Clinical and neuroimaging characterization of the first frontotemporal dementia family carrying the MAPT p.K298E mutation

We present an in-depth clinical and neuroimaging analysis of a family carrying the MAPT K298E mutation associated with frontotemporal dementia (FTD). Initial identification of this mutation in a single clinical case led to a comprehensive investigation involving four affected siblings allowing to elucidate the mutation's phenotypic expression.A 60-year-old male presented with significant behavioral changes and progressed rapidly, exhibiting speech difficulties and cognitive decline. Neuroimaging via FDG-PET revealed asymmetrical frontotemporal hypometabolism. Three siblings subsequently showed varied but consistent clinical manifestations, including abnormal behavior, speech impairments, memory deficits, and motor symptoms correlating with asymmetric frontotemporal atrophy observed in MRI scans.Based on the genotype-phenotype correlation, we propose that the p.K298E mutation results in early-onset behavioral variant FTD, accompanied by a various constellation of speech and motor impairment.This detailed characterization expands the understanding of the p.K298E mutation's clinical and neuroimaging features, underlining its role in the pathogenesis of FTD. Further research is crucial to comprehensively delineate the clinical and epidemiological implications of the MAPT p.K298E mutation.

Left and right corticobasal syndrome: comparison of cognitive profiles between metabolic imaging - matched groups

BACKGROUND

Corticobasal syndrome (CBS) is typically asymmetric. Case reports suggest that left-hemisphere CBS (lhCBS) is associated with major language impairment, and right-hemisphere CBS (rhCBS) is associated with major visuospatial deficits, but no group study has ever verified these observations. In our study, we enrolled 49 patients with CBS, classified them as lhCBS or rhCBS based on asymmetry of hypometabolism on brain FDG-PET and compared their cognitive and behavioural profiles.

METHODS

We defined asymmetry of hypometabolism upon visual inspection of qualitative PET images and confirmed it through paired comparison of left- and right-hemisphere FDG uptake values. The two groups were also matched for severity of hypometabolism within the more affected and more preserved hemispheres, to unravel differences in the cognitive profiles ascribable specifically to each hemisphere's functional specializations. All patients were assessed for memory, language, executive and visuospatial deficits, apraxia, neglect, dyscalculia, agraphia and behavioural disturbances.

RESULTS

LhCBS (n. 26) and rhCBS (n. 23) patients did not differ for demographics, disease duration and severity of global cognitive impairment. The two cognitive profiles were largely overlapping, with two exceptions: Digit span forward was poorer in lhCBS, and visual neglect was more frequent in rhCBS.

CONCLUSIONS

After balancing out patients for hemispheric hypometabolism, we did not confirm worse language or visuospatial deficits in, respectively, lhCBS and rhCBS. However, verbal short-term memory was more impaired in lhCBS, and spatial attention was more impaired in rhCBS. Both of these functions reflect the functional specialization of the left and right fronto-parietal pathways, i.e. of the main loci of neurodegeneration in CBS.

A ROI-based quantitative pipeline for 18F-FDG PET metabolism and pCASL perfusion joint analysis: Validation of the 18F-FDG PET line

In Mild Cognitive Impairment (MCI), the study of brain metabolism, provided by 18F-FluoroDeoxyGlucose Positron Emission Tomography (18F-FDG PET) can be integrated with brain perfusion through pseudo-Continuous Arterial Spin Labeling Magnetic Resonance sequences (MR pCASL). Cortical hypometabolism identification generally relies on wide control group datasets; pCASL control groups are instead not publicly available yet, due to lack of standardization in the acquisition parameters. This study presents a quantitative pipeline to be applied to PET and pCASL data to coherently analyze metabolism and perfusion inside 16 matching cortical regions of interest (ROIs) derived from the AAL3 atlas. The PET line is tuned on 36 MCI patients and 107 healthy control subjects, to agree in identifying hypometabolic regions with clinical reference methods (visual analysis supported by a vendor tool and Statistical Parametric Mapping, SPM, with two parametrizations here identified as SPM-A and SPM-B). The analysis was conducted for each ROI separately. The proposed PET analysis pipeline obtained accuracy 78 % and Cohen's к 60 % vs visual analysis, accuracy 79 % and Cohen's к 58 % vs SPM-A, accuracy 77 % and Cohen's к 54 % vs SPM-B. Cohen's к resulted not significantly different from SPM-A and SPM-B Cohen's к when assuming visual analysis as reference method (p-value 0.61 and 0.31 respectively). Considering SPM-A as reference method, Cohen's к is not significantly different from SPM-B Cohen's к as well (p-value = 1.00). The complete PET-pCASL pipeline was then preliminarily applied on 5 MCI patients and metabolism-perfusion regional correlations were assessed. The proposed approach can be considered as a promising tool for PET-pCASL joint analyses in MCI, even in the absence of a pCASL control group, to perform metabolism-perfusion regional correlation studies, and to assess and compare perfusion in hypometabolic or normo-metabolic areas.

A cognitive marker for Alzheimer disease pathology in primary progressive aphasia? A validation study in the clinical setting

We validated in the clinical setting a putative clinical marker for a biological diagnosis of primary progressive aphasia (PPA) due to amyloid previously identified in an autopsy cohort and including impaired (score ≤4) digit span (DS) as index of phonological loop dysfunction and broadened criteria for logopenic PPA. In 29 PPA patients with an amyloid-positive (A+) biomarker and 28 PPA patients with an amyloid-negative (A-) biomarker, Receiver Operating Characteristics (ROC) curve analysis showed moderate specificity (71%) but insufficient sensitivity (41%) for the proposed marker. Specificity was particularly poor (58%) for the discrimination between A+ PPA and the A- subgroup with nonfluent PPA. DS may be compromised in both logopenic and nonfluent PPA, whose loci of neurodegeneration lie at the 2 ends of the left fronto-parieto-temporal system that underpins phonology. An Statistical Parametric Mapping (SPM) correlation analysis between DS score and metabolism on brain 18-fluoro-deoxy-glucose positron emission tomography also showed a major contribution of the left frontal cortex to impaired span.

Abstract P6-01-42: BASELINE 18FDG-PET METABOLIC TUMOUR VOLUME (MTV) AS A POTENTIAL PREDICTIVE FACTOR OF RESPONSE TO METRONOMIC CHEMOTHERAPY (mCHT) IN HR+/HER2- METASTATIC BREAST CANCER (MBC) PATIENTS (pts). PRELIMINARY RESULTS OF THE METRO-PET STUDY

Background: MBC is an incurable disease and chemotherapy (CHT) represents one option of treatment upfront, in TNBC pts, or at failure of an endocrine therapy + targeted agents in HR+ ones. mCHT was extensively studied in different types of ABC pts and is largely used in clinical practice. 18FDG-PET is often used as a tool for disease staging at baseline and for disease restaging during treatment. Different quantitative and semi-quantitative 18FDG-PET parameters have been investigated as predictive and prognostic biomarkers in NSCLC and other tumours. Aim of the present study is to evaluate the role of baseline SUVmax , global SUVmean, SUVpeak, Metabolic Tumour Volume (MTV) and Total Lesion Glycolysis (TLG) as predictive factors of response to mCHT.

Patients and Methods: We identified 36 MBC pts treated with mCHT between 2014 and 2021, with at least two separate 18FDG-PET evaluations. Patients and biological tumour characteristics, previous treatments, site of relapse as well as quantitative pre-treatment 18FDG-PET parameters have been collected. Tumour response was assessed using PERCIST Criteria. Median and mean ± SD 18FDG-PET parameters have been reported according to the type of response. Complete and Partial responses have been grouped together with Stable Disease.

Results: Median age was 69 (33-82). Luminal pts were 25 (67.6%), TNBC pts were 16.2%); most were heavily pre-treated for their metastatic disease (≥ 3 lines: 14, 37.8%) and presented ≥ 3 metastatic sites (14, 37.8%). All pts received mCHT, 26 (70.3%) as combination therapy (VRL+CAPE or VRL+CAPE+CTX), or single agent (VRL, 11). Bone was the commonest metastatic site (62.2%). ORR was 43.2%; 7 pts had SD (18.9%), the remaining developed PD (37.8%). Similar values have been observed between the 2 groups in terms of SUVmax , global SUVmean and SUVpeak,. Mean MTV was higher in responder (n=22) vs non responder (n=14) pts, as TLG. Details are reported in Table 1.

Conclusions: High mean baseline MTV and TLG seem to be related to response to mCHT in MBC pts. Our observation is in contrast to what is described for other cancer types, especially NSCLC, and for standard neoadjuvant treatment of BC. Considering the peculiar mechanisms of action of mCHT, our preliminary findings warrant further exploration in a larger series of BC pts.

