Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis

Abstract

The diagnostic values of diffusion weighted imaging (DWI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for N-staging of gastric cancer (GC) were identified and compared. After a systematic search to identify relevant articles, meta-analysis was used to summarize the sensitivities, specificities, and areas under curves (AUCs) for DWI and PET/CT. To better understand the diagnostic utility of DWI and PET/CT for N-staging, the performance of multi-detector computed tomography (MDCT) was used as a reference. Fifteen studies were analyzed. The pooled sensitivity, specificity, and AUC with 95% confidence intervals of DWI were 0.79 (0.73–0.85), 0.69 (0.61–0.77), and 0.81 (0.77–0.84), respectively. For PET/CT, the corresponding values were 0.52 (0.39–0.64), 0.88 (0.61–0.97), and 0.66 (0.62–0.70), respectively. Comparison of the two techniques revealed DWI had higher sensitivity and AUC, but no difference in specificity. DWI exhibited higher sensitivity but lower specificity than MDCT, and 18F-FDG PET/CT had lower sensitivity and equivalent specificity. Overall, DWI performed better than 18F-FDG PET/CT for preoperative N-staging in GC. When the efficacy of MDCT was taken as a reference, DWI represented a complementary imaging technique, while 18F-FDG PET/CT had limited utility for preoperative N-staging.

Diffusion-Weighted Imaging in Oncology: An Update

“…However, Cai et al have recently proposed a reduced field-of-view DWI to yield better image quality and more accurate ADC measurements [ 48 ]. Further, Further, DWI has proven to be accurate in detecting nodal locations of gastric cancer in pre-operative staging (sensitivity, specificity, and accuracy of 79%, 69%, and 81%, respectively), being even superior to PET/CT [ 49 ].…”

Evidence-Based PET for Abdominal and Pelvic Tumours

“…Seven meta-analyses analysed the role of 18 F-FDG PET/CT in gastric cancer [15][16][17][18][19][20][21]. Three meta-analyses found a good accuracy in a staging setting, but with low sensitivity in detecting lymph nodal (N) involvement [15,19,21]. Conversely, other meta-analyses showed a good accuracy in a restaging setting [17,18,20].…”

Is Accurate N – Staging for Gastric Cancer Possible?

“…Compared with MDCT, MRI presents similar diagnostic accuracy, specificity and sensitivity ( 15 ). Compared with PET, MRI presents better specificity but inferior sensitivity ( 16 ). While most studies suffer from limitations such as small sample size, heterogeneity in used technique, non prospective character or measurement in different samples, they also establish MRI role in gastric cancer staging, particularly N staging.…”

“…Sensitivity for N1 disease is low ranging from 18–46% ( 20 ) Furthermore PET scan has a lower tracer accumulation for diffuse and mucinous cancer types, both common in gastric cancer, and associated with a worse prognosis ( 21 ). According to a recent meta – analysis PET sensitivity for N – staging is 52% and specificity is 88% ( 16 ). PET accuracy remains low as N-stage increases, with sensitivity ranging between 33–46% for N2 and 44–63% for N3 disease ( 20 ).…”