Deep-inspiration breath-hold 18F-FDG-PET/CT is useful for assessment of connective tissue disease associated interstitial pneumonia

A novel objective method for discriminating pathological and physiological colorectal uptake in the lower abdominal region using whole-body dynamic 18F-FDG-PET

OBJECTIVES

To investigate whether the center-of-mass shift distance (CMSD) analysis on whole-body dynamic positron emission tomography (WBD-PET) with continuous bed motion is an objective index for discriminating pathological and physiological uptake in the lower abdominal colon.

METHODS

We retrospectively analyzed the CMSD in 39 patients who underwent delayed imaging to detect incidental focal uptake that was difficult to determine as pathological and physiological on a conventional early-PET (early) image reconstructed by 5-phase WBD-PET images. The CMSD between each phase of WBD-PET images and between conventional early and delayed (two-phase) PET images were classified into pathological and physiological uptake groups based on endoscopic histology or other imaging diagnostics. The diagnostic performance of CMSD analysis on WBD-PET images was evaluated by receiver operator characteristic (ROC) analysis and compared to that of two-phase PET images.

RESULTS

A total of 66 incidental focal uptake detected early image were classified into 19 and 47 pathological and physiological uptake groups, respectively. The CMSD on WBD-PET and two-phase PET images in the pathological uptake group was significantly lower than that in the physiological uptake group (p < 0.01), respectively. The sensitivity, specificity, and accuracy in CMSD analysis on WBD-PET images at the optimal cutoff of 5.2 mm estimated by the Youden index were 94.7%, 89.4%, and 89.4%, respectively, which were not significantly different (p = 0.74) from those of two-phase PET images.

CONCLUSIONS

The CMSD analysis on WBD-PET was useful in discriminating pathological and physiological colorectal uptake in the lower abdominal region, and its diagnostic performance was comparable to that of two-phase PET images. We suggested that CMSD analysis on WBD-PET images would be a novel objective method to omit unnecessary additional delayed imaging.

Novel tracers for molecular imaging of interstitial lung disease: A state of the art review

Interstitial lung disease is an overarching term for a wide range of disorders characterized by inflammation and/or fibrosis in the lungs. Most prevalent forms, among others, include idiopathic pulmonary fibrosis (IPF) and connective tissue disease associated interstitial lung disease (CTD-ILD). Currently, only disease modifying treatment options are available for IPF and progressive fibrotic CTD-ILD, leading to reduction or stabilization in the rate of lung function decline at best. Management of these patients would greatly advance if we identify new strategies to improve (1) early detection of ILD, (2) predicting ILD progression, (3) predicting response to therapy and (4) understanding pathophysiology. Over the last years, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have emerged as promising molecular imaging techniques to improve ILD management. Both are non-invasive diagnostic tools to assess molecular characteristics of an individual patient with the potential to apply personalized treatment. In this review, we encompass the currently available pre-clinical and clinical studies on molecular imaging with PET and SPECT in IPF and CTD-ILD. We provide recommendations for potential future clinical applications of these tracers and directions for future research.

Positron Emission Tomography to Improve Assessment of Interstitial Lung Disease in Patients With Systemic Sclerosis Eligible for Autologous Stem Cell Transplantation

Positron emission tomography (PET) is a promising technique to improve the assessment of systemic sclerosis associated interstitial lung disease (SSc-ILD). This technique could be of particular value in patients with severe diffuse cutaneous SSc (dcSSc) that are possibly eligible for autologous hematopoietic stem cell transplantation (aHSCT). aHSCT is a potentially effective therapy for patients with severe dcSSc and ILD, leading to stabilization or improvement of lung function. However, there is a high need to improve patient selection, which includes (1) the selection of patients with rapidly progressive ILD for early rather than last-resort aHSCT (2) the prediction of treatment response on ILD and (3) the understanding of the mechanism(s) of action of aHSCT in the lungs. As previous studies with 18F-FDG PET in SSc-ILD and other forms of ILD have demonstrated its potential value in predicting disease progression and reactivity to anti-inflammatory treatment, we discuss the potential benefit of using this technique in patients with early severe dcSSc and ILD in the context of aHSCT. In addition, we discuss the potential value of other PET tracers in the assessment of ILD and understanding the mechanisms of action of aHSCT in the lung. Finally, we provide several suggestions for future research.

