ABSTRACT
Background: Small bowel adenocarcinoma (SBA) is a rare malignancy that accounts for 3% of all gastrointestinal tumors. We evaluated the clinical characteristics, outcomes, and prognostic factors of primary SBAs. Methods: We retrospectively analyzed the clinicopathological features and clinical outcomes of 300 patients with SBA from three institutions in China between January 2003 and July 2020. Overall survival (OS) was analyzed using the Kaplan-Meier method and it was statistically compared using the log-rank test. Single-variable and multivariate analyses were used to identify the significant correlates of OS. Results: The primary tumor was on the duodenal papilla in 156 patients (52%), in the duodenum in 60 patients (20%), and in the jejunum-ileum in 84 patients (28%). The median OS of the entire cohort was 32.5 months (range, 0-213 months), with a 1-year OS rate of 78.0%. For jejunoileal adenocarcinoma, advanced age, advanced T stage, advanced N stage, more positive lymph nodes, distant metastasis, high carcinoembryonic antigen (CEA), and lymphocyte-to-monocyte ratio < 2.32 predicted worse survival on single-variable analysis. Multivariate analysis showed that advanced age, advanced tumor node metastases (TNM) stage, high CEA level, high alpha fetoprotein (AFP) level, and low prealbumin level were independent prognostic factors for non-ampullary SBA. The independent prognostic factors for duodenal papilla adenocarcinoma included TNM Stage III, nerve invasion, low platelet/lymphocyte ratio, and high CA19-9. Conclusion: We found different independent prognostic factors for tumors at different locations. This finding warrants further investigation to ensure more effective management strategies for SBA.
ABSTRACT
Distributed fiber sensing (DFS) can provide real-time signals and warnings. The entire length of fiber optic cable can act as a sensing element, but the accuracy is sometimes limited. On the other hand, point-to-point fiber sensing (PPFS) is usually implemented using one or more fiber Bragg gratings (FBGs) at specific positions along with the fiber for the monitoring of specific parameters (temperature, strain, pressure, and so on). However, the cost becomes expensive when the number of FBGs increases. A hybrid fiber sensing scheme is thus proposed, combining the advantages of DFS and PPFS. It is based on a Brillouin optical time-domain analysis (BOTDA) fiber system with additional FBGs embedded at certain positions where it is necessary to detect specific parameters. The hybrid fiber sensing system has the advantages of full sensing coverage at essential locations that need to be carefully monitored. In our work, the test results showed that the proposed system could achieve a sensing distance of 16 km with the single-mode fiber with a 2 m spatial resolution. For FBG parameter measurements, the temperature variation was 52 °C, from 25 °C to 77 °C, with a temperature sensitivity of 23 pm/°C, and the strain was from 0 to 400 µÎµ, with a strain sensitivity of 0.975 pm/µÎµ, respectively, using two FBGs.
