Impact of partial-volume correction in oncological PET studies:A systematic review and meta-analysis

Purpose: Positron-emission tomography can be useful in oncology for diagnosis, (re)staging, determining prognosis, and response assessment. However, partial-volume effects hamper accurate quantification of lesions &lt;2–3× the PET system’s spatial resolution, and the clinical impact of this is not evident. This systematic review provides an up-to-date overview of studies investigating the impact of partial-volume correction (PVC) in oncological PET studies.Methods: We searched in PubMed and Embase databases according to the PRISMA statement, including studies from inception till May 9, 2016. Two reviewers independently screened all abstracts and eligible full-text articles and performed quality assessment according to QUADAS-2 and QUIPS criteria. For a set of similar diagnostic studies, we statistically pooled the results using bivariate meta-regression.Results: Thirty-one studies were eligible for inclusion. Overall, study quality was good. For diagnosis and nodal staging, PVC yielded a strong trend of increased sensitivity at expense of specificity. Meta-analysis of six studies investigating diagnosis of pulmonary nodules (679 lesions) showed no significant change in diagnostic accuracy after PVC (p = 0.222). Prognostication was not improved for non-small cell lung cancer and esophageal cancer, whereas it did improve for head and neck cancer. Response assessment was not improved by PVC for (locally advanced) breast cancer or rectal cancer, and it worsened in metastatic colorectal cancer.Conclusions: The accumulated evidence to date does not support routine application of PVC in standard clinical PET practice. Consensus on the preferred PVC methodology in oncological PET should be reached. Partial-volume-corrected data should be used as adjuncts to, but not yet replacement for, uncorrected data.</p

Interobserver reliability of diagnosis in patients with complex regional pain syndrome

Abstract Complex regional pain syndrome type I (CRPS-I), formerly reflex sympathetic dystrophy (RSD), is a chronic pain syndrome of unknown aetiology. Its diagnosis is a clinical one, for which several criteria systems have been defined. Despite their widespread use, the reliability of these criteria has never been studied. In this interobserver study 25 chronic CRPS patients were interviewed and examined by six physicians. Through structured questionnaires signs, symptoms, and diagnosis were recorded, after which observer agreement for these was calculated with j statistics. PhysiciansÕ agreement in assessment of signs and symptoms in CRPS patients varied greatly. More importantly, final diagnosis of CRPS showed poor observer agreement (j: 0.20). The j values were higher, had physicians applied IASP criteria, but still insufficient. The application of BruehlÕs criteria results in a fair j of 0.38, but then frequency of CRPS diagnosis in our study population decreased from 73% to 43% in comparison with physiciansÕ own diagnosis. We conclude that, using current criteria systems, the diagnosis of CRPS is not reliable

Minimally important change determined by a visual method integrating an anchor-based and a distribution-based approach

Background: Minimally important changes (MIC) in scores help interpret results from health status instruments. Various distribution-based and anchor-based approaches have been proposed to assess MIC. Objectives: To describe and apply a visual method, called the anchor-based MIC distribution method, which integrates both approaches. Method: Using an anchor, patients are categorized as persons with an important improvement, an important deterioration, or without important change. For these three groups the distribution of the change scores on the health status instrument are depicted in a graph. We present two cut-off points for an MIC: the ROC cut-off point and the 95% limit cut-off point. Results: We illustrate our anchor-based MIC distribution method determining the MIC for the Pain Intensity Numerical Rating Scale in patients with low back pain, using two conceivable definitions of minimal important change on the anchor. The graph shows the distribution of the scores of the health status instrument for the relevant categories on the anchor, and also the consequences of choosing the ROC cut-off point or the 95% limit cut-off point. Discussion: The anchor-based MIC distribution method provides a general framework, applicable to all kind of anchors. This method forces researchers to choose and justify their choice of an appropriate anchor and to define minimal importance on that anchor. The MIC is not an invariable characteristic of a measurement instrument, but may depend, among other things, on the perspective from which minimal importance is considered and the baseline values on the measurement instrument under study. A balance needs to be struck between the practicality of a single MIC value and the validity of a range of MIC values. © 2006 Springer Science+Business Media B.V

Interobserver reliability of diagnosis in patients with complex regional pain syndrome

Abstract Complex regional pain syndrome type I (CRPS-I), formerly reflex sympathetic dystrophy (RSD), is a chronic pain syndrome of unknown aetiology. Its diagnosis is a clinical one, for which several criteria systems have been defined. Despite their widespread use, the reliability of these criteria has never been studied. In this interobserver study 25 chronic CRPS patients were interviewed and examined by six physicians. Through structured questionnaires signs, symptoms, and diagnosis were recorded, after which observer agreement for these was calculated with j statistics. PhysiciansÕ agreement in assessment of signs and symptoms in CRPS patients varied greatly. More importantly, final diagnosis of CRPS showed poor observer agreement (j: 0.20). The j values were higher, had physicians applied IASP criteria, but still insufficient. The application of BruehlÕs criteria results in a fair j of 0.38, but then frequency of CRPS diagnosis in our study population decreased from 73% to 43% in comparison with physiciansÕ own diagnosis. We conclude that, using current criteria systems, the diagnosis of CRPS is not reliable

