 men, 12 women; age range: 39-72 years) with histologically confirmed DTC, who presented with recurrent or persistent disease as indicated by elevated serum thyroglobulin (Tg) levels after initial treatment (serum Tg > 10 ng/ml off T4 suppression for 4-6 weeks). All patients were negative on the Iodine-131 posttherapy whole-body scans. Fluorine-18 fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) was performed in all patients. SSTR scintigraphy was true positive in 23 cases (82.1%), true negative in two cases (7.1%) and false negative in three cases (10.7%) which resulted in a sensitivity of 88.46%, specificity of 100% and an accuracy of 89.2%. Sensitivity of (99m)Tc-Hynic-TOC scan was higher (93.7%) for patients with advanced stages, that is stages III and IV. (18)F-FDG showed a sensitivity of 93.7%, a specificity of 50% and an accuracy of 89.3%. (18)F-FDG PET was found to be more sensitive, with lower specificity due to false positive results in 2 patients. Analysis on a lesion basis demonstrated substantial agreement between the two imaging techniques with a Cohen's kappa of 0.66. Scintigraphy with (99m)Tc-Hynic-TOC might be a promising tool for treatment planning; it is easy to perform and showed sufficient accuracy for localization diagnostics in thyroid cancer patients with recurrent or metastatic disease.

Radiosynovectomy of Painful Synovitis of Knee Joints Due to Rheumatoid Arthritis by Intra-Articular Administration of (177)Lu-Labeled Hydroxyapatite Particulates: First Human Study and Initial Indian Experience.

The aim of this study is to assess the effectiveness of Radiosynovectomy (RSV) using (177)Lu-labeled hydroxyapatite ((177)Lu-HA) in the treatment of painful synovitis and recurrent joint effusion of knee joints in rheumatoid arthritis (RA). Ten patients, diagnosed with RA and suffering from chronic painful resistant synovitis of the knee joints were referred for RSV. The joints were treated with 333 ± 46 MBq of (177)Lu-HA particles administered intra-articularly. Monitoring of activity distribution was performed by static imaging of knee joint and whole-body gamma imaging. The patients were evaluated clinically before RSV and at 6 months after the treatment by considering the pain improvement from baseline values in terms of a 100-point visual analog scale (VAS), the improvement of knee flexibility and the pain remission during the night. RSV response was classified as poor (VAS < 25), fair (VAS ≥ 25-50), good (VAS ≥ 50-75) and excellent (VAS ≥ 75), with excellent and good results considered to be success, while fair and poor as failure and also by range of motion. Three phase bone scan (BS) was repeated after 6 months and changes in the second phase of BS3 were assessed visually, using a four-degree scale and in the third phase, semiquantitatively with J/B ratio to see the response. Biochemical analysis of C-reactive protein (CRP) and fibrinogen was repeated after 48 h, 4 and 24 weeks. In all 10 patients, no leakage of administered activity to nontarget organs was visible in the whole-body scan. Static scans of the joint at 1 month revealed complete retention of (177)Lu-HA in the joints. All patients showed decreased joint swelling and pains, resulting in increased joint motion after 6 months. The percentage of VAS improvement from baseline values was 79.5 ± 20.0% 6 months after RS and found to be significantly related to patients' age (P = 0.01) and duration of the disease (P = 0.03). Knees with Steinbrocker's Grades 0 and I responded better than those with more advanced changes (Steinbrocker's Grades III and IV) in terms of VAS improvement (75% vs. 45.8%) (P < 0.001). The overall success rate (VAS ≥ 50) was 80%. Remission of pain during the night was achieved in 100%, and knee flexibility was improved in 80%. The changes in the blood pool phase before RSV were 3.2 ± 0.7 and after the therapy 1.4 ± 0.7 (P < 0.001). The J/B ratio was: Before RSV 2.4 ± 0.3; after treatment 1.0 ± 0.2 (P < 0.05). CRP concentration 4 and 24 weeks after the therapy was significantly lower than before treatment. The fibrinogen level was not different before and after RSV. RSV side-effects assessed for the whole follow-up period were minor and not significant. RSV with (177)Lu-HA was safe and effective in patients with knee joint chronic painful synovitis of rheumatoid origin. It exhibited significant therapeutic effect after 6 months follow-up period with no significant side-effects. The preliminary investigations reveal that (177)Lu-labeled HA particles hold considerable promise as a cost-effective agent for RSV. More elaborate and controlled clinical trials are necessary to evaluate the therapeutic efficacy and safety of the agent compared with the treatment with other radionuclides and glucocorticosteroids.