Table 1 Baseline 18FDG-PET uptake values in responder and non responder patients

Citation Format: Marco Meazza Prina, Irene Gotuzzo, Marina Elena Cazzaniga, Elisabetta De Bernardi, Pietro Cafaro, Serena Capici, Viola Cogliati, Francesca Fulvia Pepe, Federica Cicchiello, Francesca Riva, Nicoletta Cordani, Maria Grazia Cerrito, Elia Anna Turolla, Claudio Landoni, Federica Elisei, Cinzia Crivellaro, Leonardo Virdone, Lavinia Monaco, Alessandro Guidi, Luca Guerra. BASELINE 18FDG-PET METABOLIC TUMOUR VOLUME (MTV) AS A POTENTIAL PREDICTIVE FACTOR OF RESPONSE TO METRONOMIC CHEMOTHERAPY (mCHT) IN HR+/HER2- METASTATIC BREAST CANCER (MBC) PATIENTS (pts). PRELIMINARY RESULTS OF THE METRO-PET STUDY [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-42.

Clinical and metabolic imaging features of late-onset and early-onset posterior cortical atrophy

BACKGROUND AND PURPOSE

Late-onset (LO) and early-onset (EO) dementia show neurobiological and clinical differences. Clinical and ¹⁸ fluoro-deoxy-glucose positron emission tomography (FDG-PET) features of LO and EO posterior cortical atrophy (LO_PCA, EO_PCA), the visual variant of Alzheimer's disease (AD), were compared. LO_PCA patients were also compared with a group of patients with LO typical AD (tAD).

METHODS

Thirty-seven LO_PCA patients (onset age ≥ 65 years), 29 EO_PCA patients and 40 tAD patients who all underwent a standard neuropsychological battery were recruited; PCA patients were also assessed for the presence of posterior signs and symptoms. Brain FDG-PET was available in 32 LO_PCA cases, 23 EO_PCA cases and all tAD cases, and their scans were compared with scans from 30 healthy elderly controls. Within the entire PCA sample FDG uptake was also correlated with age at onset as a continuous variable.

RESULTS

The main difference between the two PCA groups was a higher prevalence of Bálint-Holmes symptoms in EO cases, which was associated with the presence of severe bilateral occipito-temporo-parietal hypometabolism, whilst LO_PCA patients showed reduction of FDG uptake mainly in the right posterior regions. The latter group also showed mesial temporal hypometabolism, similarly to the tAD group, although with a right rather than left lateralization. Correlation analysis confirmed the association between older age and decreased limbic metabolism and between younger age and decreased left parietal metabolism.

CONCLUSIONS

The major involvement of the temporal cortex in LO cases and of the parietal cortex in EO cases reported previously within the AD spectrum holds true also for the visual variant of AD.

Reduced phonemic fluency in progressive supranuclear palsy is due to dysfunction of dominant BA6

Background

Reduced phonemic fluency is extremely frequent in progressive supranuclear palsy (PSP), but its neural correlate is yet to be defined.

Objective

We explored the hypothesis that poor fluency in PSP might be due to neurodegeneration within a dominant frontal circuit known to be involved in speech fluency, including the opercular area, the superior frontal cortex (BA6), and the frontal aslant tract connecting these two regions.

Methods

We correlated performance on a letter fluency task (F, A, and S, 60 s for each letter) with brain metabolism as measured with Fluoro-deoxy-glucose Positron Emission Tomography, using Statistical Parametric Mapping, in 31 patients with PSP.

Results

Reduced letter fluency was associated with significant hypometabolism at the level of left BA6.

Conclusion

Our finding is the first evidence that in PSP, as in other neurogical disorders, poor self-initiated, effortful verbal retrieval appears to be linked to dysfunction of the dominant opercular-aslant-BA6 circuit.

Learning From Mistakes: Cognitive and Metabolic Correlates of Errors on Picture Naming in the Alzheimer’s Disease Spectrum

Background: Analysis of subtypes of picture naming errors produced by patients with Alzheimer’s disease (AD) have seldom been investigated yet may clarify the cognitive and neural underpinnings of naming in the AD spectrum. Objective: To elucidate the neurocognitive bases of picture naming in AD through a qualitative analysis of errors. Methods: Over 1000 naming errors produced by 70 patients with amnestic, visuospatial, linguistic, or frontal AD were correlated with general cognitive tests and with distribution of hypometabolism on FDG-PET. Results: Principal component analysis identified 1) a Visual processing factor clustering visuospatial tests and unrecognized stimuli, pure visual errors and visual-semantic errors, associated with right parieto-occipital hypometabolism; 2) a Concept-Lemma factor grouping language tests and anomias, circumlocutions, superordinates, and coordinates, correlated with left basal temporal hypometabolism; 3) a Lemma-Phonology factor including the digit span and phonological errors, linked with left temporo-parietal hypometabolism. Regression of brain metabolism on individual errors showed that errors due to impairment of basic and higher-order processing of object visual attributes or of their interaction with semantics, were related with bilateral occipital and left occipito-temporal dysfunction. Omissions and superordinates were linked to degradation of broad and basic concepts in the left basal temporal cortex. Semantic-lexical errors derived from faulty semantically- and phonologically-driven lexical retrieval in the left superior and middle temporal gyri. Generation of nonwords was underpinned by of phonological impairment within the left inferior parietal cortex. Conclusion: Analysis of individual naming errors allowed to outline a comprehensive anatomo-functional model of picture naming in classical and atypical AD.

Validity of cingulate–precuneus–temporo-parietal hypometabolism for single-subject diagnosis of biomarker-proven atypical variants of Alzheimer’s Disease

The aim of our study was to establish empirically to what extent reduced glucose uptake in the precuneus, posterior cingulate and/or temporo-parietal cortex (PCTP), which is thought to indicate brain amyloidosis in patients with dementia or MCI due to Alzheimer’s Disease (AD), permits to distinguish amyloid-positive from amyloid-negative patients with non-classical AD phenotypes at the single-case level. We enrolled 127 neurodegenerative patients with cognitive impairment and a positive (n. 63) or negative (n. 64) amyloid marker (cerebrospinal fluid or amy-PET). Three rating methods of FDG-PET scan were applied: purely qualitative visual interpretation of uptake images (VIUI), and visual reading assisted by a semi-automated and semi-quantitative tool: INLAB, provided by the Italian National Research Council, or Cortex ID Suite, marketed by GE Healthcare. Fourteen scans (11.0%) patients remained unclassified by VIUI or INLAB procedures, therefore, validity values were computed on the remaining 113 cases. The three rating approaches showed good total accuracy (77–78%), good to optimal sensitivity (81–93%), but poorer specificity (62–75%). VIUI showed the highest sensitivity and the lowest specificity, and also the highest proportion of unclassified cases. Cases with asymmetric temporo-parietal hypometabolism and a progressive aphasia or corticobasal clinical profile, in particular, tended to be rated as AD-like, even if biomarkers indicated non-amyloid pathology. Our findings provide formal support to the value of PCTP hypometabolism for single-level diagnosis of amyloid pathophysiology in atypical AD, but also highlight the risk of qualitative assessment to misclassify patients with non-AD PPA or CBS underpinned by asymmetric temporo-parietal hypometabolism.

Clinical Application of a High Sensitivity BGO PET/CT Scanner: Effects of Acquisition Protocols and Reconstruction Parameters on Lesions Quantification

AIMS

The aim of this retrospective study was to investigate SUVs variability with respect to lesion size, administered dose, and reconstruction algorithm.

BACKGROUND

SUVmax and SUVpeak are influenced by technical factors as count statistics and reconstruction algorithms.

OBJECTIVE

To fulfill the aim, we evaluated the SUVs variability with respect to lesion size, administered dose, and reconstruction algorithm (ordered - subset expectation maximization plus point spread function option - OSEM+PSF, regularized Bayesian Penalized Likelihood - BPL) in a 5 - rings BGO PET/CT scanner.

METHOD

Discovery IQ scanner (GE Healthcare, Milwaukee, Wisconsin, US) was used for list mode acquisition of 25 FDG patients, 12 injected with 3.7 MBq/kg (Standard Dose protocol - SD) and 13 injected with 1.8 MBq/kg (Low Dose protocol - LD). Each acquisition was reconstructed at different time/FOV with both OSEM+PSF algorithm and BPL using seven different beta factors. SUVs were calculated in 70 lesions and analysed in function of time/FOV and Beta. Image quality was evaluated as a coefficient of variation of the liver (CV - liver).

