The 68 Ge phantom-based FDG-PET site qualification program for clinical trials adopted by FIL (Italian Foundation on Lymphoma)

Chauvie, Stéphane; Bergesio, Fabrizio; Fioroni, Federica; Brambilla, Marco; Biggi, Alberto; Versari, Annibale; Guerra, Luca; Storto, Giovanni; Musto, Pellegrino; Luminari, Stefano; Cabras, Maria Giuseppina; Balzarotti, Monica; Rigacci, Luigi; Martelli, Maurizio; Vitolo, Umberto; Federico, Massimo; Gallamini, Andrea

doi:10.1016/j.ejmp.2016.04.004

Cited by 22 publications

(20 citation statements)

References 44 publications

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“…However, to our knowledge, no ongoing trials have been launched using the TMTV to guide therapy. Even if the prerequisite for this type of trial is quality control, as done using various existing control systems (7,19,20), it is anyway required for good PET clinical practice. The main problem is which TMTV technique measurement should be chosen because there is no established consensus.…”

Section: Discussionmentioning

confidence: 99%

Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma

et al. 2016

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The purpose of this study was to compare in a large series of peripheral T cell lymphoma, as a model of diffuse disease, the prognostic value of baseline total metabolic tumor volume (TMTV) measured on 18 F-FDG PET/CT with adaptive thresholding methods with TMTV measured with a fixed 41% SUV max threshold method. Methods: One hundred six patients with peripheral T cell lymphoma, staged with PET/CT, were enrolled from 5 Lymphoma Study Association centers. In this series, TMTV computed with the 41% SUV max threshold is a strong predictor of outcome. On a dedicated workstation, we measured the TMTV with 4 adaptive thresholding methods based on characteristic image parameters: Daisne (Da) modified, based on signal-to-background ratio; Nestle (Ns), based on tumor and background intensities; Fit, including a 3-dimensional geometric model based on spatial resolution (Fit); and Black (Bl), based on mean SUV max . The TMTV values obtained with each adaptive method were compared with those obtained with the 41% SUV max method. Their respective prognostic impacts on outcome prediction were compared using receiver-operatingcharacteristic (ROC) curve analysis and Kaplan-Meier survival curves. Results: The median value of TMTV 41% , TMTV Da , TMTV Ns , TMTV Fit , and TMTV Bl were, respectively, 231 cm 3 (range, 5-3,824), 175 cm 3 (range, 8-3,510), 198 cm 3 (range, 3-3,934), 175 cm 3 (range, 8-3,512), and 333 cm 3 (range, 3-5,113). The intraclass correlation coefficients were excellent, from 0.972 to 0.988, for TMTV Da , TMTV Fit , and TMTV Ns , and less good for TMTV Bl (0.856). The mean differences obtained from the Bland-Altman plots were 48.5, 47.2, 19.5, and 2253.3 cm 3 , respectively. Except for Black, there was no significant difference within the methods between the ROC curves (P . 0.4) for progression-free survival and overall survival. Survival curves with the ROC optimal cutoff for each method separated the same groups of low-risk (volume # cutoff) from high-risk patients (volume . cutoff), with similar 2-y progression-free survival (range, 66%-72% vs. 26%-29%; hazard ratio, 3.7-4.1) and 2-y overall survival (79%-83% vs. 50%-53%; hazard ratio, 3.0-3.5). Conclusion: The prognostic value of TMTV remained quite similar whatever the methods, adaptive or 41% SUV max , supporting its use as a strong prognosticator in lymphoma. However, for implementation of TMTV in clinical trials 1 single method easily applicable in a multicentric PET review must be selected and kept all along the trial. PET/ CT with 18 F-FDG has been recognized as the best imaging tool for staging and response assessment in FDG-avid lymphoma. The last International Conference on Malignant Lymphoma recommendations (1) encourage investigating the quantitative analysis of 18 F-FDG PET/CT at staging. In this regard, the measurement of the total metabolic tumor volume (TMTV), which gives an estimation of the total tumor burden, has gained special interest. Indeed, several series have shown that TMTV was predictive of outcome in different lymphoma subtypes: d...

