Diagnostic and prognostic value of 18F-FDG PET/CT in comparison with morphological imaging in primary adrenal gland malignancies - a multicenter experience.

OBJECTIVE: To evaluate the diagnostic and prognostic role of fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) in comparison to morphological imaging such as computed tomography in primary adrenal malignancies. MATERIALS AND METHODS: In this multicenter retrospective study, 68 patients with adrenal malignancy were included. All patients had histologically proven diagnosis of primary adrenal malignancy (adrenocortical carcinoma, malignant pheochromocytoma, neuroblastoma and lymphoma), one whole body (18)F-FDG PET/CT scan and one whole-body contrast enhancement computed tomography (CECT) scan acquired within one month and were followed clinically and by performing morphological tests for at least 12 months. RESULTS: Overall sensitivity, specificity, accuracy, positive and negative predictive values for CECT and (18)F-FDG PET/CT were respectively, 59%, 100%, 65%, 100%, 27% and 75%, 100%, 82%, 100% and 63%. For adrenocortical carcinomas, (18)F-FDG PET/CT showed a better accuracy (93.4%) than CECT (75%). For neuroblastomas (18)F-FDG PET/CT also showed better accuracy (70.4%) than CECT (66.7%). For malignant pheochromocytomas (18)F-FDG PET/CT and CECT showed the same accuracy (90%). For primary adrenal lymphomas, (18)F-FDG PET/CT showed better accuracy (100%) than CECT (74.41%). Kaplan-Mayer curves showed that "histotypes" and "metastases at the last follow-up" were similarly detected for both disease free survival (DFS) and overall survival (OS), while "global 18F-FDG PET/CT" and "presence of metastases at diagnosis" were significant for DFS. Stratifying the sample by the presence or absence of metastases at diagnosis, standardized uptake value (SUVmax) was a significant prognostic factor for DFS when metastases were absent (Wald test=7.035, P=0.008). CONCLUSION: Our multicenter study demonstrated that (18)F-FDG PET/CT better than CECT diagnosed adrenal malignancies achieving also a good prognostic performance. Therefore management algorithms should include (18)F-FDG PET/CT.

Lack of association between autonomously functioning thyroid nodules and germline polymorphisms of the thyrotropin receptor and Gαs genes in a mild to moderate iodine-deficient Caucasian population.

BACKGROUND: Mutations of the thyrotropin receptor (TSHR) and/or Gαs gene have been found in a number of, but not all, autonomously functioning thyroid nodules (AFTNs). Recently, in a 15-year-old girl with a hyperfunctioning papillary thyroid carcinoma, we found two somatic and germline single nucleotide polymorphisms (SNPs): a SNP of the TSHR gene (exon 7, codon 187) and a SNP of Gαs gene (exon 8, codon 185). The same silent SNP of the TSHR gene had been reported in patients with AFTN or familial non-autoimmune hyperthyroidism. No further data about the prevalence of the two SNPs in AFTNs as well as in the general population are available in the literature. AIM: To clarify the possible role of these SNPs in predisposing to AFTN. METHODS: Germline DNA was extracted from blood leukocytes of 115 patients with AFTNs (43 males and 72 females, aged 31-85 years, mean ± SD = 64 ± 13) and 100 sex-matched healthy individuals from the same geographic area, which is marginally iodine deficient. The genotype distribution of the two SNPs was investigated by restriction fragment length polymorphism-polymerase chain reaction. RESULTS: The prevalence of the two SNPs in our study population was low and not different to that found in healthy individuals: 8 % of patients vs. 9 % of controls were heterozygous for the TSHR SNP and 4 % patients vs. 6 % controls were heterozygous for the Gαs SNP. One patient harbored both SNPs. CONCLUSIONS: These results suggest that these two SNPs do not confer susceptibility for the development of AFTN.

Is %ΔSUVmax a useful indicator of survival in patients with advanced nonsmall-cell lung cancer?

