  Background: Automatic treatment planning promises many benefits for both
research and clinical environments. For clinics, autoplanning promises to
reduce planning time and achieve more comparable treatment plans and thereby
reduce inter-planner variability. Further, it can assist clinicians in quality
assurance by providing a minimum plan quality standard. Finally, autoplanning
is an essential part of patient selection, which is crucial for the advancement
of proton therapy itself.
  Methods: A retrospective planning study using a cohort of 17 head-and-neck
cancer patients treated at our institute. The clinically accepted plans created
by dosimetrists (d-plans) were compared to automatically generated JulianA
plans (j-plans). Both methods used the same beam arrangement. The plans were
analysed by two expert reviewers without knowing how each plan was created.
They assessed the plan quality and stated a preference.
  Results: All of the j-plans were deemed rather or clearly acceptable,
resulting in a higher acceptability than the d-plans. The j-plan was considered
superior in 14 (82.4%) cases, of equal quality for 1 (5.9%) and inferior to the
d-plan for only 2 (11.8%) of the cases. The reviewers concluded that JulianA
achieves more conformal dose distributions for the 15 (88.2%) cases where the
j-plans were at least as good as the d-plans.
  Conclusions: The results show that the JulianA is ready to be used as a
clinical quality assurance tool and research platform at our institute. While
these results are encouraging, further research is needed to reduce the number
of spots further and introduce robustness considerations into the optimisation
algorithm in order to employ it on a daily basis for patient treatment.