Radiochemistry, pre-clinical studies and first clinical investigation of 90Y-labeled hydroxyapatite (HA) particles prepared utilizing 90Y produced by (n,γ) route.

INTRODUCTION: The scope of using no carrier added (NCA) (90)Y [T(1/2) = 64.1 h, Eß(max) = 2.28 MeV] obtained from (90)Sr/(90)Y generator in radiation synovectomy (RSV) is widely accepted. In the present study, the prospect of using (90)Y produced by (n,γ) route in a medium flux research reactor for use in RSV was explored. METHODS: Yttrium-90 was produced by thermal neutron irradiation of Y(2)O(3) target at a neutron flux of ~1×10(14) n/cm(2).s for 14 d. The influence of various experimental parameters were systematically investigated and optimized to arrive at the most favorable conditions for the formulation of (90)Y labeled hydroxyapatite (HA) using HA particles of 1-10 µm size range. An optimized kit formulation strategy was developed for convenient one-step compounding of (90)Y-HA, which is easily adaptable at hospital radiopharmacy. The pre-clinical biological evaluation of (90)Y-HA particles was studied by carrying out biodistribution and bioluminiscence imaging studies in Wistar rats. The first clinical investigation using the radiolabeled preparation was performed on a patient suffering from chronic arthritis in knee joint by administering 185 MBq (90)Y-HA formulated at the hospital radiopharmacy deploying the proposed strategy. RESULTS: Yttrium-90 was produced with a specific activity of 851 ± 111 MBq/mg and radionuclidic purity of 99.95 ± 0.02%. (90)Y-labeled HA particles (185 ± 10 MBq doses) were formulated in high radiochemical purity (>99%) and excellent in vitro stability. The preparation showed promising results in pre-clinical studies carried out in Wistar rats. The preliminary results of the first clinical investigation of (90)Y-HA preparation in a patient with rheumatoid arthritis in knee joints demonstrated the effectiveness of the formulation prepared using (90)Y produced via (n,γ) route in the management of the disease. CONCLUSION: The studies revealed that effective utilization of (90)Y produced via (n,γ) route in a medium flux research reactor coupled with the developed strategy of using HA kits for convenient formulation of (90)Y-HA at the hospital radiopharmacy can contribute to sustainable growth in the clinical utilization of (90)Y in RSV in the foreseeable future.

Single vial freeze-dried TRODAT-1 kit: preparation and demonstration of clinical efficacy of [(99m)Tc]TRODAT-1 in Indian scenario.

A single vial freeze-dried kit formulation for preparation of three patients' dose of [(99m)Tc]TRODAT-1 has been developed for early diagnosis of Parkinson's disease (PD). Kits were evaluated to ascertain the purity, stability and batch to batch variations. Preclinical evaluation was carried out in laboratory animals and clinical imaging was performed in human patients with PD. The labeling yield and purity of [(99m)Tc]TRODAT-1 was >90%. Swiss mice showed retention of [(99m)Tc]TRODAT-1 in the mid brain region. Clinical studies showed decreased striatal uptake with increasing severity of PD.

Persistent high grade flurodeoxyglucose uptake in lipomatous hypertrophy of the interatrial septum on dual time point imaging and with ambient warming.

Lipomatous hypertrophy of the interatrial septum (LHIS) is a relatively uncommon disorder of the heart characterized by benign fatty infiltration of the interatrial septum that usually spares the fossa ovalis. LHIS showing flurodeoxyglucose uptake has been reported, and is presumed to be due to activated brown adipose tissue (BAT). We here report a case of a patient who had isolated mediastinal uptake in interatrial septum, mimicking metastasis. Rescanning with external warming to deactivate BAT and a delayed time point image was done, which showed persistent and progressively increasing metabolic uptake respectively, suggesting that LHIS uptake might be unrelated to activated BAT or inflammation.

