gross tumor volume
Also written as: GTV — Gross Tumor Volume
The visible or palpable tumor mass that can be detected by physical examination or imaging studies.
Full Definition
Gross tumor volume (GTV) represents the demonstrable tumor as defined by physical examination, imaging studies, or endoscopic visualization. The GTV forms the foundation for radiation treatment planning, as all other target volumes are derived from this initial contour. Accurate GTV delineation requires integration of multiple imaging modalities, pathological information, and clinical findings. The GTV does not include margins for microscopic disease extension or setup uncertainties, which are addressed in subsequent target volume definitions. For medical editors, understanding GTV as distinct from clinical target volume (CTV) and planning target volume (PTV) is essential for accurately interpreting radiation oncology treatment planning documentation.
Usage
Usage note: Foundation for all other target volumes. Distinct from CTV (includes microscopic disease) and PTV (includes setup margins).
In Context
- "The gross tumor volume was carefully delineated using multiparametric MRI and PET imaging." — Treatment planning description
- "Post-surgical changes made gross tumor volume definition challenging in the tumor bed." — Contouring consideration