18F-FDG PET/CT and HRCT: a combined tool for risk stratification in idiopathic inflammatory myopathy-associated interstitial lung disease

OBJECTIVES

Rapidly progressive interstitial lung disease (RP-ILD) is a life-threatening form of idiopathic inflammatory myopathy (IIM)-associated interstitial lung disease (ILD). We aimed to assess the combination of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) and high-resolution computed tomography (HRCT) for the quantification of IIM-ILD activity and risk stratification for RP-ILD.

METHOD

Patients with IIM and undergoing ¹⁸F-FDG PET/CT were included in this retrospective study. Pulmonary FDG uptake was assessed using the maximum standardized uptake value (SUV_lung) and visual score (PET score). HRCT was evaluated using visual analysis (HRCT score). Multivariable logistic regression was used to identify risk factors for RP-ILD.

RESULTS

Seventy-three patients with IIM (17 with RP-ILD, 38 with non-RP-ILD, and 18 without ILD) were included. SUV_lung, PET score, and HRCT score were significantly higher in RP-ILD than in non-RP-ILD. Strong positive correlations were observed between SUV_lung, PET score, and the HRCT parameters. The area under the curve (AUC) of the PET score to differentiate between RP-ILD and non-RP-ILD (AUC = 0.860) was higher than that of the SUV_lung (AUC = 0.802) and HRCT scores (AUC = 0.806). We developed a risk score based on the number of positive risk factors (PET score > 18, HRCT score > 140, and positive anti-melanoma differentiation-associated gene 5 (MDA5) antibody) to differentiate between RP-ILD and non-RP-ILD (AUC = 0.955). Patients with higher risk scores had significantly worse prognoses.

CONCLUSIONS

¹⁸F-FDG PET/CT is useful for assessing disease activity in patients with IIM-ILD. The combination of PET score, HRCT score, and anti-MDA5 antibody can be used to identify patients at increased risk of RP-ILD and with poor prognoses.

[Value of CT and transthoracic lung ultrasound in patients with systemic sclerosis : Joint statement of the ÖRG/ÖGP/ÖGR/ÖGUM]

Die Lungenbeteiligung ist die häufigste Todesursache bei Patienten mit systemischer Sklerose (SSc). Da eine Lungenbeteiligung häufig asymptomatisch ist, wird derzeit empfohlen, bei allen Patienten mit einer neu diagnostizierten SSc eine Thorax-CT durchzuführen. Uneinigkeit herrscht derzeit darüber, wie SSc-Patienten, bei denen zum Diagnosezeitpunkt keine Lungenbeteiligung gefunden wurde, weiterverfolgt werden sollen. Basierend auf einem Konsensus österreichischer Rheumatologen, Pneumologen und Radiologen, wird empfohlen, bei asymptomatischen PatientInnen mit einer negativen CT zum Zeitpunkt der Erstdiagnose jährlich transthorakale Ultraschalluntersuchungen sowie Lungenfunktionsuntersuchungen alle 6 bis 12 Monate durchzuführen. Bei Vorliegen eines positiven Lungenultraschallbefundes wird eine ergänzende CT zur weiterführenden Abklärung empfohlen. Aufgrund der Datenlage werden bei PatientInnen mit einem höheren Risiko, definiert durch entsprechende Risikofaktoren, jährliche CT-Verlaufskontrollen empfohlen.

Krebs von den Lungen-6 levels in untreated idiopathic pulmonary fibrosis

Background

Serum Krebs von den Lungen‐6 (KL‐6) has been reported to be elevated in patients with idiopathic pulmonary fibrosis (IPF).

