Murat Fani Bozkurt

Detection of ectopic gastric mucosa using 99mTc pertechnetate: review of the literature

Technetium-99m (99mTc) pertechnetate scintigraphy in a child with acute gastrointestinal bleeding of unknown origin suggests ectopic gastric mucosa caused by Meckel’s diverticulum or gastrointestinal duplication cysts. Our objective was to define the patterns of scintigraphic findings likely to be encountered in patients with ectopic gastric mucosa with illustrative cases and to review the literature. Fifty children (age 1 year to 14 years) were evaluated for ectopic gastric mucosa using 99mTc pertechnetate scintigraphy. Functioning ectopic gastric mucosa was detected in eight patients with Meckel’s diverticula and three patients with bowel duplication. Three patients showed atypical findings on scintigraphy which were perforated appendix, calyceal stasis, and regional enteritis. Ectopic functioning gastric mucosa in Meckel’s diverticulum is visualized simultaneously with the stomach, whereas in intestinal duplications tracer activity can be visualized in the dynamic sequence or before gastric tracer visualization in an irregular pattern. A variety of scintigraphic patterns can be found in patients with ectopic gastric mucosa undergoing 99mTc pertechnetate scintigraphy depending on the location and size of the ectopic tissue. Also, acquisition of delayed images is useful when the initial images are equivocal in children.

The EANM clinical and technical guidelines for lymphoscintigraphy and sentinel node localization in gynaecological cancers

The accurate harvesting of a sentinel node in gynaecological cancer (i.e. vaginal, vulvar, cervical, endometrial or ovarian cancer) includes a sequence of procedures with components from different medical specialities (nuclear medicine, radiology, surgical oncology and pathology). These guidelines are divided into sectione entitled: Purpose, Background information and definitions, Clinical indications and contraindications for SLN detection, Procedures (in the nuclear medicine department, in the surgical suite, and for radiation dosimetry), and Issues requiring further clarification. The guidelines were prepared for nuclear medicine physicians. The intention is to offer assistance in optimizing the diagnostic information that can currently be obtained from sentinel lymph node procedures. If specific recommendations given cannot be based on evidence from original scientific studies, referral is made to “general consensus” and similar expressions. The recommendations are designed to assist in the practice of referral to, and the performance, interpretation and reporting of all steps of the sentinel node procedure in the hope of setting state-of-the-art standards for high-quality evaluation of possible metastatic spread to the lymphatic system in gynaecological cancer. The final result has been discussed by a group of distinguished experts from the EANM Oncology Committee and the European Society of Gynaecological Oncology (ESGO). The document has been endorsed by the SNMMI Board.

SPECT in a patient with postictal PLEDs: is hyperperfusion evidence of electrical seizure?

The pathophysiological relation between periodic lateralized epileptiform discharges (PLEDs) and epileptic seizures is not known and the exact causative mechanism of PLEDs still remains unclear. In this report, the authors present a case in which the EEG displayed PLEDs after a complex partial seizure. This patient, with a long history of complex partial seizures, had previously undergone right standard anterior temporal lobectomy with hippocampectomy, with a diagnosis of mesial temporal sclerosis. She had one complex partial seizure 72 days after operation and was admitted to hospital. Her brain MRI revealed changes due to temporal lobectomy and small residual posterior hippocampic anomalies. PLEDs over the right temporal lobe were seen in postictal EEGs and persisted for 4 days despite the patients normal mental status and normal neurologic examination. Brain perfusion scintigraphy with Tc-99m-HMPAO during PLEDs was performed on the second day after the seizure, and right temporal hyperperfusion was detected. EEGs and scintigraphic imaging were repeated after cessation of PLEDs. The repeated brain scan displayed right temporal hypoperfusion. PLEDs during the postictal period may actually be an ictal pattern, and if hyperperfusion in the brain SPECT studies during PLEDs is seen, further aggressive antiepileptic drug therapy may be necessary in some cases.

Guideline for PET/CT imaging of neuroendocrine neoplasms with 68Ga-DOTA-conjugated somatostatin receptor targeting peptides and 18F–DOPA

Purpose & MethodsNeuroendocrine neoplasms are a heterogenous group of tumours, for which nuclear medicine plays an important role in the diagnostic work-up as well as in the targeted therapeutic options. This guideline is aimed to assist nuclear medicine physicians in recommending, performing, reporting and interpreting the results of somatostatin receptor (SSTR) PET/CT imaging using 68Ga-DOTA-conjugated peptides, as well as 18F-DOPA imaging for various neuroendocrine neoplasms.Results & ConclusionThe previous procedural guideline by EANM regarding the use PET/CT tumour imaging with 68Ga-conjugated peptides has been revised and updated with the relevant and recent literature in the field with contribution of distinguished experts.

