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Background: The objective of this study was to characterize tumor activity and mineralization status in newly-detected multiple myeloma (MM) bone lesions using 2- 18 F-fluoro-2-deoxy-D-glucose ( 18 F-FDG)-PET/CT and 18 F-sodium fluoride ( 18 F-NaF)-PET/CT before and after antitumor treatment., Materials and Methods: In this retrospective study, seven patients with histologically-verified MM were included (four women, three men; median age=57 years, standard deviation=11.23 years). PET/CT was performed with 18 F-FDG and with 18 F-NaF, both at baseline and after treatment. All patients had positive scans. Volumes of interest (VOIs) were drawn over all 18 F-FDG-PET/CT-positive bone lesions, as well as the corresponding regions in 18 F-NaF-PET/CT. For characterization of bone lesions, semi-quantitative standard uptake value (SUV) parameters were measured., Results: 18 F-FDG-PET/CT in the seven patients detected 39 metabolically active lesions that were correlated with the corresponding sites in 18 F-fluoride-PET/CT. Overall, the lesions showed a response to therapy, with a significant decrease in SUV max on PET/CT using 18 F-FDG (p<0.001) and with 18 F-NaF (p<0.001). In four patients with a second follow-up scan (at a median of 17 months after baseline scan), there was no significant change in lesion uptake., Conclusion: Based on our data, antitumor therapy in MM reduces not only tumor activity, but also the mineralization status of bone lesions. A second follow-up scan in a subset of the cohort yielded no change in mineralization status., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Aim: We evaluated the clinical usefulness of 6-[ 18 F]fluoro-3,4-dihydroxy-L-phenylalanine( 18 F-FDOPA)-positron-emission tomography (PET)/computed tomography (CT) in insulinoma detection with contrast enhancement, early acquisition time, and no carbidopa premedication., Patients and Methods: Twenty-six patients diagnosed with hyperinsulinemic hypoglycemia underwent an 18 F-FDOPA PET/CT examination. Patients without carbidopa premedication and contrast-enhanced CT were included. Imaging findings were compared to the overall final diagnosis (histological findings)., Results: In 10 of 26 patients (eight women, two men; mean age=53 years; age range=30-94 years), a detected lesion was confirmed histologically as an insulinoma. 18 F-FDOPA PET detected the tumor in five out of ten patients. Contrast-enhanced CT also detected the tumor in five out of ten. Overall, 18 F-FDOPA PET/CT, with contrast enhancement and without carbidopa premedication, was able to detect the insulinoma in seven out of ten patients (70%)., Conclusion: Based on our data, 18 F-DOPA PET/CT, with contrast enhancement and without carbidopa premedication, as a 'one-stop' diagnostic modality is a viable option for insulinoma detection., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Aim: To evaluate (18)F-fluorodihydroxyphenylalanine-positron emission tomography/ contrast-enhanced computed tomography ((18)F-DOPA PET/CT) for the detection of paragangliomas (PARA) without any patient selection, such as genetic predisposition for the development of these tumors, history of metastatic PARA or hormonal status., Patients and Methods: In this retrospective study, 28 consecutive patients (15 women, 13 men; mean age=46.4 years; age range=19-73 years), who were referred to our PET/CT center for the detection of clinically suspected PARA, were included. Final diagnosis was confirmed by histological reports of surgically proven lesions and/or clinical follow-up (including laboratory results and/or PET/CT follow-up)., Results: On a per-lesion basis (45 lesions) analysis, there was a sensitivity of 64.3% for CT, 73.8% for PET, 100% for PET/CT and a positive predictive value (PPV) of 93.1% for CT, 96.9% for PET and 100% for PET/CT. On a per-patient basis analysis, the sensitivity, specificity and accuracy for CT was 86.7%, 84.6% and 85.7%, respectively, and, for PET 80%, 100% and 89.3%, respectively, and, for PET/CT 100%., Conclusion: Based on our data, (18)F-DOPA PET/CT is a "one-stop diagnostic modality" for the assessment of patients with suspected PARA., (Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Aim: To evaluate the diagnostic accuracy of (11)C-acetate positron-emission tomography (PET) in the detection of bone metastasis in patients with prostate cancer with biochemical recurrence., Patients and Methods: Ninety patients (100%) with rising prostate-specific antigen (PSA) levels (>0.2 ng/ml) after radical prostatectomy, who had both (11)C-acetate PET and bone scan performed and who had clinical follow-up/imaging follow-up for bone metastasis, considered a gold standard, were included. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for (11)C-acetate PET were calculated on a per-patient basis., Results: (11)C-Acetate PET and (99m)Tc-dicarboxypropane-diphosphonate findings were concordant in 84 (93.3%) patients [35 (38.9%) true-positive, 49 (54.4%) true-negative]. Discordant findings were observed in six patients (6.7%). (11)C-Acetate PET presented two (2.2%) false-positive and four (4.4%) false-negative findings. The sensitivity, specificity, PPV, and NPV for (11)C-acetate PET were 89.7%, 96.1%, 94.6%, and 92.2%, respectively. The median PSA of patients with multiple skeletal metastases (median=23.64 ng/ml, range=3.16-551.1 ng/ml) differed significantly (p=0.018) from that of patients with focal metastases (median=6.7 ng/ml, range=0.31-12.8 ng/ml)., Conclusion: (11)C-Acetate PET is a useful tool for patients with prostate cancer with biochemical recurrence, as it can depict multiple sites of recurrence and in particularly shows a high diagnostic value equivalent to that of bone scan for the detection of bone metastases., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Aim: The American thyroid association (ATA) recommends that additional imaging procedures supplement cervical ultrasonography (US) in any patient with a basal calcitonin value above 150 pg/ml in the follow-up of medullary thyroid carcinoma (MTC). The aim of the present study was to reaffirm or challenge this cut-off for 18-Fluorine-Fluorodihydroxyphenylalanine positron emission tomography (18F-DOPA PET) and conventional imaging ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI))., Materials and Methods: Thirty-nine patients (18 females, 21 males), mean age 62 years, range from 35 to 86, followed-up for MTC were included in the present retrospective study. In our patients 64 18F-DOPA scans, 28 neck US, 28 CT and 8 MRI were performed. For all cases basal calcitonin values were available. Sensitivity and specificity of 18F-DOPA PET and conventional imaging (US, CT, MRI) related to calcitonin values were calculated., Results: According to the calcitonin cut-off of 150 pg/ml, we found the following sensitivities and specificities: 79% and 80% for 18F-DOPA PET, 75% and 92% for US, 80% and 25% for CT, 50% and 75% for MRI. Taking the level of detectable calcitonin, we calculated the following sensitivities: 52% for 18F-DOPA PET, 46% for US, 79% for CT and 38% for MRI., Conclusion: We cannot confirm the calcitonin cut-off proposed by the ATA for the detection of MTC recurrences and contemporaneously we cannot state that 18F-DOPA PET has a very high sensitivity. For the neck region 18F-DOPA PET and US showed similar results. 18F-DOPA PET/CT seems to be the best imaging modality for whole-body tumor detection. Bone metastases are best detected by MRI., (Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

Aim: To describe the (18)F-fluorodihydro-xyphenylalanine ((18)F-DOPA), positron emission tomography (PET) and magnetic resonance imaging (MRI) appearance of pheochromocytomas, with a focus on the presence or absence of typical MRI features., Materials and Methods: Eleven patients with histologically-verified pheochromocytoma [sporadic (n=9), multiple endocrine neoplasia (MEN) 2A syndrome (n=2)] were enrolled retrospectively. All patients underwent an MRI examination of the upper abdomen. Nine out of 11 patients underwent (18)F-DOPA PET/CT, and the remaining two patients underwent independent PET and computed tomography (CT) examinations. (18)F-DOPA-PET/CT examinations were considered positive when an increased tracer accumulation in the adrenal region, as shown on CT images, was observed. When an adrenal mass was detected on MRI, the T1 and T2 signal intensity and contrast enhancement pattern were recorded. Based on MR characteristics, the lesions were divided into typical and atypical., Results: Ten out of 11 patients had one lesion, while one patient had two lesions. All pheochromocytomas were detected by both PET/CT and MRI. On (18)F-DOPA scans, all lesions showed an increased tracer accumulation, with a mean maximum standardized uptake value (SUVmax) of 13.7±5.75. Eight out of 12 pheochromocytomas exhibited typical MRI features, with intermediate signal intensity on T1-weighted images in-phase, absence of signal drop on T1-weighted images out-of-phase, high signal intensity on T2-weighted images, and clear contrast enhancement in the arterial phase. The remaining four lesions exhibited atypical MRI features, namely absence of one of the listed criteria., Conclusion: In the assessment of pheochromocytoma, the combination of (18)F-DOPA PET with MRI is superior to MRI-alone. (18)F-DOPA PET/MRI may yield a higher diagnostic confidence for the detection of pheochromocytoma than (18)F-DOPA PET/CT.

