Genetic imaging study with [Tc-99m] TRODAT-1 SPECT in adolescents with ADHD using OROS-methylphenidate.

AIM: To examine theeffects on the brain of 2-month treatment withamethylphenidate extended-release formulation (OROS-MPH) using [Tc-99m] TRODAT-1SPECT in a sample of treatment-naïve adolescents with Attention Deficit/Hyperactivity Disorder (ADHD). In addition, to assess whether risk alleles (homozygosity for 10-repeat allele at the DAT1 gene were associated with alterations in striatal DAT availability. METHODS: Twenty adolescents with ADHD underwent brain single-photon emission computed tomography (SPECT) scans with [Tc-99m] TRODAT-1 at baseline and two months after starting OROS-MPH treatment with dosages up to 1 mg/kg/day. Severity of illness was estimated using the Clinical Global Impression Scale (CGI-S) and DuPaul ADHD Rating Scale-Clinician version (ARS) before treatment,1 month and 2 months after initiating OROS-MPH treatment. RESULTS: Decreased DAT availability was found in both the right caudate (pretreatment DAT binding: 224.76 ±â€¯33.77, post-treatment DAT binding: 208.86 ±â€¯28.75, p = 0.02) and right putamen (pre-treatment DAT binding: 314.41 ±â€¯55.24, post-treatment DAT binding: 285.66 ±â€¯39.20, p = 0.05) in adolescents with ADHD receiving OROS-MPH treatment. Adolescents with ADHD who showed a robust response to OROS-MPH (n = 7) had significantly greater reduction of DAT density in the right putamen than adolescents who showed less robust response to OROS-MPH (n = 13) (p = 0.02). However, between-group differences by treatment responses were not related with DAT density in the right caudate. Risk alleles (homozygosity for the 10-repeat allele of DAT1 gene) in the DAT1 gene were not associated with alterations in striatal DAT availability. CONCLUSION: Two months of OROS-MPH treatment decreased DAT availability in both the right caudate and putamen. Adolescents with ADHD who showed a robust response to OROS-MPH had greater reduction of DAT density in the right putamen. However,our findings did not support an association between homozygosity for a 10-repeat allele in the DAT1 gene and DAT density, assessedusing[Tc-99m] TRODAT-1SPECT.

Atomoxetine treatment may decrease striatal dopaminergic transporter availability after 8 weeks: pilot SPECT report of three cases.

Attention deficit/hyperactivity disorder is one of the most common neurodevelopmental disorders. The pathophysiology is thought to involve noradrenaline and dopamine. The role of dopamine transporter (DAT) was evaluated in imaging studies using mostly dopamine reuptake inhibitors. Atomoxetine is a selective noradrenaline reuptake inhibitor. Here we report the results of a pilot study conducted to evaluate changes in striatal DAT after 8 weeks of atomoxetine treatment. Our results suggest that 8 weeks of atomoxetine treatment may change striatal DAT bioavailability as measured via SPECT but that change was not correlated with genotype or clinical improvement.

Hypertrophic pulmonary osteoarthropathy on bone scintigraphy and 18F-fluorodeoxyglucose positron emission tomography/computed tomography in a patient with lung adenocarcinoma.

Hypertrophic pulmonary osteoarthropathy (HPOA) is not an uncommon paraneoplastic syndrome that is frequently associated with lung cancer. A 54-year-old male patient with lung adenocarcinoma underwent bone scintigraphy and fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scanning for initial staging. Bone scintigraphy revealed increased periosteal activity in lower extremities. FDG PET/CT revealed hypermetabolic right lung mass, mediastinal lymph nodes, and mildly increased periosteal FDG uptake in both femurs and tibias. The findings in lower extremities on bone scan and FDG PET/CT were interpreted as HPOA.

Testis scintigraphy in a patient with acute lymphoblastic leukemia.

UNLABELLED: Acute lymphoblastic leukemia (ALL) is a pediatric malignancy associated with remissions and relapses. Common relapsing sitesare meninges, testis and ovary. Testicular scintigraphy is a highly specific modality used mainly in the differential diagnosis of testicular torsion and epidydimitis/epidydimo-orchitis. There is only one interesting image on leukemic infiltration with scrotal scintigraphy in the literature. The aim of this case presentation is to report that although the scintigraphic appearance of testicular torsion was observed in a patient with the diagnosis of ALL, testicular ALL infiltration was revealed in pathologic examination. CONFLICT OF INTEREST: None declared.

Evaluation of (131)I-pentamidine for scintigraphy of experimentally Leishmania tropica-infected hamsters.

