Roberta Danieli

18F-choline PET/CT physiological distribution and pitfalls in image interpretation: experience in 80 patients with prostate cancer.

Objectives18F-choline positron emission tomography (PET)/computed tomography (CT) is an integral part in restaging of patients with prostate cancer (PC). The aim of this study was to describe the whole-body physiologic distribution of 18F-choline and to discuss some abnormal sites of uptake not related to PC we observed. Materials and methodsEighty consecutive patients submitted to 18F-choline PET/CT imaging for primary staging or biochemical recurrence (prostate specific antigen rising) after treatment of PC was considered. Whole-body PET/CT was acquired approximately 40 min after 18F-choline injection. ResultsWe observed physiological 18F-choline uptake in liver, pancreas, spleen, salivary and lachrymal glands and also, owing to renal excretion, in urinary tract. Other sites of less intense tracer uptake were bone marrow and intestines. We found abnormal and unexpected PET findings in 15 patients (18.7%), not owing to PC localizations. The majority of these findings were owing to inflammation (12 of 15); a case of low grade lymphoma was detected; two patients showed focal brain uptake of 18F-choline and were subsequently submitted to magnetic resonance: in one a meningioma and in the other a low-grade brain tumour were diagnosed. ConclusionAccurate knowledge of the biodistribution of 18F-choline is essential for the correct interpretation of PET/CT imaging. CT enables differentiation of physiological bowel activity and 18F-choline excretion in the ureters. In our series, 18F-choline uptake in benign pathological conditions mainly included sites of inflammation; nevertheless, accumulation in tumour deposits not because PC cannot be excluded, particularly in the brain, where correlative imaging with magnetic resonance is of the utmost importance.

Role of PET/CT in the detection of liver metastases from colorectal cancer

PurposeThe aim of this study was to compare the diagnostic accuracy of 2-[fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography (18F-FDG-PET) and computed tomography (CT) with PET/CT in the detection of liver metastases during tumour staging in patients suffering from colorectal carcinoma for the purposes of correct surgical planning and follow-up.Materials and methodsA total of 467 patients underwent a PET/CT scan using an iodinated contrast medium. We compared images obtained by the single PET scan, the single CT scan and by the fusion of the two procedures (PET/CT). The final diagnosis was obtained by histological examination and/or by the follow-up of all patients, including those who did not undergo surgery or biopsy.ResultsThe PET scan had 94.05% sensitivity, 91.60% specificity and 93.36% accuracy; the CT scan had 91.07% sensitivity, 95.42% specificity and 92.29% accuracy. The combined procedures (PET/CT) had the following values: sensitivity 97.92%, specificity 97.71% and accuracy 97.86%.ConclusionsThis study indicates that PET/CT is very useful in staging and restaging patients suffering from colorectal cancer. It was particularly useful when recurrences could not be visualised either clinically or by imaging despite increasing tumour markers, as it guaranteed an earlier diagnosis. PET/CT not only provides high diagnostic performance in terms of sensitivity and specificity, enabling modification of patient treatment, but it is also a unique, high-profile procedure that can produce cost savings.RiassuntoObiettivoComparare l’accuratezza diagnostica della 18F-FDG-PET e della TC con quella della PET/TC nel rilievo di metastasi epatiche in pazienti affetti da carcinoma del colon-retto in fase di staging ai fini di un corretto planning chirurgico e follow-up.Materiali e metodiSono stati valutati 467 pazienti mediante PET/TC effettuata con somministrazione di MdC organoiodato. È stata effettuata una comparazione tra le immagini ottenute dalla sola rilevazione PET, dalla sola rilevazione TC e quelle ottenute mediante fusione PET/TC. La diagnosi definitiva è stata ottenuta mediante conferma istologica e/o attraverso il follow-up di tutti i pazienti, anche di quelli non sottoposti a procedure bioptiche o ad intervento chirurgico.RisultatiLa tecnica PET è risultata avere una sensibilità pari al 94,05%, una specificità pari al 91,60% ed un’accuratezza del 93,36%; la tecnica TC una sensibilità pari al 91,07%, una specificità pari al 95,42% ed un’accuratezza del 92,29%. La tecnica combinata (PET/TC) è risultata avere una sensibilità pari al 97,92%, una specificità pari al 97,71%, ed un’accuratezza del 97,86%.ConclusioniLa PET/TC è risultata di notevole utilità nella stadiazione e ristadiazione dei pazienti affetti da tumore del colon-retto. Essa è risultata particolarmente efficace quando, pur in presenza di un innalzamento progressivo dei marcatori, non era visualizzabile clinicamente o strumentalmente ripresa di malattia, garantendo così un’anticipazione diagnostica. La PET/TC non solo offre una performance diagnostica ottimale in termini di sensibilità e specificità, permettendo peraltro di modificare l’iter terapeutico del paziente, ma riveste anche caratteri di indagine unica di elezione, con conseguenti risparmi economici.Purpose. The aim of this study was to compare the diagnostic accuracy of 2-[fluorine-18] fluoro-2-deoxy-Dglucose positron emission tomography ( 18 F-FDG-PET) and computed tomography (CT) with PET/CT in the detection of liver metastases during tumour staging in patients suffering from colorectal carcinoma for the purposes of correct surgical planning and follow-up. Materials and methods. A total of 467 patients underwent a PET/CT scan using an iodinated contrast medium. We compared images obtained by the single PET scan, the single CT scan and by the fusion of the two procedures (PET/CT). The final diagnosis was obtained by histological examination and/or by the follow-up of all patients, including those who did not undergo surgery or biopsy.

