Planning Target Volume
Pronunciation: P-T-V
Also written as: PTV — Planning Target Volume
Geometric volume encompassing the clinical target volume plus margins for setup uncertainties and organ motion.
Full Definition
The Planning Target Volume represents the final treatment volume used in radiation therapy planning, incorporating the clinical target volume plus additional margins to account for patient setup uncertainties, organ motion, and beam delivery variations. PTV definition is critical for ensuring adequate tumor coverage while minimizing normal tissue irradiation. The PTV margin varies based on treatment site, immobilization techniques, and imaging guidance capabilities, requiring careful consideration of anatomical factors and institutional protocols.
Usage
Usage note: Always distinguish from other treatment volumes in radiation therapy reports.
In Context
- "The PTV encompassed the clinical target volume with a 5mm margin for setup uncertainty." — Treatment planning report
- "Daily imaging confirmed adequate PTV coverage throughout the treatment course." — Treatment verification