Quantitative Radionuclide Imaging Analysis of Enhanced Drug Delivery Induced by Photoimmunotherapy.

Photoimmunotherapy (PIT) is an upcoming potential cancer treatment modality, the effect of which is improved in combination with chemotherapy. PIT causes a super-enhanced permeability and retention (SUPR) effect. Here, we quantitatively evaluated the SUPR effect using radiolabeled drugs of varying molecular weights (18F-5FU, 111In-DTPA, 99mTc-HSA-D, and 111In-IgG) to determine the appropriate drug size. PIT was conducted with an indocyanine green-labeled anti-HER2 antibody and an 808 nm laser irradiation. Mice were subcutaneously inoculated with HER2-positive cells in both hindlimbs. The tumor on one side was treated with PIT, and the contralateral side was not treated. The differences between tumor accumulations were evaluated using positron emission tomography or single-photon emission computed tomography. Imaging studies found increased tumor accumulation of agents after PIT. PIT-treated tumors showed significantly increased uptake of 18F-5FU (p < 0.001) and 99mTc-HSA-D (p < 0.001). A tendency toward increased accumulation of 111In-DTPA and 111In-IgG was observed. These findings suggest that some low- and medium-molecular-weight agents are promising candidates for combined PIT, as are macromolecules; hence, administration after PIT could enhance their efficacy. Our findings encourage further preclinical and clinical studies to develop a combination therapy of PIT with conventional anticancer drugs.

Pediatric Solid Gastric Emptying Scintigraphy: Normative Value Guidelines and Nonstandard Meal Alternatives.

INTRODUCTION: Adult standards for gastric emptying scintigraphy, including the type of meal and range of normative values for percent gastric emptying, are routinely used in pediatric practice, but to date have not been validated. The purpose of this study is to determine whether the use of adult criteria for gastric emptying scintigraphy is valid for children and whether alternative nonstandard meals can also be offered based on these criteria. METHODS: This retrospective study analyzed patients (n = 1,151 total) who underwent solid-phase gastric emptying scintigraphy. Patients were stratified into normal and delayed gastric emptying cohorts based on adult criteria, i.e., with normal gastric emptying defined as ≤10% gastric retention at 4 hours. Patients were further stratified based on the type of meal, namely complete or partial adult standard meals or alternative cheese-based meals. Percent gastric retention values at 1, 2, 3, and 4 hours were compared. RESULTS: The median (95% upper reference limit) percentage gastric retention values for the complete standard meal were 72% (93%) at 1 hour, 39% (65%) at 2 hours, 15% (33%) at 3 hours, and 6% (10 %) at 4 hours. By comparison, the values for cheese-based meals were 60% (87%) at 1 hour, 29% (61%) at 2 hours, 10% (30%) at 3 hours, and 5% (10%) at 4 hours. Consumption of at least 50% of the standard meal yielded similar retention percentages; 68% (89%) at 1 hour, 32% (57%) at 2 hours, 10% (29%) at 3 hours, and 5% (10%) at 4 hours. There were no significant age- or sex-specific differences using the adult criteria. DISCUSSION: The adult normative standards for gastric emptying scintigraphy are applicable for use in the pediatric population. These same standards can be also be applied to nonstandard meal options, including cheese-based alternative meals and partial standard meals.

Rapid induction of clinical remission in SAPHO syndrome using high-dose Tripterygium glycosides: A case report.