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Section: Discussionmentioning

confidence: 99%

Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma

et al. 2016

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“…Recently, it has been shown that variability across a network of hospitals can vary based on whether long-lived 68 Ge/ 68 Ga or short-lived 18 F sources are used (35). We note that there is a subtlety in quality control of SUVs, in that short-lived phantoms can detect more sources of variability but cannot separate them.…”

Section: Discussionmentioning

confidence: 99%

“…Long-lived phantoms can separate bias instability in the scanner and dose calibrator and follow extremely stable decay curves, but may miss effects such as clock synchronization or incomplete dose injection. Short-lived phantoms are commonly used to assess scanner bias for clinic accreditation (35–37), and in 1 such study, 12% of scanners tested (N = 101) were found to have biases >10% (36). This shows that quality control for PET is essential, and we believe that long-lived sources have a key role to play in characterizing SUV variability in time.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Cross-Calibrated 68Ge/68Ga Phantoms for Assessing PET/CT Measurement Bias in Oncology Imaging for Single- and Multicenter Trials

et al. 2016

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Quantitative PET imaging is an important tool for clinical trials evaluating the response of cancers to investigational therapies. The standardized uptake value, used as a quantitative imaging biomarker, is dependent on multiple parameters that may contribute bias and variability. The use of long-lived, sealed PET calibration phantoms offers the advantages of known radioactivity activity concentration and simpler use than aqueous phantoms. We evaluated scanner and dose calibrator sources from two batches of commercially available kits, together at a single site and distributed across a local multicenter PET imaging network. We found that radioactivity concentration was uniform within the phantoms. Within the regions of interest drawn in the phantom images, coefficients of variation of voxel values were less than 2%. Across phantoms, coefficients of variation for mean signal were close to 1%. Biases of the standardized uptake value estimated with the kits varied by site and were seen to change in time by approximately ±5%. We conclude that these biases cannot be assumed constant over time. The kits provide a robust method to monitor PET scanner and dose calibrator biases, and resulting biases in standardized uptake values.

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“…Effort of cross-calibration through the measurements of different phantoms permits achievement of a variability less than 10% in multi-centre clinical trials [23,24,25,26,27,28,29,30], while 5% should be a good requirement for using PET/CT in a quantitative way [31,32]. …”

Section: Sources Of Errors In Uptake Evaluationmentioning

confidence: 99%

“…The response was assessed by adopting the 5-point scale Deauville criteria as a qualitative index and the SUV max as a quantitative index. A response was defined as a reduction in the Deauville score or, if there was no change in it, a reduction in SUV compared to baseline.Scanners underwent clinical trial qualification for semi-quantitative analysis from the FIL core lab [30]. That is, before patients’ accrual, all PET/CT sites acquire two phantoms and sends them to the core lab.…”

Section: Strategies Of Error Reduction In Onco-heamatological Clinmentioning

confidence: 99%

The Strategies to Homogenize PET/CT Metrics: The Case of Onco-Haematological Clinical Trials

Chauvie¹,

Bergesio²

2016

Biomedicines

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Positron emission tomography (PET) has been a widely used tool in oncology for staging lymphomas for a long time. Recently, several large clinical trials demonstrated its utility in therapy management during treatment, paving the way to personalized medicine. In doing so, the traditional way of reporting PET based on the extent of disease has been complemented by a discrete scale that takes in account tumour metabolism. However, due to several technical, physical and biological limitations in the use of PET uptake as a biomarker, stringent rules have been used in clinical trials to reduce the errors in its evaluation. Within this manuscript we will describe shortly the evolution in PET reporting, examine the main errors in uptake measurement, and analyse which strategy the clinical trials applied to reduce them.

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The 68 Ge phantom-based FDG-PET site qualification program for clinical trials adopted by FIL (Italian Foundation on Lymphoma)

Abstract: The (68)Ge phantom proved a reliable tool for PET scanner qualification, able to significantly reduce the potential sources of error while increasing the reproducibility of PET derived quantitative parameter measurement.

Cited by 22 publications

References 44 publications

Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma

Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma

Evaluation of Cross-Calibrated 68Ge/68Ga Phantoms for Assessing PET/CT Measurement Bias in Oncology Imaging for Single- and Multicenter Trials

The Strategies to Homogenize PET/CT Metrics: The Case of Onco-Haematological Clinical Trials

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