Objective

The aim of this study was to evaluate the diagnostic value of KL‐6 and whether the expression value of KL‐6 could indicate the severity of the disease in IPF patients. To address this question, it is necessary to see whether the patients' physical characteristics and other clinical conditions could affect the baseline KL‐6 level.

Design

We conducted a study of 100 patients who were diagnosed with IPF. Lung function, computed tomography (CT), and serological lab tests data were analyzed.

Results

The tests showed that there is a significant elevation of KL‐6 in IPF patients compared with other interstitial lung disease (ILD) and healthy controls. It was noted that serum KL‐6 is a stable biomarker not affected by lung infection and smoking, though IPF patients with antinuclear antibody (ANA) showed higher KL‐6 levels. KL‐6, in conjunction with poor pulmonary function and higher radiological fibrosis scores, indicates the severity of the disease but not poor survival.

Conclusions

It is identified that serum KL‐6 is a useful noninvasive biomarker to help improve the certainty of IPF diagnosis from other interstitial lung disease and assist evaluation of disease severity and prognosis.

Radiological Characteristics of Patients With Anti-MDA5-Antibody-Positive Dermatomyositis in 18F-FDG PET/CT: A Pilot Study

Objective: To elucidate the ¹⁸F-fluorodeoxyglucose (FDG) PET/CT characteristics and its prognostic value in the patients with anti-melanoma differentiation associated protein 5 antibody positive (anti-MDA5+) dermatomyositis (DM). Methods: This retrospective cross-sectional study included 26 patients with anti-MDA5+ DM and 43 patients with anti-MDA5 negative (anti-MDA5-) idiopathic inflammatory myopathy (IIM) who were examined by ¹⁸F-FDG PET/CT from January 1, 2017 to December 31, 2020. The maximum standardized uptake value (SUVmax) of multiple organs and other clinical characteristics of the patients were measured and analyzed. Results: Compared with the anti-MDA5- group, the patients in the anti-MDA5+ group showed higher bilateral lung SUVmax (p = 0.029), higher SUVmax of spleen (p = 0.011), and bone marrow (p = 0.048). Significant correlations between the spleen SUVmax and serum ferritin levels (r = 0.398, p < 0.001), erythrocyte sedimentation rate (ESR) (r = 0.274, p = 0.023), platelet count (r = -0.265, p= 0.028), myositis disease activity assessment score (r = 0.332, p = 0.005), bone marrow SUVmax (r = 0.564, p < 0.001), and bilateral lung SUVmax (r = 0.393, p < 0.001) were observed. Conclusion: ¹⁸F-FDG PET/CT was found valuable in quantifying the pulmonary focal inflammation and potentially unveil the distinctive characteristics and pathophysiological mechanisms in the patients with anti-MDA5+ DM.

ACR Appropriateness Criteria® Diffuse Lung Disease

Diffuse lung disease, frequently referred to as interstitial lung disease, encompasses numerous disorders affecting the lung parenchyma. The potential etiologies of diffuse lung disease are broad with several hundred established clinical syndromes and pathologies currently identified. Imaging plays a critical role in diagnosis and follow-up of many of these diseases, although multidisciplinary discussion is the current standard for diagnosis of several DLDs. This document aims to establish guidelines for evaluation of diffuse lung diseases for 1) initial imaging of suspected diffuse lung disease, 2) initial imaging of suspected acute exacerbation or acute deterioration in cases of confirmed diffuse lung disease, and 3) clinically indicated routine follow-up of confirmed diffuse lung disease without acute deterioration. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Increased 18F-FDG accumulation in less-affected lung area in patients with non-small cell lung cancer and postoperative acute exacerbation of interstitial lung disease

