The Diagnostic Utility of PET-CT for the Preoperative Evaluation of Lymph Node Metastasis in Gastric Cancer Patients

위암 환자의 수술 전 림프절 전이 평가를 위한 PET-CT의 진단적 유용성

Purpose: The purpose of this study was to assess the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting the lymph node (LN) metastasis of gastric cancer. Materials and Methods: 119 patients (M : F=89 : 30; mean age: 64) with gastric cancer were referred for preoperative FDG-PET/CT scanning and spiral enhanced abdominal pelvic CT from June 2006 to July 2008, and these were the subjects of our study. All the patients underwent curative radical gastrectomy and lymph node dissection. A final diagnosis was made for all the patients by the histology of the surgical specimens. Results: Both PET/CT and enhanced CT showed similar sensitivity for detecting regional lymph node metastasis (32.6% vs 39.5%, respectively). PET/CT was more accurate than enhanced CT for detecting regional lymph node metastasis (67.2% vs 63.0%, respectively), and PET/CT showed better specificity (86.8% vs 76.3, respectively) and a better positive predictive value (PPV) (58.3% vs 48.6%, respectively). PET/CT showed better specificity (98.0% vs 88.2%, respectively) and accuracy (79.4% vs 73.9%, respectively) than enhanced CT for detecting early gastric cancer. PET/CT showed better specificity (64.0% vs 52.0%, respectively), a better PPV (60.9% vs 57.1%), a better negative predictive value (NPV) (48.5% vs 46.4%, respectively) and better accuracy (53.6% vs 51.8%, respectively) than enhanced CT for detecting advanced gastric cancer. Conclusion: FDG-PET/CT is more usefulness than enhanced CT for making the preoperative diagnosis of regional LN metastases from gastric cancers.

목적: PET-CT가 림프절 전이를 발견하는데 있어 그 정확도를 조사하여 수술 전 진단 도구로써의 유용성을 평가하였다. 대상 및 방법: 2006년 6월부터 2008년 7월까지 원주기독병원에서 위암으로 수술 전 복부(위)전산화단층촬영술 및 PET-CT를 시행 후 근치적 위절제술을 시행한 환자를 대상으로 복부(위)전산화단층촬영술과 PET-CT의 민감도, 특이도, 양성예측률, 음성예측률 그리고 정확도를 비교 평가하였다. 결과: 전체 119명의 PET-CT의 민감도는 32.6%, 복부(위)전산화단층촬영술의 민감도는 39.5%였다. 특이도는 PET-CT 86.8%였으며 복부(위)전산화단층촬영술은 76.3%였다. 양성예측률은 PET-CT 58.3%, 복부(위)전산화단층촬영술 48.6%, 음성예측률은 PET-CT 69.5%, 복부(위)전산화단층촬영술 69.0%였다. 정확도는 PET-CT 67.2%, 복부(위)전산화단층촬영술 63.0%였다. 조기 위암의 경우 PET-CT와 복부(위)전산화단층 촬영술의 특이도는 98.0%와 88.2%, 음성예측률 80.6%와 80.4%, 정확도 67.2%와 63.0%이었다. 진행성 위암인 경우에는 PET-CT와 복부(위)전산화단층촬영술의 민감도는 45.2%와 51.6%, 특이도 64.0%와 52.0%, 양성예측률 60.9%와 57.1%, 음성예측률 48.5%와 46.4%, 정확도 53.6%와 51.8%였다. 결론: 수술 전 PET-CT를 이용한 림프절 전이 여부 평가는 복부(위)전산화단층촬영술에 비해 치료 지침을 결정하는데 더 많은 도움을 줄 수 있을 것으로 사료된다.