RESULT

SUVs were not considerably affected by time/FOV. However, SUVs were influenced by beta: differences were higher in small lesions (37% for SUVmax, 15% for SUVpeak) compared to larger ones (14% and 6%). CV - liver ranged from 6% with Beta-500 (LD and SD) to 13% with Beta-200 (LD). CV - liver of BPL with Beta-350 (optimized for clinical practice in our institution) in LD was lower than CV - liver of OSEM+PSF in SD.

CONCLUSION

When a high sensitivity 5 - rings BGO PET/CT scanner is used with the same reconstruction algorithm, quantification by means of SUVmax and SUVpeak is a robust standard compared to the activity and scan duration. However, both SUVs and image quality are influenced by reconstruction algorithms and the related parameters should be considered to obtain the best compromise between detectability, quantification, and noise.

Respiratory Gating and the Performance of PET/CT in Pulmonary Lesions

Background

Motion artifacts related to the patient’s breathing can be the cause of underestimation of the lesion uptake and can lead to missing of small lung lesions. The respiratory gating (RG) technology has demonstrated a significant increase in image quality.

Objective

The aim of this paper was to evaluate the advantages of RG technique on PET/CT performance in lung lesions. The impact of 4D-PET/CT on diagnosis (metabolic characterization), staging and re-staging lung cancer was also assessed, including its application for radiotherapy planning. Finally, new technologies for respiratory motion management were also discussed.

Methods

A comprehensive electronic search of the literature was performed by using Medline database (PubMed) searching “PET/CT”, “gated” and “lung”. Original articles, review articles, and editorials published in the last 10 years were selected, included and critically reviewed in order to select relevant articles.

Results

Many papers compared Standardized Uptake Value (SUV) in gated and ungated PET studies showing an increase in SUV of gated images, particularly for the small lesions located in medium and lower lung. In addition, other features as Metabolic Tumor Volume (MTV), Total Lesion Glycolysis (TLG) and textural-features presented differences when obtained from gated and ungated PET acquisitions. Besides the increase in quantification, gating techniques can determine an increase in the diagnostic accuracy of PET/CT. Gated PET/CT was evaluated for lung cancer staging, therapy response assessment and for radiation therapy planning.

Conclusion

New technologies able to track the motion of organs lesion directly from raw PET data, can reduce or definitively solve problems (i.e.: extended acquisition time, radiation exposure) currently limiting the use of gated PET/CT in clinical routine.

Cardiotoxicity in breast cancer patients: the role of gated myocardial perfusion SPECT

Funding Acknowledgements

Type of funding sources: None.

Background

Patients undergoing chemotherapy (CHT) for breast cancer (BC) need a monitoring of cardiac function due to the possible onset of cardiotoxicity. Cardiotoxicity may occur with heart failure but is often asymptomatic and is detectable only by assessing an increase in cardiac volumes (left ventricular end-diastolic (LV-EDV) and end-systolic (LV-ESV) volumes) and/or by a reduction of the left ventricular ejection fraction (LV-EF). The primary purpose of this study was to evaluate the role of gated SPECT myocardial perfusion imaging in this setting. Dosimetric evaluation was also assessed.

Methods

Seventeen BC patients (mean age 55.93 ± 11.04 years)with invasive ductal carcinoma HER2 + treated with surgery and with an anthracycline-based adjuvant CHT, were enrolled. The trend of cardiac function was assessed by evaluation of LV-EF, LV-EDV and LV-ESV using gSPECT in baseline conditions and at 12, 15 and 52 weeks during treatment and then at 6, 12, 24 and 48 months during follow-up. Each patient was studied 15-20 min after injection of 555 MBq of 99mTc-Tetrofosmin with gSPECT (16 frames/cardiac cycle) using an Infinia Hawkeye IV gamma-camera. Dosimetry was assed according to ICRP reports.

Results

Two out of the 17 patients enrolled left the protocol: one because of a second tumor and the other due to the appearance of cardiotoxicity. 15 patients completed the study: mean LVEF at baseline was 70.67 ± 5.68. The greatest modification occurred after 15th week of treatment, when mean LV-EF showed a significant decrease  to 65.67 ± 8.27, while mean LV-EDV and mean LV-ESV increased from 73.60 ± 16.72 up to 84.73 ± 21.11 and from 21.93 ± 7.17 up to 30.27 ± 14.16, respectively. All parameters progressively returned similar to baseline values at the final examination (after 48th month): mean LV-EF 70.20 ± 5.65, LV-EDV 73.40 ± 16.15 and ESV 22.07 ± 7.50. In one case cardiotoxicity occurred at 15th week: LV-EF decreased from 69 to 47%, LV-EDV increased from 92 up to 142 ml and LV-ESV from 28 up to 75 ml. According to our image protocols, effective dose for gSPECT was 3.83 mSv (ICRP 106). The use of gSPET instead of MUGA (6.47 mSv–ICRP 80) allowed a dose effective saving of 2.64 mSv/each control with a total saving of 21.12 mSv/patient.

Conclusions

Although the small sample size, gSPECT was demonstrated to be an applicable tool for monitoring cardiac  function because it correctly identified  BC patient with cardiotoxicity. gSPECT also allowed a significant radiation dose saving compared to MUGA: this is particularly relevant in cardiotoxicity studies that require repeated and close evaluations.

Metabolic Parameters as Biomarkers of Response to Immunotherapy and Prognosis in Non-Small Cell Lung Cancer (NSCLC): A Real World Experience

Immune-checkpoint inhibitors (ICIs) have been proven to have great efficacy in non-small cell lung cancer (NSCLC) as single agents or in combination therapy, being capable to induce deep and durable remission. However, severe adverse events may occur and about 40% of patients do not benefit from the treatment. Predictive factors of response to ICIs are needed in order to customize treatment. The aim of this study is to evaluate the correlation between quantitative positron emission tomography (PET) parameters defined before starting ICI therapy and responses to treatment and patient outcome. We retrospectively analyzed 92 NSCLC patients treated with nivolumab, pembrolizumab or atezolizumab. Basal PET/computed tomography (CT) scan parameters (whole-body metabolic tumor volume-wMTV, total lesion glycolysis-wTLG, higher standardized uptake volume maximum and mean-SUVmax and SUVmean) were calculated for each patient and correlated with outcomes. Patients who achieved disease control (complete response + partial response + stable disease) had significantly lower MTV median values than patients who had not (progressive disease) (77 vs. 160.2, p = 0.039). Furthermore, patients with MTV and TLG values lower than the median values had improved OS compared to patients with higher MTV and TLG (p = 0.03 and 0.05, respectively). No relation was found between the other parameters and outcome. In conclusion, baseline metabolic tumor burden, measured with MTV, might be an independent predictor of treatment response to ICI and a prognostic biomarker in NSCLC patients.

Temporal lobe dysfunction in late-onset epilepsy of unknown origin

OBJECTIVE

Epilepsy with onset in the adulthood is an increasing health problem, due to the progressive aging of the worldwide population. Whether the causes remain undetermined, the disease is defined as Late-Onset Epilepsy of Unknown origin (LOEU). The aim of this study was to evaluate the semiological, electroencephalographic, metabolic, and neuropsychological features of LOEU.

METHODS

We selected patients with late-onset epilepsy (LOE) (≥55 years), whose causes of the disease have been excluded with a deep clinical-instrumental characterization, including brain MRI, EEG, ¹⁸F-labeled fluoro-2-deoxyglucose positron emission tomography (FDG-PET), and neuropsychological assessment.

RESULTS

Twenty-three LOEU cases were retrospectively recruited. Half presented focal-onset seizures (FOS), the others focal to bilateral tonic-clonic seizures (FBTCS). All demonstrated a mild phenotype, with no recurrence of seizures on single antiseizure treatment at prolonged follow-up. Brain MRI scans were normal in 12 patients (52.3%) and showed nonspecific gliosis or mild atrophy in ten (43.5%); hippocampal sclerosis (HS) was observed in one. In 17/23 (73.9%), the EEG showed slow and/or epileptiform activity of the temporal areas. Brain FDG-PET revealed temporal lobe hypometabolism, mostly ipsilateral to EEG abnormal activity, or multifocal temporal and extra-temporal (cortical, subcortical and subtentorial) clusters of hypometabolism. The neuropsychological analysis demonstrated three different profiles: normal (43.5%), with focal deficits (39.1%) or mild multidomain impairment (17.4%).

