Multicriteria plan optimization in the hands of physicians: a pilot study in prostate cancer and brain tumors

Abstract

BackgroundThe purpose of this study was to demonstrate the feasibility of physician driven planning in intensity modulated radiotherapy (IMRT) with a multicriteria optimization (MCO) treatment planning system and template based plan optimization. Exploiting the full planning potential of MCO navigation, this alternative planning approach intends to improve planning efficiency and individual plan quality.MethodsPlanning was retrospectively performed on 12 brain tumor and 10 post-prostatectomy prostate patients previously treated with MCO-IMRT. For each patient, physicians were provided with a template-based generated Pareto surface of optimal plans to navigate, using the beam angles from the original clinical plans. We compared physician generated plans to clinically delivered plans (created by dosimetrists) in terms of dosimetric differences, physician preferences and planning times.ResultsPlan qualities were similar, however physician generated and clinical plans differed in the prioritization of clinical goals. Physician derived prostate plans showed significantly better sparing of the high dose rectum and bladder regions (p(D1) < 0.05; D1: dose received by 1% of the corresponding structure). Physicians’ brain tumor plans indicated higher doses for targets and brainstem (p(D1) < 0.05). Within blinded plan comparisons physicians preferred the clinical plans more often (brain: 6:3 out of 12, prostate: 2:6 out of 10) (not statistically significant). While times of physician involvement were comparable for prostate planning, the new workflow reduced the average involved time for brain cases by 30%. Planner times were reduced for all cases. Subjective benefits, such as a better understanding of planning situations, were observed by clinicians through the insight into plan optimization and experiencing dosimetric trade-offs.ConclusionsWe introduce physician driven planning with MCO for brain and prostate tumors as a feasible planning workflow. The proposed approach standardizes the planning process by utilizing site specific templates and integrates physicians more tightly into treatment planning. Physicians’ navigated plan qualities were comparable to the clinical plans. Given the reduction of planning time of the planner and the equal or lower planning time of physicians, this approach has the potential to improve departmental efficiencies.

Automation in intensity modulated radiotherapy treatment planning—a review of recent innovations

“…100 The quality of plans generated by Auto-Planning in Pinnacle has also been reported to be dependent on the input from experience treatment planners to set the initial user settings and define good clinical protocols which are also an important consideration. 100 Multicriteria optimization A posteriori MCO clinical implementations (all in RayStation) have been investigated and validated in different clinical sites including prostate cancer, 168,169,171,176,179 head and neck cancer, 164,171 brain, 168 lung cancer, 172 and lower GI cancers. 177 All studies report better or comparable plan quality with a reduction of planning time.…”

“…Muller et al report a reduction in planning time by around 10 min for post-prostatectomy cases and 45 min for brain tumour cases. 168 Chen et al used MCO to generate 20 field IMRT plans for prostate cancer and head and neck cancer to then use the resulting DVH information as the basis for defining optimisation objectives for VMAT plan optimisation. Using this method, they were able to match the quality of single arc VMAT with the quality of a 20 field IMRT plan (where there is high quality due to the large degree of freedom).…”

“…Müller et al investigated this retrospectively in prostate and brain cancer planning and demonstrated potential time savings, but further prospective studies are required. 168 In the context of a technique like a posteriori MCO, how the clinician and planner role will evolve will likely vary between different countries. For example in the UK, the Clinical Oncologists are responsible for administering both radiotherapy and other non-surgical treatments such as chemotherapy whereas in other countries there is a different approach with Radiation Oncologists who are more focused in radiotherapy.…”

Voxel-based automatic multi-criteria optimization for intensity modulated radiation therapy

“…These factors represent the importance of specific organs that are difficult to assign before optimization. Therefore, the dosimetrists must manually tune these parameters through a trial-and-error process [ 6 – 8 ], which leads to a time-consuming planning procedure; moreover, the final plan’s quality highly depends on dosimetrist’s experience [ 9 – 11 ].…”

Utilisation of Pareto navigation techniques to calibrate a fully automated radiotherapy treatment planning solution

“…Secondly, an automated solution was derived in a time efficient manner with minimal trial and error. These advantages have been demonstrated on a per-patient basis by a number of studies [22,25,26] and this work indicates that similar benefits can be realised by applying this technique at a patient cohort level.…”