[18F]FDG PET/CT Signal Correlates with Neoangiogenesis Markers in Patients with Fibrotic Interstitial Lung Disease Who Underwent Lung Biopsy: Implication for the Use of PET/CT in Diffuse Lung Diseases

The use of [18F]FDG PET/CT as a biomarker in diffuse lung diseases is increasingly recognized. We investigated the correlation between [18F]FDG uptake with histologic markers on lung biopsy of patients with fibrotic interstitial lung disease (fILD). Methods: We recruited 18 patients with fILD awaiting lung biopsy for [18F]FDG PET/CT. We derived a target-to-background ratio (TBR) of maximum pulmonary uptake of [18F]FDG (SUVmax) divided by the lung background (SUVmin). Consecutive paraffin-embedded lung biopsy sections were immunostained for alveolar and interstitial macrophages (CD68), microvessel density (MVD) (CD31 and CD105/endoglin), and glucose transporter 1. MVD was expressed as vessel area percentage per high-power field (Va%/hpf). Differences in imaging and angiogenesis markers between histologic usual interstitial pneumonia (UIP) and non-UIP were assessed using a nonparametric Mann-Whitney test. Correlation of imaging with angiogenesis markers was assessed using the nonparametric Spearman rank correlation. Univariate Kaplan-Meier survival analysis assessed the difference in the survival curves for each of the angiogenesis markers (separated by their respective optimal cutoff) using the log-rank test. Statistical analysis was performed using SPSS. Results: In total, 18 patients were followed for an average of 41.36 mo (range, 5.69-132.46 mo; median, 30.07 mo). Only CD105 MVD showed a significantly positive correlation with [18F]FDG TBR (Spearman rank correlation, 0.556; P < 0.05, n = 13). There was no correlation between [18F]FDG uptake and macrophage expression of glucose transporter 1. CD105 and CD31 were higher for UIP than for non-UIP, with CD105 reaching statistical significance (P = 0.011). In all patients, MVD assessed with either CD105 or CD31 quantification on biopsy predicted overall survival. Patients with CD105 MVD of less than 12 Va%/hpf or CD31 MVD of less than 35 Va%/hpf had a significantly better prognosis (no deaths during follow-up in the case of CD105) than did patients with higher scores of CD105 MVD (median survival, 35 mo; P = 0.041, n = 13) or CD31 MVD (median survival, 28 mo; P = 0.014, n = 13). Conclusion: Previous work has used [18F]FDG uptake in PET/CT as a biomarker in fILD. Here, we highlight a correlation between angiogenesis and [18F]FDG TBR. We show that MVD is higher for UIP than for non-UIP and is associated with mortality in patients with fILD. These data set the scene to investigate the potential role of vasculature and angiogenesis in fibrosis.

EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy

Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.

Unusual Presentation of Solitary Penile Metastasis of Prostate Cancer on 68 Ga-PSMA PET/CT

ABSTRACT

A 75-year-old patient was referred with biochemical recurrence for prostate cancer. The patient underwent 68 Ga-PSMA (prostate-specific membrane antigen) PET/CT scan, which revealed a focal PSMA activity in the proximal left lateral penile margin. Although a subsequent ultrasound did not identify the abnormality, MRI pelvis revealed a 10-mm lesion in the left proximal corpus cavernosum. This lesion was consistent with metastatic acinar adenocarcinoma of the prostate on postresection histopathology. This unusual presentation of asymptomatic, histopathology-proven, penile solitary metastases was documented 3 years after robotic-assisted laparoscopic prostatectomy and pelvic external beam radiotherapy.

Theranostics in Neurooncology: Heading Toward New Horizons

Therapeutic approaches to brain tumors remain a challenge, with considerable limitations regarding delivery of drugs. There has been renewed and increasing interest in translating the popular theranostic approach well known from prostate and neuroendocrine cancer to neurooncology. Although far from perfect, some of these approaches show encouraging preliminary results, such as for meningioma and leptomeningeal spread of certain pediatric brain tumors. In brain metastases and gliomas, clinical results have failed to impress. Perspectives on these theranostic approaches regarding meningiomas, brain metastases, gliomas, and common pediatric brain tumors will be discussed. For each tumor entity, the general context, an overview of the literature, and future perspectives will be provided. Ongoing studies will be discussed in the supplemental materials. As most theranostic agents are unlikely to cross the blood-brain barrier, the delivery of these agents will be dependent on the successful development and clinical implementation of techniques enhancing permeability and retention. Moreover, the international community should strive toward sufficiently large and randomized studies to generate high-level evidence on theranostic approaches with radioligand therapies for central nervous system tumors.

Myocardial, Retro-orbital, and Bilateral Testicular Metastases of an Ileal Neuroendocrine Tumor in 68 Ga-DOTATATE PET/CT

ABSTRACT

A 71-year-old man with a newly discovered metastatic grade II neuroendocrine tumor of the terminal ileum was referred for a 68 Ga-DOTATATE PET/CT scan to stage the disease and assess suitability for PRRT (peptide receptor radionuclide therapy). The patient was known to have secondary nodal and bone/liver metastatic disease through prior morphological investigations. PET images revealed an atypical pattern of metastatic disease, showcasing secondary lesions in bilateral extraocular muscles, the myocardium, and both testes. The patient was pauci-symptomatic and only reported fatigue and diarrhea. Management involved lanreotide administration, and PRRT is being envisaged.

PET/CT in treatment response assessment in lung cancer. When should it be recommended?

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Different treatment options are now possible both for surgical candidates and for those NSCLC patients deemed not suitable for surgery. Despite the treatments available, only a limited number of less advanced stages are potentially curable, with many patients suffering local recurrence or distant metastases. FDG-PET/CT is commonly used in many centers for post-treatment evaluation, follow-up, or surveillance; Nonetheless, there is no clear consensus regarding the indications in these cases. Based upon the results of a literature review and local expertise from a large lung cancer unit, we built clinical evidence-based recommendations for the use of FDG-PET/CT in response assessment. We found that in general this is not recommended earlier than 3 months from treatment; however, as described in detail the correct timing will also depend upon the type of treatment used. We also present a structured approach to assessing treatment changes when reporting FDG-PET/CT, using visual or quantitative approaches.

