RT Journal Article
SR Electronic
T1 Prospective Evaluation of Changes in Tumor Size and Tumor Metabolism in Patients with Advanced Gastric Cancer Undergoing Chemotherapy: Association and Clinical Implication
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 899
OP 904
DO 10.2967/jnumed.116.182675
VO 58
IS 6
A1 Seongyeol Park
A1 Seunggyun Ha
A1 Hyun Woo Kwon
A1 Woo Hyoung Kim
A1 Tae-Yong Kim
A1 Do-Youn Oh
A1 Gi Jeong Cheon
A1 Yung-Jue Bang
YR 2017
UL http://jnm.snmjournals.org/content/58/6/899.abstract
AB A change in tumor size is a well-validated and commonly used value for evaluating response to chemotherapy in cancer. Metabolic changes induced by chemotherapy are related to prognosis in several tumor types. However, the clinical implication of metabolic changes in patients with advanced gastric cancer (AGC) undergoing chemotherapy remains unclear. We aimed to evaluate response of tumor size and metabolism in AGC during chemotherapy and to reveal the relationship between them in view of their impact on patient survival. Methods: We prospectively enrolled patients with AGC before the initiation of first-line palliative chemotherapy. Using baseline and follow-up contrast-enhanced CT and 18F-FDG PET, we assessed the tumor diameter, SUVmax, and total lesion glycolysis in each lesion and their changes during chemotherapy at the same time. We included all lesions with the maximal longest diameters over 1 cm on CT, and each lesion was evaluated by matched 18F-FDG PET. We analyzed the association between changes in tumor metabolism and tumor size and performed outcome analysis on overall survival (OS) and progression-free survival (PFS). Results: Seventy-four patients were enrolled, and the number of all lesions included in this study was 620. Compared with adenocarcinomas, poorly cohesive carcinomas demonstrated lower SUVmax irrespective of tumor size (P < 0.001). Human epidermal growth factor receptor 2 (HER2)–positive tumors showed higher SUVmax than HER2-negative tumors (P = 0.002). The changes in SUVmax due to chemotherapy had a linear correlation with the changes in tumor size of each lesion, and a 30% tumor size reduction was associated with a 50% SUVmax reduction (P < 0.001). Total lesion glycolysis changes also correlated with tumor size changes (P < 0.001). Better OS and PFS were obtained in patients with both tumor size and SUVmax reduction than in patients with either size or SUVmax reduction only (OS, P = 0.003; PFS, P = 0.038). Conclusion: Changes in tumor metabolism induced by chemotherapy correlated with changes in tumor size in AGC. Considering both changes in metabolism and size could help predict a more accurate prognosis for AGC patients undergoing chemotherapy.