PURPOSE

To investigate whether or not ¹⁸F-FDG accumulation in normal or less-affected lung fields increased in non-small cell lung cancer (NSCLC) patients with postoperative acute exacerbation (PAE) of interstitial lung disease (ILD) MATERIAL AND METHODS: Thirty-six NSCLC patients with ILD and 50 patients without ILD (non-ILD patients) underwent pre-operative ¹⁸F-FDG-PET/CT at 2 institutions. Volume-of-interest (VOI) was placed to measure the mean standardized uptake value (SUV_mean) in normal or less-affected lung fields at pre-defined 12 areas on ventral and dorsal locations of both lungs. SUV_{tissue fraction (TF)} was defined as corrected SUV_mean by using TF and mean computed tomography density on PET/CT. Harmonized SUV_mean (hSUV_mean) and SUV_TF (hSUV_TF) were calculated based on results of phantom study, which was performed to optimize the measured SUV difference among 2 institutions. Both the h-SUV_mean and the h-SUV_TF were compared between 8 patients with PAE of ILD (PAE group) or remaining 28 patients without PAE of ILD (non-PAE group) and non-ILD patients in each of the 12 areas.

RESULTS

The hSUV_mean in PAE group was higher in 9 out of 12 locations as compared with non-ILD patients, whereas the hSUV_mean was mostly similar between non-PAE group and non-ILD patients. In contrast, the hSUV_TF in non-PAE group was similar to that in PAE group, and higher than in non-ILD patients in most locations.

CONCLUSION

¹⁸F-FDG-PET/CT demonstrated increased SUV_mean along with elevated SUV_TF in normal or less-affected lung fields for NSCLC patients with PAE of ILD, which may reflect regional invisible fibrosis and inflammatory change.

Multimodality imaging in connective tissue disease-related interstitial lung disease

Interstitial lung disease is a well-recognised manifestation and a major cause of morbidity and mortality in patients with connective tissue diseases. Interstitial lung disease may arise in the context of an established connective tissue disease or be the initial manifestation of an otherwise occult autoimmune disorder. Early detection and characterisation are paramount for adequate patient management and require a multidisciplinary approach, in which imaging plays a vital role. Computed tomography is currently the imaging method of choice; however, other imaging techniques have recently been investigated, namely ultrasound, magnetic resonance imaging, and positron-emission tomography, with promising results. The aim of this review is to describe the imaging findings of connective tissue disease-related interstitial lung disease and explain the role of each imaging technique in diagnosis and disease characterisation.

The quantitative assessment of interstitial lung disease with positron emission tomography scanning in systemic sclerosis patients

Objectives

The reversibility of interstitial lung disease (ILD) in SSc is difficult to assess by current diagnostic modalities and there is clinical need for imaging techniques that allow for treatment stratification and monitoring. ¹⁸F-Fluorodeoxyglucose (FDG) PET/CT scanning may be of interest for this purpose by detection of metabolic activity in lung tissue. This study aimed to investigate the potential role of ¹⁸F-FDG PET/CT scanning for the quantitative assessment of SSc-related active ILD.

Methods

¹⁸F-FDG PET/CT scans and high resolution CT scans of eight SSc patients, including five with ILD, were analysed. For comparison, reference groups were included: eight SLE patients and four primary Sjögren’s syndrome (pSS) patients, all without ILD. A total of 22 regions of interest were drawn in each patient at apical, medial and dorsobasal lung levels. ¹⁸F-FDG uptake was measured as mean standardized uptake value (SUVmean) in each region of interest. Subsequently, basal/apical (B/A) and medial/apical (M/A) ratios were calculated at patient level (B/A-p and M/A-p) and at tissue level (B/A-t and M/A-t).

Results

SUVmean values in dorsobasal ROIs and B/A-p ratios were increased in SSc with ILD compared with SSc without ILD (P = 0.04 and P = 0.07, respectively), SLE (P = 0.003 and P = 0.002, respectively) and pSS (P = 0.03 and P = 0.02, respectively). Increased uptake in the dorsobasal lungs and increased B/A-t ratios corresponded to both ground glass and reticulation on high resolution CT.

Conclusion

Semi-quantitative assessment of ¹⁸F-FDG PET/CT is able to distinguish ILD from non-affected lung tissue in SSc, suggesting that it may be used as a new biomarker for SSc-ILD disease activity.