[ 18 F] FDG PET/CT Imaging in a Rare Case of Sarcoidosis With Involvement of Epididymis

ABSTRACT

Genitourinary involvement of sarcoidosis is an uncommon occurrence. In this report, we present [ 18 F] FDG PET/CT of a young adult man with sarcoidosis involving the epididymis, and we discuss the utility of FDG PET imaging in diagnosis and assessment of response to treatment.

Identifying and troubleshooting the pitfalls of ictal/interictal brain perfusion SPECT studies

Epilepsy is a prevalent condition, and surgical intervention can benefit patients with refractory seizures. Single photon emission computed tomography (SPECT) using 99mTc-HMPAO or 99mTc-ECD provides assessment of regional cerebral blood flow and is the primary non-invasive approach for imaging brain perfusion in ictal and interictal states. Ictal/interictal SPECT is valuable in localising epileptogenic foci, particularly when MRI and electroencephalography are negative. However, to obtain accurate images reflecting brain perfusion in both states, meticulous preparation of the patient, timely radiotracer injection and close coordination between neurology and nuclear medicine teams are essential. Tracers also have inherent limitations, and patients may present with coexisting brain pathologies for which coregistration of SPECT images with MRI is recommended to improve diagnostic accuracy. Inconclusive SPECT findings may require repeating the exam or considering additional investigations. A comprehensive approach, considering various factors, is crucial for accurate interpretation of SPECT studies in presurgical epilepsy evaluations. This article provides a summary of the organisation and key challenges involved in conducting ictal/interictal SPECT studies, covering the entire process from a patient's hospital arrival to the integration of results within their presurgical pathway and using our experience of 182 patients over 10 years.

Mapping glioma heterogeneity using multiparametric 18 F-choline PET/MRI in childhood and teenage-young adults

OBJECTIVE

The heterogeneity of post-treatment imaging remains a significant challenge in children and teenagers/young adults (TYA) diagnosed with glioma. The aim of this study was to evaluate the utility of 18 F-choline PET/MRI in determining intratumoural heterogeneity in paediatric and TYA gliomas.

METHODS

Twenty-six patients (mean age 16 years, range 8-22 years) with suspected glioma disease progression were evaluated with 18 F-choline PET/MRI. Relative cerebral blood volume (rCBV), apparent diffusion coefficient (ADC) and maximum standardised uptake values (SUV max ) in enhancing (enh) and non-enhancing (ne) tumour volumes and normal-appearing white matter (wm) were calculated (rCBV enh , rCBV ne , rCBV wm , ADC enh , ADC ne , ADC wm , SUV enh , SUV ne and SUV wm ).

RESULTS

Significantly higher SUV enh and SUV ne compared with SUV wm were observed [SUV enh 0.89 (0.23-1.90), SUV ne 0.36 (0.16-0.78) versus SUV wm 0.15 (0.04-1.19); P  < 0.001 and P  = 0.004, respectively]. Equivalent results were observed for ADV and rCBV (ADC enh , ADC ne : P  < 0.001 versus ADC wm ; rCBV enh , rCBV ne : P  < 0.001 versus rCBV wm ). The highest values for mean SUV max [0.89 (0.23-1.90)] and mean rCBV [2.1 (0.74-5.08)] were in the enhancing component, while the highest values for ADC [1780 mm 2 /s (863-2811)] were in the necrotic component.

CONCLUSION

18 F-choline PET/MRI is able map imaging heterogeneity in paediatric and TYA gliomas, detecting post-treatment enhancing, non-enhancing, and necrotic tumour components equivalent to ADC and DSC-derived rCBV. This offers potential in the response assessment of diffuse non-enhancing gliomas and in selected cases such as posterior fossa tumours where quantitative MRI is technically difficult.

Filtration-histogram based texture analysis and CALIPER based pattern analysis as quantitative CT techniques in idiopathic pulmonary fibrosis: head-to-head comparison

OBJECTIVE

To assess the prognostic performance of two quantitative CT (qCT) techniques in idiopathic pulmonary fibrosis (IPF) compared to established clinical measures of disease severity (GAP index).

METHODS

Retrospective analysis of high-resolution CT scans for 59 patients (age 70.5 ± 8.8 years) with two qCT methods. Computer-aided lung informatics for pathology evaluation and ratings based analysis classified the lung parenchyma into six different patterns: normal, ground glass, reticulation, hyperlucent, honeycombing and pulmonary vessels. Filtration histogram-based texture analysis extracted texture features: mean intensity, standard deviation (SD), entropy, mean of positive pixels (MPPs), skewness and kurtosis at different spatial scale filters. Univariate Kaplan-Meier survival analysis assessed the different qCT parameters' performance to predict patient outcome and refine the standard GAP staging system. Multivariate cox regression analysis assessed the independence of the significant univariate predictors of patient outcome.

RESULTS

The predominant parenchymal lung pattern was reticulation (16.6% ± 13.9), with pulmonary vessel percentage being the most predictive of worse patient outcome (p = 0.009). Higher SD, entropy and MPP, in addition to lower skewness and kurtosis at fine texture scale (SSF2), were the most significant predictors of worse outcome (p < 0.001). Multivariate cox regression analysis demonstrated that SD (SSF2) was the only independent predictor of survival (p < 0.001). Better patient outcome prediction was achieved after adding total vessel percentage and SD (SSF2) to the GAP staging system (p = 0.006).

CONCLUSION

Filtration-histogram texture analysis can be an independent predictor of patient mortality in IPF patients.

ADVANCES IN KNOWLEDGE

qCT analysis can help in risk stratifying IPF patients in addition to clinical markers.

FDG-PET/CT in colorectal cancer: potential for vascular-metabolic imaging to provide markers of prognosis

PURPOSE

This study assesses the potential for vascular-metabolic imaging with FluoroDeoxyGlucose (FDG)-Positron Emission Tomography/Computed Tomography (PET/CT) perfusion to provide markers of prognosis specific to the site and stage of colorectal cancer.

