ESTRO 2023 - Abstract Book

S1368

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ESTRO 2023

criteria, slip factors). After training, the same parameters were then used to validation study of slightly more plans with a few prescription schemes and corresponding clinical criteria and compared with manual plans. Those parameter templates were then clinically implemented to plan that disease site with widely different prescription scheme and can easily adapt to changing clinical practice. If the clinical prescription schemes or criteria are modified moderately, ECHO can easily adjust to those clinical changes.

From 4/2017 to 10/2022, over 6000 patients underwent radiotherapy using 6764 ECHO produced plans. Figure 1 shows treated ECHO plans for different disease sites. PTV s varied greatly with median 91 cc (range 1.0 - 1854). The median time to produce one ECHO plan was 27 minutes (range 7 - 201) mainly depending on the PTV and patient size.

Table 2 summarize the performance of ECHO for each disease site. Disease Site Only one Run (%) Had 2 Runs (%) Had > 2 Runs (%) #1 rerun reason

#2 rerun reason

Paraspinal 63 Oligomets 80

17 12

20

some criteria not met beam modified

8 7

beam modified

criteria changed

Prostate

88 61

5

some criteria not met contour modified

Lung

20

19

criteria changed

beam modified

Conclusion