Different patterns of cardiac sympathetic denervation in tremor-type compared to akinetic-rigid-type Parkinson's disease: Molecular imaging with 123I-MIBG

The aim of this study was to evaluate the correlation between the clinical motor phenotypes of Parkinsons disease (PD) and ¹²³I-MIBG myocardial uptake. In total, 53 patients with PD [31 males and 22 females, mean age 62±10 years; 19 Hoehn & Yahr (H&Y) stage 1, 9 stage 1.5, 15 stage 2 and 10 at stage 3] were examined and subdivided into different clinical forms on the basis of dominance of resting tremor (n=19, TDT) and bradykinesia plus rigidity (n=34, ART). This status was correlated with the semi-quantitative analysis of ¹²³I-MIBG myocardial uptake. An age-matched control group of 18 patients was recruited (8 males and 10 females, mean age 62.4±16.3 years). ¹²³I-MIBG myocardial uptake significantly correlated with disease duration in early (r²=0.1894; P=0.0028) and delayed images (r²=0.1795; P=0.0037) in PD patients, while no correlation was found when considering age at examination, UPDRS III motor examination section score and H&Y score. PD patients showed a reduced ¹²³I-MIBG myocardial uptake compared to the control group in early (P=0.0026) and delayed images (P=0.0040), and ¹²³I-MIBG myocardial uptake was significantly lower in delayed images in TDT patients compared with ART patients (P=0.0167). A decrease was detected in the heart-to-mediastinum (H/M) ratio in delayed images compared to that of the early images in TDT patients (P=0.0040) and in the whole PD population (P=0.0012), while no differences were found in ART patients (P=0.1043). The results of the present study revealed that the cardiac sympathetic system is more severely impaired in TDT than in ART patients and ¹²³I-MIBG molecular imaging has the potential help in improving therapeutic planning in these patients.

Integrated multislice CT and Tc–99m Sestamibi SPECT–CT evaluation of solitary pulmonary nodules