METHODS

This prospective observational study comprised of participants with suspected colorectal cancer categorized as either (a) non-metastatic colon cancer (M0colon), (b) non-metastatic rectal cancer (M0rectum), or (c) metastatic colorectal cancer (M+). Combined FDG-PET/CT perfusion imaging was successfully performed in 286 participants (184 males, 102 females, age: 69.60 ± 10 years) deriving vascular and metabolic imaging parameters. Vascular and metabolic imaging parameters alone and in combination were investigated with respect to overall survival.

RESULTS

A vascular-metabolic signature that was significantly associated with poorer survival was identified for each patient group: M0colon - high Total Lesion Glycolysis (TLG) with increased Permeability Surface Area Product/Blood Flow (PS/BF), Hazard Ratio (HR) 3.472 (95% CI: 1.441-8.333), p = 0.006; M0rectum - high Metabolic Tumour Volume (MTV) with increased PS/BF, HR 4.567 (95% CI: 1.901-10.970), p = 0.001; M+ participants, high MTV with longer Time To Peak (TTP) enhancement, HR 2.421 (95% CI: 1.162-5.045), p = 0.018. In participants with stage 2 colon cancer as well as those with stage 3 rectal cancer, the vascular-metabolic signature could stratify the prognosis of these participants.

CONCLUSION

Vascular and metabolic imaging using FDG-PET/CT can be used to synergise prognostic markers. The hazard ratios suggest that the technique may have clinical utility.

Imaging and treatment of brain tumors through molecular targeting: Recent clinical advances

Molecular imaging techniques have rapidly progressed over recent decades providing unprecedented in vivo characterization of metabolic pathways and molecular biomarkers. Many of these new techniques have been successfully applied in the field of neuro-oncological imaging to probe tumor biology. Targeting specific signaling or metabolic pathways could help to address several unmet clinical needs that hamper the management of patients with brain tumors. This review aims to provide an overview of the recent advances in brain tumor imaging using molecular targeting with positron emission tomography and magnetic resonance imaging, as well as the role in patient management and possible therapeutic implications.

Evolution of 18F-FDG-PET/CT findings in patients following COVID-19 pneumonia: An Initial Investigation

The aim of this study was to assess the temporal evolution of pulmonary ¹⁸F-FDG uptake in patients with coronavirus disease 2019 (COVID-19) and post–COVID-19 lung disease (PCLD). Methods: Using our hospital’s clinical electronic records, we retrospectively identified 23 acute COVID-19, 18 PCLD, and 9 completely recovered ¹⁸F-FDG PET/CT patients during the 2 peaks of the U.K. pandemic. Pulmonary ¹⁸F-FDG uptake was measured as a lung target-to-background ratio (TBR_lung = SUV_max/SUV_min) and compared with temporal stage. Results: In acute COVID-19, less than 3 wk after infection, TBR_lung was strongly correlated with time after infection (r_s = 0.81, P < 0.001) and was significantly higher in the late stage than in the early stage (P = 0.001). In PCLD, TBR_lung was lower in patients treated with high-dose steroids (P = 0.003) and in asymptomatic patients (P < 0.001). Conclusion: Pulmonary ¹⁸F-FDG uptake in COVID-19 increases with time after infection. In PCLD, pulmonary ¹⁸F-FDG uptake rises despite viral clearance, suggesting ongoing inflammation. There was lower pulmonary ¹⁸F-FDG uptake in PCLD patients treated with steroids.

Cerebrospinal Fluid Biomarkers in Cerebral Amyloid Angiopathy

Background:

There is limited data on cerebrospinal fluid (CSF) biomarkers in sporadic amyloid-β (Aβ) cerebral amyloid angiopathy (CAA).

Objective:

To determine the profile of biomarkers relevant to neurodegenerative disease in the CSF of patients with CAA.

Methods:

We performed a detailed comparison of CSF markers, comparing patients with CAA, Alzheimer’s disease (AD), and control (CS) participants, recruited from the Biomarkers and Outcomes in CAA (BOCAA) study, and a Specialist Cognitive Disorders Service.

Results:

We included 10 CAA, 20 AD, and 10 CS participants (mean age 68.6, 62.5, and 62.2 years, respectively). In unadjusted analyses, CAA patients had a distinctive CSF biomarker profile, with significantly lower (p < 0.01) median concentrations of Aβ₃₈, Aβ₄₀, Aβ₄₂, sAβPPα, and sAβPPβ. CAA patients had higher levels of neurofilament light (NFL) than the CS group (p < 0.01), but there were no significant differences in CSF total tau, phospho-tau, soluble TREM2 (sTREM2), or neurogranin concentrations. AD patients had higher total tau, phospho-tau and neurogranin than CS and CAA groups. In age-adjusted analyses, differences for the CAA group remained for Aβ₃₈, Aβ₄₀, Aβ₄₂, and sAβPPβ. Comparing CAA patients with amyloid-PET positive (n = 5) and negative (n = 5) scans, PET positive individuals had lower (p < 0.05) concentrations of CSF Aβ₄₂, and higher total tau, phospho-tau, NFL, and neurogranin concentrations, consistent with an “AD-like” profile.

Conclusion:

CAA has a characteristic biomarker profile, suggestive of a global, rather than selective, accumulation of amyloid species; we also provide evidence of different phenotypes according to amyloid-PET positivity. Further replication and validation of these preliminary findings in larger cohorts is needed.

Whole Body 3.0 T Magnetic Resonance Imaging in Lymphomas: Comparison of Different Sequence Combinations for Staging Hodgkin's and Diffuse Large B Cell Lymphomas