RATIONALE: Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare disease without standard treatments. Tripterygium wilfordii hook f (TwHF) is a traditional Chinese herb with anti-inflammatory effect, and 1.0 mg/(kg·d) dose of Tripterygium glycosides has been reported to significantly improve the disease activity of a SAPHO patient in a case report. However, the optimal dose of TwHF is still unclear. Here, we report the first case of SAPHO patient who achieved rapid remission in clinical symptoms after receiving 1.5 mg/(kg·d) dose of Tripterygium glycosides treatment. PATIENT CONCERNS: A 67-year-old woman noted palmoplantar pustulosis and pain in the anterior chest wall and waist. Bone scintigraphy demonstrated the typical tracer accumulation feature and magnetic resonance images showed bone marrow edema in lumbosacral vertebra. DIAGNOSES: The diagnosis was made by dermatological and osteoarticular manifestations and classical signs in bone scintigraphy in accordance with the diagnostic criteria proposed in 2012. INTERVENTIONS: Tripterygium glycosides was given with a primary dose of 1.5 mg/(kg·d) for 1 month and then reduced at a rate of 10 mg every 2 weeks until 1.0 mg/(kg·d) for a long-term maintenance. OUTCOMES: Fast-induced remission on clinical manifestations was achieved and magnetic resonance imaging abnormality was improved significantly. Additionally, no apparent side effects were observed. LESSONS: 1.5 mg/(kg·d) dose of Tripterygium glycosides seems to have fast-induced remission than 1.0 mg/(kg·d) with reliable safety. Besides, Tripterygium glycosides may also have a pharmacological effect of inhibiting osteolysis and enhancing bone strength.

Meta-analysis does not support routine traditional nuclear medicine studies for malignant otitis.

OBJECTIVES: The role of traditional nuclear medicine studies in the management of malignant otitis externa (MOE) is unclear and there are ongoing debates regarding their diagnostic value. The authors perform a systematic review and meta-analysis to assess the sensitivity and specificity of traditional nuclear medicine studies in the diagnosis of MOE. METHODS: In accordance with PRISMA guidelines, a query of the Medline, Embase, Web of Science, and Cochrane databases was undertaken. The primary outcomes of interest were the sensitivity and specificity of traditional nuclear medicine studies to detect MOE. RESULTS: Of the initial 1317 hits from the four databases, 20 articles with a combined 608 patients were ultimately included in the review. The pooled sensitivities for Technetium-99 and Gallium-67 were 85.1% (95% CI, 72.0-98.1%) and 71.2% (95% CI, 55.1-87.3%) respectively. The available evidence suggested poor specificity of these modalities, but was insufficient for meta-analysis. Neither modality was shown to be effective in the assessment of disease resolution. CONCLUSION: The sensitivities of Technetium-99 and Gallium-67 to detect MOE are less favorable than was initially thought. Given this finding and their poor specificity, lack of anatomic resolution, unproven ability to detect disease resolution and variable availability, this review does not support the routine use of these studies in the management of MOE. LEVEL OF EVIDENCE: N/A Laryngoscope, 130:1812-1816, 2020.

Population-based validation of the National Cancer Comprehensive Network recommendations for baseline imaging workup of cutaneous melanoma.

The aim of the current study is to assess the performance of some of the imaging scans recommended in the National Comprehensive Cancer Network Guidelines as part of baseline staging for cutaneous melanoma, regarding the detection of lung, brain, bone, and liver metastases. Surveillance, Epidemiology and End Results database (2010-2015) was used to extract the data, and cases with cutaneous melanoma and complete information about TN stages and sites of distant metastases were explored. Performance parameters assessed in the current study included positive predictive value (PPV), negative predictive value, sensitivity, specificity, number needed to investigate (NNI), and accuracy. A total of 109 971 patients were included in the analysis. If all stage III patients in the study cohort are to be staged through routine imaging, PPV (for the recognition of lung metastases) will be 2.9% and NNI to detect one case of lung metastasis will be 34. Likewise, PPV (for the recognition of bone metastases) will be 1.8% and NNI to detect one case of bone metastasis will be 55. Moreover, PPV (for the recognition of liver metastases) will be 1.8% and NNI to detect one case of liver metastasis will be 55. Excluding stage III patients with clinically node-negative/sentinel node-positive disease would improve PPV and decrease NNI for the three metastatic sites. Adherence to current National Comprehensive Cancer Network guidelines for cutaneous melanoma imaging for baseline staging results in low rates of failure to detect asymptomatic lung, liver, brain, or bone metastases.