Purpose.The purpose of this study was to evaluate efficacy of multislice computed tomography (MSCT) and single photon emission computed tomography (SPECT)–CT with Tc–99m Sestamibi in the assessment of solitary pulmonary nodules of uncertain significance. Scintigraphy was performed using a ‘hybrid’ g–camera that allows simultaneous acquisition of SPECT and CT images, with interesting results in diagnostic oncology.Materials and methods.Between September 2003 and August 2004, 23 patients with a solitary pulmonary nodule detected on CT underwent SPECT–CT using Tc–99m Sestamibi as a radiotracer. Nodules with positive scintigraphy were immediately subjected to biopsy or surgical resection. Nodules with negative scintigraphy were followed up after 3–4 months by MSCT with automatic segmentation software (Advanced Lung Analysis, ALA) and histological characterisation.Results.Of the 23 nodules (size range 0.8–2 cm) discovered with MSCT, 11 showed intense uptake of Tc–99m Sestamibi. Ten lesions were true positive: seven adenocarcinomas, one squamous cell carcinoma, one large cell carcinoma and one metastasis. The only false positive was histologically classified as a large cell granuloma. Twelve lesions had negative scintigraphy: five fibrous lesions, three hamartomas, three granulomas and one adenocarcinoma (false negative). Benign nodules without tracer uptake underwent another CT scan 3–4 months later, which confirmed stability of the nodule size. Correlation of Sestamibi SPECT with histology showed sensitivity (Se) of 90.9 %, specificity (Sp) of 91.6 %, diagnostic accuracy of 91.3 %, positive predictive value (PPV) of 90.9% and negative predictive value (NPV) of 91.6 %.Conclusions.The integrated use of MSCT and Tc–99m Sestamibi SPECT–CT could be very useful in the management of solitary pulmonary nodules (SPNs). In particular, in our preliminary study, scintigraphy provided significant diagnostic information to differentiate benign from suspicious pulmonary nodules. The use of scintigraphy could be helpful to anticipate histological assessment and surgical treatment of SPNs identified at CT.

Is cerebral glucose metabolism affected by chemotherapy in patients with Hodgkin's lymphoma?

ObjectiveThe aim of the study was to investigate the effect of chemotherapy treatment with ABVD on brain glucose metabolism in patients with Hodgkin’s disease (HD). MethodsA total of 49 patients (23 men, 26 women; mean age 32±9 years) diagnosed with HD were included in the study. All of them underwent a baseline (PET0) and an interim (PET2) 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) PET/computed tomography (CT) brain scan. All patients were treated after PET0 with two cycles of ABVD consisting of doxorubicin (adriamycin), bleomycin, vinblastine, and dacarbazine for 2 months. Thirty-five patients were evaluated further 15±6 days after four additional cycles (PET6). Differences in brain 18F-FDG uptake were analyzed by statistical parametric mapping (SPM2). ResultsCompared with PET0, PET2 showed a significantly higher metabolic activity in the right angular gyrus (Brodmann area 39) and a significant metabolic reduction in Brodmann areas 10, 11, and 32 bilaterally. All these changes disappeared at PET6. ConclusionOur results support the conclusion of a very limited impact of ABVD chemotherapy on brain metabolism in patients with HD.

Initial staging of hodgkin's disease: Role of contrast-enhanced 18F FDG PET/CT

AbstractThe objective of this study was to compare the diagnostic accuracy of positron emission tomography/low-dose computed tomography (PET/ldCT) versus the same technique implemented by contrast-enhanced computed tomography (ceCT) in staging Hodgkin’s disease (HD).Forty patients (18 men and 22 women, mean age 30 ± 9.6) with biopsy-proven HD underwent a PET/ldCT study for initial staging including an unenhanced low-dose computed tomography for attenuation correction with positron emission tomography acquisition and a ceCT, performed at the end of the PET/ldCT scan, in the same exam session. A detailed datasheet was generated for illness locations for separate imaging modality comparison and then merged in order to compare the separate imaging method results (PET/ldCT and ceCT) versus merged results positron emission tomography/contrast-enhanced computed tomography (PET/ceCT). The nodal and extranodal lesions detected by each technique were then compared with follow-up data that served as the reference standard.No significant differences were found at staging between PET/ldCT and PET/ceCT in our series. One hundred and eighty four stations of nodal involvement have been found with no differences in both modalities. Extranodal involvement was identified in 26 sites by PET/ldCT and in 28 by PET/ceCT. We did not find significant differences concerning the stage (Ann Arbor).Our study shows a good concordance and conjunction between PET/ldCT and ceCT in both nodal and extranodal sites in the initial staging of HD, suggesting that PET/ldCT could suffice in most of these patients.

