[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.

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.

A comparison of the psychological burden of PET/MRI and PET/CT scans and association to initial state anxiety and previous imaging experiences

OBJECTIVE

To investigate the level of psychological burden experienced by patients undergoing positron emission tomography (PET)/MRI scanning compared with PET/CT.

METHODS

100 adult patients referred for PET/CT and underwent PET/MRI scanning were eligible. Initial state, psychological burden of PET/CT and PET/MRI, scan satisfaction and preference were assessed using a purpose-designed questionnaire, comprising 61 five-point Likert scale questions and a three-point tick box question indicating preference between PET/CT and PET/MRI. State anxiety was assessed using the state portion of the State Trait Anxiety Inventory. Wilcoxon signed-rank tests compared psychological burden experienced by participants following PET/CT and PET/MRI scan.

RESULTS

A greater level of psychological burden was experienced by patients during PET/MRI than PET/CT p ≤ 0.001, consistent with patients' preference for PET/CT over PET/MRI (p = 0.013). There was a significant relationship between PET/CT psychological burden and initial state (r = 0.386, p ≤ 0.001). No significant relationship was identified between Initial state and psychological burden of PET MRI (r = -0.089; p = 217). There was a significant relationship between psychological burden of PET/CT and PET/MRI (r = 0.354; p = 0.001).

CONCLUSION

Patients' experience increased psychological burden during PET/MRI compared with PET/CT. Previous scanning experiences and patients' interactions prior to and during PET/MRI improved patient satisfaction. Interventions could be implemented to improve imaging outcome.

ADVANCES IN KNOWLEDGE

This study provides evidence for the increased psychological burden of PET/MRI compared with PET/CT, and that people prefer the PET/CT procedure. We have shown that the patients who expressed a preference for PET/MRI demonstrated significantly lower psychological burden for that procedure than those that preferred PET/CT, which indicates that the benefit of reduced psychological burden could be facilitated by an appropriate intervention.

Cognitive function in children with brain tumors in the first year after diagnosis compared to healthy matched controls

BACKGROUND

Improved survival of children with brain tumors (BTs) has increased focus on ameliorating morbidity. To reduce the risk of progressive cognitive decline, remedial strategies need to be instituted early, based upon accurate appraisal of need, yet few studies have investigated cognition in BT children early post-diagnosis. The study aims were to investigate cognition in children with primary BTs 1, 6, and 12 months post-diagnosis compared with healthy children, exploring the impact of disease and treatment variables.

METHODS

Forty-eight children aged 2-16 years with primary BTs, referred to a Regional Neurosurgical Unit over the 2-year study period were eligible for enrollment. The "best friends" model was used to recruit matched controls. Cognition was assessed using age-appropriate Wechsler Intelligence scales; Children's Memory Scale; Test of Everyday Attention for Children, and Wechsler Quicktest.

RESULTS

Patients with BTs had significantly reduced performance compared to controls early post-diagnosis in tests of Performance IQ, processing speed, verbal and visual memory, and selective attention. Improved performance over 12 months was seen in patients with BTs although also, for some measures, in controls. Significant deficits in cognitive performance were seen one year post-diagnosis for Verbal IQ; processing speed, visual and verbal immediate memory, and selective attention. Infratentorial site, high tumor grade, hydrocephalus, radiotherapy, and chemotherapy were associated with poorer functioning.

CONCLUSION

Early cognitive impairment is present in BT children, sometimes prior to radiotherapy/chemotherapy treatment, and is associated with hydrocephalus, high tumor grade and infratentorial site. Future studies should investigate the role of early rehabilitation in improving cognition.

Areas of normal pulmonary parenchyma on HRCT exhibit increased FDG PET signal in IPF patients

PURPOSE

Patients with idiopathic pulmonary fibrosis (IPF) show increased PET signal at sites of morphological abnormality on high-resolution computed tomography (HRCT). The purpose of this investigation was to investigate the PET signal at sites of normal-appearing lung on HRCT in IPF.

