Early Treatment Response Evaluation Using 31P MRSI at 7T in Liver Metastases of 4 Patients With Gastroesophageal Cancer Given Systemic Treatment

Motivation: Patients with metastatic gastroesophageal cancer(GEC) have a poor prognosis. Timely treatment response evaluation could prevent continuation of ineffective treatment and improve quality of life. Goal(s): To compare treatment-induced changes in 31P MRSI PME/PDE ratios in liver metastases of GEC between baseline and after 2 weeks of treatment with CT-based response evaluation at 9 weeks. Approach: Four patients with liver metastases of GEC who received first-line systemic therapy underwent 31P MRSI at 7 Tesla at baseline and after 2 weeks of treatment. Results: Poor response at 9 weeks was associated with increased PME/PDE after 2 weeks, whereas good response was associated with decreased PME/PDE. Impact: This study shows promising results of 31P MRSI to evaluate systemic therapy response after only 2 weeks in patients with liver metastases of gastroesophageal cancer.