Brain metabolic changes in hodgkin disease patients following diagnosis and during the disease course: An 18F-FDG PET/CT study

The aim of the present study was to investigate brain glucose metabolism in patients with Hodgkin disease (HD) after diagnosis and during chemotherapy treatment. Following the administration of first-line doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy, 74 HD patients underwent 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography brain scans, both baseline (PET0) and interim (PET2) at the Department of Biomedicine and Prevention, University of Rome Tor Vergata (Rome, Italy). Fifty-seven patients were further evaluated 15±6 days after four additional cycles (PET6). Furthermore, a control group (CG) of 40 chemotherapy-naïve subjects was enrolled. Differences in brain 18F-FDG uptake between the CG, PET0, PET2 and PET6 scans were analyzed using statistical parametric mapping. Compared with the PET0 and CG scans, the PET2 scan demonstrated a higher metabolic activity in Brodmann area (BA) 39, and a metabolic reduction in BA 11 bilaterally and in left BA 32. All of these changes disappeared at PET6. The results of the present study indicate that ABVD chemotherapy has a limited impact on brain metabolism.

Role of [18F]-FDG-PET/MDCT in evaluating early response in patients with Hodgkin’s lymphoma

PurposeThe authors evaluated the prognostic role of 18-fluoro-fluorodeoxyglucose positron emission tomography/multidetector computed tomography ([18F]-FDG PET/MDCT) in treating patients with Hodgkin’s lymphoma (HL).Materials and methodsWe retrospectively evaluated 132 patients with HL studied with PET/MDCT before the start of chemotherapy (CTX) for staging purposes and again after two CTX cycles with [doxorubicin (Adriblastin), bleomycin, vinblastine, dacarbazine (ABVD_] (interim PET/MDCT), at least 30 days after the end of the last CTX cycle and/or 3 months after the end of radiotherapy, if delivered (final PET-MDCT).ResultsInterim PET-MDCT was negative in 104/132 patients (79%), and their final PET-MDCT showed complete remission in 102/104 (98%) of cases, with disease recurrence/persistence in two (2%). In the remaining 28 (21%) patients, interim PET-MDCT revealed an early response in 68% of cases and chemoresistance with disease progression in 32% of cases; in these 28 patients, final PET-MDCT showed a lack of response to treatment in 43% of cases (43%) and complete remission in 57% of cases. Statistical analysis of these data showed that interim PET-MDCT had a negative predictive value of 98% and a positive predictive value of 42%, with values of sensitivity, specificity and diagnostic accuracy of 85.7%, 86.4% and 86.4%, respectively.ConclusionsInterim PET-MDCT has a reliable prognostic role in diagnosis and treatment of patients with HL, as it helps predict which patients are more likely to achieve a complete response at the end of treatment. PET/MDCT may also lead to a change in treatment, with reduced treatment-related toxic effects and significantly reduced total costs.RiassuntoObiettivoValutare il ruolo prognostico della 18F-FDG PET/TCms nel trattamento dei pazienti con linfoma di Hodgkin (LH).Materiali e metodiSono stati studiati retrospettivamente 132 pazienti affetti da LH con PET-TCms alla stadiazione della malattia e prima della terapia, dopo 2 cicli di chemioterapia (CHT) ABVD [doxorubicina (Adriblastina), Bleomicina, Vinblastina e Dacarbazina] (PET-TCms “in itinere”), almeno dopo 30 giorni dall’ultimo ciclo di CHT e/o dopo tre mesi dal termine della radioterapia, quando prevista (PET-TCms finale).Risultati104 (79%), dei 132 pazienti studiati, hanno presentato la PET-TCms “in itinere” negativa; la PETTCms finale in tali pazienti ha mostrato la remissione completa in 102 pazienti (98%) ed una recidiva/persistenza di malattia in 2 (2%). In 28 pazienti (21%) abbiamo riscontrato alla PET-TCms “in itinere”, una risposta precoce parziale nel 68% e una chemioresistenza con progressione di malattia nel 32%; in tali pazienti la PET-TCms finale ha mostrato una mancata risposta al trattamento in 12 casi (43%) e una remissione completa in 16 (57%). Dall’analisi statistica di questi dati è emerso che la PET-TCms “in itinere” possiede un valore predittivo negativo (VPN) del 98% ed un valore predittivo positivo (VPP) del 42% con valori del 85,7%, 86,4% ed 86,4% rispettivamente di sensibilità, la specificità e di accuratezza diagnostica [intervallo di confidenza (IC) 95].ConclusioniLa PET-TCms “in itinere” può avere un importante significato prognostico durante il percorso diagnostico-terapeutico dei pazienti affetti da LH, permettendo di identificare precocemente il numero di pazienti con elevata probabilità di risposta completa della malattia al termine della terapia. Può anche essere utile nelle scelte terapeutiche con riduzione degli effetti tossici correlati e dei costi complessivi.

