Predictive factors of [18F]-Choline PET/CT in 170 patients with increasing PSA after primary radical treatment

Aim

The purpose of this study was to evaluate the potential usefulness of [18F]-Choline PET/CT in the restaging of prostate cancer patients, who presented a rising PSA.

Materials and methods

We evaluated 170 prostate cancer patients, previously radically treated, that were referred for restaging with [18F]-Choline PET/CT.

Results

A total of 129 patients (median PSA 4.29 ng/ml at relapse) showed one or more areas of high uptake on PET/CT scan, while 41 patients with a median PSA of 1.07 ng/ml at relapse showed negative PET/CT scans. No false negative was found, while 31 patients were identified as false positive. Specificity of Choline PET/CT in our series was 56.9 %, while sensibility was 100 %. At the time of restaging, a PSA value superior or equal to 1 ng/ml was found to be a statistically significant predictive factor of PET positivity, either at the univariate (p < 0.0001) and at the multivariate analysis (p < 0.0001).

Conclusions

Based on our findings, [18F]-Choline PET/CT is confirmed as a useful diagnostic tool to detect early recurrence, in patients with increasing PSA after primary treatment. However, in case of a mild increase in PSA, positive results must be validated with other techniques, as specificity and positive predictive value of [18F]-Choline PET/CT decrease with the lower values of PSA.     

Visual rating of medial temporal lobe metabolism in mild cognitive impairment and Alzheimer’s disease using FDG-PET

Purpose This study was designed to examine the utility of visual inspection of medial temporal lobe (MTL) metabolism in the diagnosis of mild cognitive impairment (MCI) and Alzheimers disease (AD) using FDG-PET scans.Methods Seventy-five subjects [27 normal controls (NL), 26 MCI, and 22 AD] with FDG-PET and MRI scans were included in this study. We developed a four-point visual rating scale to evaluate the presence and severity of MTL hypometabolism on FDG-PET scans. The visual MTL ratings were compared with quantitative glucose metabolic rate (MR_glc) data extracted using regions of interest (ROIs) from the MRI-coregistered PET scans of all subjects. A standard rating evaluation of neocortical hypometabolism was also completed. Logistic regressions were used to determine and compare the diagnostic accuracy of the MTL and cortical ratings.Results For both MTL and cortical ratings, high intra- and inter-rater reliabilities were found (p values <0.001). The MTL rating was highly correlated with and yielded a diagnostic accuracy equivalent to the ROI MR_glc measures (p values <0.001). The combination of MTL and cortical ratings significantly improved the diagnostic accuracy over the cortical rating alone, with 100% of AD, 77% of MCI, and 85% of NL cases being correctly identified.Conclusion This study shows that the visual rating of MTL hypometabolism on PET is reliable, yields a diagnostic accuracy equal to the quantitative ROI measures, and is clinically useful and more sensitive than cortical ratings for patients with MCI. We suggest this method be further evaluated for its potential in the early diagnosis of AD.     

Functional neuroimaging in anorexia nervosa: A clinical approach

Aims

To provide a review of the available literature about the functional neuroimaging of anorexia nervosa, and to summarize the possible role of neurobiological factors in its pathogenesis.

Methods

A systematic review of the literature was performed using PubMed and Medline electronic database (1950-September 2009). Eligible studies were restricted to those involving the main parameters of cerebral activity and functional neuroimaging techniques. Findings of the reviewed studies have been grouped on a diagnostic subtype basis, and their comparison has been interpreted in terms of concordance.

Results

We found a high level of concordance among available studies with regard to the presence of frontal, parietal and cingulate functional disturbances in both anorexia nervosa restricting and binge/purging subtypes. Concordance among studies conducted regardless of the anorexia nervosa subtypes suggests an alteration in temporal and parietal functions and striatal metabolism.

Conclusions

The most consistent alterations in anorexia nervosa cerebral activity seem to involve the dorsolateral prefrontal cortex, the inferior parietal lobule, the anterior cingulate cortex and the caudate nucleus. They may affect different neural systems such as the frontal visual system, the attention network, the arousal and emotional processing systems, the reward processing network, and the network for the body schema.     

