The additive value of restaging-CT during neoadjuvant chemotherapy for gastric cancer

Computed tomography (CT) is used for restaging of gastric cancer patients during neoadjuvant chemotherapy (NAC). The treatment strategy could be altered after detection of distant interval metastases, possibly leading to a reduction in unnecessary chemotherapy cycles, its related toxicity, and surgical procedures. The aim of this study was to evaluate the additive value of restaging-CT during NAC in guiding clinical decision making in gastric cancer.

This retrospective, multicenter cohort study identified all patients with surgically resectable gastric adenocarcinoma (cT1-4a-x, N0-3-x, M0-x), who started NAC with curative intent. Restaging-CT was performed after 2 out of 3 cycles of NAC. The primary outcome was treatment alterations made based on restaging-CT by a multidisciplinary tumor board. Confirmation of metastases was obtained by surgery or biopsy.

Between 2007 and 2015, CT-restaging was performed in 122 out of 152 included patients and timed after 2 cycles (n = 76) or after 3 cycles (n = 46) of NAC. Restaging-CT revealed a metastasis in 1 out of 122 restaged patients (1%) after which surgical resection was omitted, whereas 4 patients (3%) with distant interval metastases were not identified by restaging-CT and underwent a futile laparotomy. In 5 out of 76 patients (7%) disease progression was detected while undergoing NAC, leading to omission of the 3rd cycle of chemotherapy.

The additive value of restaging-CT during NAC in gastric cancer is limited in guiding clinical decision making and therefore not recommended. Further studies may identify subgroups that may benefit of alternative diagnostic modalities.