We read with great interest the original research article by Dr. Chen et al. [1] whose aim was to evaluate the value of preoperative CT features for predicting the disease-free survival (DFS) after curative resection for patients with primary gastric GISTs (gastrointestinal stromal tumor). We have some questions and doubts regarding certain aspects of this study.

Firstly, within 30 days before resection the patients underwent dual-phase contrast-enhanced CT examination and later the authors refer to plain phase images which in my presumption refer to the same (former). We wonder whether the point in time at which this dual-phase contrast-enhanced CT was conducted has had a significant influence on the study results, since it did not consider a CT exam conducted very close to the day of surgery. Moreover, after surgery, patients underwent contrast-enhanced abdominal and pelvic CT examination every 6–12 months for the first 3 years and then annually. What was the reason for using dual-phase contrast enhancement before surgery but normal contrast-enhanced CT for follow-up? (Since we extracted imaging features and analyzed from the follow-up studies).

Furthermore, we noted that calcification and hemorrhage were manually excluded. The purpose behind this step is unclear to us. We wonder whether this is performed to avoid interfering with the results of this study.

Next, it is not clear to us whether the histopathological diagnosis referred to in the article refers to endoscopic preoperative diagnosis or postoperative histopathologic analysis. Possibly, the histopathology reports can provide more information of regarding the enhancing regions which could in turn be used to direct future nuclear medicine studies.

Finally, in table 3, we are curious to know why multivariate analysis was only performed for serosal invasion and enhancing tissue volume but not for the other parameters. We would very much appreciate if the authors could give their stance/opinion with regards to the above so as to get these doubts clarified.

Thank you.