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Introduction: 18F-deoxy-glucose positron emission tomography combined with computed tomography (18F-FDG PET/CT) is routinely used in the detection of malignant disease based on the property of malignant cells to fuel their growth and replication by increased glucose uptake. Malignant lesions are rare in the sellar region, while pituitary adenomas are the most common pathology. These are benign neoplasms with insidious onset and low proliferation activity, and therefore are only exceptionally detected by 18F-FDG PET/CT. Studies that compare the biology of pituitary adenomas and their radiological properties using PET/CT are still lacking. Case report: We investigate and discuss tumour biology in light of increased 18F-FDG avidity in a symptom-free, 70-year-old male patient, previously treated for two different malignancies (lung and rectal). Increased tracer accumulation in the sellar region was incidentally detected on a follow-up 18F-FDG PET/CT scan. Additional MRI disclosed pituitary adenoma. Normal hormonal status was found, consistent with the diagnosis of non-functioning pituitary adenoma. Analysis of tumour tissue after pituitary surgery confirmed a silent gonadotroph adenoma with low proliferation index. Low expression of oncogene-induced senescence markers did not support senescence as the explanation for the tumour’s low proliferative activity although it was in consonance with the hormonal activity. Conclusions: Pituitary adenomas can manifest as hypermetabolic foci on 18F-FDG PET/CT imaging with increased tracer uptake even in indolent, clinically silent pituitary adenomas with low mitotic activity. Special attention should be paid to evaluation of 18F-FDG avid pituitary adenomas in patients with multiple malignancies, bearing in mind that avidity does not always mirror its biological behaviour.

Radio-guided surgery offers several advantages in treatment of primary hyperparathyroidism. It is considered less helpful in renal hyperparathyroidism, but it could be of great advantage in the treatment of persistent or recurrent secondary hyperparathyroidism. One of the surgical options for symptomatic renal hyperparathyroidism is total parathyroidectomy with autotransplantation of hyperplastic parathyroid tissue in forearm muscles or sternocleidomastoid muscle. Recurrence can occur and is most likely caused by graft hyperplasia. In this report we present the case of 54-year-old woman with recurrent renal hyperparathyroidism caused by hyperplasia of the graft in sternocleidomastoid muscle. Unfortunately no sutures or clips were placed at initial surgery to identify the location of the parathyroid tissue. The preoperative assessment consisting of 99mTc-sestamibi scintigraphy identified a parathyroid tissue in the in the middle third of sternocleidomastoid muscle. The patient underwent a radio-guided neck re-exploration that allowed a rapid localization and excision of the hyperplastic graft.

The aim of this study is a research of single photon emission tomography (SPET) values with talium 201 and tehnetium 99m MIBI, comparing it with other methods CT, MRI and ultrasonography. In our investigation there were two groups of patients 24 treated with Tl-201 and 17 with Tc-99m-MIBI. Before the therapy 7 patients had been tested with Tl 201 and was 100% proved the sensibility, specificity, sensitivity and also 6 patients as really positive TP and 1 patient really negative TN. The same result was gotten in the group where TC 99m was used, where 3 of them were really positive and 1 negative. All discoveries were confirmed pathohistologically and leaning on this we determined the status of really positive and really negative patients. After the therapy there were 7 positive and 7 negative patients, and also one positive, and 2 negatives that were false, who were threaded by thalium. On the basis of formula of sensibility these findings show that 77,8%, if it observed only a group of patients who were being tested after the therapy, while all sensibility of method is 86,7%, where in the analyze was included a group of patients at whom was registered the primary tumor. The specificity of the method for this group of patients after the therapy is 87,5% , and the whole 88,9% where the accuracy is 82,4% in the group after therapy and the whole is 87,5%.

