Petersen index (PI) | |||
---|---|---|---|

Equation | PI = (peritoneal involvement) + (vascular invasion) + (margin involvement) + (tumour perforation) | ||

Variables | Peritoneal involvement = 1 | Margin involvement = 1 | |

Vascular invasion = 1 | Tumour perforation = 2 | ||

Risk | Low risk PI between 0 and 1 | ||

High risk PI between 2 and 5 |