We aimed to assess the ability of (131)I-Pentamidine scintigraphy to detect the lesions of Leishmania tropica infection. An experimental model of cutaneous leishmaniasis was developed. The presence of cutaneous leishmaniasis was confirmed. Pentamidine was radioiodinated with (131)I. The radiolabeled pentamidine was validated by the requisite quality control tests to check its radiolabeling efficiency, in vitro stability. (131)I-Pentamidine (activity: 18.5 MBq/100 µl) was injected intracardiacally into infected hamsters. Static whole body images of the hamsters were acquired under the gamma camera at 5 and 30 min, 2, 6 and 24 h following the administration. On the scintigrams, anatomically adjusted regions of interest (ROIs) were drawn over the right feet (target) and left feet (not-target) and various organs. Accumulation of (131)I-Pentamidine at sites of infection is expressed as the target to non-target (T/NT) ratio. The results T/NT ratio decreased with time. In concluding the (131)I-Pentamidine has poor sensitivity in detection of L. tropica infection.

Three synchronous primary tumors with different histology detected by ¹8F-FDG PET/CT.

The aim of this study is to present a patient with 3 primaries diagnosed with the ¹8F-FDG PET/CT study performed for the staging of endometrial cancer. Pathologic accumulations of the tracer were detected in both lobes of the thyroid gland, in the left lung and in the known primary of the uterus. A bilateral multifocal differentiated thyroid carcinoma and a peripheral carcinoid tumor in left lung were the final diagnosis as shown by histology. In conclusion, in this patient the PET/CT study performed for staging endometrial cancer demonstrated two new synchronous primary tumors. This is the second similar case but the first where all three primaries had entirely different histology.

Relation Between Metabolic Activity of the Broca Region and F-18 FDG Uptake in Vocal Cords.

OBJECTIVE: We aimed to investigate if increased F-18 Fluoro Deoxyglucose (F-18 FDG) uptake observed in vocal cords (VC) of the patients on Positron Emission Tomography/Computarize Tomography (PET/CT) scans is connected to speaking of the patients or not. If so, we expected to detect an increased metabolic activity in Broca's area. In this study, we have retrospectively searched for a correlation between the activity in the Broca's area and vocal cords of patients who had undergone FDG PET for different indications. MATERIAL AND METHODS: FDG PET/CT scans of 30 patients with (VC [+]) and 30 patients without (VC [-]) bilateral F-18 FDG uptake on their vocal cords were retrospectively evaluated. Brain quantification was carried out on NeuroQ software with 20 iterations using patients' transaxial brain cross sections. On the 20th-23rd-26th-29th cross sections, area/whole brain ratios of the right (R) and left (L) for Broca's area were calculated. VC (+) and VC (-) patients' R and L Broca's areas were compared using Student's t-test. RESULTS: There was no significant difference between the Broca's areas of VC (+) and VC (-) patients. L Broca's areas of both VC (+) and VC (-) patients were more active than R Broca's areas (p<0.05). There was a negative correlation between VC (+) patients' SUVmax values in the vocal cords and the activity in their R Broca's region. CONCLUSION: In our study, we did not find a significant difference between Broca's areas of VC (+) patients and VC (-) patients, so the activity in their vocal cords does not seem to be related to increased metabolic activity in Broca's areas. We have concluded that the vocal cord activity is not related to speaking of the patients. The activity in the vocal cord might be due to inflammation or, as in the eye muscles, may be associated with high metabolism in laryngeal muscles. CONFLICT OF INTEREST: None declared.

99mTc-d-penicillamine-glucuronide: synthesis, radiolabeling, in vitro and in vivo evaluation.

The current study was aimed at synthesizing a glucuronide derivative of D-penicillamine (D-PA) to be used for imaging purposes. First of all, D-PA-glucuronide (D-PA-Glu) was synthesized by experimental treatments starting with uridine 5'-diphospho-glucuronosyltransferase enzyme rich microsome preparate. Then, the synthesized compound was labeled with technetium ((99m)Tc) by using a reduction method with stannous chloride. Quality controls were performed by using high-performance liquid chromatography and thin-layer radio chromatography (TLRC). Radiolabeling yield of (99m)Tc-D-PA-Glu was more than 98% according to TLRC results. In vitro evaluations of radiolabeled complexes were investigated on PC-3 human prostate cancer cells. (99m)Tc-D-PA-Glu exhibited more accumulation on PC-3 cells versus (99m)Tc-D-PA at 240 minutes. In order to determine its radiopharmaceutical potential, biodistribution studies were carried out in male Albino Wistar rats. The biodistribution results of (99m)Tc-D-PA-Glu, showed the highest uptake in prostate at 120 minutes postinjection with the main excretion route being through kidneys and bladder. (99m)Tc-D-PA-Glu and (99m)Tc-D-PA have exhibited different biodistribution results.