FDG PET uptake characterization through texture analysis: investigating the complementary nature of heterogeneity and functional tumor volume in a multi-cancer site patient cohort.: FDG-PET heterogeneity and volume

International audienceIntra-tumor uptake heterogeneity in 18F-FDG PET has been associated with patient treatment outcomes in several cancer types. Textural features (TF) analysis is a promising method for its quantification. An open issue associated with the use of TF for the quantification of intratumoral heterogeneity concerns its added contribution and dependence on the metabolically active tumor volume (MATV), which has already been shown as a significant predictive and prognostic parameter. Our objective was to address this question using a larger cohort of patients covering different cancer types.METHODS:A single database of 555 pre-treatment 18F-FDG PET images (breast, cervix, esophageal, head & neck and lung cancer tumors) was assembled. Four robust and reproducible TF-derived parameters were considered. The issues associated with the calculation of TF using co-occurrence matrices (such as the quantization and spatial directionality relationships) were also investigated. The relationship between these features and MATV, as well as among the features themselves was investigated using Spearman rank coefficients, for different volume ranges. The complementary prognostic value of MATV and TF was assessed through multivariate Cox analysis in the esophageal and NSCLC cohorts.RESULTS:A large range of MATVs was included in the population considered (3-415 cm3, mean = 35, median = 19, SD=50). The correlation between MATV and TF varied greatly depending on the MATVs, with reduced correlation for increasing volumes. These findings were reproducible across the different cancer types. The quantization and the calculation method both had an impact on the correlation. Volume and heterogeneity were independent prognostic factors (P = 0.0053 and 0.0093 respectively) along with stage (P = 0.002) in NSCLC, but in the esophageal tumors, volume and heterogeneity had less complementary value due to smaller overall volumes.CONCLUSION:Our results suggest that heterogeneity quantification and volume may provide valuable complementary information for volumes above 10cm3, although the complementary information increases substantially with larger volumes

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries

Synthese, marquage et evaluation de vecteurs macromoleculaires et microcapsulaires utilisables en imagerie medicale

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Qualitative versus quantitative assessment of intra-tumor FDG heterogeneity for assessing patient outcome in NSCLC

International audienceObjectives: Intra-tumor FDG distribution heterogeneity has been recently proposed as a PET image derived index for assessing and/or predicting therapy response and patient survival considering multiple cancer models. Such an evaluation has been almost exclusively based on the use of textural features allowing to quantitatively assess heterogeneity at different spatial scales. The objective of this study is to compare a qualitative assessment of FDG uptake distribution heterogeneity with a quantitative analysis based on textural features in patients with non-small cell lung cancer (NSCLC), considering both response to therapy and progression free survival. Methods: 95 NSCLC patients were included in this retrospective study. All patients underwent a PET/CT scan as part of the initial staging procedure. Response to treatment was assessed using the RESIST criteria and a minimum of 2 years follow up was available for all patients. FDG intra-tumor heterogeneity was assessed visually using a three levels scale by two nuclear medicine physicians. On the other hand textural features were used to quantitatively assess local, regional and global tumor uptake heterogeneity. The predictive value of all these heterogeneity parameters was evaluated using Kruskal-Wallis tests and receiver operating characteristics analysis. The prognostic value of each parameter for overall survival was investigated using Kaplan-Meier and Cox regression models for univariate and multivariate analyses, respectively. Results: Both visual and quantitative FDG tumor uptake heterogeneity correlated significantly with patient response to therapy. Visual heterogeneity assessment better correlated with regional quantitative heterogeneity indices. There was a high inter-observer agreement on the evaluation of visual heterogeneity. Conclusions: Intra-tumor heterogeneity assessed qualitatively and quantitatively allows predicting response to therapy and patient outcome and may be useful in stratifying patient management in NSCLC

Visual Versus Quantitative Assessment of Intratumor 18F-FDG PET Uptake Heterogeneity: Prognostic Value in Non-Small Cell Lung Cancer.: FDG PET heterogeneity in NSCLC

International audienceThe goal of this study was to compare visual assessment of intra-tumor 18F-FDG PET uptake distribution with a textural features (TF) automated quantification and to establish their respective prognostic value in non-small cell lung cancer (NSCLC).METHODS: The study retrospectively included 102 consecutive patients. Only primary tumors were considered. Intra-tumor heterogeneity was visually scored (3-level scale (Hvisu)) by two nuclear medicine physicians. Tumor volumes were automatically delineated and heterogeneity was quantified with TF. Mean and maximum SUV were also included. Visual inter-observer agreement and correlations with quantitative assessment were evaluated using the Kappa test and Spearman rank (r) coefficient respectively. Association with overall survival (OS) and recurrence-free survival (RFS) was investigated using the Kaplan-Meier method and Cox regression models.RESULTS: Moderate correlations (0.4<r<0.6) between TF parameters and Hvisu were observed. Inter-observer agreement for Hvisu was moderate (kappa=0.64, discrepancies in 27% of the cases). High SUV, large metabolic volumes and high heterogeneity according to TF was associated with poorer OS and RFS, and remained an independent prognostic factor of OS with respect to clinical variables.CONCLUSIONS: Quantification of 18F-FDG uptake heterogeneity in NSCLC through TF was correlated with visual assessment by experts. However, TF also constitute an objective heterogeneity quantification, with reduced inter-observer variability, and independent prognostic value potentially useful for patient stratification and management