Treatment of gastric cancer has evolved with the advent of randomized trials demonstrating chemotherapeutic agents with efficacy in advanced disease. Level I evidence supports delivering chemotherapy in the neoadjuvant setting; the data shows improvement in progression-free and overall survival. A clinical response to therapy is associated with improved R0 resection rates, pathologic response, and outcome in patients with locally advanced disease. Early assessment of metabolic response to therapy can potentially be utilized to tailor treatment.