[show abstract][hide abstract] ABSTRACT: Subdural hygroma is the collection of cerebrospinal fluid in the subdural space. Most often these resolve spontaneously. However, in cases with neurological complications surgical drainage may be needed. We here, present the case of an 8-year-old boy with post meningitis subdural hygroma. (99m)Tc-ehylene cysteine dimer ((99m)Tc-ECD) hybrid single photon emission tomography/computed tomography (SPECT/CT) carried out in this patient, demonstrated the subdural hygroma as well as the associated cerebral hypoperfusion. If (99m)Tc-ECD SPECT/CT is integrated into management of these patients, it can help in decision making with respect to conservative versus surgical management.
Indian journal of nuclear medicine : IJNM : the official journal of the Society of Nuclear Medicine, India. 01/2013; 28(1):23-5.
[show abstract][hide abstract] ABSTRACT: Though the hepatobiliary excretion of Technetium-99m ethylene dicysteine (99mTc-EC) is very low and usually does not effect image interpretation on routine posterior imaging, the possibility of visualization of the gall bladder should be kept in mind while reporting the 99mTc-EC scan especially, when anterior imaging is performed as in renal transplant patients.
Indian journal of nuclear medicine : IJNM : the official journal of the Society of Nuclear Medicine, India. 10/2012; 27(4):257-8.
[show abstract][hide abstract] ABSTRACT: Peptide receptor radionuclide therapy (PRRT), employed for treatment of neuroendocrine tumors (NETs) is based on over-expression of Somatostatin Receptors (SSTRs) on NETs. It is, however, limited by high uptake and retention of radiolabeled peptide in kidneys resulting in unnecessary radiation exposure thus causing nephrotoxicity. Employing a nanocarrier to deliver PRRT drugs specifically to the tumor can reduce the associated nephrotoxicity. Based on this, (177)Lu-DOTATATE loaded PLGA nanoparticles (NPs) were formulated in the present study, as a potential therapeutic model for NETs.
DOTATATE was labeled with Lutetium-177 ((177)Lu) (labeling efficiency 98%; R(f)∼0.8). Polyethylene Glycol (PEG) coated (177)Lu-DOTATATE-PLGA NPs (50:50 and 75:25) formulated, were spherical with mean size of 304.5±80.8 and 733.4±101.3 nm (uncoated) and 303.8±67.2 and 494.3±71.8 nm (coated) for PLGA(50:50) and PLGA(75:25) respectively. Encapsulation efficiency (EE) and In-vitro release kinetics for uncoated and coated NPs of PLGA (50:50 & 75:25) were assessed and compared. Mean EE was 77.375±4.98% & 67.885±5.12% (uncoated) and 65.385±5.67% & 58.495±5.35% (coated). NPs showed initial burst release between 16.64-21.65% with total 42.83-44.79% over 21 days. The release increased with coating to 20.4-23.95% initially and 60.97-69.12% over 21 days. In-vivo studies were done in rats injected with (177)Lu-DOTATATE and (177)Lu-DOTATATE-NP (uncoated and PEG-coated) by imaging and organ counting after sacrificing rats at different time points over 24 hr post-injection. With (177)Lu-DOTATATE, renal uptake of 37.89±10.2%ID/g was observed, which reduced to 4.6±1.97% and 5.27±1.66%ID/g with uncoated and coated (177)Lu-DOTATATE-NP. The high liver uptake with uncoated (177)Lu-DOTATATE-NP (13.68±3.08% ID/g), reduced to 7.20±2.04%ID/g (p = 0.02) with PEG coating.
PLGA NPs were easily formulated and modified for desired release properties. PLGA 50:50 NPs were a more suitable delivery vehicle for (177)Lu-DOTATATE than PLGA 75:25 because of higher EE and slower release rate. Reduced renal retention of (177)Lu-DOTATATE and reduced opsonisation strongly advocate the potential of (177)Lu-DOTATATE-PLGA-PEG NPs to reduce radiation dose in PRRT.
PLoS ONE 01/2012; 7(3):e34019. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Objectives: The aim of this study was to compare 18F-DOPA PET/CT over 131I-MIBG planar scintigraphy in evaluation of patients with pheochromocytoma
Methods: Fifteen patients with suspicion for pheochromocytomas were prospectively enrolled and scheduled for 131I-MIBG scintigraphy and 18F-DOPA PET/CT. Images were analyzed independently by two nuclear medicine physicians. Subsequently, six patients underwent surgery and were diagnosed as pheochromocytoma. Five other patients were diagnosed as pheochromocytoma/paraganglioma based on biochemical workup and clinical follow up. Rest four patients were classified as true negative on imaging and clinical follow up.