METHODS

Consecutive IPF patients (22 men, 3 women) were prospectively recruited. The patients underwent (18)F-FDG PET/HRCT. The pulmonary imaging findings in the IPF patients were compared to the findings in a control population. Pulmonary uptake of (18)F-FDG (mean SUV) was quantified at sites of morphologically normal parenchyma on HRCT. SUVs were also corrected for tissue fraction (TF). The mean SUV in IPF patients was compared with that in 25 controls (patients with lymphoma in remission or suspected paraneoplastic syndrome with normal PET/CT appearances).

RESULTS

The pulmonary SUV (mean ± SD) uncorrected for TF in the controls was 0.48 ± 0.14 and 0.78 ± 0.24 taken from normal lung regions in IPF patients (p < 0.001). The TF-corrected mean SUV in the controls was 2.24 ± 0.29 and 3.24 ± 0.84 in IPF patients (p < 0.001).

CONCLUSION

IPF patients have increased pulmonary uptake of (18)F-FDG on PET in areas of lung with a normal morphological appearance on HRCT. This may have implications for determining disease mechanisms and treatment monitoring.

The experience of mothers caring for a child with a brain tumour

BACKGROUND

Brain tumours are the second most common form of childhood cancer, accounting for over 20% of all cases in European children. Understanding the impact of diagnosis and treatment of a brain tumour on the family is an essential pre-requisite to identifying ways to provide effective support.

AIM

(1) To explore the impact of having a child with a brain tumour on the main caregiver in the family; (2) to describe mothers' experiences of coping with their child's illness, including personal barriers and strengths; and (3) to identify causes of stress and sources of support to inform improvements in care delivery.

METHOD

Participants were drawn from a group of caregivers enrolled in a longitudinal study of outcome following diagnosis of a childhood brain tumour. Six caregivers took part, two from each of the high-, medium- and low-impact groups based on their Impact on Families Scale scores. Semi-structured interviews were used, with questions covering: (1) impact of the diagnosis on main caregiver and family; (2) personal barriers and strengths; and (3) causes of stress and sources of support. Interviews were transcribed verbatim and coded manually into five themes, which comprised 19 subthemes.

FINDINGS

Coping methods and provision of help and support were major preoccupations for main caregivers from all impact groups. Caregivers in the high-impact group reported less conflict. High- and medium-impact group caregivers had experienced less 'hindrance and heartache', than those with low impact scores, suggesting that the stress associated with diagnosis and treatment of the tumour may have increased cohesion and acceptance within these families.

CONCLUSION

Families of children diagnosed with a brain tumour experience considerable negative impact and may perceive themselves as struggling to cope. Provision of help and support, within and outside the extended family, including from health, education and other services, is perceived as helpful.

Tumor heterogeneity and permeability as measured on the CT component of PET/CT predict survival in patients with non-small cell lung cancer

PURPOSE

We prospectively examined the role of tumor textural heterogeneity on positron emission tomography/computed tomography (PET/CT) in predicting survival compared with other clinical and imaging parameters in patients with non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

The feasibility study consisted of 56 assessed consecutive patients with NSCLC (32 males, 24 females; mean age 67 ± 9.7 years) who underwent combined fluorodeoxyglucose (FDG) PET/CT. The validation study population consisted of 66 prospectively recruited consecutive consenting patients with NSCLC (37 males, 29 females; mean age, 67.5 ± 7.8 years) who successfully underwent combined FDG PET/CT-dynamic contrast-enhanced (DCE) CT. Images were used to derive tumoral PET/CT textural heterogeneity, DCE CT permeability, and FDG uptake (SUVmax). The mean follow-up periods were 22.6 ± 13.3 months and 28.5± 13.2 months for the feasibility and validation studies, respectively. Optimum threshold was determined for clinical stage and each of the above biomarkers (where available) from the feasibility study population. Kaplan-Meier analysis was used to assess the ability of the biomarkers to predict survival in the validation study. Cox regression determined survival factor independence.