Anti-carbamylated proteins antibody repertoire in rheumatoid arthritis: evidence of a new autoantibody linked to interstitial lung disease

OBJECTIVE

To analyse the association between anti-carbamylated protein antibodies (Anti-CarP) and interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients.

METHODS

Cross-sectional study including RA patients fulfilling the 2010 ACR/EULAR criteria. The main population comprised two groups: (1) RA patients diagnosed with RA-ILD (RA-ILD group); (2) RA patients without ILD (non-ILD RA group). Non-ILD RA patients in whom ILD was suspected underwent a diagnostic work-up and, if ILD was diagnosed, were switched to the RA-ILD group. ILD was diagnosed by high-resolution computed tomography and confirmed by a multidisciplinary committee. An independent replication sample was also obtained. Three Anti-CarP IgG autoantibodies against fetal calf serum (Anti-FCS), fibrinogen (Anti-Fib) and chimeric fibrine/filagrine homocitrullinated peptide (Anti-CFFHP) and one Anti-CarP IgA against FCS (Anti-FCS-IgA) were determined by home-made ELISA. Associations between Anti-CarP and ILD were analysed using multivariable logistic regression adjusted by smoking, sex, age, RA disease duration, rheumatoid factor and anticitrullinated protein antibodies.

RESULTS

We enrolled 179 patients: 37 (21%) were finally diagnosed with RA-ILD. Anti-CarP specificities were more frequent in RA-ILD patients (Anti-FCS 70% vs 43%; Anti-Fib 73% vs 51%; Anti-CFFHP 38% vs 19%; Anti-CarP-IgA 51% vs 20%, p<0.05 for all comparisons). Serum titers of Anti-CarP were significantly higher in RA-ILD patients. Anti-CarP specificities showed a robust effect towards increasing the odds of ILD in the multivariate analysis (Anti-FCS (OR: 3.42; 95% CI: 1.13 to 10.40), Anti-Fib (OR: 2.85; 95% CI: 0.83 to 9.70), Anti-CFFHP (OR: 3.11; 95% CI: 1.06 to 9.14) and Anti-FCS-IgA (OR: 4.30; 95% CI: 1.41 to 13.04)). Similar findings were observed in the replication sample.

CONCLUSIONS

Anti-CarP were strongly associated with ILD. The role of homocitrullination in RA-ILD merits further investigation.

PET Scan: Nuclear Medicine Imaging in Myositis

PURPOSE OF REVIEW

Positron emission tomography (PET) combined with computed tomography (CT) has proven useful as a cancer screening technique in patients with inflammatory myopathy, mainly dermatomyositis. In this review, we focus on advances in this direction and other potential applications of PET/CT in patients with inflammatory myopathy.

RECENT FINDINGS

Cancer screening by PET/CT seems suitable and cost-effective in patients with myositis. It has also shown value as a hybrid technique for diagnosing myositis versus controls and could be of interest for differentiating between polymyositis and sporadic inclusion body myositis. Quantification of muscle activity by PET/CT seems reliable. Preliminary data suggest that it could also be used to diagnose and measure the activity of the disease in the lung. PET/CT should be in the toolbox of physicians managing patients with myositis. The multiple applications of PET/CT include its value for cancer screening, measuring the activity of the disease in muscle, and helping to differentiate between myositis phenotypes. The possibility to diagnose and monitor inflammatory lung activity remains to be demonstrated in well-designed studies.

