nuove applicazioni della medicina nucleare in ambito diagnostico ii parte

Summary Introduction Positron-emission tomography (PET) and single photon emission computed tomography (SPECT) are effective diagnostic imaging tools in several clinical settings. The aim of this article (the second of a 2-part series) is to examine some of the more recent applications of nuclear medicine imaging techniques, particularly in the fields of neurology, cardiology, and infection/inflammation. Discussion A review of the literature reveals that in the field of neurology nuclear medicine techniques are most widely used to investigate cognitive deficits and dementia (particularly those associated with Alzheimer disease), epilepsy, and movement disorders. In cardiology, SPECT and PET also play important roles in the work-up of patients with coronary artery disease, providing accurate information on the state of the myocardium (perfusion, metabolism, and innervation). White blood cell scintigraphy and FDG-PET are widely used to investigate many infectious/inflammatory processes. In each of these areas, the review discusses the use of recently developed radiopharmaceuticals, the growth of tomographic nuclear medicine techniques, and the ways in which these advances are improving molecular imaging of biologic processes at the cellular level

Does 18F-Fluorocholine PET/CT add value to positive parathyroid scintigraphy in the presurgical assessment of primary hyperparathyroidism?

IntroductionTo investigate the value of presurgical 18F-FCH PET/CT in detecting additional hyperfunctioning parathyroids despite a positive 99mTc-sestamibi parathyroid scintigraphy in patients with primary hyperparathyroidism (pHPT).MethodsThis is a retrospective study involving patients with pHPT, positive parathyroid scintigraphy performed before 18F-FCH PET/CT, and parathyroid surgery achieved after PET/CT. Imaging procedures were performed according to the EANM practice guidelines. Images were qualitatively interpreted as positive or negative. The number of pathological findings, their topography, and ectopic location were recorded. Histopathology, Miami criterion, and biological follow-up were considered to ensure effective parathyroidectomy confirming the complete excision of all hyperfunctioning glands. The impact of 18F-FCH PET/CT on therapeutic strategy was recorded.Results64/632 scanned pHPT patients (10%) were included in the analysis. According to a per lesion-based analysis, sensitivity, specificity, positive predictive value, and negative predictive value of 99mTc-sestamibi scintigraphy were 82, 95, 87, and 93%, respectively. The same values for 18F-FCH PET/CT were 93, 99, 99, and 97%, respectively. 18F-FCH PET/CT showed a significantly higher global accuracy than 99mTc-sestamibi scintigraphy: 98% (CI: 95–99) vs. 91% (CI: 87–94%). Youden Index was 0.79 and 0.92 for 99mTc-sestamibi scintigraphy and 18F-FCH PET/CT, respectively. Scintigraphy and PET/CT were discordant in 13/64 (20%) patients (49 glands). 18F-FCH PET/CT identified nine pathologic parathyroids not detected by 99mTc-sestamibi scintigraphy in 8 patients (12.5%). Moreover, 18F-FCH PET/CT allowed the reconsideration of false-positive scintigraphic diagnosis (scinti+/PET-) for 8 parathyroids in 7 patients (11%). The 18F-FCH PET/CT influenced the surgical strategy in 7 cases (11% of the study population).ConclusionIn a preoperative setting, 18F-FCH PET/CT seems more accurate and useful than 99mTc-sestamibi scan in pHPT patients with positive scintigraphic results. Positive parathyroid scintigraphy could be not satisfactory before neck surgery particularly in patients with multiglandular disease, suggesting a need to evolve the practice and define new preoperative imaging algorithms including 18F-FCH PET/CT at the fore-front in pHPT patients

Nuove applicazioni della medicina nucleare in ambito diagnostico (I parte)

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Incidental thyroid 99mTc-MDP uptake in a patient affected by differentiated thyroid cancer

We report a case of incidental uptake of 99mTc-methylene diphosphonate in the thyroid in a 62-year-old female with a history of breast cancer treated with quadrantectomy, chemotherapy and radiotherapy, who underwent total-body-bone scintigraphy during follow up. Planar scintigraphy was followed by neck SPECT-CT that demonstrated an area of increased tracer uptake in the neck at the left lobe of the thyroid. Neck ultrasonography showed a nodule corresponding to SPECT-CT finding and the ultrasound-guided fine needle aspiration documented the presence of papillary carcinoma. The patient underwent total thyroidectomy and ipsilateral lymphadenectomy; histological examination confirmed the presence of a papillary carcinoma and the patient underwent ablation therapy with iodine-131

un caso raro di angiomatosi epatica diffusa nell adulto ruolo della scintigrafia con emazie marcate nell ambito dell imaging diagnostico multimodale

Summary Introduction Angiomas are one of the most common primary tumors of the liver. Diffuse hepatic angiomatosis, however, is quite rare and usually observed in pediatric patients. We report a rare case of diffuse hepatic hemangiomatosis in a 33-year-old woman. Case report The patient presented with abdominal pain and a palpable upper abdominal mass. Abdominal CT and magnetic resonance imaging (MRI) findings suggested diffuse hepatic hemangiomatosis, but this finding was not confirmed by subsequent contrast-enhanced abdominal ultrasonography (US). The patient then underwent single photon emission computed tomography (SPECT)/CT scintigraphy with Tc-99m-labeling of red blood cells (RBC). This examination revealed increased uptake of labeled erythrocytes in several of the hepatic lesions corresponding to CT and RM findings, thereby confirming the clinical hypothesis of diffuse hepatic hemangiomatosis. Discussion RBC scintigraphy with SPECT/CT can facilitate the comparison of other cross-sectional imaging methods such as CT and MRI. This case highlights the importance of a multiple-modality approach in the imaging diagnosis of this condition

