Table 1.

Risk Probability Number (RPN) Scores for Selected “Top-Ranked” Failure Modes

Failure Mode	RPN
Incorrectly exporting films to record and verify system	160
Needing to re-mark patient after treatment shifts are made	160
Incorrect beams and energy are chosen	160
Inability to verify patient’s marks are valid for treatment	128
Incorrect treatment plan generated because of incorrect physician contours	100
Treatment plan and film are exported incorrectly to treatment machine	96
Simulation therapist creates incorrect patient file	96
Radiation therapist write patient setup information on paper leading to incorrect information	96
Therapists incorrectly re-mark patient because of shifts that were written incorrectly on paper	96
Incorrect verification by radiation therapists of paper setup instructions written at the time of simulation	80
Incorrect treatment plan generated because of incorrect beam placement by dosimetry	80
Dosimetrists export dose information to dose calculation program incorrectly	80
Radiation therapist shifts the patient’s position based on treatment plan incorrectly	80
Incorrect instructions on contrast administered to patient	75
Immobilization for patient is incorrect	75