Aim: The aim of this study was to determine the diagnostic value of the serum tumor marker beta-2 microglobulin (β2M) as well as positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) in confirming or eliminating the diagnosis of non-Hodgkin lymphoma (NHL)., Patients and Methods: Retrospective analysis of 180 patients with NHL referred for a PET scan was performed. Patients' data regarding demographic information, clinical history, and diagnostic procedures were collected. The sensitivity, specificity, and positive/negative predictive value of serum β2M levels and FDG-PET, compared to a compound gold standard consisting of imaging modalities (computed tomography, magnetic resonance tomography, ultrasound) and/or biopsy, were assessed and compared., Results: β2M had a sensitivity and specificity of 49% and 52% for all types and settings, respectively, as well as a low positive predictive value (66%) and a very low negative predictive value (36%). The overall sensitivity and specificity of FDG-PET for all types of NHL in all settings was 87% and 92%, respectively., Conclusion: Due to its low sensitivity and specificity, β2M cannot be used in the clinical routine as a diagnostic marker for the diagnosis of NHL. On the other hand, in accordance with previous studies, we found that FDG-PET is an excellent tool for the diagnosis of NHL.

The aim of the study was to evaluate the possible changes in CD4+ and CD8+ T-cell cytokine production patterns in Hashimoto's thyroiditis (HT) with elevated calcitonin (CT). Fourteen consecutive patients with verified HT were included in the present study. Patients were divided into two groups. Group I: 7 HT patients with elevated CT levels (>10 pg/ml); Group II: 7 HT patients with CT levels <10 pg/ml). All patients underwent intracellular cytokine detection in CD4+ and CD8+ T-cells of peripheral blood mononuclear cells (PBMC) by flow cytometry. Patients with elevated CT levels (group I) had significantly higher percentages of CD8+ cells producing IFN-gamma compared to healthy donors. A detailed analysis of cytokine production patterns revealed that this was accompanied by an increased frequency of single IFN-gamma positive cells, i.e., cells not expressing most of the other cytokines tested. Similarly, patients in group I also showed higher percentages of CD8+ TNF-alpha positive cells than healthy donors. In this case, cells co-expressing TNF-alpha and IFN-gamma were found at significantly higher frequencies. No increase in Th1 type cytokines, such as IFN-gamma or TNF-alpha, was detectable in CD4+ T-cells. In contrast, CD4+ T-cells from group I patients showed significantly higher percentages of cells producing Th2 cytokines, such as IL-4 or IL-13. The lack of increased Th1 cytokine production accompanied by an increased Th2 cytokine production seems to be a special feature of HT patients with elevated CT levels that may reflect a pathogenetic mechanism for tumor initiation.

The measurement of basal serum calcitonin (CT) in patients with evidence of Hashimoto's thyroiditis (HT) has been proposed in a recent study demonstrating an increased prevalence of elevated basal and stimulated CT. The aim of this study was to evaluate the frequency and relevance of elevated CT levels in HT. The basal sera CT were measured in 568 consecutive HT patients using a chemiluminescent immuno-assay. Whenever the serum CT was > 10 pg/ml, a pentagastrin (PG) stimulation test was performed. Two patients with abnormal/pathological PG tests were identified. Total thyroidectomy and lymph node dissection revealed for the first patient medullary thyroid carcinoma (MTC) and for the second patient C cell hyperplasia (CCH), together with papillary thyroid carcinoma. Our data showed a low prevalence of MTC and its premalignant condition CCH in HT patients; nevertheless, the patient with MTC presented lymph node metastasis. The fact that both cases presented without evidence of nodular thyroid disease highlights the persistent diagnostic dilemma of CT screening programs.