Objective. In patients with advanced-stage epithelial ovarian cancer (EOC), a diagnostic laparoscopy (DLS) to determine treatment regime prevents futile laparotomies and seems cost-neutral. The... Show moreObjective. In patients with advanced-stage epithelial ovarian cancer (EOC), a diagnostic laparoscopy (DLS) to determine treatment regime prevents futile laparotomies and seems cost-neutral. The uptake of DLS in current practice is unknown. We evaluated the clinical application of routine DLS in treatment planning in patients with advanced-stage EOC in the Netherlands. Methods: The implementation was evaluated over the period 2017-2019, using a health technology assessment including clinical, organizational, and economic factors. Barriers for implementation were identified and DLS use was assessed using semi-structured surveys with healthcare professionals. Data from the Dutch Gynecological Oncology Audit were used to determine (un)successful CRS rates. To assess the economic impact, we performed a budget impact analysis (BIA) of the combined interventions of DLS and primary CRS. Results: The DLS use to guide treatment planning increased from 16% to 20%. The majority of the centers did not support routine DLS implementation, mainly because of logistic barriers and its invasive nature. The primary CRS rate of all CRS decreased from 44% to 36%, in favor of interval CRS. The unsuccessful primary CRS rate decreased from 15% to 9% resulting in fewer patients needed a second interval CRS. Consequently, total health care costs decreased from (sic)4.457.496 to (sic)4.274.751. Conclusions: The implementation of routine DLS for guiding treatment planning in patients with advancedstage EOC has limited support in the Netherlands. Over the years, total health care costs decreased. For current practice, it is advised that a DLS is useful in case it is uncertain whether a successful primary CRS is feasible based on conventional work-up. (C) 2022 Elsevier Inc. All rights reserved. Show less