Evaluation of technetium 99m cyclobutylpropylene amine oxime as a potential brain perfusion imaging agent for SPET

Technetium 99md,l-cyclobutylpropylene amine oxime (^99mTc-CBPAO) has been developed as a brain-imaging agent for single photon emission tomography (SPET).^99mTc-CBPAO can be prepared using a simple labelling procedure suitable for routine clinical use. It has a high in vitro stability, as has been demonstrated by high-pressure liquid chromatography (HPLC) analysis. This shows that 3 h after labelling, less than 5% of the primary lipophilic complex which is capable of crossing the blood-brain barrier (BBB) converts to a secondary hydrophilic complex. Brain uptake (% dose/g wet tissue) of^99mTc-CBPAO, determined at 5 and 30 min after injection in two groups of six adult male Sprague-Dawley rats, was found to be 0.74±0.06 and 0.73±0.13 (mean ± SD), respectively. These values are not significantly different from those obtained repeating the experiment with^99mTc-labelled hexamethylpropylene amine oxime (^99mTc-HMPAO) (0.72±0.15 at 5 min and 0.88 ± 0.24 at 30 min after injection). Since the rat brain uptake of^99mTc-CBPAO remained unchanged for a period of time suitable for tomographic study, the comparison of the two tracers was extended to two groups of ten patients. The latter were affected by neurological and psychiatric disorders and were studied with SPET. Human brain uptake (% dose/cc cortical grey matter) of^99mTc-CBPAO and^99mTc-HMPAO were 3.04±0.57 and 4.22±0.46 (mean × 10^–3 ± SD × 10^–3), respectively, with a 32% significant difference. In two other groups of five patients, the first transit time-activity curves of the two tracers were compared. From the analysis of these curves we suggest that^99mTc-CBPAO has a higher binding effect on blood components and/or a higher degradation rate in blood than that of^99mTc-HMPAO. This may account for the reduced human brain uptake. In conclusion, SPET images of^99mTc-CBPAO reflect blood perfusion, and they have a good diagnostic quality. The main advantage of^99mTc-CBPAO is its in vitro stability; however,^99mTc-HMPAO is a superior imaging agent.     

Abnormal response to mental stress in patients with Takotsubo cardiomyopathy detected by gated single photon emission computed tomography

Purpose  

Persistent abnormalities are usually not detected in patients with Takotsubo cardiomyopathy (TTC). Since sympathetically mediated myocardial damage has been proposed as a causative mechanism of TTC, we explored whether mental stress could evoke abnormalities in these patients.     

Spatial relationship between coronary microvascular dysfunction and delayed contrast enhancement in patients with hypertrophic cardiomyopathy.

To clarify the spatial relationship between coronary microvascular dysfunction and myocardial fibrosis in hypertrophic cardiomyopathy (HCM), we compared the measurement of hyperemic myocardial blood flow (hMBF) by PET with the extent of delayed contrast enhancement (DCE) detected by MRI. METHODS: In 34 patients with HCM, PET was performed using (13)N-labeled ammonia during hyperemia induced by intravenous dipyridamole. DCE and systolic thickening were assessed by MRI. Left ventricular myocardial segments were classified as with DCE, either transmural (DCE-T) or nontransmural (DCE-NT), and without DCE, either contiguous to DCE segments (NoDCE-C) or remote from them (NoDCE-R). RESULTS: In the group with DCE, hMBF was significantly lower than in the group without DCE (1.81 +/- 0.94 vs. 2.13 +/- 1.11 mL/min/g; P < 0.001). DCE-T segments had lower hMBF than did DCE-NT segments (1.43 +/- 0.52 vs. 1.91 +/- 1 mL/min/g, P < 0.001). Similarly, NoDCE-C segments had lower hMBF than did NoDCE-R (1.98 +/- 1.10 vs. 2.29 +/- 1.10 mL/min/g, P < 0.01) and had no significant difference from DCE-NT segments. Severe coronary microvascular dysfunction (hMBF in the lowest tertile of all segments) was more prevalent among NoDCE-C than NoDCE-R segments (33% vs. 24%, P < 0.05). Systolic thickening was inversely correlated with percentage transmurality of DCE (Spearman rho = -0.37, P < 0.0001) and directly correlated with hMBF (Spearman rho = 0.20, P < 0.0001). CONCLUSION: In myocardial segments exhibiting DCE, hMBF is reduced. DCE extent is inversely correlated and hMBF directly correlated with systolic thickening. In segments without DCE but contiguous to DCE areas, hMBF is significantly lower than in those remote from DCE and is similar to the value obtained in nontransmural DCE segments. These results suggest that increasing degrees of coronary microvascular dysfunction might play a causative role for myocardial fibrosis in HCM.     