To investigate the diagnostic value of different whole-body magnetic resonance imaging (WB-MRI) protocols for staging Hodgkin and diffuse-large B-cell lymphomas (HL and DLBCL), twenty-two patients (M/F 12/10, median age 32, range 22-87, HL/DLBCL 14/8) underwent baseline WB-MRI and 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET) fused with computed tomography (CT) scan 18F-FDG-PET-CT. The 3.0 T WB-MRI was performed using pre-contrast modified Dixon (mDixon), T2-weighted turbo-spin-echo (TSE), diffusion-weighted-imaging (DWI), dynamic-contrast-enhanced (DCE) liver/spleen, contrast-enhanced (CE) lung MRI and CE whole-body mDixon. WB-MRI scans were divided into: (1) "WB-MRI DWI+IP": whole-body DWI + in-phase mDixon (2) "WB-MRI T2-TSE": whole-body T2-TSE (3) "WB-MRI Post-C": whole-body CE mDixon + DCE liver/spleen and CE lung mDixon (4) "WB-MRI All ": the entire protocol. Two radiologists evaluated WB-MRIs at random, independently and then in consensus. Two nuclear-medicine-physicians reviewed 18F-FDG PET-CT in consensus. An enhanced-reference-standard (ERS) was derived using all available baseline and follow-up imaging. The sensitivity and specificity of WB-MRI protocols for nodal and extra-nodal staging was derived against the ERS. Agreement between the WB-MRI protocols and the ERS for overall staging was assessed using kappa statistic. For consensus WB-MRI, the sensitivity and specificity for nodal staging were 75%, 98% for WB-MRI DWI+IP, 76%, 98% for WB-MRI Post-C, 83%, 99% for WB-MRI T2-TSE and 87%, 100% for WB-MRI All. The sensitivity and specificity for extra-nodal staging were 67% 100% for WB-MRI DWI+IP, 89%, 100% for WB-MRI Post-C, 89%, 100% for WB-MRI T2-TSE and 100%, 100% for the WB-MRI All. The consensus WB-MRI All read had perfect agreement with the ERS for overall staging [kappa = 1.00 (95% CI: 1.00-1.00)]. The best diagnostic performance is achieved combining all available WB-MRI sequences.

IMG-18. ASSESSMENT OF SUSPECTED DISEASE PROGRESSION USING MULTIPARAMETRIC 18F-CHOLINE PET/MRI IN CHILDHOOD AND TEENAGE-YOUNG ADULT GLIOMAS

OBJECTIVES

Evaluation of post-treatment glioma burden remains a significant challenge in children, teenagers and young adults (TYA). The aim of this study was to evaluate the utility of ChoPET/MRI for evaluation of suspected disease progression in childhood and TYA gliomas.

METHODS

27 patients (mean age 14 years, range 6–21 years) with suspected glioma disease progression were evaluated with ChoPET/MRI (n=59). Relative cerebral blood volume (rCBV), apparent diffusion coefficient (ADC) and maximum standardised uptake values (SUV_max) in enhancing (enh) and non-enhancing (ne) tumour and normal-appearing white matter (wm) were calculated (rCBV_enh, rCBV_ne, rCBV_wm, ADC_enh, ADC_ne, ADC_wm, SUV_enh, SUV_ne, SUV_wm). 2 blinded radiologists scored tumour probability (1 = unlikely; 5 = definitely). Sensitivity and specificity calculated with gold standard histopathology or clinical follow-up.

RESULTS

Accuracy for the detection of residual/recurrent tumour on conventional MRI was 96.3% (91.7% ≤14 years, 100% ≥15 years) and ChoPET was 73.1% (66.7% ≤14 years, 80.0% ≥15 years). Lack of agreement was observed in 9/27 patients, with ChoPET superior to MRI in 1 case of a posterior fossa tumour. Tumour component analysis demonstrated significantly higher SUV_enh and SUV_ne than SUV_wm (SUV_enh: p<0.001; SUV_ne: p=0.004, equivalent to results were observed for ADV and rCBV (ADC_enh, ADC_ne: p<0.001 vs ADC_wm; rCBV_enh, rCBV_ne: p<0.001 vs rCBV_wm).

CONCLUSIONS

MRI is more sensitive than ChoPET in the evaluation of suspected disease progression in TYA gliomas. However, quanititative ChoPET is able to detect enhancing and non-enhancing tumour and may be helpful in evaluating posterior fossa disease where MRI is equivocal.

Consensus Recommendations on the Use of 18F-FDG PET/CT in Lung Disease

PET with ¹⁸F-FDG has been increasingly applied, predominantly in the research setting, to study drug effects and pulmonary biology and to monitor disease progression and treatment outcomes in lung diseases that interfere with gas exchange through alterations of the pulmonary parenchyma, airways, or vasculature. To date, however, there are no widely accepted standard acquisition protocols or imaging data analysis methods for pulmonary ¹⁸F-FDG PET/CT in these diseases, resulting in disparate approaches. Hence, comparison of data across the literature is challenging. To help harmonize the acquisition and analysis and promote reproducibility, we collated details of acquisition protocols and analysis methods from 7 PET centers. From this information and our discussions, we reached the consensus recommendations given here on patient preparation, choice of dynamic versus static imaging, image reconstruction, and image analysis reporting.

A twisted tale-radiological imaging features of COVID-19 on 18F-FDG PET/CT

The COVID-19 pandemic has had a major impact on health care systems across the globe in a short period of time. There is a growing body of evidence surrounding the findings on hybrid imaging with FDG-PET/CT, and this case highlights the importance of molecular imaging in better understanding of the biomarkers of the disease which ultimately determine the success in building a model to predict the disease severity and monitoring the response to treatment.

Combined PET/MRI in brain glioma imaging

Gliomas are the most common primary brain tumours in children and adults, consisting of a heterogeneous group of neoplastic diseases arise from the supporting cells of the CNS (glial cells). Their histopathological and molecular characteristics vary considerably as do their management and prognosis. Conventional gadolinium-enhanced magnetic resonance imaging (MRI) is considered the primary imaging modality for initial work up and follow up of patients with gliomas, although it has some limitations, especially in differentiating high from low grade tumours and in distinguishing disease recurrence from post-therapy changes. Hybrid positron emission tomography (PET)/MRI is a relatively novel tool that combines MRI sequences with metabolic information from PET, and therefore different PET radiotracers, in a single scan. This article discusses the main advantages and disadvantages of combined PET/MRI compared to other conventional or more widely available imaging tools, such as MRI or combined positron emission tomography-computed tomography. The main uses of PET/MRI and the most commonly used PET radiotracers in providing diagnostic, prognostic and predictive information in patients with glioma are covered.