"Hyperfrontality" as seen on FDG PET in unmedicated schizophrenia patients with positive symptoms.

INTRODUCTION: Decreased frontal activity has been reported widely in unmedicated schizophrenic patients with predominantly negative symptoms. Not many studies have assessed the frontal lobe status in unmedicated patients with positive symptoms. PATIENTS AND METHODS: Fifty-one patients with schizophrenia (all unmedicated, 38 never medicated) and 12 healthy age-matched controls were evaluated with FDG PET CT. The patients met ICD-10 and DSM-IV criteria for schizophrenia, and all reported psychotic, "positive" symptoms when tested. RESULTS: Schizophrenic patients with positive symptoms had a hypermetabolic frontal metabolic pattern on quantification by region to occipital ratio comparison. Associated statistically significant differences were also found when comparing ratios of occipital to thalamic, striatal and temporal cortex in schizophrenic patients. CONCLUSION: The finding of a hyperfrontality in unmedicated and never medicated psychotic schizophrenic patients is observed when there is a predominance of positive symptoms. There could be a possible disruption of cortico-striato-thalamic feedback loops causing hyperfrontality as seen in experimentally induced models of psychosis .

Preparation, evaluation, and first clinical use of 177Lu-labeled hydroxyapatite (HA) particles in the treatment of rheumatoid arthritis: utility of cold kits for convenient dose formulation at hospital radiopharmacy.

While radiation synovectomy (RSV) constitutes a successful paradigm for the treatment of arthritis, a major cornerstone of its success resides in the selection of appropriate radiolabeled agent. Among the radionuclide used for RSV, the scope of using (177)Lu [T1/2 = 6.65 d, Eß(max) = 497 keV, Eγ = 113 KeV (6.4%), 208 KeV (11%)] seemed to be attractive owing to its suitable decay characteristics, easy availability, and cost-effective production route. The present article describes a formulation of (177)Lu-labeled hydroxyapatite (HA) using ready-to-use kits of HA particles of 1-10 µm size range. The developed kits enable convenient one-step preparation of (177)Lu-HA (400 ± 30 MBq doses) in high radiochemical purity (>99%) and stability at hospital radiopharmacy. The preparation showed promising results in pre-clinical studies carried out in Wistar rats bearing arthritis in knee joints. In preliminary clinical investigation, significant improvement in the disease conditions was reported in 10 patients with rheumatoid arthritis of knee joints treated with 333 ± 46 MBq doses of (177)Lu-HA. The studies reveal that while (177)Lu labeled HA particles holds considerable promise as a cost-effective agent for RSV, the adopted strategy of using HA kits could be a potential step toward wider clinical utilization of radiolanthanide-labeled HA particles.

Preparation of therapeutic dose of 177Lu-DOTA-TATE using a novel single vial freeze-dried kit: a comparison with 'in-situ' preparation at hospital radiopharmacy.

OBJECTIVE: Patient dose of (177)Lu-DOTA-TATE, used for providing radiotherapeutic treatment to the patients suffering from cancers of neuroendocrine origin, could be prepared at the hospital radiopharmacy either 'in-situ' or by using freezedried kits. The objective of the present work is to formulate and evaluate a single vial freeze-dried DOTA-TATE kit, which is capable of producing up to 7.4 GBq (200 mCi) dose of (177)Lu-DOTA-TATE and to compare the two methodologies presently used for the preparation of the agent. EXPERIMENTAL: Freeze-dried DOTA-TATE kits, comprising a lyophilized mixture of DOTA-TATE, gentisic acid and ammonium acetate, were prepared and used for the formulation of patient doses of (177)Lu-DOTA-TATE. The kits were subjected to detailed radiochemical evaluation and the shelf-life of the kits was determined. The pharmacokinetic behavior of the agent was studied in normal Wistar rats. These kits were utilized for treating the patients suffering from various types of neuroendocrine cancers. RESULTS: The freeze-dried kits were used for the preparation of up to 7.4 GBq (200 mCi) therapeutic doses of (177)Lu- DOTA-TATE with a radiochemical purity of >99% and were found to have sufficiently long shelf-life. Biological studies carried out in normal Wistar rats exhibited no significant accumulation of activity in any of the vital organs/tissue except in kidneys and non-accumulated activity showed major renal clearance. Clinical studies carried out in cancer patients exhibited accumulation of activity in the cancerous lesions and metastatic sites. CONCLUSION: The kit was useful for the convenient preparation of therapeutic dose of (177)Lu-DOTA-TATE, suitable for human administration. The use of kit is expected to reduce the batch failure and radiation exposure to the working personnel.