SIGNIFICANCE

Late-Onset Epilepsy of Unknown origin can present as FOS or FBTCS, both with good prognosis. The application of metabolic imaging and neurophysiology techniques in these patients points to the dysfunction of the temporal structures, whose role in the pathogenetic process of the disease remains to be clarified.

Combining positron emission tomography/computed tomography, radiomics, and sentinel lymph node mapping for nodal staging of endometrial cancer patients

OBJECTIVE

To evaluate the combination of positron emission tomography/computed tomography (PET/CT) and sentinel lymph node (SLN) biopsy in women with apparent early-stage endometrial carcinoma. The correlation between radiomics features extracted from PET images of the primary tumor and the presence of nodal metastases was also analyzed.

METHODS

From November 2006 to March 2019, 167 patients with endometrial cancer were included. All women underwent PET/CT and surgical staging: 60/167 underwent systematic lymphadenectomy (Group 1) while, more recently, 107/167 underwent SLN biopsy (Group 2) with technetium-99m +blue dye or indocyanine green. Histology was used as standard reference. PET endometrial lesions were segmented (n=98); 167 radiomics features were computed inside tumor contours using standard Image Biomarker Standardization Initiative (IBSI) methods. Radiomics features associated with lymph node metastases were identified (Mann-Whitney test) in the training group (A); receiver operating characteristic (ROC) curves, area under the curve (AUC) values were computed and optimal cut-off (Youden index) were assessed in the test group (B).

RESULTS

In Group 1, eight patients had nodal metastases (13%): seven correctly ridentified by PET/CT true-positive with one false-negative case. In Group 2, 27 patients (25%) had nodal metastases: 13 true-positive and 14 false-negative. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT for pelvic nodal metastases were 87%, 94%, 93%, 70%, and 98% in Group 1 and 48%, 97%, 85%, 87%, and 85% in Group 2, respectively. On radiomics analysis a significant association was found between the presence of lymph node metastases and 64 features. Volume-density, a measurement of shape irregularity, was the most predictive feature (p=0001, AUC=0,77, cut-off 0.35). When testing cut-off in Group B to discriminate metastatic tumors, PET false-negative findings were reduced from 14 to 8 (-43%).

CONCLUSIONS

PET/CT demonstrated high specificity in detecting nodal metastases. SLN and histologic ultrastaging increased false-negative PET/CT findings, reducing the sensitivity of the technique. PET radiomics features of the primary tumor seem promising for predicting the presence of nodal metastases not detected by visual analysis.

A Metabolic Imaging Study of Lexical and Phonological Naming Errors in Alzheimer Disease

Patients with Alzheimer disease (AD) produce a variety of errors on confrontation naming that indicate multiple loci of impairment along the naming process in this disease. We correlated brain hypometabolism, measured with 18fluoro-deoxy-glucose positron emission tomography, with semantic and formal errors, as well as nonwords deriving from phonological errors produced in a picture-naming test by 63 patients with AD. Findings suggest that neurodegeneration leads to: (1) phonemic errors, by interfering with phonological short-term memory, or with control over retrieval of phonological or prearticulatory representations, within the left supramarginal gyrus; (2) semantic errors, by disrupting general semantic or visual-semantic representations at the level of the left posterior middle and inferior occipitotemporal cortex, respectively; (3) formal errors, by damaging the lexical-phonological output interface in the left mid-anterior segment of middle and superior temporal gyri. This topography of semantic-lexical-phonological steps of naming is in substantial agreement with dual-stream neurocognitive models of word generation.

Role of F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in malignant ovarian germ cell tumors: a single-center experience with long term follow-up

INTRODUCTION

¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) is a diagnostic tool widely used in oncology, but to date there are no established recommendations for its use in malignant ovarian germ cell tumors. The aim of this study was to evaluate the role of ¹⁸F-FDG PET/CT in the clinical management of patients with malignant ovarian germ cell tumors.

METHODS

This was a retrospective review of ¹⁸F-FDG PET/CT scans performed in patients diagnosed with malignant ovarian germ cell tumors treated at the gynecology department of San Gerardo Hospital (Monza, Italy) from June 2006 to December 2016. Data collected included clinical history, radiological, biochemical and pathological evaluation, treatment, follow-up, outcome, and clinical indication for the PET/CT scan. PET/CT findings were categorized as negative/normal (no abnormal FDG uptake or physiological uptake), positive/abnormal (FDG uptake considered to indicate active germ cell malignancy), or equivocal (FDG uptake of uncertain significance, not clearly correlated to neoplastic disease).

RESULTS

A total of 69 PET/CT scans in 37 patients were evaluated. The mean age at diagnosis was 25 years (range 20-48). The majority of patients had International Federation of Gynecology and Obstetrics (FIGO) stage I (22/37) disease and had a diagnosis of dysgerminomas (18/37). Imaging indications were initial staging before treatment (4/69, 6%), staging after inadequate staging surgery (24/69, 35%), restaging after adjuvant chemotherapy (17/69, 25%), relapse suspect (9/69, 13%), and follow-up (15/69, 21%). Pathology confirmation of PET/CT results was available in 28/69 (40.5%) studies. All negative PET/CT (15/28) cases were confirmed with laparoscopy as true negative; among 13/28 positive PET cases, histopathology confirmed 7 (54%) as true positive and 6 (46%) as false positive (5 inflammatory and 1 mature teratoma implants). Patient-based analysis showed 100% sensitivity, 71% specificity, 54% positive predictive value, 100% negative predictive value, and 79% accuracy. Clinical follow-up was available in 41 (59.4%) of 69 PET/CT images: 28/41 studies were negative and 13/41 positive. A mean follow-up of 28 months (median 15, range 5-102) confirmed negative PET/CT studies. A total of 13 positive PET/CT patients underwent chemotherapy with subsequent evidence of disease response.

DISCUSSION

PET/CT in malignant ovarian germ cell tumors was mainly performed for staging after inadequate staging surgery or for restaging after adjuvant chemotherapy. PET/CT was associated with high sensitivity and negative predictive value.

Motion Management in PET/CT: Technological Solutions

BACKGROUND AND OBJECTIVE

Motion due to patient's breathing can introduce heavy bias in PET/CT, both in image quality and quantitation. This paper is a review of the main technical solutions available to manage movement in PET/CT studies: a) Respiratory Gated (RG), b) Motion Free (MF), c) End Expiration (EE), d) Banana Artefact Management (BAM) and e) Data Driven Gating (DDG).

METHODS

The most diffused solutions (RG, MF and EE) are based on LIST mode acquisition of a PET Field of View (4D FOV), centered on the anatomical region of interest; to link PET data not only to time and to spatial position but also to the corresponding breathing phase, the synchronized acquisition of the patient's breathing curve is performed by an external tracking device. Different commercial tools to track and to record patient breathing cycle are available to associate the internal organ motion with a measurable external parameter; for example these systems can measure the pressure on a chest elastic belt, the air flow trough patient nose, the breath-in and breath-out air temperature or the markers movement on the thorax/ abdominal region. Recently DDG techniques are developed to correct respiratory motion without the help of external motion tracking devices and to obtain a comparable result to that based on standard RG protocols.

RESULTS

The final result of an RG or DDG protocol is a sequence of 3D images showing organs and lesions movement; using the other motion management options a single 3D motion-free image is obtained without motion artefacts and degradation. Compared to the previously described options the BAM solution is not a real motion management protocol but just a Banana Artefact correction technique obtained using an Attenuation Correction Map calculated merging the Whole Body Helical CT with a Cine CT on the diaphragm area.

CONCLUSION

The motion management in PET/CT imaging shows benefits in terms of image quality, quantification and lesion detectability and it is useful both in diagnostic and radiotherapy planning.

Radiomics of the primary tumour as a tool to improve 18F-FDG-PET sensitivity in detecting nodal metastases in endometrial cancer

Background

A radiomic approach was applied in 18F-FDG PET endometrial cancer, to investigate if imaging features computed on the primary tumour could improve sensitivity in nodal metastases detection. One hundred fifteen women with histologically proven endometrial cancer who underwent preoperative 18F-FDG PET/CT were retrospectively considered. SUV, MTV, TLG, geometrical shape, histograms and texture features were computed inside tumour contours. On a first group of 86 patients (DB1), univariate association with LN metastases was computed by Mann-Whitney test and a neural network multivariate model was developed. Univariate and multivariate models were assessed with leave one out on 20 training sessions and on a second group of 29 patients (DB2). A unified framework combining LN metastases visual detection results and radiomic analysis was also assessed.