PET/MRI attenuation estimation in the lung: A review of past, present, and potential techniques

Positron emission tomography/magnetic resonance imaging (PET/MRI) potentially offers several advantages over positron emission tomography/computed tomography (PET/CT), for example, no CT radiation dose and soft tissue images from MR acquired at the same time as the PET. However, obtaining accurate linear attenuation correction (LAC) factors for the lung remains difficult in PET/MRI. LACs depend on electron density and in the lung, these vary significantly both within an individual and from person to person. Current commercial practice is to use a single‐valued population‐based lung LAC, and better estimation is needed to improve quantification. Given the under‐appreciation of lung attenuation estimation as an issue, the inaccuracy of PET quantification due to the use of single‐valued lung LACs, the unique challenges of lung estimation, and the emerging status of PET/MRI scanners in lung disease, a review is timely. This paper highlights past and present methods, categorizing them into segmentation, atlas/mapping, and emission‐based schemes. Potential strategies for future developments are also presented.

Correction to: Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group

In the original version of this article unfortunately two authors were missing: Dr. Jürgen Weidemann and Dr. Daniel Berthold. The correct list of authors is presented above.

Arterial Spin Labeling Reveals Disrupted Brain Networks and Functional Connectivity in Drug-Resistant Temporal Epilepsy

Resting-state networks (RSNs) and functional connectivity (FC) have been increasingly exploited for mapping brain activity and identifying abnormalities in pathologies, including epilepsy. The majority of studies currently available are based on blood-oxygenation-level-dependent (BOLD) contrast in combination with either independent component analysis (ICA) or pairwise region of interest (ROI) correlations. Despite its success, this approach has several shortcomings as BOLD is only an indirect and non-quantitative measure of brain activity. Conversely, promising results have recently been achieved by arterial spin labeling (ASL) MRI, primarily developed to quantify brain perfusion. However, the wide application of ASL-based FC has been hampered by its complexity and relatively low robustness to noise, leaving several aspects of this approach still largely unexplored. In this study, we firstly aimed at evaluating the effect of noise reduction on spatio-temporal ASL analyses and quantifying the impact of two ad-hoc processing pipelines (basic and advanced) on connectivity measures. Once the optimal strategy had been defined, we investigated the applicability of ASL for connectivity mapping in patients with drug-resistant temporal epilepsy vs. controls (10 per group), aiming at revealing between-group voxel-wise differences in each RSN and ROI-wise FC changes. We first found ASL was able to identify the main network (DMN) along with all the others generally detected with BOLD but never previously reported from ASL. For all RSNs, ICA-based denoising (advanced pipeline) allowed to increase their similarity with the corresponding BOLD template. ASL-based RSNs were visibly consistent with literature findings; however, group differences could be identified in the structure of some networks. Indeed, statistics revealed areas of significant FC decrease in patients within different RSNs, such as DMN and cerebellum (CER), while significant increases were found in some cases, such as the visual networks. Finally, the ROI-based analyses identified several inter-hemispheric dysfunctional links (controls > patients) mainly between areas belonging to the DMN, right-left thalamus and right-left temporal lobe. Conversely, fewer connections, predominantly intra-hemispheric, showed the opposite pattern (controls < patients). All these elements provide novel insights into the pathological modulations characterizing a "network disease" as epilepsy, shading light on the importance of perfusion-based approaches for identifying the disrupted areas and communications between brain regions.

Synergistic application of pulmonary 18F-FDG PET/HRCT and computer-based CT analysis with conventional severity measures to refine current risk stratification in idiopathic pulmonary fibrosis (IPF)

INTRODUCTION

To investigate the combined performance of quantitative CT (qCT) following a computer algorithm analysis (IMBIO) and ¹⁸F-FDG PET/CT to assess survival in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

A total of 113 IPF patients (age 70 ± 9 years) prospectively and consecutively underwent ¹⁸F-FDG PET/CT and high-resolution CT (HRCT) at our institution. During a mean follow-up of 29.6 ± 26 months, 44 (48%) patients died. As part of the qCT analysis, pattern evaluation of HRCT (using IMBIO software) included the total extent (percentage) of the following features: normal-appearing lung, hyperlucent lung, parenchymal damage (comprising ground-glass opacification, reticular pattern and honeycombing), and the pulmonary vessels. The maximum (SUV_max) and minimum (SUV_min) standardized uptake value (SUV) for ¹⁸F-FDG uptake in the lungs, and the target-to-background (SUV_max/SUV_min) ratio (TBR) were quantified using routine region-of-interest (ROI) analysis. Pulmonary functional tests (PFTs) were acquired within 14 days of the PET/CT/HRCT scan. Kaplan-Meier (KM) survival analysis was used to identify associations with mortality.

RESULTS

Data from 91 patients were available for comparative analysis. The average ± SD GAP [gender, age, physiology] score was 4.2 ± 1.7 (range 0-8). The average ± SD SUV_max, SUV_min, and TBR were 3.4 ± 1.4, 0.7 ± 0.2, and 5.6 ± 2.8, respectively. In all patients, qCT analysis demonstrated a predominantly reticular lung pattern (14.9 ± 12.4%). KM analysis showed that TBR (p = 0.018) and parenchymal damage assessed by qCT (p = 0.0002) were the best predictors of survival. Adding TBR and qCT to the GAP score significantly increased the ability to differentiate between high and low risk (p < 0.0001).

CONCLUSION

¹⁸F-FDG PET and qCT are independent and synergistic in predicting mortality in patients with IPF.

Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group

Studies of chest computed tomography (CT) in patients with primary antibody deficiency syndromes (ADS) suggest a broad range of bronchial pathology. However, there are as yet no multicentre studies to assess the variety of bronchial pathology in this patient group. One of the underlying reasons is the lack of a consensus methodology, a prerequisite to jointly document chest CT findings. We aimed to establish an international platform for the evaluation of bronchial pathology as assessed by chest CT and to describe the range of bronchial pathologies in patients with antibody deficiency. Ffteen immunodeficiency centres from 9 countries evaluated chest CT scans of patients with ADS using a predefined list of potential findings including an extent score for bronchiectasis. Data of 282 patients with ADS were collected. Patients with common variable immunodeficiency disorders (CVID) comprised the largest subgroup (232 patients, 82.3%). Eighty percent of CVID patients had radiological evidence of bronchial pathology including bronchiectasis in 61%, bronchial wall thickening in 44% and mucus plugging in 29%. Bronchiectasis was detected in 44% of CVID patients aged less than 20 years. Cough was a better predictor for bronchiectasis than spirometry values. Delay of diagnosis as well as duration of disease correlated positively with presence of bronchiectasis. The use of consensus diagnostic criteria and a pre-defined list of bronchial pathologies allows for comparison of chest CT data in multicentre studies. Our data suggest a high prevalence of bronchial pathology in CVID due to late diagnosis or duration of disease.

