Metabolic Volume Measurements in Multiple Myeloma

Abstract

Multiple myeloma (MM) accounts for 10–15% of all hematologic malignancies, as well as 20% of deaths related to hematologic malignant tumors, predominantly affecting bone and bone marrow. Positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (FDG-PET/CT) is an important method to assess the tumor burden of these patients. It is often challenging to classify the extent of disease involvement in the PET scans for many of these patients because both focal and diffuse bone lesions may coexist, with varying degrees of FDG uptake. Different metrics involving volumetric parameters and texture features have been proposed to objectively assess these images. Here, we review some metabolic parameters that can be extracted from FDG-PET/CT images of MM patients, including technical aspects and predicting MM outcome impact. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are volumetric parameters known to be independent predictors of MM outcome. However, they have not been adopted in clinical practice due to the lack of measuring standards. CT-based segmentation allows automated, and therefore reproducible, calculation of bone metabolic metrics in patients with MM, such as maximum, mean and standard deviation of the standardized uptake values (SUV) for the entire skeleton. Intensity of bone involvement (IBI) is a new parameter that also takes advantage of this approach with promising results. Other indirect parameters obtained from FDG-PET/CT images, such as visceral adipose tissue glucose uptake and subcutaneous adipose tissue radiodensity, may also be useful to evaluate the prognosis of MM patients. Furthermore, the use and quantification of new radiotracers can address different metabolic aspects of MM and may have important prognostic implications.

The usefulness of the total metabolic tumor volume for predicting the postoperative recurrence of thoracic esophageal squamous cell carcinoma

“…The SUVpeak was calculated in a 1.2-cm-dia. Region of interest (ROI) placed on the uptake lesions and defined as the average SUV inside an ROI centered in the highest uptake volume of the lesion [ 5 ]. The SUVpeak was normalized to the SULpeak as follows: SUVpeak × [lean body mass] / [total body mass].…”

“…Total lesion glycolysis (TLG) and the metabolic tumor volume (MTV) are representative PET volumetric parameters. The MTV is an important parameter to determine the local tumor burden and the total tumor burden obtained by a commonly fixed threshold method, and it is usually expressed in milliliters or cubic centimeters [ 5 ]. The TLG value provides information about total tumor glycolysis calculated from the following formula: SUVmean × MTV [ 5 ].…”

“…The MTV is an important parameter to determine the local tumor burden and the total tumor burden obtained by a commonly fixed threshold method, and it is usually expressed in milliliters or cubic centimeters [ 5 ]. The TLG value provides information about total tumor glycolysis calculated from the following formula: SUVmean × MTV [ 5 ]. In other words, the TLG takes into account the intensity of radiotracer uptake and a volumetric factor [ 5 ].…”

“…The TLG value provides information about total tumor glycolysis calculated from the following formula: SUVmean × MTV [ 5 ]. In other words, the TLG takes into account the intensity of radiotracer uptake and a volumetric factor [ 5 ].…”

Value of 18F-FDG PET/CT Based on PD-L1 to Predict Outcomes of Immunotherapy in NSCLC

“…MTV is a volume index measured by a specific SUV threshold and mainly describes the metabolic volume of tumors. TLG is the product of the average SUV value of all voxels in the tumor and MTV, representing the uptake degree of 18 F-FDG and tumor size, as well as the overall metabolic and volumetric load of the tumor [36]. 18 F-FDG PET/CT is widely used in monitoring the efficacy of systemic chemoradiotherapy or targeted therapy for a variety of cancers, and plays an important role in monitoring the efficacy of immunotherapy in NSCLC patients in particular.…”