Cortical metabolic arrangement during olfactory processing: proposal for a 18F FDG PET/CT methodological approach.

Abstract The aim of this article is to investigate the cortical metabolic arrangements in olfactory processing by using 18F fluorodeoxyglucose (FDG) positron emission tomography/computed tomography. Twenty-six normosmic individuals (14 women and 12 men; mean age 46.7 ± 10 years) were exposed to a neutral olfactory condition (NC) and, after 1 month, to a pure olfactory condition (OC) in a relatively ecological environment, that is, outside the scanner. All the subjects were injected with 185–210 megabecquerel of 18F FDG during both stimulations. Statistical parametric mapping version 2 was used in order to assess differences between NC and OC. As a result, we found a significant higher glucose consumption during OC in the cuneus, lingual, and parahippocampal gyri, mainly in the left hemisphere. During NC, our results show a relative higher glucose metabolism in the left superior, inferior, middle, medial frontal, and orbital gyri as well as in the anterior cingulate cortex. The present investigation, performed with a widely available functional imaging clinical tool, may help to better understand the neural responses associated to olfactory processing in healthy individuals and in patients with olfactory disorders by acquiring data in an ecologic, noise-free, and resting condition in which possible cerebral activations related to unwanted attentional processes might be avoided.

Early cortical metabolic rearrangement related to clinical data in idiopathic sudden sensorineural hearing loss

Abstract Results in studies concerning cortical changes in idiopathic sudden sensorineural hearing loss (ISSNHL) are not homogeneous, in particular due to the different neuroimaging techniques implemented and the diverse stages of ISSNHL studied. Considering the recent advances in state‐of‐the‐art positron emission tomography (PET) cameras, the aim of this study was to gain more insight into the neuroanatomical differences associated with the earliest stages of unilateral ISSNHL and clinical‐perceptual performance changes. After an audiological examination including the mean auditory threshold (mean AT), mean speech discrimination score (mean SDS) and Tinnitus Handicap Inventory (THI), 14 right‐handed ISSNHL patients underwent brain [18F]fluorodeoxyglucose (FDG)‐PET within 72 h of the onset of symptoms. When compared to an homogeneous group of 35 healthy subjects by means of statistical parametric mapping, a relative increase in FDG uptake was found in the right superior and medial frontal gyrus as well as in the right anterior cingulate cortex in ISSNHL patients. Conversely, the same group showed a significant relative decrease in FDG uptake in the right middle temporal, precentral and postcentral gyrus as well as in the left posterior cingulate cortex, left lingual, superior, middle temporal and middle frontal gyrus and in the left insula. Regression analysis showed a positive correlation between mean THI and glucose consumption in the right anterior cingulate cortex and a positive correlation between mean SDS and glucose consumption in the left precentral gyrus. The relative changes in FDG uptake found in these brain regions and the positive correlation with mean SDS and THI scores in ISSNHL could possibly highlight new aspects of cerebral rearrangement, contributing to further explain changes in those functions that support speech recognition during the sudden impairment of unilateral auditory input. HighlightsBrain changes in idiopathic sudden sensorineural hearing loss are not homogeneous.FDG PET/CT was demonstrated to be a quiet and reliable auditory imaging technique.FDG uptake decrease was found in auditory scene analysis network in ISSNHL.Positive correlation between anterior cingulated cortex and tinnitus score.Positive correlation between insula and speech discrimination score.