Relationship of sustained brain natriuretic peptide release after reperfused acute myocardial infarction with gated SPECT infarct measurements and its connection with collagen turnover and left ventricular remodeling

Background. The relationship among plasma brain natriuretic peptide (BNP), markers of extracellular matrix (ECM) remodeling, and left ventricular (LV) dilation after reperfused acute myocardial infarction is poorly known. Methods and Results. Echocardiogram, plasma BNP, and ECM degradation markers (serum amino-terminal telopeptide of type I procollagen and type III procollagen and carboxy-terminal telopeptide of type I procollagen [ICTP]) were evaluated in 34 patients at days 1, 3, and 30 after first reperfused acute myocardial infarction. At 1 month, infarct size and severity and LV volume were measured by sestamibi gated single photon emission computed tomography. Patients were stratified according to day 3 BNP levels into 2 groups: group 1 (n=17) had BNP values over the median value, and group 2 (n=17) had BNP values under the median value. Infarct size and severity were similar in the 2 groups. LV volumes increased in group 1 but decreased in group 2 (P<.01). BNP values, LV volume/mass index, and infarct size were independent predictors of 1-month LV dilation (β=.58 [P=.001], β=.41 [P=.01], and β=.32 [P=.03], respectively). Levels of serum amino-terminal propeptide of type I procollagen and type III procollagen were similar in both groups. The level of ICTP increased significantly in group 1 only, and after 3 days, it was higher (P<.01) than in group 2. In group 1 ICTP significantly interacted with the relationship between BNP release and serial changes in LV volumes (F=4.87, P=.03). Conclusions. ICTP is related to elevated BNP level independently of infarct size and severity and interacts with the relationship between BNP and LV dilation. BNP levels could play a role in LV remodeling by favoring ECM degradation. (J Nucl Cardiol 2008;15:644-54.) This study was supported by a research grant from the A.R. CARD ONLUS Foundation, Florence, Italy, and by an unrestricted grant from the Cassa di Risparmio Foundation of Florence, Italy.     

Role of whole-body 18F-choline PET/CT in disease detection in patients with biochemical relapse after radical treatment for prostate cancer

Purpose

The aim of this study was to evaluate the role of whole body ¹⁸F-choline (FCH) positron emission tomography—computed tomography (PET-CT) in detecting and localising disease recurrence in patients presenting biochemical relapse after radical treatment for prostate cancer.

Materials and methods

Fifty-six consecutive patients with increased serum prostate-specific antigen (PSA) levels after radical prostatectomy were included in the study. None of them was receiving hormone treatment at the time of the examination or had been treated during the previous 6 months. All patients underwent whole-body ¹⁸F-choline PET imaging, and the pathological findings were compared with those of further imaging exams, biopsy and follow-up. On the basis of the PSA levels, we divided our patient population into three subgroups: PSA≤1, 15 ng/ml.

Results

Overall, the PET scan detected disease relapse in 42.9% of cases (24/56). PET sensitivity was closely related to serum PSA levels, showing values of 20%, 44% and 81.8% in the PSA≤1, 15ng/ml subgroups, respectively.

Conclusions

In patients with biochemical relapse after radical treatment for prostate cancer, ¹⁸F-choline PET-CT represents a single step, whole-body, noninvasive study that allows disease detection and localisation. The disease detection rate is related to serum PSA levels.     

Use of technetium-99m hexamethylpropylene amine oxime SPET for the study of cerebral blood flow reactivity after acetazolamide infusion in patients with Behçet’s disease

The purpose of this study was to characterise the nature of the baseline perfusion defects found in patients with Beh?et’s disease using hexamethylpropylene amine oxime single-photon emission tomography in conjunction with acetazolamide test (Acz SPET). Eleven patients underwent both baseline and Acz SPET. Regions of interest (ROIs) were drawn on the areas with decreased perfusion (D-ROI) and, in the same section, on areas with normal perfusion (N-ROI). The ROIs were then repositioned on the corresponding section on Acz SPET. The mean ROI counts were then transformed into a perfusion index value (PIV) with reference to the global brain counts. In total we found 24 D-ROIs (17 in the cortical and 7 in subcortical grey matter). The influence of Acz infusion was selectively registered in the D-ROIs, where PIVs changed from 1.23±0.17 (baseline SPET) to 1.63±0.23 (Acz SPET) (P<0.001). No significant difference was seen in the N-ROIs (1.46±0.21 and 1.40±0.17, respectively, on baseline SPET and Acz SPET). Our results demonstrate that Acz infusion increases the regional cerebral blood flow within baseline grey matter perfusion defects. This finding suggests that baseline perfusion abnormalities could reflect a disconnection rather than local vasculitic involvement. Received 10 November 1999 and in revised form 29 January 2000