TY  - JOUR
A1  - Gelbrich, Götz
A1  - Morbach, Caroline
A1  - Deutschbein, Timo
A1  - Fassnacht, Martin
A1  - Störk, Stefan
A1  - Heuschmann, Peter U.
T1  - The population comparison index: an intuitive measure to calibrate the extent of impairments in patient cohorts in relation to healthy and diseased populations
JF  - International Journal of Environmental Research and Public Health
N2  - We assume that a specific health constraint, e.g., a certain aspect of bodily function or quality of life that is measured by a variable X, is absent (or irrelevant) in a healthy reference population (Ref0), and it is materially present and precisely measured in a diseased reference population (Ref1). We further assume that some amount of this constraint of interest is suspected to be present in a population under study (SP). In order to quantify this issue, we propose the introduction of an intuitive measure, the population comparison index (PCI), that relates the mean value of X in population SP to the mean values of X in populations Ref0 and Ref1. This measure is defined as PCI[X] = (mean[X|SP] − mean[X|Ref0])/(mean[X|Ref1] − mean[X|Ref0]) × 100[%], where mean[X|.] is the average value of X in the respective group of individuals. For interpretation, PCI[X] ≈ 0 indicates that the values of X in the population SP are similar to those in population Ref0, and hence, the impairment measured by X is not materially present in the individuals in population SP. On the other hand, PCI[X] ≈ 100 means that the individuals in SP exhibit values of X comparable to those occurring in Ref1, i.e., the constraint of interest is equally present in populations SP and Ref1. A value of 0 < PCI[X] < 100 indicates that a certain percentage of the constraint is present in SP, and it is more than in Ref0 but less than in Ref1. A value of PCI[X] > 100 means that population SP is even more affected by the constraint than population Ref1.
KW  - reference data
KW  - normal values
KW  - disease severity
KW  - disease score
KW  - comparability
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304933
SN  - 1660-4601
VL  - 20
IS  - 3
ER  - 
TY  - JOUR
A1  - Hartrampf, Philipp E.
A1  - Heinrich, Marieke
A1  - Seitz, Anna Katharina
A1  - Brumberg, Joachim
A1  - Sokolakis, Ioannis
A1  - Kalogirou, Charis
A1  - Schirbel, Andreas
A1  - Kübler, Hubert
A1  - Buck, Andreas K.
A1  - Lapa, Constantin
A1  - Krebs, Markus
T1  - Metabolic Tumour Volume from PSMA PET/CT Scans of Prostate Cancer Patients during Chemotherapy — Do Different Software Solutions Deliver Comparable Results?
JF  - Journal of Clinical Medicine
N2  - (1) Background: Prostate-specific membrane antigen (PSMA)-derived tumour volume (PSMA-TV) and total lesion PSMA (TL-PSMA) from PSMA PET/CT scans are promising biomarkers for assessing treatment response in prostate cancer (PCa). Currently, it is unclear whether different software tools for assessing PSMA-TV and TL-PSMA produce comparable results. (2) Methods: \(^{68}\)Ga-PSMA PET/CT scans from n = 21 patients with castration-resistant PCa (CRPC) receiving chemotherapy were identified from our single-centre database. PSMA-TV and TL-PSMA were calculated with Syngo.via (Siemens) as well as the freely available Beth Israel plugin for FIJI (Fiji Is Just ImageJ) before and after chemotherapy. While statistical comparability was illustrated and quantified via Bland-Altman diagrams, the clinical agreement was estimated by matching PSMA-TV, TL-PSMA and relative changes of both variables during chemotherapy with changes in serum PSA (ΔPSA) and PERCIST (Positron Emission Response Criteria in Solid Tumors). (3) Results: Comparing absolute PSMA-TV and TL-PSMA as well as Bland–Altman plotting revealed a good statistical comparability of both software algorithms. For clinical agreement, classifying therapy response did not differ between PSMA-TV and TL-PSMA for both software solutions and showed highly positive correlations with BR. (4) Conclusions: due to the high levels of statistical and clinical agreement in our CRPC patient cohort undergoing taxane chemotherapy, comparing PSMA-TV and TL-PSMA determined by Syngo.via and FIJI appears feasible.
KW  - prostate-specific membrane antigen (PSMA)
KW  - metabolic tumour volume (MTV)
KW  - total lesion PSMA
KW  - biomarker
KW  - software
KW  - comparability
KW  - agreement
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-205893
SN  - 2077-0383
VL  - 9
IS  - 5
ER  -