| Abbreviation | Definition |
|---|---|
| SSDL | Secondary Standards Dosimetry Laboratory |
| SSSG | Steady State Serum Glucose |
| STEL | Short-Term (15-minute) Exposure Limit |
| STT | Segmented Treatment Table |
| TAR | Tissue-Air Ratio |
| TCP | Tumor Control Probability |
| TCPE | Transient Charged Particle Equilibrium |
| TD | Target Dose |
| TECDOC | TEChnical DOCument |
| TL | ThermoLuminescence |
| TLD | ThermoLuminescent Dosimetry |
| TMR | Tissue-Maximum Ratio |
| TOE | Technician Office Emergency |
| TP | Treatment Planning |
| TPR | Tissue-Phantom Ratio |
| TPR10 | Tissue-Phantom Ratio at depth of 10 centimeters in water |
| TPR20 | Tissue-Phantom Ratio at depth of 20 centimeters in water |
| TPS | Treatment Planning System |
| TRF | Tuned Radio Frequency |
| TSEI | Total Skin Electron Irradiation |