Development and Gamma Scintigraphy Study of Trigonella foenum-graecum (Fenugreek) Polysaccharide-Based Colon Tablet.

The major concern with the use of some synthetic excipients is their safety towards biological tissues, hence influencing the reliability of products. With the aim to minimize dependency on highly toxic synthetic excipients, the present study was designed to deliver metronidazole (MNZ) into the colonic region for localized treatment of amoebiasis using natural polysaccharide-based drug delivery. Compression-coated tablets were prepared using water extractable natural polysaccharide from Trigonella foenum-graecum (FG). Physical properties of the tablets were evaluated and dissolution study was performed at pH 1.2, 6.8, and 7.4 with rat cecal material. Results indicate that all batches demonstrated pH-dependent drug release and prevented release into the stomach, allowing traces into the intestine and highest availability into the colon. A significant correlation (r2 = 0.975) was found between the coating levels of extracted polysaccharide and lag time release of drug. Gamma scintigraphy images of in vivo study conducted on human volunteers showed a small intestinal transit time, i.e., 3-5 (4.2 ± 0.4) h and confirmed that the tablets reached the colon within 6-8 h. The present study revealed that the FG polysaccharide-based double compression tablets may be promising colon-specific drug carriers with reduced toxic effects of commonly used synthetic excipients.

Unenhanced MRI as an Alternative to 99mTc-Labeled Dimercaptosuccinic Acid Scintigraphy in the Detection of Pediatric Renal Scarring.

OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.

Measurements of Soil Carbon by Neutron-Gamma Analysis in Static and Scanning Modes.

The herein described application of the inelastic neutron scattering (INS) method for soil carbon analysis is based on the registration and analysis of gamma rays created when neutrons interact with soil elements. The main parts of the INS system are a pulsed neutron generator, NaI(Tl) gamma detectors, split electronics to separate gamma spectra due to INS and thermo-neutron capture (TNC) processes, and software for gamma spectra acquisition and data processing. This method has several advantages over other methods in that it is a non-destructive in situ method that measures the average carbon content in large soil volumes, is negligibly impacted by local sharp changes in soil carbon, and can be used in stationary or scanning modes. The result of the INS method is the carbon content from a site with a footprint of ~2.5 - 3 m2 in the stationary regime, or the average carbon content of the traversed area in the scanning regime. The measurement range of the current INS system is >1.5 carbon weight % (standard deviation ± 0.3 w%) in the upper 10 cm soil layer for a 1 hmeasurement.

Adjunctive Breast-Specific Gamma Imaging for Detecting Cancer in Women with Calcifications at Mammography.

BACKGROUND: Mammography detects calcium deposits sensitively, but the specificity for differentiating malignancy from benign calcifications is low. Thus, we investigated whether adjunctive breast-specific gamma imaging (BSGI) has incremental value for detecting cancer in women with suspicious calcifications detected by mammography, and compared BSGI with adjunctive ultrasonography (US). METHODS: The medical records of women without a personal history of breast cancer who underwent mammography for breast evaluation from 2009 to 2014 were reviewed retrospectively. Patients who had calcifications detected by mammography, with a result of Breast Imaging Reporting and Data System (BI-RADS) categories 3-5, underwent adjunctive US and BSGI and were included in this study. A total of 302 breast lesions in 266 women (mean age ± standard deviation 49 ± 9 years) were selected for this study. RESULTS: For detecting breast cancer using mammography plus BSGI, the sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating curve with 95% confidence intervals were 94% (91-96), 90% (86-93), 91% (87-94), 94% (90-96), and 0.92 (0.89-0.95), respectively. For mammography plus US, the respective values were 97% (94-98), 51% (46-57), 68% (63-73), 94% (90-96), and 0.74 (0.70-0.78). CONCLUSIONS: Adjunctive BSGI had higher specificity than adjunctive US without loss of sensitivity. This finding suggests that adjunctive BSGI may be a useful complementary initial imaging method to improve the detection of breast cancer in women who have calcifications with suspicious morphology at mammography.