Value of symptoms and additional diagnostic tests for colorectal cancer in primary care: systematic review and meta-analysis

Objective To summarise available evidence on diagnostic tests that might help primary care physicians to identify patients with an increased risk for colorectal cancer among those consulting for non-acute lower abdominal symptoms

Quality of reporting of diagnostic accuracy studies

PURPOSE: To evaluate quality of reporting in diagnostic accuracy articles published in 2000 in journals with impact factor of at least 4 by using items of Standards for Reporting of Diagnostic Accuracy (STARD) statement published later in 2003. MATERIALS AND METHODS: English-language articles on primary diagnostic accuracy studies in 2000 were identified with validated search strategy in MEDLINE. Articles published in journals with impact factor of 4 or higher that regularly publish articles on diagnostic accuracy were selected. Two independent reviewers evaluated quality of reporting by using STARD statement, which consists of 25 items and encourages use of a flow diagram. Total STARD score for each article was calculated by summing number of reported items. Subgroup analyses were performed for study design (case-control or cohort study) by using Student t tests for continuous outcomes and chi(2) tests for dichotomous outcomes. RESULTS: Included were 124 articles published in 2000 in 12 journals: 33 case-control and 91 cohort studies. Only 41% of articles (51 of 124) reported on more than 50% of STARD items, while no articles reported on more than 80%. A flow chart was presented in two articles. Assessment of reporting on individual items of STARD statement revealed wide variation, with some items described in 11% of articles and others in 92%. Mean STARD score (0-25 points available) was 11.9 (range, 3.5-19.5). Mean difference in STARD score between cohort studies and case-control studies was 1.53 (95% confidence interval: 0.24, 2.82). CONCLUSION: Quality of reporting in diagnostic accuracy articles published in 2000 is less than optimal, even in journals with high impact factor. Authors, editors, and reviewers should pay more attention to reporting by checking STARD statement items and including a flow diagram to represent study design and patient flow. Supplemental material: radiology.rsnajnls.org/cgi/content/full/2352040507/DC1 (c) RSNA, 200

¹⁸F-FDG PET baseline radiomics features improve the prediction of treatment outcome in diffuse large B-cell lymphoma

PURPOSE: Accurate prognostic markers are urgently needed to identify diffuse large B-Cell lymphoma (DLBCL) patients at high risk of progression or relapse. Our purpose was to investigate the potential added value of baseline radiomics features to the international prognostic index (IPI) in predicting outcome after first-line treatment. METHODS: Three hundred seventeen newly diagnosed DLBCL patients were included. Lesions were delineated using a semi-automated segmentation method (standardized uptake value ≥ 4.0), and 490 radiomics features were extracted. We used logistic regression with backward feature selection to predict 2-year time to progression (TTP). The area under the curve (AUC) of the receiver operator characteristic curve was calculated to assess model performance. High-risk groups were defined based on prevalence of events; diagnostic performance was assessed using positive and negative predictive values. RESULTS: The IPI model yielded an AUC of 0.68. The optimal radiomics model comprised the natural logarithms of metabolic tumor volume (MTV) and of SUV(peak) and the maximal distance between the largest lesion and any other lesion (Dmax(bulk), AUC 0.76). Combining radiomics and clinical features showed that a combination of tumor- (MTV, SUV(peak) and Dmax(bulk)) and patient-related parameters (WHO performance status and age > 60 years) performed best (AUC 0.79). Adding radiomics features to clinical predictors increased PPV with 15%, with more accurate selection of high-risk patients compared to the IPI model (progression at 2-year TTP, 44% vs 28%, respectively). CONCLUSION: Prediction models using baseline radiomics combined with currently used clinical predictors identify patients at risk of relapse at baseline and significantly improved model performance. TRIAL REGISTRATION NUMBER AND DATE: EudraCT: 2006–005,174-42, 01–08-2008. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00259-021-05480-3

Rating the methodological quality in systematic reviews of studies on measurement properties: a scoring system for the COSMIN checklist

Background: The COSMIN checklist is a standardized tool for assessing the methodological quality of studies on measurement properties. It contains 9 boxes, each dealing with one measurement property, with 5-18 items per box about design aspects and statistical methods. Our aim was to develop a scoring system for the COSMIN checklist to calculate quality scores per measurement property when using the checklist in systematic reviews of measurement properties. Methods: The scoring system was developed based on discussions among experts and testing of the scoring system on 46 articles from a systematic review. Four response options were defined for each COSMIN item (excellent, good, fair, and poor). A quality score per measurement property is obtained by taking the lowest rating of any item in a box ("worst score counts"). Results: Specific criteria for excellent, good, fair, and poor quality for each COSMIN item are described. In defining the criteria, the "worst score counts" algorithm was taken into consideration. This means that only fatal flaws were defined as poor quality. The scores of the 46 articles show how the scoring system can be used to provide an overview of the methodological quality of studies included in a systematic review of measurement properties. Conclusions: Based on experience in testing this scoring system on 46 articles, the COSMIN checklist with the proposed scoring system seems to be a useful tool for assessing the methodological quality of studies included in systematic reviews of measurement properties. © The Author(s) 2011