PURPOSE: To investigate the impact of the maximum standardized uptake value (SUVmax), size of primary lung lesion, and %ΔSUVmax on outcome (overall survival (OS) and 2-year disease-free survival (2-year DFS)) of patients with advanced nonsmall-cell lung cancer (NSCLC). MATERIALS AND METHODS: 86 stage III-IV NSCLC patients underwent 18 F-FDGPET/CT, before and after chemotherapy, and were classified into subgroups according to the response criteria of the European Organization for Research and Treatment of Cancer. SUVmax values and tumor size with the best prognostic significance were searched. Correlation between the SUVmax value and the initial response to therapy (best response) and the relationship between %ΔSUVmax and OS were assessed. RESULTS: In patients in PD (20/86), the average pretreatment SUVmax was 11.8 ± 5.23, and the mean size of the primary lesion was 43.35 mm ± 16.63. In SD, PR, and CR patients (66/86), the average pretreatment SUVmax was 12.7 ± 8.05, and the mean size of the primary lesion was 41.6 mm ± 21.15. Correlation was identified only for %ΔSUVmax; patients with PD (ΔSUVmax > +25%) showed a worse OS than patients with ΔSUVmax < +25% (CR, PR, and SD) (P = 0.0235). CONCLUSIONS: In stage III-IV NSCLC, among the assessed factors, only %ΔSUVmax may be considered as a useful prognostic factor.

Oxidative Stress: Harms and Benefits for Human Health.

Oxidative stress is a phenomenon caused by an imbalance between production and accumulation of oxygen reactive species (ROS) in cells and tissues and the ability of a biological system to detoxify these reactive products. ROS can play, and in fact they do it, several physiological roles (i.e., cell signaling), and they are normally generated as by-products of oxygen metabolism; despite this, environmental stressors (i.e., UV, ionizing radiations, pollutants, and heavy metals) and xenobiotics (i.e., antiblastic drugs) contribute to greatly increase ROS production, therefore causing the imbalance that leads to cell and tissue damage (oxidative stress). Several antioxidants have been exploited in recent years for their actual or supposed beneficial effect against oxidative stress, such as vitamin E, flavonoids, and polyphenols. While we tend to describe oxidative stress just as harmful for human body, it is true as well that it is exploited as a therapeutic approach to treat clinical conditions such as cancer, with a certain degree of clinical success. In this review, we will describe the most recent findings in the oxidative stress field, highlighting both its bad and good sides for human health.

A didactic experiment showing the Compton scattering by means of a clinical gamma camera.

We describe a didactic approach aimed to explain the effect of Compton scattering in nuclear medicine imaging, exploiting the comparison of a didactic experiment with a gamma camera with the outcomes from a Monte Carlo simulation of the same experimental apparatus. We employed a 99mTc source emitting 140.5keV photons, collimated in the upper direction through two pinholes, shielded by 6mm of lead. An aluminium cylinder was placed on the source at 50mm of distance. The energy of the scattered photons was measured on the spectra acquired by the gamma camera. We observed that the gamma ray energy measured at each step of rotation gradually decreased from the characteristic energy of 140.5keV at 0° to 102.5keV at 120°. A comparison between the obtained data and the expected results from the Compton formula and from the Monte Carlo simulation revealed a full agreement within the experimental error (relative errors between -0.56% and 1.19%), given by the energy resolution of the gamma camera. Also the electron rest mass has been evaluated satisfactorily. The experiment was found useful in explaining nuclear medicine residents the phenomenology of the Compton scattering and its importance in the nuclear medicine imaging, and it can be profitably proposed during the training of medical physics residents as well.

Role of molecular imaging in the management of patients affected by inflammatory bowel disease: State-of-the-art.