Experimental and quantitative imaging techniques in interstitial lung disease

Interstitial lung diseases (ILDs) are a heterogeneous group of conditions, with a wide and complex variety of imaging features. Difficulty in monitoring, treating and exploring novel therapies for these conditions is in part due to the lack of robust, readily available biomarkers. Radiological studies are vital in the assessment and follow-up of ILD, but currently CT analysis in clinical practice is qualitative and therefore somewhat subjective. In this article, we report on the role of novel and quantitative imaging techniques across a range of imaging modalities in ILD and consider how they may be applied in the assessment and understanding of ILD. We critically appraised evidence found from searches of Ovid online, PubMed and the TRIP database for novel and quantitative imaging studies in ILD. Recent studies have explored the capability of texture-based lung parenchymal analysis in accurately quantifying several ILD features. Newer techniques are helping to overcome the challenges inherent to such approaches, in particular distinguishing peripheral reticulation of lung parenchyma from pleura and accurately identifying the complex density patterns that accompany honeycombing. Robust and validated texture-based analysis may remove the subjectivity that is inherent to qualitative reporting and allow greater objective measurements of change over time. In addition to lung parenchymal feature quantification, pulmonary vessel volume analysis on CT has demonstrated prognostic value in two retrospective analyses and may be a sign of vascular changes in ILD which, to date, have been difficult to quantify in the absence of overt pulmonary hypertension. Novel applications of existing imaging techniques, such as hyperpolarised gas MRI and positron emission tomography (PET), show promise in combining structural and functional information. Although structural imaging of lung tissue is inherently challenging in terms of conventional proton MRI techniques, inroads are being made with ultrashort echo time, and dynamic contrast-enhanced MRI may be used for lung perfusion assessment. In addition, inhaled hyperpolarised ¹²⁹Xenon gas MRI may provide multifunctional imaging metrics, including assessment of ventilation, intra-acinar gas diffusion and alveolar-capillary diffusion. PET has demonstrated high standard uptake values (SUVs) of ¹⁸F-fluorodeoxyglucose in fibrosed lung tissue, challenging the assumption that these are ‘burned out’ and metabolically inactive regions. Regions that appear structurally normal also appear to have higher SUV, warranting further exploration with future longitudinal studies to assess if this precedes future regions of macroscopic structural change. Given the subtleties involved in diagnosing, assessing and predicting future deterioration in many forms of ILD, multimodal quantitative lung structure-function imaging may provide the means of identifying novel, sensitive and clinically applicable imaging markers of disease. Such imaging metrics may provide mechanistic and phenotypic information that can help direct appropriate personalised therapy, can be used to predict outcomes and could potentially be more sensitive and specific than global pulmonary function testing. Quantitative assessment may objectively assess subtle change in character or extent of disease that can assist in efficacy of antifibrotic therapy or detecting early changes of potentially pneumotoxic drugs involved in early intervention studies.

Clinical value of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography for interstitial lung disease and myositis in patients with dermatomyositis

¹⁸ F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is usually used to screen malignancy in patients with dermatomyositis (DM). Additionally, it is well known that FDG-PET/CT provides valuable information for evaluating the activity of several inflammatory diseases, such as sarcoidosis, atherosclerosis, inflammatory bowel disease and rheumatoid arthritis. Therefore, the objective of this study was to evaluate the clinical usefulness of FDG-PET/CT for the detection of inflammatory lesions and disease activity of both myopathy and interstitial lung disease (ILD) in DM patients. We measured the maximum standardized uptake value (SUVmax) in the muscles and lungs in 22 DM patients, and compared with magnetic resonance imaging (MRI) and high-resolution computed tomography (HRCT) findings in the same muscle and lung regions as well as with clinical findings. We found that the location of increased FDG uptake was nearly consistent with the region of ILD and myositis detected by HRCT or MRI, respectively. There was a significant positive correlation between lung HRCT score and SUVmax in each lung. Serum Krebs von den Lungen-6 levels also revealed significant positive correlation with total SUVmax of right and left lungs. Regarding FDG-PET/CT and myopathy, total SUVmax in the muscles was significantly correlated with serum cytokeratin levels. Our results suggest that FDG uptake (SUVmax) might be useful for not only the detection of malignant tumors, but also the evaluation of the location and activity of ILD and myositis in DM patients.

Visualisation of interstitial lung disease by molecular imaging of integrin αvβ3 and somatostatin receptor 2

OBJECTIVE

To evaluate integrin αvβ3 (alpha-v-beta-3)-targeted and somatostatin receptor 2 (SSTR2)-targeted nuclear imaging for the visualisation of interstitial lung disease (ILD).

