Impact of 18F FDG-PET/CT and Laparoscopy in Staging of Locally Advanced Gastric Cancer: A Cost Analysis in the Prospective Multicenter PLASTIC-Study.

BACKGROUND: Unnecessary D2-gastrectomy and associated costs can be prevented after detecting non-curable gastric cancer, but impact of staging on treatment costs is unclear. This study determined the cost impact of 18 F-fluorodeoxyglucose positron emission tomography/computed tomography (18F FDG-PET/CT) and staging laparoscopy (SL) in gastric cancer staging.

MATERIALS AND METHODS: In this cost analysis, four staging strategies were modeled in a decision tree: (1) 18F FDG-PET/CT first, then SL, (2) SL only, (3) 18F FDG-PET/CT only, and (4) neither SL nor 18F FDG-PET/CT. Costs were assessed on the basis of the prospective PLASTIC-study, which evaluated adding 18F FDG-PET/CT and SL to staging advanced gastric cancer (cT3-4 and/or cN+) in 18 Dutch hospitals. The Dutch Healthcare Authority provided 18F FDG-PET/CT unit costs. SL unit costs were calculated bottom-up. Gastrectomy-associated costs were collected with hospital claim data until 30 days postoperatively. Uncertainty was assessed in a probabilistic sensitivity analysis (1000 iterations).

RESULTS: 18F FDG-PET/CT costs were €1104 including biopsy/cytology. Bottom-up calculations totaled €1537 per SL. D2-gastrectomy costs were €19,308. Total costs per patient were €18,137 for strategy 1, €17,079 for strategy 2, and €19,805 for strategy 3. If all patients undergo gastrectomy, total costs were €18,959 per patient (strategy 4). Performing SL only reduced costs by €1880 per patient. Adding 18F FDG-PET/CT to SL increased costs by €1058 per patient; IQR €870-1253 in the sensitivity analysis.

CONCLUSIONS: For advanced gastric cancer, performing SL resulted in substantial cost savings by reducing unnecessary gastrectomies. In contrast, routine 18F FDG-PET/CT increased costs without substantially reducing unnecessary gastrectomies, and is not recommended due to limited impact with major costs.

TRIAL REGISTRATION: NCT03208621. This trial was registered prospectively on 30-06-2017.