Table 2.
Lesion Volume with 100% Normal Tissue Perfusion
| Source Voltage (Volts) | D=63% (mm3) | D=100% (mm3) | IT=42°C (mm3)1 | IT=47°C (mm3)1 | IT=60°C (mm3) | C43=340 min (mm3) |
|---|---|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 2.5 | 0 | 0 | 0 | 0 | 0 | 0 |
| 5.0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 7.5 | 0 | 0 | 0 | 0 | 0 | 0 |
| 10.0 | 0 | 0 | 64 | 0 | 0 | 0 |
| 12.5 | 0 | 0 | 1592 | 32 | 0 | 132 |
| 15.0 | 0 | 0 | 7404 | 268 | 0 | 1488 |
| 17.5 | 48 | 32 | 11890 | 2104 | 24 | 6576 |
| 20.0 | 236 | 164 | 16360 | 7144 | 88 | 10480 |
| 22.5 | 1136 | 760 | 21030 | 11420 | 700 | 14380 |
The 42°C and 47°C isothermal volumes were chosen specifically because they are frequently used to establish damage thresholds in hyperthermia and radiofrequency ablation, respectively.
Values represent the total volume of tissue necroses calculated over the course of the simulated ablation using various cell damage thresholds (D), isothermal temperatures (IT), and thermal dosing times (C43) with 100% normal tissue perfusion (6.4 x 10-3 mb3/mt3/s). The data show that lesion volume is grossly overestimated when calculated using isothermal temperatures (905-1751%) and thermal dosing (1165%) descriptions. Thermal dosing volume is calculated as the region of tissue where the cumulative equivalent minutes exceed known tissue damage at 43°C. Since tissue damage is calculated using a first order rate law, the 63% tissue damage limit is used as a comparison to all values in the table.