Results: 131I-MIBG showed a sensitivity of 73 % and specificity of 100%. 18F-DOPA PET/CT showed a sensitivity of 82 % and specificity of 100%. However 18F-DOPA detected more number of individual lesions as compared to 131I-MIBG scintigraphy. 18F-DOPA was particularly more superior in evaluation of metastatic pheochromocytoma and paraganglioma.
Conclusions: Overall, 18F-DOPA PET/CT showed a superior sensitivity in comparison to 131I-MIBG scintigraphy in the evaluation of pheochromocytoma/paraganglioma. However, 18F-DOPA PET/CT had an incremental value in the evaluation of metastatic pheochromocytomas and paraganglioma
[show abstract][hide abstract] ABSTRACT: The present study aimed to explore the possibility of developing a immuno-imaging/therapeutic agent for hCG-expressing tumors by using antibodies raised against them. Three human cancer cell lines were selected:lung adenocarcinoma (A549), glioblastoma (U87MG) and breast cancer (MCF7). Anti-β-hCG monoclonal antibody, obtained from ascitic fluid, was purified by affinity chromatography followed by characterization and titration. Ectopic expression of hCG on these cell lines was tested by flow cytometry and in-vitro cytotoxicity with antibodies was tested by MTT assay on the cell line with the highest percentage binding. For positive and negative controls, immortalized trophoblast cells (SW71) and peripheral blood monocytes were used. Antibody was then radiolabeled with lutetium-177 ((177)Lu) and in vivo biodistribution studies were conducted in murine tumor model. Antibodies could be purified to homogeneity with a concentration 28mg/mL. Percentage receptor expression on A549, U87MG and MCF7 cells was 95%, 66% and 55% respectively. About 90% of A549 cells could be killed with antibody at 72h post-treatment. No cytotoxicity was observed on SW71 despite a high binding percentage (96%). Antibodies were radiolabeled with high efficiency (∼98%). In-vivo studies using radiolabeled antibodies showed hepato-biliary excretion route and significant uptake in A549 tumor. In conclusion, among the 3 cancer cell lines, lung adenocarcinoma significantly expresses β-hCG and shows dose dependent cytotoxicity with anti-β-hCG antibody. Radiolabeling of this antibody can aid in imaging and also has the potential of enhancing its therapeutic potential. This study provides a platform for further studies for targeted radio-immuno imaging and subsequent therapy of hCG-expressing cancers.
Hellenic journal of nuclear medicine 15(2):108-13. · 0.68 Impact Factor
[show abstract][hide abstract] ABSTRACT: Breast milk oligosaccharides act as soluble receptors for different pathogens which protect the newborn child from infection. The differentiation between loosening of prosthesis due to infective pathology septic or otherwise aseptic plays an important role in the patient management. We have labeled hydroxypropyl-β-cyclodextrin, oligosaccharide derivative, with technetium-99m ((99m)Tc-HPβCD). The quality control of (99m)Tc-HPβCD was done by ITLC and characterized by electron microscopy and (1)H-nuclear magnetic resonance. The route of excretion of (99m)Tc-HPβCD nanoparticulate radiopharmaceutical was assessed in rats. Nanoparticles (99m)Tc HPβCD were injected in human subjects with clinically confirmed infected knee joints. Docking studies were done for ligand - protein interaction. The (99m)Tc-HPβCD was stable with good radiochemical yield (>98%) at pH 4.0 and 6.5. For single patient dose, 0.5-1.0mg HPβCD quantity was sufficient. (99m)Tc HPβCD was observed to form nanoparticles of 60-180 μm. The (1)H NMR studies revealed the binding of (99m)Tc at C-8/H-8 position of HPβCD. The excretion of (99m)Tc HPβCD showed renal route of excretion. Docking studies demonstrated the interaction between HPβCD and bacterial maltose binding protein (MBP). The differentiation between septic and aseptic loosening was also evident on single photon emission tomography (SPET). In conclusion, these data indicated that (99m)Tc HPβCD is a promising radiopharmaceutical and may serve as molecular nanoprobe for infection imaging.
Hellenic journal of nuclear medicine 13(3):218-23. · 0.68 Impact Factor