Internal dosimetry with the Monte Carlo code GATE: validation using the ICRP/ICRU female reference computational model.

The purpose of this work was to validate GATE-based clinical scale absorbed dose calculations in nuclear medicine dosimetry. GATE (version 6.2) and MCNPX (version 2.7.a) were used to derive dosimetric parameters (absorbed fractions, specific absorbed fractions and S-values) for the reference female computational model proposed by the International Commission on Radiological Protection in ICRP report 110. Monoenergetic photons and electrons (from 50 keV to 2 MeV) and four isotopes currently used in nuclear medicine (fluorine-18, lutetium-177, iodine-131 and yttrium-90) were investigated. Absorbed fractions, specific absorbed fractions and S-values were generated with GATE and MCNPX for 12 regions of interest in the ICRP 110 female computational model, thereby leading to 144 source/target pair configurations. Relative differences between GATE and MCNPX obtained in specific configurations (self-irradiation or cross-irradiation) are presented. Relative differences in absorbed fractions, specific absorbed fractions or S-values are below 10%, and in most cases less than 5%. Dosimetric results generated with GATE for the 12 volumes of interest are available as supplemental data. GATE can be safely used for radiopharmaceutical dosimetry at the clinical scale. This makes GATE a viable option for Monte Carlo modelling of both imaging and absorbed dose in nuclear medicine.

Abordagem percutânea das doenças da artéria renal / Percutaneous approach to renal artery disease

A estenose da artéria renal (EAR) é uma importante causa de hipertensão arterial sistêmica (HAS) secundária e disfunção renal. O principal mecanismo é por doença aterosclerótica unilateral ou bilateral. O diagnóstico precoce é importante para se evitar falência renal terminal e graves complicações cardiovasculares. O início de HAS precoce ou tardia, sopros abdominais, déficit renal sem causa aparente e HAS resistente são achados clínicos para se suspeitar de EAR, sendo necessários exames complementares como o Doppler colorido, angiotomografia ou ressonância nuclear magnética das artérias renais. A arteriografia renal é o padrão ouro para confirmação diagnóstica. O tratamento medicamentoso está indicado para os pacientes assintomáticos ou que mantêm controle clínico satisfatórios. A intervenção percutânea da artéria renal com uso de stents tem sido motivo de controvérsia, ficando restrita aos pacientes com perda progressiva da função renal e estenose bilateral, hipertensão arterial resistente ao tratamento medicamentoso, edema agudo de pulmão hipertensivo de repetição e disfunção de enxerto renal no caso de pacientes submetidos ao transplante renal

Renal artery stenosis (RAS) is an important cause of secondary systemic hypertension and renal dysfunction. The main mechanism is unilateral or bilateral atherosclerotic disease. Early diagnosis is important to avoid terminal renal failure and severe cardiovascular complications. The onset of early or late secondary systemic hypertension, abdominal murmurs, renal failure without apparent cause, and resistant secondary systemic hypertension are clinical findings to suspect RAS, and complementary exams such as color Doppler, angiotomography or magnetic nuclear magnetic resonance imaging of the renal arteries are necessary. Renal arteriography is the gold standard for diagnostic confirmation. Drug treatment is indicated for patients who are asymptomatic or who maintain satisfactory clinical control. Percutaneous renal artery intervention with stents has been controversial, being restricted to patients with progressive renal function loss and bilateral stenosis, drug-resistant hypertension, acute repetitive hypertensive pulmonary edema and renal graft dysfunction in patients submitted to kidney transplant

Linfedema primario en miembro superior asociado a síndrome de Klippel-Trénaunay (displasia angiectasia congénita) / Primary upper limb lymphedema associated with Klippel-Trénaunay syndrome (congenital dysplastic angiectasia)