AIM: To present the current state-of-the art of molecular imaging in the management of patients affected by inflammatory bowel disease (IBD). METHODS: A systematic review of the literature was performed in order to find important original articles on the role of molecular imaging in the management of patients affected by IBD. The search was updated until February 2016 and limited to articles in English. RESULTS: Fifty-five original articles were included in this review, highlighting the role of single photon emission tomography and positron emission tomography. CONCLUSION: To date, molecular imaging represents a useful tool to detect active disease in IBD. However, the available data need to be validated in prospective multicenter studies on larger patient samples.

Gliomas with intratumoral abscess formation: Description of new cases, review of the literature, and the role of (99m)TC-Leukoscan.

Abscess formation within a brain tumor is uncommon. Intrasellar or parasellar tumors are the most common neoplasms that develop such complications. Cerebral gliomas with abscesses are extremely rare. In this paper three rare cases of glioma associated with abscess formation are described. The diagnosis of brain tumor associated with abscess is particularly difficult by conventional neuroradiological studies. (99m)Tc-labeled sulesomab can be useful in the diagnosis of brain tumors with intratumoral abscesses. There are no precise guidelines for the diagnosis and treatment of cerebral gliomas associated with abscesses formation for the low number of cases reported to date. Appropriate treatment, aimed at radical surgery, and a suitable antibiotic-protocol, deferring adjuvant postoperative therapy, is associated with a more favorable outcome. A review of the pertinent literature is also performed.

Is malignant nodule topography an additional risk factor for metastatic disease in low-risk differentiated thyroid cancer?

BACKGROUND: Differentiated thyroid cancer (DTC) is the most common endocrine malignancy. In recent decades, the incidence has been increasing, largely due to increased detection of patients with low-risk or very low-risk DTC. According to European Thyroid Association and American Thyroid Association guidelines, radioiodine (RAI) thyroid remnant ablation is not indicated in very low-risk patients, while its role is still debated in low-risk patients. Accordingly, risk stratification of DTC patients is pivotal when deciding for or against RAI ablation. Presently, risk stratification is based on pTNM staging integrated with clinical parameters. The aim of our study was to evaluate the relationship between location of malignant thyroid nodules within the thyroid gland and the presence of loco-regional and/or distant metastases in patients with pT1a-pT1b DTCs. METHODS: We reviewed the records of 246 patients (214 women, 32 men; female-to-male ratio 6.7:1) affected by unifocal DTC ≤ 2 cm, who had undergone RAI thyroid remnant ablation (activity ranged 555-4588 MBq) after levothyroxine withdrawal or after recombinant human TSH (rhTSH) stimulation. The majority of the patients (91.5%) were affected by papillary thyroid carcinoma. RESULTS: Metastases were discovered by posttreatment whole-body scintigraphy in 29 out of 246 (11.8%) patients. In patients with metastases, malignant thyroid nodules were located in the right lobe (14/123, 11.4%), left lobe (7/95, 7.4%), and isthmus (8/27, 29.6%). The prevalence of metastases was significantly higher in patients with DTC located in the isthmus, compared to other sites (χ(2) = 9.6, p = 0.002). CONCLUSIONS: Our data show for the first time that a location of a thyroid cancer in the isthmus is an additional risk factor for RAI avid metastatic disease in pT1a-pT1b DTC patients, regardless of the presence or absence of other risk factors.

Peptide receptor imaging in neuroendocrine tumors: comparison between diagnostic scintigraphy and post-therapy whole-body scan.