Clinical Impact of Respiratory Motion Correction in Simultaneous PET/MR, Using a Joint PET/MR Predictive Motion Model

In PET imaging, patient motion due to respiration can lead to artifacts and blurring, in addition to quantification errors. The integration of PET imaging with MRI in PET/MRI scanners provides spatially aligned complementary clinical information and allows the use of high-contrast, high-spatial-resolution MR images to monitor and correct motion-corrupted PET data. On a patient cohort, we tested the ability of our joint PET/MRI-based predictive motion model to correct respiratory motion in PET and show it can improve lesion detectability and quantitation and reduce image artifacts. Methods: Using multiple tracers and multiple organ locations, we applied our motion correction method to 42 clinical PET/MRI patient datasets containing 162 PET-avid lesions. Quantitative changes were calculated using SUV changes in avid lesions. Lesion detectability changes were explored with a study in which 2 radiologists identified lesions in uncorrected and motion-corrected images and provided confidence scores. Results: Mean increases of 12.4% for SUV_peak and 17.6% for SUV_max after motion correction were found. In the detectability study, confidence scores for detecting avid lesions increased, with a rise in mean score from 2.67 to 3.01 (of 4) after motion correction and a rise in detection rate from 74% to 84%. Of 162 confirmed lesions, 49 showed an increase in all 3 metrics—SUV_peak, SUV_max, and combined reader confidence score—whereas only 2 lesions showed a decrease. We also present clinical case studies demonstrating the effect that respiratory motion correction of PET data can have on patient management, with increased numbers of detected lesions, improved lesion sharpness and localization, and reduced attenuation-based artifacts. Conclusion: We demonstrated significant improvements in quantification and detection of PET-avid lesions, with specific case study examples showing where motion correction has the potential to affect diagnosis or patient care.

Corrigendum: Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution

This corrects the article DOI: 10.1038/nature22364.

Phylogenetic ctDNA analysis depicts early-stage lung cancer evolution

The early detection of relapse following primary surgery for non-small-cell lung cancer and the characterization of emerging subclones, which seed metastatic sites, might offer new therapeutic approaches for limiting tumour recurrence. The ability to track the evolutionary dynamics of early-stage lung cancer non-invasively in circulating tumour DNA (ctDNA) has not yet been demonstrated. Here we use a tumour-specific phylogenetic approach to profile the ctDNA of the first 100 TRACERx (Tracking Non-Small-Cell Lung Cancer Evolution Through Therapy (Rx)) study participants, including one patient who was also recruited to the PEACE (Posthumous Evaluation of Advanced Cancer Environment) post-mortem study. We identify independent predictors of ctDNA release and analyse the tumour-volume detection limit. Through blinded profiling of postoperative plasma, we observe evidence of adjuvant chemotherapy resistance and identify patients who are very likely to experience recurrence of their lung cancer. Finally, we show that phylogenetic ctDNA profiling tracks the subclonal nature of lung cancer relapse and metastasis, providing a new approach for ctDNA-driven therapeutic studies.

Evaluation of treatment response using integrated 18F-labeled choline positron emission tomography/magnetic resonance imaging in adolescents with intracranial non-germinomatous germ cell tumours

The efficacy of hybrid 18F-Fluroethyl-Choline (FEC) positron emission tomography (PET)/magnetic resonance imaging (MRI) was investigated as an imaging modality for diagnosis and assessment of treatment response and remission status in four patients with proven or suspected intracranial non-germinomatous germ cell tumours (NGGCT). In two patients faint or absent choline avidity correlated with negative histology, whereas in other two patients, persistent choline avidity in the residual mass was suggestive of presence of viable tumour, subsequently confirmed histologically. We conclude that FEC-PET/MRI may be an effective imaging tool in detecting viable residual tumour in patients with intracranial NGGCT post treatment.

Lung magnetic resonance imaging with diffusion weighted imaging provides regional structural as well as functional information without radiation exposure in primary antibody deficiencies

Purpose

Primary antibody deficiency patients suffer from infectious and non-infectious pulmonary complications leading over time to chronic lung disease. The complexity of this pulmonary involvement poses significant challenge in differential diagnosis in patients with long life disease and increased radio sensitivity. We planned to verify the utility of chest Magnetic Resolution Imaging with Diffusion-Weighted Imaging as a radiation free technique.

Methods

Prospective evaluation of 18 patients with Common Variable Immunodeficiency and X-linked Agammaglobulinemia. On the same day, patients underwent Magnetic Resonance Imaging with Diffusion Weighted Imaging sequences, High Resolution Computerized Tomography and Pulmonary Function Tests, including diffusing capacity factor for carbon monoxide. Images were scored using a modified version of the Bhalla scoring system.

Results

Magnetic Resonance Imaging was non-inferior to High Resolution Computerized Tomography in the capacity to identify bronchial and parenchymal abnormalities. HRCT had a higher capacity to identify peripheral airways abnormalities, defined as an involvement of bronchial generation up to the fifth and distal (scores 2–3). Bronchial scores negatively related to pulmonary function tests. One third of consolidations and nodules had Diffusion Weighted Imaging restrictions associated with systemic granulomatous disease and systemic lymphadenopathy. Lung Magnetic Resolution Imaging detected an improvement of bronchial and parenchymal abnormalities, in recently diagnosed patients soon after starting Ig replacement.

Conclusions

Magnetic Resonance Imaging with Diffusion Weighted Imaging was a reliable technique to detect lung alterations in patients with Primary Antibody Deficiencies.

Electronic supplementary material

The online version of this article (doi:10.1007/s10875-015-0172-2) contains supplementary material, which is available to authorized users.

Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT

OBJECTIVES

To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults.

METHODS

Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated.

RESULTS

MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100% (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease.

CONCLUSIONS

Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations).

KEY POINTS

PROPELLER MRI does not match CT sensitivity to assess CF lung disease. PROPELLER MRI has lower sensitivity than CT to detect severe bronchiectasis. PROPELLER MRI has good to very good intra- and inter-observer variability. PROPELLER MRI can be used for short-term follow-up studies in CF.

