Gadolinium-Loaded Solid Lipid Nanoparticles for Colorectal Tumor in MR Colonography

The current study aims to investigate the possibility of using solid lipid nanoparticles (SLNs)-enhanced magnetic resonance (MR) colonography to diagnose colorectal cancer. Gd-FITC-SLNs were synthesized by loading gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) and fluorescein isothiocyanate (FITC) simultaneously. Twenty mice received azoxymethane/dextran sulfate sodium (AOM/DSS) to induce adenocarcinoma of the colon and were divided into 4 groups, and 5 in per group. MR colonography were performed at different time periods before and after enema or intravenous injection of Gd-FITC-SLNs or Gd-DTPA. The results demonstrated SNR (signal-to-noise ratio) significantly increased from 1.56- to 1.76-fold within the colorectal tumors after the enema of Gd-FITC-SLNs (p < 0.001). No differences in SNR were observed after the enema of Gd-DTPA (p > 0.05). Besides, SNR increased from 1.54- to 1.72-fold within the colorectal tumors after the intravenous injection of Gd-FITC-SLNs (p < 0.001) while SNR increased from 1.39to 1.57-fold within the colorectal tumors after the injection of Gd-DTPA (p < 0.001). In addition, SNR within colorectal tumors significantly increased ranging from 20th to 140th min, and lasted for about 120 min (p < 0.05) after the enema of Gd-FITC-SLNs and SNR within colorectal tumors also significantly increased ranging from 0th hour to 8th hour, lasted for about 8 hour (p < 0.05) after the injection of Gd-FITC-SLNs. However, after the injection of Gd-DTPA, SNR within colorectal tumors significantly increased only ranging from 0th min to 20th min after administration (p < 0.01). Furthermore, hematoxylin and eosin (H&E) staining revealed that all mice developed adenocarcinoma of the colon. In summary, it is feasible by using Gd-FITC-SLNs in MR colonography to diagnose colorectal cancer. Enema of Gd-FITC-SLNs can provide marked enhancement of colorectal tumors quickly, and safer while intravenous injection of Gd-FITC-SLNs can provide a long-lasting enhancement of colorectal tumors in MR colonography. These findings present a potential clinical application of Gd-FITC-SLNs on MR colonography.

A prospective comparative study of detection of colonic polyposis by magnetic resonance colonography versus conventional colonoscopy

Background: Colorectal cancer mostly arises from adenomatous polyp and the transition time to convert into carcinoma is around ten years. As the progress to adenocarcinoma is a slow process so, early detection and endoscope resection is claimed to be effective in decreasing incidence and mortality by colorectal cancer. MR colonography is a non-invasive method for evaluating entire colon. It can detect precancerous lesion, cancer and staging. It is non-invasive tool for screening. Acceptability of the patient is better for MR colonography.Methods: Present study is a prospective comparative evaluation of magnetic resonance colonography verses colonoscopy conducted in the Department of Radiology, Konaseema Institute of Medical Science, and other establishments from August 2015 to January 2018. The sample size was calculated to be 112. Specificity, sensitivity and predictive value were calculated by medical statistical software.Results: For all size of tumours, sensitivity was 85.71%, specificity was 92.85%, positive predictive value was 92.30%, negative predictive value was 86.66% and accuracy was 94.34%. The positive predictive value was 90.00% negative predictive value was 92.68% and accuracy was 92.16%. For 1 mm to 4 mm size of polyp the sensitive was 28.57%, specificity was 92.31%, positive predictive value was 66.67%, negative predictive value was 70.59% and accuracy was 70%.Conclusions: In present study we have found that there was male predominance in patient and gastrointestinal bleeding was common clinical presentation. We have also observed that all size of poly MR colonography as having sensitivity and specificity around 90% but MR colonography is highly sensitive and specific for polyp size above 8mm but it is less sensitive for size below 4 mm.

Health economic aspects of evaluation with diffusion weighted MR and MR colonography compared to standard evaluation with colonoscopy and CT before rectal cancer surgery

Background Colorectal cancer is a frequent type of cancer, and with the risk of synchronous disease, the need for a complete staging leads to an extensive and costly preoperative diagnostic evaluation. Previously we described a total preoperative evaluation using magnetic resonance (MR) colonography and diffusion-weighted MR of the liver. Purpose To compare the economic aspects of this modality with the standard evaluation in an analysis of the different cost drivers. Material and Methods Based on the results from previous studies, two calculations were performed, a theoretical cost calculation and a practical cost calculation. The cost drivers utilized are an average cost based on the cost of all procedures and diagnostic modalities performed in hospitalized patients (DRG) and outpatients (DAGS [Danish outpatient grouping system]) in Denmark. Results The total cost for a full colorectal evaluation and computed tomography (CT) scan of the thorax/abdomen was less for the new modality group in all theoretical models proposed; €225 using model A, €322 using model B, and €383 using model C. Using results from previous studies, the actual difference and the potential difference in cost between the two preoperative diagnostic modalities per patient were €312 and €712, respectively. Conclusion This cost analysis shows the cost effectiveness of the new modality as the future standard preoperative diagnostic work-up by reducing total cost and by having a higher sensitivity and completion rate.