RESULTS

Univariate analysis revealed that tumor CT-derived heterogeneity (P < 0.001), PET-derived heterogeneity (P = 0.003), CT-derived permeability (P = 0.002), and stage (P < 0.001) were all significant survival predictors. The thresholds used in this study were derived from a previously conducted feasibility study. Tumor SUVmax did not predict survival. Using multivariable analysis, tumor CT textural heterogeneity (P = 0.021), stage (P = 0.001), and permeability (P < 0.001) were independent survival predictors. These predictors were independent of patient treatment.

CONCLUSIONS

Tumor stage and CT-derived textural heterogeneity were the best predictors of survival in NSCLC. The use of CT-derived textural heterogeneity should assist the management of many patients with NSCLC.

Novel positron emission tomography/computed tomography of diffuse parenchymal lung disease combining a labeled somatostatin receptor analogue and 2-deoxy-2[18F]fluoro-D-glucose

We prospectively investigated the potential of positron emission tomography (PET) using the somatostatin receptor (SSTR) analogue ⁶⁸Ga-DOTATATE and 2-deoxy-2[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) in diffuse parenchymal lung disease (DPLD). Twenty-six patients (mean age 68.9 ± 11.0 years) with DPLD were recruited for ⁶⁸Ga-DOTATATE and ¹⁸F-FDG combined PET/high-resolution computed tomography (HRCT) studies. Ten patients had idiopathic pulmonary fibrosis (IPF), 12 patients had nonspecific interstitial pneumonia (NSIP), and 4 patients had other forms of DPLD. Using PET, the pulmonary tracer uptake (maximum standardized uptake value [SUV(max)]) was calculated. The distribution of PET tracer was compared to the distribution of lung parenchymal changes on HRCT. All patients demonstrated increased pulmonary PET signal with ⁶⁸Ga-DOTATATE and ¹⁸F-FDG. The distribution of parenchymal uptake was similar, with both tracers corresponding to the distribution of HRCT changes. The mean SUV(max) was 2.2 ± 0.7 for ⁶⁸Ga-DOTATATE and 2.8 ± 1.0 (t-test, p  =  .018) for ¹⁸F-FDG. The mean ⁶⁸Ga-DOTATATE SUV(max) in IPF patients was 2.5 ± 0.9, whereas it was 2.0 ± 0.7 (p  =  .235) in NSIP patients. The correlation between ⁶⁸Ga-DOTATATE SUV(max) and gas transfer (transfer factor of the lung for carbon monoxide [TLCO]) was r  =  -.34 (p  =  .127) and r  =  -.49 (p  =  .028) between ¹⁸F-FDG SUV(max) and TLCO. We provide noninvasive in vivo evidence in humans showing that SSTRs may be detected in the lungs of patients with DPLD in a similar distribution to sites of increased uptake of ¹⁸F-FDG on PET.

Novel Positron Emission Tomography/Computed Tomography of Diffuse Parenchymal Lung Disease Combining a Labeled Somatostatin Receptor Analogue and 2-Deoxy-2 [18F] Fluoro-D-Glucose

We prospectively investigated the potential of positron emission tomography (PET) using the somatostatin receptor (SSTR) analogue 68Ga-DOTATATE and 2-deoxy-2[18F]fluoro-D-glucose (18F-FDG) in diffuse parenchymal lung disease (DPLD). Twenty-six patients (mean age 68.9 ± 11.0 years) with DPLD were recruited for 68Ga-DOTATATE and 18F-FDG combined PET/high-resolution computed tomography (HRCT) studies. Ten patients had idiopathic pulmonary fibrosis (IPF), 12 patients had nonspecific interstitial pneumonia (NSIP), and 4 patients had other forms of DPLD. Using PET, the pulmonary tracer uptake (maximum standardized uptake value [SUVmax]) was calculated. The distribution of PET tracer was compared to the distribution of lung parenchymal changes on HRCT. All patients demonstrated increased pulmonary PET signal with 68Ga-DOTATATE and 18F-FDG. The distribution of parenchymal uptake was similar, with both tracers corresponding to the distribution of HRCT changes. The mean SUVmax was 2.2 ± 0.7 for 68Ga-DOTATATE and 2.8 ± 1.0 ( t-test, p = .018) for 18F-FDG. The mean 68Ga-DOTATATE SUVmax in IPF patients was 2.5 ± 0.9, whereas it was 2.0 ± 0.7 ( p = .235) in NSIP patients. The correlation between 68Ga-DOTATATE SUVmax and gas transfer (transfer factor of the lung for carbon monoxide [TLCO]) was r = .34 ( p = .127) and r = .49 ( p = .028) between 18F-FDG SUVmax and TLCO. We provide noninvasive in vivo evidence in humans showing that SSTRs may be detected in the lungs of patients with DPLD in a similar distribution to sites of increased uptake of 18F-FDG on PET.