METHODS

The pulmonary expression of integrin αvβ3 and SSTR2 was analysed in patients with different forms of ILD as well as in bleomycin (BLM)-treated mice and respective controls using immunohistochemistry. Single photon emission CT/CT (SPECT/CT) was performed on days 3, 7 and 14 after BLM instillation using the integrin αvβ3-targeting ¹⁷⁷Lu-DOTA-RGD and the SSTR2-targeting ¹⁷⁷Lu-DOTA-NOC radiotracer. The specific pulmonary accumulation of the radiotracers over time was assessed by in vivo and ex vivo SPECT/CT scans and by biodistribution studies.

RESULTS

Expression of integrin αvβ3 and SSTR2 was substantially increased in human ILD regardless of the subtype. Similarly, in lungs of BLM-challenged mice, but not of controls, both imaging targets were stage-specifically overexpressed. While integrin αvβ3 was most abundantly upregulated on day 7, the inflammatory stage of BLM-induced lung fibrosis, SSTR2 expression peaked on day 14, the established fibrotic stage. In agreement with the findings on tissue level, targeted nuclear imaging using SPECT/CT specifically detected both imaging targets ex vivo and in vivo, and thus visualised different stages of experimental ILD.

CONCLUSION

Our preclinical proof-of-concept study suggests that specific visualisation of molecular processes in ILD by targeted nuclear imaging is feasible. If transferred into clinics, where imaging is considered an integral part of patients' management, the additional information derived from specific imaging tools could represent a first step towards precision medicine in ILD.

Comprehensive review of current diagnostic and treatment approaches to interstitial lung disease associated with rheumatoid arthritis

Interstitial lung disease (ILD) is one of the extra-articular involvement forms of rheumatoid arthritis (RA), and it is associated with increased mortality. The presence of genetic susceptibility, smoking, rheumatoid factor positivity, and the presence of anticitrulline peptide antibodies are factors contributing to the development of ILD in patients with RA. Early diagnosis and treatment of ILD contribute to the reduction of morbidity and mortality. We herein evaluated the current literature for the diagnosis and treatment of RA-associated ILD.

The predictive prognostic factors for polymyositis/dermatomyositis-associated interstitial lung disease

BACKGROUND

Interstitial lung disease (ILD) is the principal cause of death in polymyositis/dermatomyositis (PM/DM). Here we investigated prognostic factors for death and serious infection in PM/DM-ILD using the multicenter database.

METHODS

We retrospectively reviewed baseline demographic, clinical and laboratory findings, treatment regimens and outcomes in patients with PM/DM-ILD. The distribution of ILD lesions was evaluated in four divided lung zones of high-resolution computed tomography images.

RESULTS

Of 116 patients with PM/DM-ILD, 14 died within 6 months from the diagnosis. As independent risk factors for early death, extended ILD lesions in upper lung fields (odds ratio (OR) 8.01, p = 0.016) and hypocapnia (OR 6.85, p = 0.038) were identified. Serious infection was found in 38 patients, including 11 patients who died of respiratory or multiple infections. The independent risk factors were high serum KL-6 (OR 3.68, p = 0.027), high initial dose of prednisolone (PSL) (OR 4.18, p = 0.013), and combination immunosuppressive therapies (OR 5.51, p < 0.001).

CONCLUSION

The present study shows the progression of ILD at baseline is the most critical for survival and that infection, especially respiratory infection, is an additive prognostic factor under the potent immunosuppressive treatment.