OBJECTIVE: Several different somatostatin analogs labeled with gamma or positron-emitting radionuclides exist for diagnostic imaging of neuroendocrine tumors (NETs). Differences between standard diagnostic scintigraphy (SDS) and post-therapy whole-body scan (PTWBS) at peptide receptor radionuclide therapy in lesion detection are known; such differences have been correlated with the varying degree of receptor subtype expression and the varying receptor affinity profile of the different ligands. The aim of this study is to investigate differences between SDS and PTWBS obtained using the same radiopharmaceutical. METHODS: We retrospectively reviewed clinical records of 53 patients with a diagnosis of NET, who underwent both SDS and PTWBS using (111)In-Pentetreotide. We compared the number of lesions for each body region detected by SDS and PTWBS. RESULTS: In 14/53 patients (26.4%) discrepancies between SDS and PTWBS were found. PTWBS detected 68 additional lesions with respect to SDS that were distributed as follows: head and neck, 6; mediastinum, 1; liver, 10; abdomen/pelvis, 1; bone, 44; other localizations, 6. The number of lesions detected by SDS was significantly different from that revealed by PTWBS (Wilcoxon matched pairs test, P = 0.0313). The regions that contributed significantly to reach this difference were head and neck (McNemar test, P = 0.0412), liver (McNemar test, P = 0.0044), bone (McNemar test, P < 0.0001) and other localizations (McNemar test, P = 0.0412). CONCLUSION: PTWBS shows more lesions than SDS with a significant discrepancy. We suppose that administration of higher radiopharmaceutical activity, use of larger peptide amount and the different time interval between radiopharmaceutical administration and scan execution can determine a higher sensitivity of PTWBS.

Is detection of additional lesions in post-peptide receptor radionuclide therapy scans with respect to diagnostic imaging only due to different affinity of ligands?: a report of discordance between diagnostic and posttherapy imaging using the same ligand.

It is known that different affinity profiles for somatostatin receptor subtypes among different radiopharmaceuticals result in different organ and tumor uptakes and even in different sensitivities in the detection of lesions. Such differences are considered main factors explaining cases of detecting additional lesions in posttherapy scans with respect to diagnostic imaging. We show a posttherapy scan revealing more lesions--namely, a diffuse bone involvement with many small focal bony uptake areas--than the diagnostic scan using the same radiopharmaceutical (111In-pentetreotide) in a 71-year-old man with metastases from a well-differentiated ileal neuroendocrine tumor.

Accidental discovery of lung metastases from differentiated thyroid cancer by 99mTc sodium pertechnetate scan in a patient with secondary hyperparathyroidism.

We present a 75-year-old-man affected by chronic renal failure in whom metastases from differentiated thyroid cancer (DTC) were incidentally discovered at TcO4 neck-thorax scan in the setting of a diagnosis of secondary hyperparathyroidism. Ten years before, he had undergone near-total thyroidectomy for a multinodular goiter. Result of the pathological examination was negative for DTC. At our observation, serum thyroglobulin was high in the absence of Tg-Ab, consistent with metastatic disease. Neck ultrasonographynography was negative. The patient underwent I therapy (3700 MBq) after stimulation with recombinant human thyroid-stimulating hormone. Postdose whole-body scan confirmed the metastases already demonstrated by TcO4.

Central nervous system vasculitis after starting methimazole in a woman with Graves' disease.

BACKGROUND: Graves' disease (GD), a prototypical autoimmune disorder, is associated with other autoimmune diseases, including vasculitis. Antithyroid drugs, despite their postulated immunosuppressive effects, may cause several autoimmune disorders. Here we describe the first patient with central nervous system (CNS) vasculitis that developed shortly after the start of methimazole (MMI) treatment for GD. PATIENT FINDINGS: CNS vasculitis was suspected on the basis of the clinical features and neurologic examination, showing a reinforcement of deep reflexes, especially of the left knee and Achilles reflexes. The diagnosis was confirmed by a brain magnetic resonance imaging (MRI), which showed some hyperintensive spots in the subcortical substantia alba and in the parietal area bilaterally, and by a single-photon emission computed tomography (SPECT) imaging, which showed a nonhomogenous distribution of the blood flow in the brain, with a reduced perfusion on the left side of the frontotemporal and parietal regions, and on the right side of the frontotemporal area. MMI was stopped before total thyroidectomy, and symptoms resolved in the next 5 weeks. Six months after MMI was stopped, the brain MRI and SPECT had become normal. SUMMARY: To our knowledge, this is the first report of CNS vasculitis related to MMI therapy.