Development of a prediction model and risk score for procedure-related complications in patients undergoing percutaneous computed tomography-guided lung biopsy

OBJECTIVES

To propose a risk score predicting the potential occurrence of procedure-related complications in patients undergoing computed tomography (CT)-guided lung biopsy.

METHODS

Institution review board approval was obtained. A total of 342 CT-guided lung biopsies were retrospectively evaluated taking into account procedure-related complications and associated risk factors, including patient gender and age, previous radiation therapy (RT) and/or chemotherapy (CHT), lesion size, depth and location, incomplete pulmonary fissures, associated diffuse lung diseases, previous pneumothorax (PNX), lung volumes, punctured fissures, thoracic access, needle size and operator experience. Complications were assessed on chest X-ray and/or CT scans. Stepwise logistic regression was used to identify risk factors, to evaluate their correlation with procedure-related complications and to calculate models of risk (MoRs).

RESULTS

PNX requiring chest tube placement occurred in 39 patients (11.4%), high-grade pulmonary parenchymal haemorrhage occurred in 62 patients (18.1%) and haemothorax occurred in 12 patients (3.5%). Risk factors increasing the incidence of complications were lesion size (P = 0.01), lesion depth (P = 0.01) and incomplete pulmonary fissures (P = 0.01); previous chemo-radiation therapy was correlated to a lower incidence of complications (P = 0.01). MoR for PNX was as follows: risk base line = 60%; age = +0.15%/year; punctured fissures = +20%; incomplete fissures = +9%; previous CHT/RT = -10%. MoR for parenchymal haemorrhage was as follows: risk base line = 20%, lesion depth = +0.8%/mm; age = +0.25%/year; incomplete fissures = +15%. MoR for haemothorax was as follows: risk base line = 1%; previous PNX = +20%; incomplete fissures = 7%; both previous PNX and incomplete fissures = +67%.

CONCLUSION

This study provides MoRs to predict the risk of complications in patients undergoing CT-guided percutaneous lung biopsies.

Non-small-cell lung cancer resectability: diagnostic value of PET/MR

PURPOSE

To assess the diagnostic performance of PET/MR in patients with non-small-cell lung cancer.

METHODS

Fifty consecutive consenting patients who underwent routine (18)F-FDG PET/CT for potentially radically treatable lung cancer following a staging CT scan were recruited for PET/MR imaging on the same day. Two experienced readers, unaware of the results with the other modalities, interpreted the PET/MR images independently. Discordances were resolved in consensus. PET/MR TNM staging was compared to surgical staging from thoracotomy as the reference standard in 33 patients. In the remaining 17 nonsurgical patients, TNM was determined based on histology from biopsy, imaging results (CT and PET/CT) and follow-up. ROC curve analysis was used to assess accuracy, sensitivity and specificity of the PET/MR in assessing the surgical resectability of primary tumour. The kappa statistic was used to assess interobserver agreement in the PET/MR TNM staging. Two different readers, without knowledge of the PET/MR findings, subsequently separately reviewed the PET/CT images for TNM staging. The generalized kappa statistic was used to determine intermodality agreement between PET/CT and PET/MR for TNM staging.

RESULTS

ROC curve analysis showed that PET/MR had a specificity of 92.3 % and a sensitivity of 97.3 % in the determination of resectability with an AUC of 0.95. Interobserver agreement in PET/MR reading ranged from substantial to perfect between the two readers (Cohen's kappa 0.646 - 1) for T stage, N stage and M stage. Intermodality agreement between PET/CT and PET/MR ranged from substantial to almost perfect for T stage, N stage and M stage (Cohen's kappa 0.627 - 0.823).

CONCLUSION

In lung cancer patients PET/MR appears to be a robust technique for preoperative staging.

Is 2-deoxy-2-[(18)F]fluoro-D-glucose PET/CT acquisition from the upper thigh to the vertex of skull useful in oncological patients?

AIM

To assess whether performing routinely 2-deoxy-2-[(18)F]fluoro-D-glucose PET/CT ((18)FDG PET/CT) scan from the upper thigh to the vertex of skull is clinically relevant.

MATERIALS AND METHODS

3502 (1634 female; mean-age 60+16) consecutive patients undergoing (18)FDG PET/CT were retrospectively analyzed. Patients were divided in 10 groups according to primary malignancy. Chi-square analysis was used to assess differences among proportions. A p value < 0.05 was considered significant.

RESULTS

(18)FDG PET/CT was positive in head district in 130/3502 (3,7%) patients. In all patients lesions were unknown before PET/CT examination. PET/CT showed 158 positive brain/head uptake in the 130 patients. The 158 lesions were localized in: brain (43/158; 27%), bone (52/158; 33%), lymph node (1/158; 0,6%), soft tissue (55/158; 35%) and other sites (7/158; 4,4%). According to each group, patients were positive in the head district in 1.0% for Gastrointestinal Cancer (7/690), 3.0 % for Genitourinary Cancer (3/101), 3.7 % for Haemathologic Cancer (59/1590), 2.7 % for Gynaecologic Cancer (3/112), 7.8% for Head-Neck-Thyroid and Parathyroid Cancer (26/331), 3.5% for Breast Cancer (7/200), 2.6% for Lung Cancer (7/271), 3.4% for Melanoma (2/59), 7.4% for Sarcoma (2/27), 11.6% for Unknown Primary Tumour (14/121).

CONCLUSION

Our data show a relatively high incidence of brain/head lesion in patients with Unknown Primary Tumour.

Correlation between collateral ventilation and interlobar lung fissures

BACKGROUND

New bronchoscopic techniques for end-stage emphysema treatment are nowadays available; the presence of interlobar collateral ventilation (CV) and interlobar lung fissures (ILF) is crucial for patient selection.

OBJECTIVES

Assessment of these variables has been reported previously, but it has never been anatomically validated in vivo. This is the purpose of our study.

METHODS

Twenty-one patients undergoing lung resection for lung cancer were prospectively enrolled in this study. At operation, CV was assessed by the Chartis catheter system. ILF completeness at high-resolution computed tomography (HRCT) was retrospectively reviewed. The ILF status at HRCT and at surgery was compared; furthermore, the relationship between CV and ILF status was assessed.