Functional nuclear medicine imaging of medullary thyroid cancer.

Medullary thyroid cancer (MTC) originates from parafollicular C cells of the thyroid and accounts for 3–12% of all thyroid cancers. As opposed to other types of dedifferentiated thyroid tumours, MTC cells are highly functional, producing and secreting high amounts of calcitonin and carcinoembryonic antigen. As parafollicular C cells are of neural crest origin, MTC acts as a neuroendocrine tumour also and expresses somatostatin receptors. Although conventional radiological methods such as ultrasonography, computed tomography and magnetic resonance imaging are widely used in the primary diagnosis and staging, they often fail to localize the residual or recurrent disease because the majority of MTC recurrence presents as occult disease. Thus, owing to functional characteristics of MTC, functional imaging modalities of nuclear medicine play a major role in the diagnostic and therapeutic strategies for MTC. Among nuclear medicine modalities, 99mTc(V) -dimercaptosuccinic acid, 111In-octreotide and 123I/131I-meta-iodobenzylguanidine are commonly used in the diagnostic and even more in postoperative work-up of MTC. Alternatively, 18F-fluorodeoxyglucose and other positron emission tomography radiopharmaceuticals such as 18F-fluorodopa or 18F-fluorodopamine as well as radiolabelled antibodies such as 99mTc/123I/131I anticarcinoembryonic antigen, antigastrin, and anticholecystokinin-B have promising results. Functional imaging has a great advantage for nuclear medicine techniques in the routine work-up of MTC patients and also has a wide use in experimental studies.

Biological Reactions to a Poly(l-lactide)—Hydroxyapatite Composite: A Study in Canine Mandible

In this study, bone response, possible use and ultimate fate of a chemically-synthesized poly (L-lactide)-hydroxyapatite (PLLA-HA) composite was experimented in canine mandible. Bilateral mandibular second premolars were extracted in four dogs. The PLLA-HA composite was placed into left surgical sites, and right extraction sites were used as controls. After three months of healing, bone specimens were harvested from each animal and processed for histological evaluation. Bone uptake of methylene diphosphonate (99mTc-MDP) was calculated as indicators of osteoblastic activity in the surgical sites. Histological evaluation and the amount of 99mTc-MDP uptake showed that all surgical sites had similar levels of cellular activity and the material was biocompatible. The experimental PLLA-HA composite studied is safe to be used as a small-defect filler in applications such as repair of alveolar defects, ridge augmentations, and sinus lift procedures.

Intra-Arterial Radionuclide Therapies for Liver Tumors

Intra-arterial radionuclide therapies serve essentially as internal radiation treatment options for both primary and metastatic liver tumors, which imply delivering implantable radioactive microspheres into branches of hepatic arteries that feed liver tumors to provide a high dose of targeted radiation to tumor tissue, while sparing the healthy liver tissue from hazardous effects of radiation. The principle of this therapeutic option depends on the unique preferential arterial supply of malignant liver tumors in contrast with mostly portal venous supply of normal hepatocytes as well as excess amount of arterial neovascularization in the tumor bed. Therefore, intra-arterial radionuclide therapy can provide very high radiation exposure to tumor tissue, which is impossible to reach with external radiation therapy due to serious side effects and moreover, radiation can be targeted to tumor tissue selectively with less side effects. Yttrium-90 (Y-90), a high-energetic beta emitter is the most preferred radionuclide, which is used to label microspheres. Two types of Y-90 microspheres are commercially available that are made of resin and glass. Many studies in the literature have demonstrated that Y-90 microsphere therapy is an efficient and safe locoregional therapeutic option for unresectable primary and metastatic liver tumors such as hepatocellular carcinoma and liver metastases from colorectal cancer and breast cancer as well as neuroendocrine tumors. Furthermore, limited number of studies has reported its use in some relatively uncommon metastatic liver tumors from melanoma, pancreatic, renal, and lung cancer. Besides Y-90 microspheres, Iodine-131 lipiodol, Rhenium-188 lipiodol, Rhenium-188 microspheres, Holmium-166 chitosan, and Holmium-166 microspheres have been introduced as alternative radiopharmaceuticals for intra-arterial therapy for liver tumors.

Combined use of bone and bone marrow scintigraphies for the diagnosis of active sacroiliitis: a new approach.

