Preoperative PET or PET/CT for malignant diagnosis of Gastrointestinal stromal tumors: a systematic review and meta-analysis

Gastrointestinal stromal tumors (GISTs) are the most prevalent mesenchymal tumors of the gastrointestinal system; however, preoperative imaging for the accurate diagnosis of malignancy is unavailable. We conducted a meta-analysis to comprehensively confirm the value of preoperative Positron emission tomography (PET) in diagnosing the malignant potential of GISTs, aiming to guide preoperative preparation when biopsy is confined and prognostic evaluation for patients with localized primary GISTs after curative resection. PubMed, Web of Science, Cochrane Library, and Embase databases were systematically searched from database inception till June 1, 2025, to retrieve articles reporting the predictive value of preoperative PET or PET/CT for GISTs. Overall sensitivity (SEN) and specificity (SPE) with 95% confidence intervals (CI) using forest plots were estimated. The chi-square and I2 tests were used to analyze significant heterogeneity. QUADAS-2 and Deek funnel plots were constructed to assess publication bias risk. Subgroup analyses were performed to investigate the sources of heterogeneity. Fifteen studies including 568 patients with GISTs were included. The findings demonstrated overall SEN (0.86, 95% CI: 0.74–0.93), SPE (0.87, 95% CI: 0.75–0.94), positive likelihood ratio 6.80, 95% CI: 3.09–14.96), negative likelihood ratio (0.16, 95% CI: 0.07–0.34), and the area under the receiver operating characteristics curve (0.93, 95% CI: 0.91–0.95). Subgroup analysis indicated that with cut-off values at ≥ 5, the diagnosis could have a higher accuracy (sensitivity, specificity, and area under the curve values were 0.89, 0.92, and 0.96, respectively). Preoperative PET or PET/CT exhibited excellent diagnostic performance in predicting malignancy in GISTs and may be employed as an effective non-invasive imaging device for guiding preoperative preparation when biopsy is not possible and prognostic analysis for patients with localized primary GISTs who underwent radical surgery. Our protocol was registered in PROSPERO (CRD42024545100) on May 9th, 2024.