Results

Sensitivity and specificity of LN visual detection were 50% and 99% on DB1 and 33% and 95% on DB2, respectively. A unique heterogeneity feature computed on the primary tumour (the zone percentage of the grey level size zone matrix, GLSZM ZP) was able to predict LN metastases better than any other feature or multivariate model (sensitivity and specificity of 75% and 81% on DB1 and of 89% and 80% on DB2). Tumours with LN metastases are in fact generally characterized by a lower GLSZM ZP value, i.e. by the co-presence of high-uptake and low-uptake areas. The combination of visual detection and GLSZM ZP values in a unified framework obtained sensitivity and specificity of 94% and 67% on DB1 and of 89% and 75% on DB2, respectively.

Conclusions

The computation of imaging features on the primary tumour increases nodal staging detection sensitivity in 18F-FDG PET and can be considered for a better patient stratification for treatment selection. Results need a confirmation on larger cohort studies.

Cognitive reserve maps the core loci of neurodegeneration in corticobasal degeneration

BACKGROUND AND PURPOSE

Cognitively stimulating life experiences and activities are deemed to moderate the clinical impact of brain damage progressively building a neural and cognitive reserve (CR). CR has been studied extensively in various neurodegenerative disorders, but not in corticobasal degeneration (CBD).

METHODS

Using Statistical Parametric Mapping 8, years of education, as a determinant of CR, was correlated with tracer uptake on positron emission tomography with ¹⁸ F-fluorodeoxyglucose, as a marker of neurodegeneration, in 35 patients with various phenotypes of CBD, including a cognitive-motor composite score or symptoms duration as covariates for controlling disease stage.

RESULTS

A cluster of relative hypometabolism was found associated with higher education in the left inferior regions of pre- and post-rolandic gyri and insula, which represent typical loci of neurodegeneration in CBD regardless of clinical presentation.

CONCLUSIONS

The present findings extend to CBD the evidence gathered in other neurodegenerative disorders that a higher CR has a protective effect against the clinical manifestations of brain degeneration.

Respiratory Motion Management in PET/CT: Applications and Clinical Usefulness

BACKGROUND AND OBJECTIVE

Breathing movement can introduce heavy bias in both image quality and quantitation in PET/CT. The aim of this paper is a review of the literature to evaluate the benefit of respiratory gating in terms of image quality, quantification and lesion detectability.

METHODS

A review of the literature published in the last 10 years and dealing with gated PET/CT technique has been performed, focusing on improvement in quantification, lesion detectability and diagnostic accuracy in neoplastic lesion. In addition, the improvement in the definition of radiotherapy planning has been evaluated.

RESULTS

There is a consistent increase of the Standardized Uptake Value (SUV) in gated PET images when compared to ungated ones, particularly for lesions located in liver and in lung. Respiratory gating can also increase sensitivity, specificity and accuracy of PET/CT. Gated PET/CT can be used for radiation therapy planning, reducing the uncertainty in target definition, optimizing the volume to be treated and reducing the possibility of "missing" during the dose delivery. Moreover, new technologies, able to define the movement of lesions and organs directly from the PET sinogram, can solve some problems that currently are limiting the clinical use of gated PET/CT (i.e.: extended acquisition time, radiation exposure).

CONCLUSION

The published literature demonstrated that respiratory gating PET/CT is a valid technique to improve quantification, lesion detectability of lung and liver tumors and can better define the radiotherapy planning of moving lesions and organs. If new technical improvements for motion compensation will be clinically validated, gated technique could be applied routinely in any PET/CT scan.

Role of PET/CT in the Clinical Management of Locally Advanced Pancreatic Cancer

Aim

To evaluate the role of 18F-fluorodeoxyglucose (FDG) PET/CT in: a) the selection of patients with locally advanced pancreatic cancer for helical tomotherapy with concurrent chemotherapy (HTT-ChT); b) monitoring HTT-ChT treatment efficacy in comparison with contrast-enhanced CT (c.e.CT).

Methods

Forty-two consecutive patients with unresectable locally advanced pancreatic cancer referred for HTT-ChT were enrolled in the study. All patients were pretreated with induction ChT. Before the beginning of HTT-ChT treatment patients underwent diagnostic c.e.CT (CT0) and FDG PET/CT (PET/CT0) for staging. After staging, patients received HTT-ChT. Three months after the end of HTT-ChT a control c.e.CT (CT1) was done. FDG PET/CT (PET/CT1) was repeated only in patients with positive PET/CT0. PET/CT1 and CT1 were compared with baseline imaging results to assess treatment efficacy.

Results

In 31/42 cases (74%) PET/CT0 documented pathological uptake in pancreatic lesions, while in the remaining 11/42 cases it showed no uptake. In 7/42 (17%) patients, PET/CT0 also detected distant metastases, prompting a change in the therapeutic approach. Compared to PET/CT0, PET/CT1 (n = 18) documented 3 complete metabolic responses, 9 partial metabolic responses, 2 instances of stable metabolic disease, and 4 instances of progressive metabolic disease. In the same group of 18 patients, CT1 showed 0 complete responses, 3 partial responses, 8 instances of stable disease, and 7 instances of progressive disease compared to CT0. Concordance between PET/CT and CT response was seen in 33% of cases. In 50% of cases, PET/CT1 documented a response to therapy that was not evident on CT.

Conclusions

PET/CT influenced the treatment strategy by detecting distant metastases not documented by CT, thus accurately selecting patients for HTT-ChT after induction ChT. In monitoring treatment efficacy, PET/CT can detect a metabolic response to treatment not identified by CT.

18F-FDG PET/CT in preoperative staging of vulvar cancer patients: is it really effective?

The aim of this study was to assess the role of 18F-FDG PET/CT in preoperative staging of vulvar cancer patients.29 pts (69 years, range 51-88) with vulvar cancer (clinical apparent stage I-II), underwent preoperative FDG-PET/CT scan followed by radical vulvectomy and bilateral (or monolateral in case of tumor >2 cm from midline) inguinal lymphadenectomy ± sentinel node biopsy. PET/CT images were analyzed in consensus and correlated to histological findings according to a pt-based and a groin-based analyses. SUVmax of the nodal uptake of each inguinal area (if present) was calculated and correlated to histological findings. The presence of distant metastases was also considered and confirmed.PET/CT analysis in consensus resulted negative at the inguinal LN level in 17 pts (10 true negative, 7 false negative) and positive in 12 pts (7 true positive, 5 false positive). Incidence of LN metastases resulted 48%. On pt-based analysis, sensitivity, specificity, accuracy, and negative and positive predictive value of PET/CT in detecting LN metastases were 50%, 67%, 59%, 59%, and 58%, respectively. On a groin-based analysis, considering overall 50 LN-sites, sensitivity, specificity, accuracy, and negative and positive predictive value of PET/CT were 53%, 85%, 73%, 67%, and 76%, respectively. The mean value of SUVmax was 6.1 (range 0.7-16.2) for metastatic nodes, whereas 1.6 (range 0.7 - 5.4) for negative lymph-nodes (P = .007). PET/CT detected pelvic (n = 1) and both pelvic/paraortic (n = 1) nodal metastases.In clinical early stage vulvar cancer FDG PET/CT showed low sensitivity and moderate specificity for N-staging; therefore, it is not an accurate tool for the nodal status assessment. PET/CT may not be cost-effective in detecting the rare event of distant metastases, but further studies are needed.

Added diagnostic value of respiratory-gated 4D 18F-FDG PET/CT in the detection of liver lesions: a multicenter study

PURPOSE

The aim of the present study was to evaluate the added diagnostic value of respiratory-gated 4D18F-FDG PET/CT in liver lesion detection and characterization in a European multicenter retrospective study.

METHODS

Fifty-six oncological patients (29 males and 27 females, mean age, 61.2 ± 11.2 years) from five European centers, submitted to standard 3D-PET/CT and liver 4D-PET/CT were retrospectively evaluated. Based on visual analysis, liver PET/CT findings were scored as positive, negative, or equivocal both in 3D and 4D PET/CT. The impact of 4D-PET/CT on the confidence in classifying liver lesions was assessed. PET/CT findings were compared to histology and clinical follow-up as standard reference and diagnostic accuracy was calculated for both techniques. At semi-quantitative analysis, SUVmax was calculated for each detected lesion in 3D and 4D-PET/CT.