Se presenta el caso de una paciente de 41 años que se diagnostica de flebolinfedema primario con localización en miembro superior izquierdo asociado a síndrome de Klippel-Trénaunay, que no presentó manifestación clínica hasta los 37 años de edad, momento de aparición de la tríada clínica característica de angiomas cutáneos, varicosidades e hipertrofia de los tejidos blandos. La relevancia de este artículo radica en que se trata de una enfermedad rara y congénita, que se manifiesta en la infancia o adolescencia, con afectación más frecuente en miembros inferiores. Su etiopatogenia es aún desconocida, surgiendo casos esporádicos, aunque se cree que podría ser debido a una alteración en el desarrollo del mesodermo en el feto, que afecta a las líneas angioblásticas, linfoblásticas y osteoblásticas. Es importante conocer los diferentes signos clínicos para un diagnóstico y tratamiento precoz, el cual suele ser sintomático y la rehabilitación constituye un pilar fundamental dentro del tratamiento multidisciplinar (AU)

The case is presented of a 41 years old patient with primary lymphedema diagnostic in her left upper limb associated with Klippel-Trénaunay syndrome, who did not present any clinical manifestations until 37 years old, time of appearance of the characteristic clinical triad of cutaneous angiomatosis, varicose veins and hypertrophy. The relevance of this article is that it is a rare and congenital disease. This syndrome usually manifests in childhood or adolescence with more frequent involvement of the lower limbs. Its etiopathogeny is still unexplained, emerging sporadic cases, although it is believed it could be due to fetal's mesoderm development alteration, which affecting angioblastic, lymphoblastoid and osteoblastic lines. The importance of an early correct diagnosis and its symptomatic treatment, where rehabilitation has a fundamental role within the multidisciplinary approach is emphasized (AU)

Increased Background Activity in DMSA Scintigraphy of a Nonazotemic Patient With ß-Thalassemia Major.

Renal DMSA uptake provides an index for evaluation of the functional tubular mass, which depends on the renal blood flow, proximal tubular cell membrane function, and urinary acid-base balance. We present a case of a nonazotemic 48-year-old adult with ß-thalassemia major under regular blood transfusions and iron chelation therapy that underwent DMSA scan showing minor cortical abnormalities and high background activity, featuring prominent cardiac blood pool and liver uptake. This case highlights the pitfall of high background activity during DMSA study in patients with ß-thalassemia major due to tubular disorders.

Traditional gamma cameras are preferred.

Although the new solid-state dedicated cardiac cameras provide excellent spatial and energy resolution and allow for markedly reduced SPECT acquisition times and/or injected radiopharmaceutical activity, they have some distinct disadvantages compared to traditional sodium iodide SPECT cameras. They are expensive. Attenuation correction is not available. Cardio-focused collimation, advantageous to increase depth-dependent resolution and myocardial count density, accentuates diaphragmatic attenuation and scatter from subdiaphragmatic structures. Although supplemental prone imaging is therefore routinely advised, many patients cannot tolerate it. Moreover, very large patients cannot be accommodated in the solid-state camera gantries. Since data are acquired simultaneously with an arc of solid-state detectors around the chest, no temporally dependent "rotating" projection images are obtained. Therefore, patient motion can be neither detected nor corrected. In contrast, traditional sodium iodide SPECT cameras provide rotating projection images to allow technologists and physicians to detect and correct patient motion and to accurately detect the position of soft tissue attenuators and to anticipate associated artifacts. Very large patients are easily accommodated. Low-dose x-ray attenuation correction is widely available. Also, relatively inexpensive low-count density software is provided by many vendors, allowing shorter SPECT acquisition times and reduced injected activity approaching that achievable with solid-state cameras.

Dream Doctor Intervention Instead of Sedation: Performing Radionuclide Scanning Without Sedation in Young Children: A Study in 142 Patients.

