There are multiple definitions:

1. planning target volume(English)

   • Radiotherapy /radiation

2. pre-terminal valve(English)

   • AASV, GSV, SPJ, SSV, TE, UIP
   • Vessel properties
   • https://doi.org…jvs.2005.07.020

3. pain threshold variation(English)

   • e.g. after surgery. Calculated as the ratio of the postoperative PT to preoperative PT
   • PT
   • Pain, Variability / oscillation, Ratio-based metric
   • https://doi.org…019-023-02424-w