TABLE I.

Summary of failure modes analyzed for FMEA.

Potential failure modes

Simulation

Incorrect/inadequate immobilization, patient preparation or documentation

Faulty image data

Data transfer (images and other DICOM data)

Errors in data transfer between imaging systems and TPS (human, software, hardware)

Treatment planning directive (MD orders)

Incorrect/inadequate specification of image sets, protocols, registration goals, guidelines, dose limits, or fractionation for planning or delineation

Incorrect/inadequate documentation of previous treatments

TP anatomy

Errors in image import and registration

Incorrect/inadequate critical and target structure delineation and construction

Inaccurate density map/correction

Errors in creating, using, editing, or saving anatomical models

Incorrect/inadequate dose point definitions

Treatment planning

Incorrect/inappropriate region of interest (ROI) volumes for optimization

Incorrect/incomplete/inappropriate prescription, objectives, planning/treatment techniques, beam energy, machine, isocenter, or dose calculation parameters

Errors in optimization, dose calculation, heterogeneity correction, leaf sequencing, or plan evaluation

Plan approval and preparation

Bad or incorrect plan approved

Incorrect/inadequate localization images and protocols planned

Errors in plan information indicated for treatment

Treatment

Patient medical condition changes between prescription and treatment

Incorrect patient, records, plan data, isocenter, position, treatment parameters/accessories

Errors in setup, immobilization, localization, treatment parameter data, machine operation, or treatment delivery