RESULTS

At HRCT, ILF were incomplete in 18 cases; at catheter evaluation, CV was present in 11 cases; 15 patients had incomplete ILF at operation. HRCT specificity, sensitivity and accuracy were 33, 93 and 76% compared with ILF status at surgery. HRCT accuracy was 90% on the right and 63% on the left. We demonstrated a high grade of probability of CV presence and incomplete ILF at surgery (odds ratio = 10.0).

CONCLUSIONS

There is a correlation between ILF status and CV. Both catheter evaluation of CV and HRCT assessment of ILF show some limitations. However, the cumulative information provided by these techniques allows to reliably assess the anatomical ILF status.

Clinical and research applications of simultaneous positron emission tomography and MRI

Evaluation of the molecular processes responsible for disease pathogenesis and progression represents the new frontier of clinical radiology. Multimodality imaging lies at the cutting edge, combining the power of MRI for tissue characterization, microstructural appraisal and functional assessment together with new positron emission tomography (PET) tracers designed to target specific metabolic processes. The recent commercial availability of an integrated clinical whole-body PET-MRI provides a hybrid platform for exploring and exploiting the synergies of multimodal imaging. First experiences on the clinical and research application of hybrid PET-MRI are emerging. This article reviews the rapidly evolving field and speculates on the potential future direction.

Whole-tumour CT-perfusion of unresectable lung cancer for the monitoring of anti-angiogenetic chemotherapy effects

OBJECTIVE

To determine whether CT-perfusion (CT-p) can be used to evaluate the effects of chemotherapy and anti-angiogenic treatment in patients with non-small-cell lung carcinoma (NSCLC) and whether CT-p and standard therapeutic response assessment (RECIST) data obtained before and after therapy correlate.

METHODS

55 patients with unresectable NSCLC underwent CT-p before the beginning of therapy and 50 of them repeated CT-p 90 days after it. Therapeutic protocol included platinum-based doublets plus bevacizumab for non-squamous carcinoma and platinum-based doublets for squamous carcinoma. RECIST measurements and calculations of blood flow (BF), blood volume (BV), time to peak (TTP) and permeability surface (PS) were performed, and baseline and post-treatment measurements were tested for statistically significant differences. Baseline and follow-up perfusion parameters were also compared based on histopathological subclassification (2004 World Health Organization Classification of Tumours) and therapy response assessed by RECIST.

RESULTS

Tumour histology was consistent with large cell carcinoma in 14/50 (28%) cases, adenocarcinoma in 22/50 (44%) cases and squamous cell carcinoma in the remaining 14/50 (28%) cases. BF and PS differences for all tumours between baseline and post-therapy measurements were significant (p=0.001); no significant changes were found for BV (p=0.3) and TTP (p=0.1). The highest increase of BV was demonstrated in adenocarcinoma (5.2±34.1%), whereas the highest increase of TTP was shown in large cell carcinoma (6.9±22.4%), and the highest decrease of PS was shown in squamous cell carcinoma (-21.5±18.5%). A significant difference between the three histological subtypes was demonstrated only for BV (p<0.007). On the basis of RECIST criteria, 8 (16%) patients were classified as partial response (PR), 2 (4%) as progressive disease (PD) and the remaining 40 (80%) as stable disease (SD). Among PR, a decrease of both BF (18±9.6%) and BV (12.6±9.2%) were observed; TTP increased in 3 (37.5%) cases, and PS decreased in 6 (75%) cases. SD patients showed an increase of BF, BV, TTP and PS in 6 (15%), 21 (52.5%), 23 (57.5%) and 2 (5%) cases, respectively. PD patients demonstrated an increase of BF (26±0.2%), BV (2.7±0.1%) and TTP (3.1±0.8%) while only PS decreased (23±0.2%).

CONCLUSION

CT-p can adequately evaluate therapy-induced alterations in NSCLC, and perfusion parameters correlate with therapy response assessment performed with RECIST criteria.

ADVANCES IN KNOWLEDGE

Evaluating perfusional parameters, CT-p can demonstrate therapy-induced changes in patients with different types of lung cancer and identify response to treatment with excellent agreement to RECIST measurements.

Treatment of congenital liver cysts. A surgical technique tailored through a 35-year experience

BACKGROUND

The most important aims of the treatment of CLC are long-term relief of symptoms and elimination of cysts. Treatment of choice is yet debated.

METHODS

Data of patients treated for CLC during a 35-years experience were retrospectively analyzed. Variables analyzed were: age, sex, hepatic cyst location, cyst diameter, symptoms, surgical procedure, short and long-term outcomes.

RESULTS

We examined 49 consecutive patients treated for CLC (mean follow-up, 76 months). The study was divided into two periods: 1975-1999 and 2000-2010. Procedures performed in the first period were needle aspiration and sclerotherapy (n= 6), hepatic resections (9), cystojejunostomy (4), open unroofing (10), and laparoscopic unroofing (8). Omentopexy within the residual cystic cavity was associated with seven open and two laparoscopic unroofing cases. Rates of morbidity and recurrence were 23.5% and 44.1%, respectively. One patient died in the peri-operative period. Procedures performed in the second period were open unroofing (9), laparoscopic unroofing (5), and hepatic resection (1). Omentopexy was associated with all open procedures and two laparoscopic procedures. Overall morbidity in this group was 16.6%, and recurrence occurred in one patient (6.7%).

CONCLUSIONS

Cyst unroofing and omentopexy is a safe and highly effective procedure for the treatment of CLC. Laparoscopy is confirmed as the procedure of choice except for cases in which the cysts are in the posterior right liver, where a wide mobilization of the liver is necessary.

Computed tomography and magnetic resonance imaging of the thoracic lymphatic system

Several radiographic diagnostic techniques are currently available to assess the potential involvement of mediastinal lymph nodes in thoracic oncology. In particular, computed tomography and magnetic resonance imaging have been repeatedly validated; these techniques allow adequate imaging with a reasonable accuracy. The morphologic information provided by these techniques is crucial to stage lung cancer and plan treatment. These techniques are also extremely useful to evaluate other disorders and differentiate malignancy from benign disease.