Multiple values of 18F-FDG PET/CT in idiopathic inflammatory myopathy

This study aimed to investigate the multiple values of ¹⁸F-FDG PET/CT in detecting malignant tumors, evaluating myopathy, and determining interstitial lung disease in patients with idiopathic inflammatory myopathy (IIM). We retrospectively analyzed the data of 38 patients who were examined by ¹⁸F-FDG PET/CT and eventually diagnosed as IIM. We also collected the data of another 22 cases with negative PET/CT as the control. Pulmonary HRCT images were acquired simultaneously with regular ¹⁸F-FDG PET/CT imaging for each patient. Image analysis included the presence of malignant lesions, muscular FDG uptake, and interstitial lung disease and its imaging features. IIM was classified into polymyositis (PM), classic dermatomyositis (CDM), and clinical amyopathic dermatomyositis (CADM). All suspected malignant lesions were confirmed by histopathological examination. Interstitial lung disease was diagnosed by HRCT. Rapidly progressive interstitial lung disease (RP-ILD) was determined according to clinical follow-ups. The significance of ¹⁸F-FDG PET/CT in the detection of malignancy, observation of activity of myopathy, and determination of interstitial lung disease in IIM patients was explored based on the final clinical diagnosis. In the 38 patients with IIM, 3 cases were classified as PM, 18 as CDM, and 17 as CADM. PET/CT correctly detected 7 cases (18.4%) of malignant tumors, and all of which were found in CDM and PM patients. The muscular FDG uptake in IIM patients was higher than the control population, and it was higher in patients with myopathy (including PM and CDM) than in patients with CADM. The muscular FDG uptake in IIM patients was correlated with elevated serum creatine kinase level (r = 0.332, P = 0.042) and impaired muscle strength (r = -0.605, P < 0.001). Interstitial lung disease was detected by HRCT in 30 patients (78.9%), and 7 of them were eventually confirmed as RP-ILD, according to the clinical outcome. The FDG uptake in lung lesions of RP-ILD patients was higher than those with chronic interstitial lung diseases, even though no significant difference was found between the CT features of RP-ILD and chronic interstitial lung disease. When SUV_max ≥ 2.4 was employed as the threshold for RP-ILD prediction, the diagnostic efficiency was yield with a sensitivity of 100.0% (7/7), specificity of 87.0% (20/23), and accuracy of 90.0% (27/30), respectively. For IIM patients, ¹⁸F-FDG PET/CT has multiple values in identifying malignancies, observing the status of inflammatory myopathy, detecting interstitial lung disease, and predicting the occurrence of RP-ILD. Therefore, it is recommended to use PET/CT in the clinical course of diagnosis and management of IIM.

Connective tissue disease associated interstitial pneumonia: a challenge for both rheumatologists and pulmonologists

Interstitial lung disease (ILD) can be either idiopathic, the result of exposure or may be associated with extrapulmonary diseases. Among the latter, connective tissue diseases (CTDs) make up the largest part. The identification, follow-up and treatment of CTD-associated ILD (CTD-ILD) are a challenge for every physician as ILD can occur before, during and after the diagnosis of CTD. Early detection of pulmonary involvement is an essential task for the treating rheumatologist and recognition of the underlying CTD can pose a challenge for the treating pulmonologist. Multidisciplinary engagement towards the patient is therefore indispensable for optimal clinical care. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 326-335).

Monitoring of Lung Involvement in Rheumatologic Disease

The monitoring of lung involvement in patients with connective tissue diseases is central to optimal long-term management and is directed towards: (a) the detection of supervening lung involvement not present at presentation and (b) the identification of disease progression in established lung disease. For both goals, accurate surveillance requires multi-disciplinary evaluation with the integration of symptomatic change, serial pulmonary function trends and imaging data. Evaluated in isolation, each of these monitoring domains has significant limitations. Symptomatic change may be confounded by a wide variety of systemic factors. Pulmonary function tests provide the most reliable data, but are limited by measurement variability, the heterogeneity of functional patterns and the confounding effects of non-pulmonary factors. Chest radiography is insensitive to change but may provide rapid confirmation of major disease progression or alert the clinician to respiratory co-morbidities. Although high-resolution computed tomography has a central role in assessing disease severity, it should be used very selectively as a monitoring tool due to the associated radiation burden. Ancillary tests include echocardiography and exercise testing to proactively identify cases of pulmonary hypertension and worsening of oxygenation. In summary, a multi-disciplinary approach is essential for the identification of disease progression and prompt treatment of comorbidities that severely impact on the morbidity and mortality of disease.