Standardized added metabolic activity (SAM): a partial volume independent marker of total lesion glycolysis in liver metastases

“…5. Standardized added metabolic activity (SAM) [23]. This figure-of-merit was defined as follows: a first VOI (VOI1) was drawn around the lesion and a second VOI (VOI2) was delineated.…”

Section: Tumour Uptake and Volumetric Parametersmentioning

confidence: 99%

Prognostic value of metabolic parameters and clinical impact of 18F-fluorocholine PET/CT in biochemical recurrent prostate cancer

Colombié

Campion

Bailly

et al. 2015

“…However, there is growing interest in using alternative measurements, for instance metabolically active tumour volume (MATV) and heterogeneity metrics, in order to provide a more comprehensive quantitative assessment of lesions from PET images [14,15].…”

Section: Introductionmentioning

confidence: 99%

18F-FDG PET/CT heterogeneity quantification through textural features in the era of harmonisation programs: a focus on lung cancer

Lasnon

Majdoub

Lavigne

et al. 2016

No significant difference was observed between any of the metrics considered (SUV or heterogeneity features) extracted from OSEM and PSF7 reconstructions. Furthermore, the distributions of TF for OSEM and PSF7 reconstructions according to tumour volumes were similar for all ranges of volumes.Conclusion: PSF reconstruction with Gaussian filtering chosen to meet harmonizing standards resulted in similar SUV values and heterogeneity information, compared to OSEM images, which validates its use within the harmonization strategy context. However, unfiltered PSF-reconstructed images also showed higher heterogeneity according to some metrics, as well as a wider range of heterogeneity values than OSEM images, for most of the metrics considered, especially when analysing larger tumours. This suggests that, whenever 3 available, unfiltered PSF images should also be exploited to obtain the most discriminative quantitative heterogeneity features.

“…For all these reasons, a novel parameter, called standardized added metabolic (SAM) activity recently proposed by Mertens and colleagues [16] in the European Journal of Nuclear Medicine and Molecular Imaging, may be of particular interest. The attractiveness of this parameter is its potential independence from an accurate MATV determination as well as PVE.…”

mentioning

confidence: 99%

“…A preliminary clinical evaluation of this new PET imagederived parameter was performed as part of the same study [16] considering 19 patients with colorectal carcinoma undergoing baseline and treatment follow-up PET scans (after three to six chemotherapy cycles). In this patient population, consisting of only responders and nonresponders, no statistically significant differences were found between SUV max and SAM for assessing response to therapy based on PET imaging.…”

mentioning

confidence: 99%

The age of reason for FDG PET image-derived indices

Visvikis

Hatt

Tixier

et al. 2012

The clinical use of PET imaging using 18 F-FDG is currently predominantly focused on diagnosis in the field of oncology. In this context, image analysis is largely based on visual interpretation and the use of simple image-derived indices, such as the maximum standardized uptake value (SUV max ), which corresponds to the voxel with the maximum activity concentration in the tumour scaled by the administered activity, patient weight and blood glucose concentration. On the other hand, during the last few years there has been increasing interest in the use of 18 F-FDG PET imaging for the prediction and monitoring of therapy response. In this context the SUV max has been also predominantly used, where differences between a pretreatment and posttreatment scan have been shown to closely correlate with clinical response to treatment in a number of different cancer models [1,2].The clear advantage of such a simplistic image-derived index is the ease of use, which has significantly contributed to its widespread application in clinical practice. SUV max is also in principle less dependent on partial volume effects (PVE) resulting from the limited spatial resolution of PET imaging [3]. On the other hand, there are a number of issues associated with its use, such as lack of robustness in terms of image noise, as well as in terms of the reconstruction algorithm and the associated corrections used during the reconstruction process. Clearly the impact of these issues can be minimized by standardization of the injection, acquisition, and image reconstruction and analysis protocols. In addition, the use of peak SUV (SUV peak ), calculated by averaging the voxel values inside a small region of interest centred on the tumour maximum activity concentration voxel, can reduce the sensitivity of SUV max to noise, although results may be sensitive to the actual definition of the ROI used to compute SUV peak [4]. However and most importantly, SUV max represents only very limited information in considering radiotracer accumulation and not considering information on the associated tumour uptake distribution or on the overall tumour functional volume. This is true even in the context of static acquisitions associated with routine whole-body 18 F-FDG PET imaging, where dynamic acquisitions, which offer the possibility, through kinetic modelling, of deriving quantitative glucose metabolic rates on a voxel-by-voxel basis, are not considered.Remaining with the context of static PET imaging, overall tumour activity accumulation can be alternatively characterized using the mean SUV (SUV mean ). SUV mean corresponds to the mean activity concentration in a delineated three-dimensional (3D) functional tumour volume. The most significant issues associated with the accuracy of SUV mean determination include the precision and robustness in the delineation of the tumour functional volume used [5,6], and the important influence of PVE which is closely related to the overall tumour size. The impact of PVE becomes more significant in studies of response to...