18F-FDG PET Imaging in the Evaluation of Treatment Response to New Chemotherapies beyond Imatinib for Patients with Gastrointestinal Stromal Tumors

Aim. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is a powerful tool for staging and defining “good responders” to chemotherapy in tumor setting. Gastrointestinal stromal tumors (GISTs) are sarcoma involving gastrointestinal tract and may require a chemotherapy including imatinib, a tyrosine kinase inhibitor agent. Some GIST patients become refractory to imatinib; therefore, other tyrosine kinase inhibitors or concomitant chemotherapy may be considered for treatment. The aim of this paper is to assess if 18F-FDG PET imaging is a useful tool to evaluate treatment response to new chemotherapies beyond imatinib for GIST patients. Methods. We performed a review of the literature about the role of 18F-FDG PET in the evaluation of treatment response to new chemotherapies beyond imatinib for GIST patients. Results and Conclusions. 18F-FDG PET seems to be able to assess therapy response earlier than computed tomography (CT) imaging in imatinib refractory GIST patients treated with other agents. However, a dual modality PET-CT imaging is recommendable to achieve a better detection of all lesions

Ruolo emergente nella pratica clinica della PET con 18F-FDG nei pazienti con sarcoidosi

Summary Introduction The purpose of this article is to examine the emerging role of whole-body positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with sarcoidosis. Materials and methods We reviewed the literature on the use of FDG-PET in patients with sarcoidosis to identify how this technique is being applied in clinical practice. Results and discussion Our review shows that: 1) sarcoidosis is commonly associated with increased FDG uptake. Therefore, positive findings should be interpreted with caution when FDG-PET is being used to distinguish benign from malignant abnormalities; 2) FDG-PET seems to be a very useful molecular imaging method for staging sarcoidosis, identification of occult sites of involvement, guiding biopsy procedures, and monitoring patients' responses to treatment; and 3) in patients with sarcoidosis, the diagnostic accuracy of FDG-PET is superior to that of 67Ga scintigraphy

The emerging role of whole-body 18F-fluorodeoxyglucose positron emission tomography in patients with sarcoidosis

IntroductionThe purpose of this article is to examine the emerging role of whole-body positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in patients with sarcoidosis.Materials and methodsWe reviewed the literature on the use of FDG-PET in patients with sarcoidosis to identify how this technique is being applied in clinical practice.Results and discussionOur review shows that: 1) sarcoidosis is commonly associated with increased FDG uptake. Therefore, positive findings should be interpreted with caution when FDG-PET is being used to distinguish benign from malignant abnormalities; 2) FDG-PET seems to be a very useful molecular imaging method for staging sarcoidosis, identification of occult sites of involvement, guiding biopsy procedures, and monitoring patients' responses to treatment; and 3) in patients with sarcoidosis, the diagnostic accuracy of FDG-PET is superior to that of 67Ga scintigraphy

Detection rate of FNA cytology in medullary thyroid carcinoma. a meta-analysis

Background: The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine-needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta-analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates. Research Design and Methods: A comprehensive computer literature search of the PubMed/MEDLINE, Embase and Scopus databases was conducted by searching for the terms 'medullary thyroid' AND 'cytology', 'FNA', 'FNAB', 'FNAC', 'fine needle' or 'fine-needle'. The search was updated until 21 March 2014, and no language restrictions were used. Results: Fifteen relevant studies and 641 MTC lesions that had undergone FNAC were included. The detection rate (DR) of FNAC in patients with MTC (diagnosed as 'MTC' or 'suspicious for MTC') on a per lesion-based analysis ranged from 12·5% to 88·2%, with a pooled estimate of 56·4% (95% CI: 52·6-60·1%). The included studies were statistically heterogeneous in their estimates of DR (I-square >50%). Egger's regression intercept for DR pooling was 0·03 (95% CI: -3·1 to 3·2, P = 0·9). The study that reported the largest MTC series had a DR of 45%. Data on immunohistochemistry for calcitonin in diagnosing MTC were inconsistent for the meta-analysis. Conclusions: The presented meta-analysis demonstrates that FNAC is able to detect approximately one-half of MTC lesions. These findings suggest that other techniques may be needed in combination with FNAC to diagnose MTC and avoid false negative results. © 2014 John Wiley & Sons Ltd

The Role of 18

Purpose. To provide a first evidence-based review of the literature on the role of fluorine-18-fluorodeoxyglucose positron emission tomography and positron emission tomography/computed tomography (FDG-PET and PET/CT) in patients with colorectal liver metastases (CRLM) undergoing selective internal radiation therapy (SIRT) with yttrium-90 (90Y) microspheres. Methods. A comprehensive computer literature search was conducted to find relevant published articles on whole-body FDG-PET or PET/CT in patients with CRLM undergoing SIRT. Results. We identified 19 studies including 833 patients with CRLM undergoing SIRT. The role of FDG-PET or PET/CT was analysed in treatment planning, treatment response evaluation, and as prognostic tool. Conclusion. FDG-PET and PET/CT provide additional information in treatment evaluation of CRLM patients treated with SIRT and may have a role in treatment planning and patient selection. FDG-PET/CT is emerging as good prognostic tool in these patients