Reproducibility of Baseline Tumour Metabolic Volume Measurements in Diffuse Large B-Cell Lymphoma: Is There a Superior Method?

Abstract

The metabolic tumour volume (MTV) is an independent prognostic indicator in diffuse large B-cell lymphoma (DLBCL). However, its measurement is not standardised and is subject to wide variations depending on the method used. This study aimed to compare the reproducibility of MTV measurement as well as the thresholds obtained for each method and their prognostic values. The baseline MTV was measured in 239 consecutive patients treated at Henri Becquerel Centre by two blinded evaluators. Eight methods were compared: 3 absolute (SUV (standardised uptake value) ≥ 2.5; SUV≥ liver SUVmax; SUV≥ PERCIST SUV), 1 percentage SUV threshold method (SUV ≥ 41% SUVmax) and 4 adaptive methods (Daisne, Nestle, Fitting, Black). The intraclass correlation coefficients were excellent, from 0.91 to 0.96, for the absolute SUV methods, Black and Nestle methods, and good for 41% SUVmax, Fitting and Daisne methods (0.82 to 0.88), with a significantly lower variability with absolute methods compared to 41% SUVmax (p < 0.04). Thresholds were found to be specific to each segmentation method and ranged from 295 to 552 cm3. There was a strong correlation between the MTV and patient prognosis regardless of the segmentation method used (p = 0.001 for PFS and OS). The largest inter-observer cut-off variability was observed in the 41% SUVmax method, which resulted in more inter-observer disagreements in the classification of patients between high and low MTV groups. MTV measurements based on absolute SUV criteria were found to be significantly more reproducible than those based on 41% SUVmax criteria. The threshold was specific for each of eight segmentation methods, but all predicted prognosis.

Two-Year Event-Free Survival Prediction in DLBCL Patients Based on In Vivo Radiomics and Clinical Parameters

“…3.10 (Mediso Medical Imaging Systems Ltd., Budapest, Hungary) clinical evaluation software. The average SUV-max value of the liver (3.5–5.5) served as a reference threshold for the semi-automated algorithm ( 22 ). This approach was selected to minimize the effects of patient-specific radiotracer distributions ( 23 ).…”

Integration of Baseline Metabolic Parameters and Mutational Profiles Predicts Long-Term Response to First-Line Therapy in DLBCL Patients: A Post Hoc Analysis of the SAKK38/07 Study

“…Our results provide proof of principle that integration of functional PET parameters with mutational profiling can improve risk stratification of DLBCL patients, offering a promising tool for the design of clinical trials focused on treatment optimization for newly diagnosed patients. An international process is ongoing to standardize the estimation of volumetric PET/CT parameters [ 43 , 51 , 52 , 53 ] and will hopefully allow a wider use and validation of powerful prognostic models based on integrative PET.…”

Pre‐treatment total metabolic tumour volumes in lymphoma: Does quantity matter?

“…The SUV41% method is also prone to tMTV variations caused by placement of VOI and identification of the hottest voxel in the VOI. Finally, SUV41% thresholding in patients with malignant lymphoma is consistently associated with higher interobserver variability than a fixed SUV2.5 or 4 threshold 43,45,46 …”

“…Finally, SUV41% thresholding in patients with malignant lymphoma is consistently associated with higher interobserver variability than a fixed SUV2.5 or 4 threshold. 43,45,46 A background fixed thresholding method could, in theory, solve some of the variability induced by image acquisition and reconstructions. For example, an SUV threshold defined by the average SUV of a small sphere in the liver (~30 ml) + 2 standard deviations (SD) can eliminate some variability by using thresholds that are patient-specific and reflect image noise (the SD of the liver VOI) as well as overall background activity (liver SUVmean).…”