Clinical utility of indigenously formulated single-vial lyophilized HYNIC-TOC kit in evaluating Gastro-entero Pancreatic neuro endocrine tumours.

OBJECTIVES: The objective of this study was to evaluate the performance and utility of (99m)Tc HYNIC-TOC planar scintigraphy and SPECT/CT in the diagnosis, staging and management of gastroenteropancreatic neuroendocrine tumors (GPNETs). METHODS: 22 patients (median age, 46 years) with histologically proven gastro- entero- pancreatic NETs underwent (99m)Tc HYNIC-TOC whole body scintigraphy and regional SPECT/CT as indicated. Scanning was performed after injection of 370-550 MBq (10-15 mCi) of (99m)Tc HYNIC-TOC intravenously. Images were evaluated by two experienced nuclear medicine physicians both qualitatively as well as semi quantitatively (tumor to background and tumor to normal liver ratios on SPECT -CT images). Results of SPECT/CT were compared with the results of conventional imaging. Histopathology results and follow-up somatostatin receptor scintigraphy with (99m)Tc HYNIC TOC or conventional imaging with biochemical markers were considered to be the reference standards. RESULTS: (99m)Tc HYNIC TOC showed sensitivity and specificity of 87.5% and 85.7%, respectively, for primary tumor and 100% and 86% for metastases. It was better than conventional imaging modalities for the detection of both primary tumor (P<0.001) and metastases (P<0.0001). It changed the management strategy in 6 patients (31.8%) and supported management decisions in 8 patients (36.3%). CONCLUSION: (99m)Tc HYNIC TOC SPECT/CT appears to be a highly sensitive and specific modality for the detection and staging of GPNETs. It is better than conventional imaging for the evaluation of GPNETs and can have a significant impact on patient management and planning further therapeutic options.

Empiric Therapy with Low-Dose I-131 in Differentiated Cancer Thyroid: What is the Magic Number?

Low dose radioactive iodine-131 (RAI) has been widely reported in the treatment of patients with differentiated thyroid cancer (DTC) since 1970's. However, the clinical outcomes, dosage of I-131 and criteria for successful ablation are different in various studies. The aim of this study was to assess clinical outcome 18-month after RAI therapy in selected DTC patients and identify factors associated with a good response. In this experimental study, among patients with DTC referred to the Nuclear Medicine Department and had an indication for RAI therapy in the period between December 2008 and January 2011, 108 subjects were selected randomly. The patients were randomly divided into three groups and empiric low dose therapy with 30, 50 or 75 mCi of I-131 was administered. Patients were monitored closely clinically and with serum thyroglobulin assays and I-131 whole-body scans at 6 monthly intervals for 18-month after treatment. Among 105 patients who completed follow-up, 86% were successfully ablated with a single low dose of I-131. There was no statistically significant difference in ablation rates in the subgroups receiving 30.50 or 75 mCi of I-131. Cumulative ablation rate was 99% in patients after the second dose of low dose therapy. If appropriate selection criteria are used in DTC, successful remnant ablation can be achieved with low doses of I-131 in the range of 30-75 mCi. No significant differences were found in results achieved with 30.50 or 75 mCi of I-131. As the majority of the DTC patients fall within the inclusion criteria of this study, they can be treated on an ambulatory basis with associated low cost, convenience, and low whole-body radiation-absorbed dose to the patients.