PURPOSE The aim of our study was to assess diagnostic accuracy of Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC scintigraphy for evaluation of pulmonary lesions that appeared ambiguous on computed tomography (CT). MATERIAL AND METHODS Forty-nine consecutive patients (37 men and 12 women; mean age, 60 ± 11 years) with 60 pulmonary lesions on chest radiography and CT were referred for nuclear imaging. They were prospectively allocated to undergo whole-body scintigraphy (WBS) and single photon emission computed tomography (SPECT) using either Tc-99m depreotide (26 patients, group 1) or Tc-99m-EDDA/HYNIC-TOC imaging (23 patients, group 2). Histologic findings after tissue biopsy served as a gold standard for determining diagnostic accuracy of the 2 somatostatin analogs. Visual assessment was complemented by semiquantitative analysis based on target to background ratio. RESULTS Among the 32 pulmonary lesions scanned with Tc-99m depreotide, focal uptake was increased in 22 of 25 malignancies, whereas no uptake was found in 6 of 7 benign lesions (88% sensitivity, 85% specificity, and 88% accuracy) on both WBS and SPECT. Imaging of 28 pulmonary lesions with Tc-99m-EDDA/HYNIC-TOC had a similar diagnostic yield (sensitivity 87%, specificity 84%, and accuracy 86%). Overall, target to background ratios were higher on SPECT than WBS but not significantly different between groups 1 and 2 (SPECT 2.72 ± 0.70 vs. 2.71 ± 0.50, WBS 1.61 ± 0.32 vs. 1.62 ± 0.28, respectively). CONCLUSION This study demonstrates that Tc-99m depreotide and Tc-99m-EDDA/HYNIC-TOC have similar diagnostic value for characterizing pulmonary lesions that appear ambiguous on CT.

Objective To determine the value of 201-thallium (201-Tl) and technetium-99m sestamibi (Tc-99m MIBI) single photon emission computed tomography (SPECT) for detecting primary undifferentiated carcinoma of nasopharyngeal type (UCNT), residual/recurrent tissue, and lymph node involvement. Study Design and Setting SPECT of head and neck was prospectively performed in 46 patients with a history of UCNT (201-Tl in 24 patients, Tc-99m MIBI in 22). CT/MRI findings, clinical follow-up, and pathohistological verification served as a gold standard for calculating sensitivity, specificity, and accuracy of each scintigraphic technique. Tumor-to-background index (T/Bg) was derived when SPECT findings were positive. Results Sensitivity of 201-Tl SPECT was 87 percent, with 78 percent specificity, 83 percent accuracy, and T/Bg of 4.05 ± 1.50. Tc-99m MIBI SPECT had 85 percent sensitivity, 78 percent specificity, 82 percent accuracy, and T/Bg of 4.45 ± 1.27. Conclusion and Significance 201-Tl SPECT and Tc-99m MIBI SPECT are useful for detecting primary UCNT, residual/recurrent disease, and lymph node involvement. This use is particularly valuable after chemoradiotherapy when CT/MRI may be ambiguous.

A new radionuclide method, called the 'geometric count based' (GCB) method, has been developed for the quantification of absolute left ventricular volume. As the method is based on planar radionuclide ventriculography, it is non-invasive and simple, and avoids the relatively cumbersome and longer lasting, dynamic procedure using single photon computed emission tomography, which can be used for achieving the same goal. The purpose of this study was to describe the exactness of the theoretical approach to the method and validate its accuracy both by physical experiments and the initial clinical trial, as compared to contrast ventriculography. Count based data were combined with the geometric based data assuming an ellipsoid left ventricular shape with identical short axes. The following equation for computing left ventricular end diastolic volume, EDV (in ml) was developed: EDV=2cMCtot/Cmax, where c is the manually drawn short axis (one row pixel ROI) of the prolate ellipsoid in LAO 45 degrees (cm), M is the calibrated pixel size (in cm2), Ctot is the total counts in LV ROI, and Cmax is the maximum pixel counts in the LV ROI. Physical experiments with two different 'heart shaped' phantoms were used to compare the results obtained by the GCB method with the true phantom volumes and with the method assuming LV ball shape (BLV), developed by other authors. The true volumes of cylindrical and ellipsoid phantoms of 112.5 ml and 190.5 ml were computed to be 114 ml and 196 ml by the GCB and 168 ml and 180 ml by the BLV methods, respectively. In a clinical study, GCB volumes were compared to volumes measured by using single plane contrast ventriculography in 38 coronary patients. A good correlation between the GCB method and contrast ventriculography was obtained both for EDV and end systolic ventricular volumes (r=0.94, r=0.90). Both phantom and initial clinical studies indicate that the GCB method is an accurate, non-invasive and simple radionuclide method for measuring left ventricular volumes. Additionally, it could be used even in the smallest nuclear medicine units, for example in intensive care units where there are mobile cameras.