Diagnosis of sacroiliitis (SI) with bone sointigraphy may involve difficultios even with a quantitative approach. The aim of this study was to evaluate the combined use of bone and bone marrow scintigraphies for the diagnosis of active sacroiliitis.Thirty-one patients who were clinically suspected to have SI were included in the study. Bone and bone marrow scintigraphies were done after injections of 740 MBq of99mTc-MDP (MDP) and 370 MBq of99mTc-sulfur colloid (SC) respectively with a 2-day interval. Both visual and quantitative assessment of MDP uptake and visual assessment of SC uptake in sacroiliac joints were performed. Also sacroiliac joint radiographic findings for each patient were evaluated and graded from 0 to 4 according to the New York grading system. Patients were divided into 2 groups according to their x-ray findings (Group A: grade 0–2, Group B: grade 3–4).A total of 14 patients (10 bilateral, 4 unilateral) had increased MDP uptake with decreased/normal SC uptake. Twelve of 14 patients had grade 0–2 radiographic changes while only 2 patients had grade 3–4 radiographic changes. Increased MDP uptake with decreased/normal SC uptake is the most common scintigraphic pattern seen in acute phase SI in which radiographic findings are generally found to be normal or slightly changed. In at least in 8 patients the decreased bone marrow uptake of SC was demonstrated, supporting the diagnosis.Although our results did not reveal any significant superiority of bone marrow scintigraphy to bone scan for the detection of active sacroiliitis, combined use of bone and bone marrow scintigraphies was presented as an alternative method to characterize patients with active sacroiliitis.

Atherosclerotic inflammatory activity in the aorta and its correlation with aging and gender as assessed by 18F-FDG-PET.

Recent literature demonstrates the potential of fluorine-18 fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) to detect, localize, and quantify the degree of inflammatory changes in the arterial wall due to early atherosclerosis. Our aim was to assess the correlation between the age and 18F-FDG uptake of aortic segments and determine its correlation with respect to in both age and genders. Fluorine-18-FDG uptake in aortic segments in 143 subjects (58 men, 85 women; ages 5-82 years) was evaluated in this study. Subjects were initially grouped according to the gender, and then by age (below or above 50) with at least 26 subjects per group. Mean standardized uptake value (SUV) of ascending aorta, arch, descending thoracic aorta, and abdominal aortic segments were calculated in each subject. Correlative analyses between age and mean SUV of aortic segments in all subjects were undertaken. Mean SUV between genders for all groups were also compared. There was a positive correlation between age and mean SUV of all aortic segments. The correlation values in all aortic segments were higher in subjects below 50 years old compared to those above 50 years in the entire group of patients as well as when they were subdivided and analyzed according to both genders (P<0.001). Descending thoracic and ascending aortic segments in men below 50 years of age had the highest correlation of 18F-FDG uptake and age (0.85 and 0.80, respectively) whereas abdominal aortic segments in men the above 50 years age group had the lowest correlation value (0.20). Comparison between mean SUV in four visible arterial segments between the two genders did not reveal any statistically significant difference. In conclusion, 18F-FDG uptake in aortic segments increases with age irrespective of genders. The increase with age is more significant in younger subjects compared to older subjects for both men and women. This finding may indicate a deceleration in the inflammatory component of atherosclerosis with aging in older subjects.

Gastroesophageal reflux scintigraphy: interpretation methods and inter-reader agreement

BackgroundScintigraphic imaging is a useful screening tool for patients with suspected gastroesophageal reflux. New scintigraphic interpretation methods have recently been introduced. This study was undertaken to evaluate the efficiency of various scintigraphic interpretation methods in the detection of gastroesophageal reflux and to measure their influence on inter-reader agreement.MethodsScintigraphic images of 49 children with suspected gastroesophageal reflux were interpreted by three different methods: visual interpretation, time activity curves, and condensed images. The readings were performed by three specialists and a resident. The discordant results were resolved by a consensus reading done together by all interpreters based on the three different methods. The gastroesophageal refluxes were grouped according to their number, location and intensity.ResultsGastroesophageal reflux scintigraphy revealed 22 patients with negative results and 27 with positive results. The sensitivity, positive predictive value and specificity for each of the three specialists vs. the resident were 96%, 96% and 81% vs. 96%; 93%, 90% and 96% vs. 81%; and 90%, 86%, and 95% vs. 73%, respectively. The mean inter-observer reproducibility (κ value) was 0.910 for visual interpretation, 0.652 for time activity curves and 0.789 for condensed images. Twenty-seven percent of the results were discordant and most of these refluxes were of low grade (92%), low intensity (77%) and localization in the distal esophagus (54%).ConclusionGastroesophageal scintigraphy is a useful tool for detecting patients with suspected reflux, and visual interpretation is better than the other two methods in terms of accuracy and inter-observer reproducibility.