RESULTS

Overall, 72 liver lesions were considered for the analysis. Based on visual analysis in 3D-PET/CT, 32/72 (44.4%) lesions were considered positive, 21/72 (29.2%) negative, and 19/72 (26.4%) equivocal, while in 4D-PET/CT 48/72 (66.7%) lesions were defined positive, 23/72 (31.9%) negative, and 1/72 (1.4%) equivocal. 4D-PET/CT findings increased the confidence in lesion definition in 37/72 lesions (51.4%). Considering 3D equivocal lesions as positive, sensitivity, specificity, and accuracy were 88.9, 70.0, and 83.1%, respectively, while the same figures were 67.7, 90.0, and 73.8% if 3D equivocal findings were included as negative. 4D-PET/CT sensitivity, specificity, and accuracy were 97.8, 90.0, and 95.4%, respectively, considering equivocal lesions as positive and 95.6, 90.0, and 93.8% considering equivocal lesions as negative. The SUVmax of the liver lesions in 4D-PET (mean ± SD, 6.9 ± 3.2) was significantly higher (p < 0.001) than SUVmax in 3D-PET (mean ± SD, 5.2 ± 2.3).

CONCLUSIONS

Respiratory-gated PET/CT technique is a valuable clinical tool in diagnosing liver lesions, reducing 3D undetermined findings, improving diagnostic accuracy, and confidence in reporting. 4D-PET/CT also improved the quantification of SUVmax of liver lesions.

Indocyanine Green versus Radiotracer with or without Blue Dye for Sentinel Lymph Node Mapping in Stage >IB1 Cervical Cancer (>2 cm)

STUDY OBJECTIVE

To compare sentinel lymph node (SLN) mapping in women with cervical cancer stage >IB1 (tumor size >2 cm) using indocyanine green (ICG) versus the standard technique using radioisotope technetium 99m radiocolloid (Tc99^m) radiotracer with or without blue dye.

DESIGN

European multicenter, retrospective observational study (Canadian Task Force classification II-2).

SETTING

Four academic medical centers.

PATIENTS

Ninety-five women with stage IB1 cervical cancer (>2 cm) who underwent SLN mapping with Tc99^m with or without blue dye or ICG and radical hysterectomy.

INTERVENTION

The detection rate and bilateral mapping rate were compared between ICG and standard Tc99^m radiotracer with or without blue dye. Lymphadenectomy was performed, and the false-negative rate was assessed.

MEASUREMENTS AND MAIN RESULTS

Forty-seven patients underwent SLN mapping with Tc99^m with or without blue dye, and 48 did so with ICG. All patients underwent radical hysterectomy with or without bilateral salpingo-oophorectomy between 2008 and 2016. The overall detection rate of SLN mapping was 91.5% for Tc99^m with or without blue dye and 100% for ICG. A 91.7% rate of bilateral migration was achieved for ICG, significantly higher than the 66% obtained with Tc99^m with or without blue dye (p = .025). Nine of the 23 SLN-positive patients (39.1%) were diagnosed exclusively as a result of the ultrastaging used to identify micrometastases or isolated tumor cells only.

CONCLUSIONS

In advanced cervical cancer (stage IB1 >2 cm), the detection rate and bilateral migration rate on real-time fluorescent SLN mapping were higher with ICG than with Tc99^m radiotracer with or without blue dye. SLN mapping and ultrastaging can provide additional information for nodal staging in advanced cervical cancer. In this setting, ICG is a promising tool for mapping, appearing less affected by higher disease stage compared with traditional methods.

From Conventional Radiotracer Tc-99(m) with Blue Dye to Indocyanine Green Fluorescence: A Comparison of Methods Towards Optimization of Sentinel Lymph Node Mapping in Early Stage Cervical Cancer for a Laparoscopic Approach

BACKGROUND

The credibility of sentinel lymph node (SLN) mapping is becoming increasingly more established in cervical cancer. We aimed to assess the sensitivity of SLN biopsy in terms of detection rate and bilateral mapping in women with cervical cancer by comparing technetium-99 radiocolloid (Tc-99(m)) and blue dye (BD) versus fluorescence mapping with indocyanine green (ICG).

METHODS

Data of patients with cervical cancer stage 1A2 to 1B1 from 5 European institutions were retrospectively reviewed. All centers used a laparoscopic approach with the same intracervical dye injection. Detection rate and bilateral mapping of ICG were compared, respectively, with results obtained by standard Tc-99(m) with BD.

RESULTS

Overall, 76 (53 %) of 144 of women underwent preoperative SLN mapping with radiotracer and intraoperative BD, whereas 68 of (47 %) 144 patients underwent mapping using intraoperative ICG. The detection rate of SLN mapping was 96 % and 100 % for Tc-99(m) with BD and ICG, respectively. Bilateral mapping was achieved in 98.5 % for ICG and 76.3 % for Tc-99(m) with BD; this difference was statistically significant (p < 0.0001).

CONCLUSIONS

The fluorescence SLN mapping with ICG achieved a significantly higher detection rate and bilateral mapping compared to standard radiocolloid and BD technique in women with early stage cervical cancer. Nodal staging with an intracervical injection of ICG is accurate, safe, and reproducible in patients with cervical cancer. Before replacing lymphadenectomy completely, the additional value of fluorescence SLN mapping on both perioperative morbidity and survival should be explored and confirmed by ongoing controlled trials.

Quality of Care for Cervical and Endometrial Cancer Patients: The Impact of Different Techniques of Sentinel Lymph Node Mapping on Patient Satisfaction

OBJECTIVES

The purpose of this study was to assess the quality of care in patients who underwent sentinel lymph node (SLN) mapping for endometrial and cervical cancer staging, and evaluate the impact of different techniques on patient satisfaction, i.e. radiotracer Tc99m versus indocyanine green (ICG) or methylene blue injection.

METHOD

Women with preoperative stage I endometrial cancer or stage I (1A2-1B1) cervical cancer who underwent surgical staging, including SLN mapping, were considered for this study. Patient satisfaction was assessed using the European Organisation for Research and Treatment of Cancer IN-PATSAT32 questionnaire. Women were classified into two groups according to the different nodal mapping techniques: intracervical preoperative injection of Tc99m nanocolloid + intraoperative blue dye (Group 1) versus intraoperative cervical injection of ICG or blue dye (Group 2). Differences in patient satisfaction scores between the groups were analyzed.

RESULTS

Of the 178 eligible women, 143 were included in the study (endometrial cancer n = 106, cervical cancer n = 37): 57 underwent SLN mapping with Tc99m and blue dye (Group 1), and 86 women were mapped intraoperatively with blue dye alone or ICG (Group 2). Analysis of IN-PATSAT32 questionnaire scores showed a higher patient satisfaction score for patients in Group 2 (p = 0.001), which was independent of the physician and surgical outcomes evaluated. The scores were statistically better for Group 2, and also in rating doctors (p = 0.0001), nurses (p = 0.006), and care and services organizations (p = 0.001).

CONCLUSIONS

Cervical and endometrial cancer patients who underwent SLN mapping by ICG or blue dye perceived a better quality of care when compared with those patients who underwent the combined radiocolloid and blue dye technique.

Predictive value of (18)F-FDG PET/CT in restaging patients affected by ovarian carcinoma: a multicentre study

PURPOSE

Ovarian cancer is the eighth most common malignancy among women and has a high mortality rate. Prognostic factors able to drive an effective therapy are essential. (18)F-Fluoro-2-deoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has been investigated in patients with epithelial ovarian cancer and showed promise in diagnosing, staging, detecting recurrent lesions and monitoring treatment response. Conversely, its prognostic role remains unclear. We aimed at assessing the prognostic value of (18)F-FDG PET/CT performed in the restaging process in a multicentre study.

METHODS

We evaluated 168 patients affected by ovarian carcinoma, who underwent a restaging (18)F-FDG PET/CT. The presence of local recurrences, lymph node involvement and distant metastasis was recorded as well as lesion dimensions, maximum and mean standardized uptake values (SUVmax and SUVmean, respectively). Progression-free survival (PFS) and overall survival (OS) at 3 and 4 years were computed by using Kaplan-Meier curves. Increased odds ratio was assessed using Cox regression analysis testing all lesion parameters measured by PET/CT.

RESULTS

PFS was significantly longer in patients with a negative than a positive restaging PET/CT study (3- and 4-year PFS 64 and 53% vs 23 and 12%, respectively; p < 0.001). Similarly, a negative study was associated with a significantly higher OS rate after 4 years of follow-up (67 vs 25% in negative and positive groups, respectively; p < 0.001). Lymph node or distant involvement were also independently associated with an increased risk of disease progression [hazard ratio (HR) 1.6 and 2.2, respectively; p = 0.003]. Moreover, PET/CT showed an incremental prognostic value compared to the International Federation of Gynecology and Obstetrics (FIGO) staging system. In the analysis of patient subsets, individuals with the same FIGO stage I-II but with negative PET had a significantly better 4-year OS than patients with low FIGO stage but positive PET. This implies that patients with the same FIGO stage can be further prognostically stratified using PET (p = 0.01). At receiver-operating characteristic (ROC) analysis, no thresholds for semiquantitative parameters were predictive of a worse outcome.

