RESUMEN
Flare phenomenon refers to increased radiotracer uptake in bones despite clinical findings showing a positive response to treatment. Flare phenomena are most often observed in patients with breast or prostate cancer. Here, we present a case of bone flare in a 54-year-old male who had advanced gastric cancer with bone metastases. After three cycles of chemotherapy, a bone scan showed increased intensity, but the patient's bone pain was alleviated and abdominal computed tomography revealed a decrease in the size of the primary mass and metastatic lymph nodes. We therefore continued chemotherapy using the same regimen, and a follow-up bone scan revealed decreased intensity. A flare phenomenon after treatment is rare in cases of gastric cancer with bone metastasis. Although flare phenomena are not common, they should be considered in patients with gastric cancer when the clinical results are inconsistent with bone-scan findings.