Child-related determinants of health-related quality of life in children with brain tumours 1 year after diagnosis

OBJECTIVES

Infratentorial tumour site and health-related quality of life (HRQL) 1 month after diagnosis have been shown to predict HRQL 1 year after diagnosis in children with brain tumours. This study aimed to identify additional early child-related determinants of parent- and child-report HRQL.

METHODS

Longitudinal prospective study. Semi-structured interviews took place approximately 1 and 12 months after diagnosis. HRQL was measured using the self- and parent-report Pediatric Quality of Life Scales (PedsQL 4.0) Total Scale Score and Health Utilities Index Mark 3 (HUI3) multi-attribute utility function. Child variables included performance and verbal IQ, general memory, selective attention executive function, behaviour problems, adaptive behaviour, symptoms of depression and anxiety and event related anxiety. Univariate analyses were used to identify potential early predictors of HRQL. Regression analysis was then used to identify the most important determinants of HRQL at 1 year.

RESULTS

Thirty-five patients completed the 12-month interviews. Multivariate analysis showed infratentorial tumour site remained an important determinant of HRQL 1 year after diagnosis. Infratentorial tumour site and selective attention at 1 month generally best predicted poor self- and parent-report HRQL at 12 months. Adaptive behaviour and performance IQ may be important.

CONCLUSION

Selective attention and infratentorial tumour site are most important in predicting both parent- and self-report HRQL at 1 year after diagnosis. Larger prospective studies are needed to confirm these findings. Cognitive remediation or/and pharmacological intervention, particularly aimed at children with infratentorial tumours may improve attention and subsequently HRQL and both merit further investigation.

Family, demographic and illness-related determinants of HRQL in children with brain tumours in the first year after diagnosis

AIMS

To evaluate the relationship between parent- and child-report Health-Related Quality of Life (HRQL) and demographic, tumour and family variables in children with a brain tumour in the first year after diagnosis and to identify determinants of HRQL at 12 months.

PROCEDURE

Longitudinal prospective study: Semi-structured interviews took place approximately 1, 6 and 12 months after diagnosis. HRQL was measured using the self- and parent-report PedsQL 4.0 Total Scale Score. Tumour and treatment variables considered included tumour site and grade, hydrocephalus at diagnosis, chemotherapy and radiotherapy. Family variables included measures of family function, family support and family stress, the primary carer's coping strategies and symptoms of depression and anxiety. Univariate analyses were used at all three time points, and to identify potential early predictors of HRQL at 1 year. Regression analysis was then used to identify the most important determinants of HRQL at 1 year.

RESULTS

Thirty-five patients completed the 12-month interviews. There were consistent significant negative correlations between concurrent family impact of illness and parent and self-report HRQL, and positive correlations between concurrent family support and parent-report HRQL. Treatment with radio- or chemotherapy correlated with child-report HRQL only at some time points. Multivariate analysis showed infratentorial tumour site, and poor HRQL at 1 month best predicted poor self- and parent-report HRQL at 12 months.

CONCLUSION

Children with infratentorial tumours and poor HRQL early after diagnosis tend to have poor HRQL at 1 year. While family factors are important modulators of concurrent HRQL, they do not appear important in predicting HRQL.