Role of the standardized uptake value of 18-fluorodeoxyglucose positron emission tomography–computed tomography in detecting the primary tumor and lymph node metastasis in colorectal cancers

• Published in: Surgery today (Tokyo, Japan) Japan), 2012-10, Vol.42 (10), p.956-961
• Main Authors: Uchiyama, Shuichiro, Haruyama, Yukihiro, Asada, Takashi, Hotokezaka, Masayuki, Nagamachi, Shigeki, Chijiiwa, Kazuo
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - diagnostic imaging; Adenocarcinoma - pathology; Adult; Aged; Aged, 80 and over; Colorectal Neoplasms - diagnostic imaging; Colorectal Neoplasms - pathology; Female; Fluorodeoxyglucose F18; Humans; Lymphatic Metastasis; Male; Medicine; Medicine & Public Health; Middle Aged; Multidetector Computed Tomography; Multimodal Imaging; Neoplasm Grading; Neoplasm Invasiveness; Neoplasm Staging; Original Article; Positron-Emission Tomography; Radiopharmaceuticals; Sensitivity and Specificity; Surgery; Surgical Oncology; Tomography, X-Ray Computed; Tumor Burden
• ISSN: 0941-1291; 1436-2813
• DOI: 10.1007/s00595-012-0225-6

Purpose To assess the role of positron emission tomography–computed tomography (PET–CT) and multidetector-row CT (MD-CT) in detecting the primary lesion and lymph node metastasis in patients with colorectal cancers. Methods A collective total of 80 lesions resected from 77 patients were examined pathologically. We analyzed the significance of the standardized uptake value (SUV) and its relationship with the clinicopathologic findings of primary lesions and lymph node metastasis. The detectability of primary lesions and lymph node metastases on PET–CT images was compared with that on MD-CT images. Results The detectability of primary lesions was better on PET–CT images than on MD-CT images ( p  = 0.0023). We observed no significant differences in the SUV with respect to staging, tumor grade, lymphatic or vessel invasion, and macroscopic type; however, primary tumor size analysis revealed that tumors larger than 3 cm had a higher SUV than those smaller than 3 cm. The sensitivity of PET–CT for detecting lymph node metastasis was lower than that of MD-CT, but the specificity of PET–CT was higher than that of MD-CT. Conclusions The SUV of primary cancers tends to increase in proportion to tumor size. Although the value of PET–CT in detecting lymph node metastasis is limited, PET -positive lymph nodes can be considered metastatic.