CONCLUSION

(18)F-FDG PET/CT has an important prognostic value in assessing the risk of disease progression and mortality rate. An efficacious therapy planning might therefore effectively rely on (18)F-FDG PET/CT findings. Semiquantitative data were not proven to be an effective tool to predict disease progression.

Impact of Indocyanine Green for Sentinel Lymph Node Mapping in Early Stage Endometrial and Cervical Cancer: Comparison with Conventional Radiotracer (99m)Tc and/or Blue Dye

Purpose

To compare the detection rate (DR) and bilateral optimal mapping (OM) of sentinel lymph nodes (SLNs) in women with endometrial and cervical cancer using indocyanine green (ICG) versus the standard technetium-99m radiocolloid (^99mTc) radiotracer plus methylene or isosulfan blue, or blue dye alone.

Methods

From October 2010 to May 2015, 163 women with stage I endometrial or cervical cancer (118 endometrial and 45 cervical cancer) underwent SLN mapping with ^99mTc with blue dye, blue dye alone, or ICG. DR and bilateral OM of ICG were compared respectively with the results obtained using the standard ^99mTc radiotracer with blue dye, or blue dye alone.

Results

SLN mapping with ^99mTc radiotracer with blue dye was performed on 77 of 163 women, 38 with blue dye only and 48 with ICG. The overall DR of SLN mapping was 97, 89, and 100 % for ^99mTc with blue dye, blue dye alone, and ICG, respectively. The bilateral OM rate for ICG was 85 %—significantly higher than the 58 % obtained with ^99mTc with blue dye (p = 0.003) and the 54 % for blue dye (p = 0.001). Thirty-one women (19 %) had positive SLNs. Sensitivity and negative predictive value of SLN were 100 % for all techniques.

Conclusions

SLNs mapping using ICG demonstrated higher DR compared to other modalities. In addition, ICG was significantly superior to ^99mTc with blue dye in terms of bilateral OM in women with early stage endometrial and cervical cancer. The higher number of bilateral OM may consequently reduce the overall number of complete lymphadenectomies, reducing the duration and additional costs of surgical treatment.

Focal bone lesions in HIV-positive patient treated with tenofovir

Background

Tenofovir is a widely used antiviral drug for the treatment of HIV and HBV infection. Although its side effects on renal function and bone metabolism are well known, there are no reports on focal bone lesions caused by this drug. Our case suggests this new, unusual but important scenario.

Case presentation

We report on a 46-year-old HIV-positive man treated with an antiretroviral regimen containing tenofovir who suddenly developed localized inflammatory bone lesions. The examinations performed ruled out all the disorders commonly associated with this clinical pattern, and the patient’s conditions improved only after the suspension of tenofovir.

Conclusions

The case study suggests a rare but severe adverse event, which should be taken into account when physicians treat HIV-positive patients with focal inflammatory bone lesions

(11)C-Choline PET/CT as a guide to radiation treatment planning of lymph-node relapses in prostate cancer patients

PURPOSE

To evaluate, in prostate cancer (PCa) patients the potential of (11)C-choline PET/CT as a guide to helical tomotherapy (HTT) of lymph-node (LN) relapses with simultaneous integrated boost (SIB). The efficacy and feasibility of HTT in terms of acute toxicity were assessed.

METHODS

We enrolled 83 PCa patients (mean age 68 years, range 51 - 82 years) with biochemical recurrence after radical primary treatment (mean serum PSA 7.61 ng/ml, range 0.37 - 187.00 ng/ml; PSA0) who showed pathological findings on (11)C-choline PET/CT only at the LN site. (11)C-Choline PET/CT was performed for restaging and then for radiation treatment planning (PET/CT0). Of the 83 patients, 8 experienced further LN relapse, of whom 5 were retreated once and 3 were retreated twice (total 94 radiotherapy treatments). All pelvic and/or abdominal LNs positive on PET/CT0 were treated with high doses using SIB. Doses were in the range 36 - 74 Gy administered in 28 fractions. After the end of HTT (mean 83 days, range 16 - 365 days), serum PSA was measured in all patients (PSA1) and compared with PSA0 to evaluate early biochemical response. In 47 patients PET/CT was repeated (PET/CT1) to assess metabolic responses at the treated areas. Toxicity criteria of the Radiation Therapy Oncology Group (RTOG) were used to assess acute toxicity.

RESULTS

PET/CT0 revealed pathological LNs in the pelvis in 49 patients, pathological LNs in the abdomen in 15 patients pathological LNs in both the pelvis and abdomen in 18 patients, and pathological LNs in the pelvis or abdomen and other sites in 12 patients. All these sites were treated with HTT. With respect to PSA0, PSA1 (mean 6.28 ng/ml, range 0.00 - 220.46 ng/ml) showed a complete biochemical response after 66 of the 94 HTT treatments, a partial response after 12 treatments, stable disease after 1 treatment and progression of disease after 15 treatments. Of the 47 patients receiving PET/CT1, 20 showed a complete metabolic response at the treated area, 22 a partial metabolic response, 3 progression of disease and 2 stable disease. HTT with SIB was well tolerated in all patients. Grade 3 acute toxicity in the genitourinary tract was observed in two patients.

CONCLUSION

(11)C-Choline PET/CT is a valuable tool for planning and monitoring HTT in LN relapse after primary treatment. High-dose hypofractionated (11)C-choline PET/CT-guided HTT with SIB is well tolerated and is associated with a high early biochemical response rate.

Comparative analysis of iterative reconstruction algorithms with resolution recovery for cardiac SPECT studies. A multi-center phantom study

BACKGROUND

This investigation used image data generated by a physical phantom over a wide range of count statistics to evaluate the effectiveness of several of the newer commercially available SPECT reconstruction iterative algorithms (IRR) in improving perfusion defect contrast and spatial resolution, while controlling image noise.

METHODS

A cardiac phantom was imaged using four different gamma cameras over a wide range of counts statistics (from 6 to 0.8 Mcounts). Images were reconstructed with FBP, OSEM, and the IRR available on site. IRR were applied without corrections (IRR NC), with attenuation correction (IRR AC), scatter correction (IRR SC), and attenuation + scatter corrections (IRR SCAC). Four image performance indices related to spatial resolution, contrast, and image noise were analyzed.

RESULTS

IRR NC always determined significant improvements in all indices in comparison to FBP or OSEM. Improvements were emphasized with IRR SC and IRR SCAC. Count reduction from 6 to 1.5 Mcounts did not impair the performances of any of the considered indices.

CONCLUSIONS

This is the first study comparing the relative performance of different, commercially available, IRR software, over a wide range of count statistics; the additional effect of scatter and attenuation corrections, alone or in combination, was also evaluated. Our results confirm that IRR algorithms produce substantial benefits with respect to conventional FBP or OSEM reconstruction methods, as assessed through different figures of merit, in particular when SC and/or SCAC are also included.

Preoperative 18F-FDG PET/CT in the management of advanced epithelial ovarian cancer

OBJECTIVE

The introduction of 18-FDG-PET/CT during preoperative evaluation of patients with epithelial ovarian cancer (EOC) has led to an increase of the detection of extra-abdominal metastases. However, the clinical impact of this upstage remains unclear.

METHODS

Patients with suspected advanced EOC underwent 18-FDG-PET/CT within two weeks prior to debulking surgery.

RESULTS

Between 2006 and 2011 95 patients met the inclusion criteria. Based on the concordance or the discrepancy of clinical and PET/CT stage, patients were divided into 3 groups (A: clinical and PET III; B: clinical III and PET IV; C: clinical and PET IV). Twenty-five patients were upstaged from FIGO stage III to stage IV by PET/CT. The proportion of patients who achieved a residual tumor <1cm in group B and C was similar, whereas it was significantly lower compared to group A. Similarly, complete response to adjuvant chemotherapy was achieved more frequently in patients in group A. PFS was similar in the three groups (17, 17 and 12 months in group A, B and C), as well as OS (51, 41 and 35 months).

CONCLUSIONS

PET/CT is able to detect distant metastases in EOC patients. The presence of extra-abdominal disease probably indicates a more aggressive disease which also shows a lower response to standard chemotherapy. However, upstaged patients have a similar prognosis compared to stage III patients, probably because intra-abdominal disease is more likely to lead patients to death. This might also explain why residual tumor is the most important prognostic factor for advanced EOC patients.

