Radiomics signature for prediction of long-term survival and recurrence patterns in patients with gastric cancer after radical gastrectomy: A multicenter study.

Background: This study aimed to develop and validate a radiomics score to predict the long-term survival and patterns of recurrence of gastric cancer (GC). Methods: A total of 513 patients who underwent radical gastrectomy for GC after curative resection between 2008 and 2016 at two institutions were analyzed. A radiomics score was generated using the least absolute shrinkage and selection operator Cox regression model on 327 patients and was validated in 186 patients. A nomogram consisting of the radiomics score and clinicopathological factors was created and compared with the tumor-lymph node-metastasis (TNM) staging system. Model performance was assessed using calibration, discrimination, and clinical usefulness. Results: The radiomics score was established based on five selected features. A higher score was significantly associated with poorer recurrence-free survival (RFS) and overall survival (OS) rates, both in the training and validation cohorts (P < 0.05). Multivariate analysis demonstrated that the radiomics score was an independent prognostic factor for both RFS and OS (P < 0.05). A nomogram incorporating the radiomics score had a significantly better prognostic value than the TNM system alone. Moreover, a high score was significantly associated with an increased risk of distant recurrence, a medium score was significantly associated with an increased risk of peritoneal recurrence, and a low score was significantly associated with an increased risk of locoregional recurrence, in the entire cohort (P < 0.05). Conclusions: The newly proposed radiomics score may be a powerful predictor of long-term outcomes and recurrence patterns of GC. Further studies are warranted to confirm these findings.

Intentional Replantation for a Right Mandibular Premolar.

The present study reports a case of intentional replantation (IR) for a right mandibular second premolar (#45). For the present case, root canal retreatment was first considered after removal of the metal post and core. When the metal post and core could not be removed from #45, micro-apical surgery or intentional tooth replantation was performed. Six-month postoperative evaluation revealed that the right mandibular second premolar had no obvious symptoms of discomfort, and the clinical follow-up revealed uneventful healing and good bone regeneration. The short-term clinical efficacy was acceptable. For cases with root canal treatment failure, when the apical surgical access could not be established due to the adjacent important anatomical structures, IR may be employed as an accepted endodontic treatment procedure. Key Words: Root canal treatment failure, Post-core crown, Root canal retreatment, Intentional replantation.