metabolic tumor volume
Also written as: MTV
The three-dimensional volume of metabolically active tumor tissue measured on FDG-PET imaging using standardized thresholds.
Full Definition
Metabolic tumor volume (MTV) quantifies the total volume of metabolically active tumor tissue on FDG-PET imaging by applying standardized uptake value thresholds to define tumor boundaries. MTV is typically calculated using fixed SUV thresholds (such as SUV 2.5), percentage of SUVmax thresholds (such as 41% of SUVmax), or adaptive thresholding methods. This volumetric parameter provides prognostic information complementary to SUVmax measurements and may better reflect total tumor metabolic burden. MTV is increasingly used for treatment response assessment, radiation therapy target definition, and prognostic stratification in various malignancies.
Usage
Usage note: Abbreviate as MTV; distinguish from anatomic tumor volumes
In Context
- "Baseline metabolic tumor volume of 45 mL predicted poor treatment outcome." — Prognostic analysis report
- "MTV reduction of 75% indicated excellent response to chemotherapy." — Response assessment documentation