Role of PET/CT in the clinical management of locally advanced pancreatic cancer

AIM

To evaluate the role of 18F-fluorodeoxyglucose (FDG) PET/CT in: a) the selection of patients with locally advanced pancreatic cancer for helical tomotherapy with concurrent chemotherapy (HTT-ChT); b) monitoring HTT-ChT treatment efficacy in comparison with contrast-enhanced CT (c.e.CT).

METHODS

Forty-two consecutive patients with unresectable locally advanced pancreatic cancer referred for HTT-ChT were enrolled in the study. All patients were pretreated with induction ChT. Before the beginning of HTT-ChT treatment patients underwent diagnostic c.e.CT (CT0) and FDG PET/CT (PET/CT0) for staging. After staging, patients received HTT-ChT. Three months after the end of HTT-ChT a control c.e.CT (CT1) was done. FDG PET/CT (PET/CT1) was repeated only in patients with positive PET/CT0. PET/CT1 and CT1 were compared with baseline imaging results to assess treatment efficacy.

RESULTS

In 31/42 cases (74%) PET/CT0 documented pathological uptake in pancreatic lesions, while in the remaining 11/42 cases it showed no uptake. In 7/42 (17%) patients, PET/CT0 also detected distant metastases, prompting a change in the therapeutic approach. Compared to PET/CT0, PET/CT1 (n = 18) documented 3 complete metabolic responses, 9 partial metabolic responses, 2 instances of stable metabolic disease, and 4 instances of progressive metabolic disease. In the same group of 18 patients, CT1 showed 0 complete responses, 3 partial responses, 8 instances of stable disease, and 7 instances of progressive disease compared to CT0. Concordance between PET/CT and CT response was seen in 33% of cases. In 50% of cases, PET/CT1 documented a response to therapy that was not evident on CT.

CONCLUSIONS

PET/CT influenced the treatment strategy by detecting distant metastases not documented by CT, thus accurately selecting patients for HTT-ChT after induction ChT. In monitoring treatment efficacy, PET/CT can detect a metabolic response to treatment not identified by CT.

18F-FDG PET/CT can predict nodal metastases but not recurrence in early stage uterine cervical cancer

OBJECTIVES

To evaluate the role of the metabolic characteristics of cervical tumor uptake as predictors of a) lymph node (LN) metastases, b) recurrence, in the preoperative staging of early-stage cervical cancer.

METHODS

89 patients with FIGO stage IB1 and IIA<4 cm cervical cancer were imaged with FDG-PET/CT before radical hysterectomy and pelvic lymphadenectomy. PET/CT images were analyzed and correlated to histological findings. Maximum and mean standardized uptake value (SUVmax, SUVmean), metabolic tumor volume (MTV), total lesion glycolysis (TLG) of cervical lesions were calculated by an iterative adaptive algorithm. These parameters were correlated to the presence of: a) LN metastases, b) relapse after primary treatment.

RESULTS

Out of the 89 patients who underwent preoperative PET/CT scan for staging purpose, 16 were negative at cervical level: they were all pN0 and without recurrence during follow-up (mean 34.1±14.5 months). In 69 patients MTV and TLG were significantly higher (p=0.0006 and p=0.03) in pN1 patients in comparison to pN0 patients, while SUV values did not show significant differences between the two groups. No significant correlations were found between SUVmax, SUVmean, MTV, TLG and the evidence of relapse (mean follow-up 29.2±15.5 months).

CONCLUSIONS

In early-stage cervical cancer MTV and TLG correlate with the presence of nodal metastases, but their clinical impact on patients management has to be clarified. The absence of pathological cervical uptake could be a good prognostic factor, while SUVmax, SUVmean, MTV, TLG of the cervical uptake have not been found predictors of recurrence.

PET/CT and contrast enhanced CT in single vs. two separate sessions: a cost analysis study

AIM

Aim of the study was to quantify the economic impact of PET/CT and contrast enhanced (c.e.) CT performed in a single session examination vs. stand-alone modalities in oncological patients.

METHODS

One-hundred-forty-five cancer patients referred to both PET/CT and c.e. CT, to either stage (N.=46) or re-stage (N.=99) the disease, were included. Seventy-two/145 performed both studies in a single session (innovative method) and 73/145 in two different sessions (traditional method). The cost-minimization analysis was performed by evaluating: 1) institutional costs, data obtained by hospital accountability (staff, medical materials, equipment maintenance and depreciation, departments utilities); 2) patients costs, data obtained by a specific survey provided to patients (travel, food, accommodation costs, productivity loss).

RESULTS

Economic data analysis showed that the costs for innovative method was lower than those of traditional method, both for Institution (106 € less per test) and for patient (21 € less per patient). The loss of productivity for patient and caregivers resulted lower for the innovative method than the traditional method (3 work-hour less per person).

CONCLUSION

PET/CT and c.e. CT performed in a single session is more cost-effective than stand-alone modalities, by reducing both Institutional and patients costs. These advantages are mainly due to lower Institutional cost (single procedure) and to lower cost related to travel and housing.

Unusual presentation of sarcoid-like reaction on bone marrow level associated with mediastinal lymphadenopathy on (18)F-FDG-PET/CT resembling an early recurrence of Hodgkin's Lymphoma

(18)F-FDG-PET/CT is widely employed to evaluate lymphoma patients. False positive results are quite frequent, generally due to active phase of inflammation. We describe an unusual PET/CT presentation of a sarcoid-like reaction (SLR) in a patient monitored for Hodgkin Lymphoma characterized by an intense uptake in lymph nodes and multiple bone foci in a PET/CT study. The final diagnosis was obtained by biopsy. This study draws attention to the fact that multifocal bone marrow uptakes due to a sarcoideal reaction may be a possible cause of false positive results in (18)F-FDG-PET/CT studies in oncology patients.

Performance of a SPECT collimator-detector response reconstruction algorithm: phantom studies and validation in inflammation clinical studies

AIM

To evaluate evolution for bone (EfB), one of the recent corrective collimator detector response (CDR) image reconstruction packages, resolution recovery and iterative reconstruction protocols were compared to the standard Filtered Back Projection (FBP) protocol and the possibility of time reduced acquisition (15 instead of 30 seconds/projection) was evaluated.

METHODS

Tomographic spatial resolution, contrast, noise and signal-to-noise ratio (SNR) were analyzed in phantom studies. Patient studies were conducted on sixteen [99mTc]HMPAO labeled leukocyte patients with suspected local inflammation, submitted to SPECT/CT and conventional leukocyte scintigraphy. Target background ratio (TBR) and boundary of each lesion were calculated. Images were also analyzed by visual inspection by two blinded expert physicians.

RESULTS

a) Phantom: resolution in phantom improves with the use of EfB mainly due to iterative reconstruction methods vs FBP. EfB shows a reduction in noise. No differences were found in contrast data, while SNR changes were mainly due to changes in noise. Time reduction, while increasing image noise, does not modify resolution; nevertheless, half-time EfB noise is the same as full-time FBP noise. b)

PATIENTS

lesion boundary is better defined in patient studies using iterative reconstruction vs FBP; no changes were observed for CDR vs iterative OSEM, or for full-time vs half-time acquisition. TBR is comparable in iterative and FBP protocols, while it is improved by EfB. At visual inspection, a higher score is always associated with EfB.

CONCLUSION

Resolution, noise, SNR and TBR improve when applying the resolution recovery. EfB permits reduction of acquisition time without compromising image quality.

Clinical evidence on PET/CT for radiation therapy planning in prostate cancer

The present chapter is focused on the role of positron emission tomography/computed tomography (PET/CT) and [11C]-labelled Choline ([11C]Choline) for the management of prostate cancer patients for radiation therapy planning. Although still a matter of debate, PET/CT with [11C]Choline is not routinely recommended for selecting patients for prostate cancer primary radiation treatment. However, due to its high accuracy in detecting and localizing recurrences when a biochemical failure occurs, [11C]Choline PET/CT may play a role in the re-staging phase to distinguish patients with local versus distant relapse, thus influencing patient management (curative versus palliative therapy). Limited data are currently available on the role of [11C]Choline PET/CT in target volume selection and delineation. According to available literature, [11C]Choline PET/CT is not clinically recommendable to plan target volume both for primary prostate treatment and for local recurrence. Nevertheless, promising data suggested a potential role of [11C]Choline PET/CT as an image guide tool for the irradiation of prostate cancer relapse.