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<p>Purpose: To test the ability of the TG-119 commissioning process and the IROC credentialing
to detect errors in the commissioning process for a commercial treatment planning
system.</p><p>Methods: We introduced commissioning errors into the commissioning process
for the Anisotropic Analytical Algorithm (AAA) within the Eclipse Treatment Planning
System (TPS). We included errors in MLC Dosimetric Leaf Gap (DLG), electron contamination
modeling parameters, incorrect flattening filter material, and beam profile measurement
with an inappropriately large farmer chamber (simulated using sliding window smoothing
of the input dose profiles). We evaluated the clinical impact of these errors for
a variety of clinical intensity modulated radiation therapy (IMRT) plans by looking
at PTV D99 and mean and max dose to OARs. The different cases included a head and
neck plan, low and intermediate risk prostate plans, a lung plan, and a scalp plan.
Finally, for the errors with substantial clinical impact, we determined the sensitivity
of the commissioning & credentialing processes with the TG119 C-shape and RPC IMRT
head and neck phantoms. This was determined by comparing plans before and after commissioning
errors were introduced in the commissioning process using the technique suggested
by each respective organization. IROC IMRT credentialing includes film analysis at
the midpoint between PTV and OAR using a 4mm distance to agreement metric along with
a 7% TLD dose comparison. The TG119 C-shape IMRT phantom looks at 3 separate dose
planes and using gamma criteria of 3% 3mm.</p><p>Results: The most clinically significant
commissioning errors came from large changes in the MLC DLG with a change of 1mm resulting
in up to a 5% change in the primary PTV D99. This resulted in a discrepancy in the
IROC TLDs in the PTVs and OARs of 7.1% and 13.6% respectively, which would have resulted
in detection. While use of incorrect flattening filter caused only subtle errors (<1%)
in clicnical plans, the effect was also most pronounced for the IROC TLDs in the OARs
(>6%). </p><p>Conclusion: The AAA commissioning process within the Eclipse TPS is
surprisingly robust to user error. When errors do occur, the IROC and T119 commissioning
credentialing criteria are effective at detecting them; however the OAR TLDs are the
most sensitive to errors despite the IROC currently excluding them from their analysis.</p>
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