BACKGROUND: Dream Doctors (DDs; professional medical clowns) are expanding their activities in pediatric wards. DDs were introduced as an alternative to sedation among children undergoing kidney imaging after urinary infection. The imaging requires that the patient lie completely still under the camera during the scan; otherwise the image cannot be interpreted. It is extremely difficult to get these children to cooperate, and pediatricians have to provide sedation to get good results. Giving sedation requires medical observation, and it can take hours until the child can be safely released from the hospital. METHODS: A DD intervention was introduced in an attempt to avoid sedation in these young children. The DD tried to gain the child's cooperation during the procedure. Each study was subsequently scored by a radionuclide physician to assess study quality and interpretation. RESULTS: A total of 142 patients were studied over a 14-month period. The mean age was 2 ± 1.6 years. During the study, in the presence of the DD, only five (3.2%) patients required pharmacologic sedation compared with 100% before the study. CONCLUSIONS: The introduction of DDs proved to be a good alternative to sedation in cases where the procedure does not involve pain and only requires the child's cooperation.

Diagnostic accuracy of elastography and scintigraphic imaging after thermal microwave ablation of thyroid nodules.

PURPOSE: The aim of this study is to evaluate structural alterations of thyroid tissue after microwave ablation using elastography and scintigraphic imaging to investigate the applicability of these diagnostic methods for follow-up.  MATERIALS AND METHODS: 35 patients with 39 thyroid nodules were evaluated using elastography and scintigraphic imaging before and after ultrasound-guided microwave ablation. Elastography was analyzed according to color-coded output and results were classified using a fourfold elasticity score (ES). Nodules color-coded blue were classified ES1 for high elasticity through ES2 and ES3 for lower elasticity, and nodules with very low elasticity were color-coded red and classified as ES4. (99m)Tc-pertechnetate served as a tracer for scintigraphic imaging of hot and indifferent nodules and (99m)Tc-MIBI for cold nodules. RESULTS: Before microwave ablation, elastography detected a median elasticity score of ES 2 ±â€Š0.7, and after ablation the median score was ES 3 ±â€Š0.6. Overall, the median score increased by 1ES ±â€Š0.6 (p < 0.01). Scintigraphic imaging detected a median reduction of tracer uptake in ablated tissue of 38.7 %±â€Š27.5(p < 0.01). (99m)Tc-pertechnetate scans showed a median decrease of tracer uptake of 26.3 %±â€Š16.3 and (99m)Tc-MIBI scans detected uptake reduction of 54.7 %±â€Š29.2. CONCLUSION: Scintigraphic imaging using (99m)Tc-pertechnetate and (99m)Tc-MIBI provides quantifiable results and is promising as a diagnostic follow-up after microwave ablation. Strain elastography detects decreasing tissue elasticity, but accuracy is limited by the necessary reduction of color-coded output to elasticity scores.

Radionuclide imaging of osteomyelitis.

Radionuclide procedures frequently are performed as part of the diagnostic workup of osteomyelitis. Bone scintigraphy accurately diagnoses osteomyelitis in bones not affected by underlying conditions. Degenerative joint disease, fracture, and orthopedic hardware decrease the specificity of the bone scan, making it less useful in these situations. Gallium-67 scintigraphy was often used as an adjunct to bone scintigraphy for diagnosing osteomyelitis. However, now it is used primarily for spinal infections when (18)F-FDG imaging cannot be performed. Except for the spine, in vitro-labeled leukocyte imaging is the nuclear medicine test of choice for diagnosing complicating osteomyelitis. Leukocytes accumulate in bone marrow as well as in infection. Performing complementary bone marrow imaging with (99m)Tc-sulfur colloid facilitates the differentiation between osteomyelitis and normal marrow and improves test overall accuracy. Antigranulocyte antibodies and antibody fragments, such as (99m)Tc-besilesomab and (99m)Tc-sulesomab, were developed to eliminate the disadvantages associated with in vitro-labeled leukocytes. These agents, however, have their own shortcomings and are not widely available. As biotin is used as a growth factor by certain bacteria, (111)In-biotin is useful to diagnose spinal infections. Radiolabeled synthetic fragments of ubiquicidin, a naturally occurring human antimicrobial peptide that targets bacteria, can differentiate infection from sterile inflammation and may be useful to monitor response to treatment. (18)F-FDG is extremely useful in the diagnostic workup of osteomyelitis. Sensitivity in excess of 95% and specificity ranging from 75%-99% have been reported. (18)F-FDG is the radionuclide test of choice for spinal infection. The test is sensitive, with a high negative predictive value, and reliably differentiates degenerative from infectious vertebral body end-plate abnormalities. Data on the accuracy of (18)F-FDG for diagnosing diabetic pedal osteomyelitis are contradictory, and its role for this indication remains to be determined. Initial investigations suggested that (18)F-FDG accurately diagnoses prosthetic joint infection; more recent data indicate that it cannot differentiate infection from other causes of prosthetic failure. Preliminary data on the PET agents gallium-68 and iodine-124 fialuridine indicate that these agents may have a role in diagnosing osteomyelitis.

Single amino acid chelate complexes of the M(CO)3 (+) core for correlating fluorescence and radioimaging studies (M = (99m) Tc or Re).

Single amino acid chelates (SAACs) and SAAC-like bifunctional ligands can be exploited in the design of a variety of bioconjugates for facile metallation with the M(CO)3 (+) unit with M = (99m) Tc or Re. When the donor groups of the ligand are quinolone, thiazole or other similarly conjugated heterocycles, the rhenium complexes are fluorescent, affording complementary and isostructural fluorescent probes to the radioactive (99m) Tc analogues. The versatility of the approach has been demonstrated by the preparation of bioconjugates incorporating peptides, biotin, folic acid, thymidine and vitamin B12 . In addition, the unusual photophysical properties observed for rhenium of the [bisthiazole-diamino butane-Re(CO)3 (+) ] derivative [BTBA-Re(CO)3 ](+) are discussed.

Determination of in vivo behavior of mitomycin C-loaded o/w soybean oil microemulsion and mitomycin C solution via gamma camera imaging.

In this study, a microemulsion system was evaluated for delivery of mitomycin C (MMC). To track the distribution of the formulated drug after intravenous administration, radiochemical labeling and gamma scintigraphy imaging were used. The aim was to evaluate a microemulsion system for intravenous delivery of MMC and to compare its in vivo behavior with that of the MMC solution. For microemulsion formulation, soybean oil was used as the oil phase. Lecithin and Tween 80 were surfactants and ethanol was the cosurfactant. To understand the whole body localization of MMC-loaded microemulsion, MMC was labeled with radioactive technetium and gamma scintigraphy was applied for visualization of drug distribution. Radioactivity in the bladder 30 minutes after injection of the MMC solution was observed, according to static gamma camera images. This shows that urinary excretion of the latter starts very soon. On the other hand, no radioactivity appeared in the urinary bladder during the 90 minutes following the administration of MMC-loaded microemulsion. The unabated radioactivity in the liver during the experiment shows that the localization of microemulsion formulation in the liver is stable. In the light of the foregoing, it is suggested that this microemulsion formulation may be an appropriate carrier system for anticancer agents by intravenous delivery in hepatic cancer chemotherapy.

1D-3D registration for functional nuclear imaging.

Functional nuclear imaging systems like PET or SPECT provide unique information that is used extensively in diagnosis, but it has also proven very useful for image-guided interventions. In the case of SPECT and radio-guided surgeries, 1D gamma detectors called gamma probes are routinely used during interventions to localize hotspots in conjunction with pre-operative SPECT images, or more recently, intraoperative SPECT images. As the tissue is being manipulated during surgery, these SPECT images quickly lose their validity, necessitating either new scans, which is in most cases unfeasible, or requiring the surgeon to do a mental update of the available imagery. In this paper, we present a novel 1D-3D registration procedure for functional nuclear imaging that registers tracked intra-operative 1D probe readings to a pre- or intra-operatively acquired 3D functional image. This procedure allows incorporating prior knowledge during radio-guided surgeries, enabling rapid updates of the visualization in the case of tissue deformation without the overhead of an additional complete scan. We show results using phantom data as well as patient data.