Role of EUS in Detection of Liver Metastasis
Condition: Liver Metastases; Pancreatic Neoplasms
MeSH terms: Neoplasm Metastasis; Liver Neoplasms; Pancreatic Neoplasms
Study type: Observational

Summary: 
      Liver metastasis may not be detected by CT and MRI due to their small size while they can be
      detected by EUS. Also, EUS-FNA has a great impact in improving the diagnostic accuracy of
      EUS. Objectives: To assess the feasibility of EUS in the detection of occult small hepatic
      focal lesions at the time of primary tumor staging, not seen by CT or MRI.
    

Detailed description: 
      Endoscopic ultrasound (EUS) was used firstly in 1980s as a diagnostic imaging technique for
      pancreatic lesions. It has the ability to detect the histological layers of the
      gastrointestinal (GI) tract wall as well as the periluminal structures.

      EUS has been used to perform FNA from lesions that are difficult to access by conventional
      methods. EUS has the advantage of using both ultrasound and endoscopy to give the exact
      diagnostic features of the GI tract. The use of EUS was not limited to visualization only,
      but also in obtaining tissue biopsy for diagnostic purpose through EUS guided fine needle
      aspiration (FNA), and it has played a major role in revolutionizing the diagnosis of focal
      hepatic lesions as it is a minimally invasive procedure.

      Abdominal imaging [CT, magnetic resonance imaging (MRI), and transabdominal ultrasonography
      (USG)] are the diagnostic tests of choice to detect hepatic lesions suspicious of
      metastasis.Unfortunately, these modalities are limited in their ability to detect hepatic
      lesions less than 1 cm.

      In addition, although rare, percutaneous FNA for suspected metastatic lesions carries the
      risk of implantation metastasis. Although unable to completely visualize the entirety of the
      liver, EUS can detect small hepatic lesions that may be otherwise missed by conventional
      imaging. EUS can delineate detailed anatomy of the liver from the trans-gastric and
      trans-duodenal routes with the exception of the right posterior segments.

      The prospect to obtain precise, ultrasound-guided biopsies of possible metastatic liver
      lesions can drastically alter the therapeutic conduct.

      This, combined with limited adverse events, makes EUS an excellent modality to allow staging
      in malignant conditions. Due to the vicinity of the transducer to the liver, EUS provides
      detailed images of the liver segments and its vascular structures.

      Based on the premise that EUS is more sensitive for the detection of small hepatic lesions
      then CT/MRI, Singh et al. proved that EUS was superior to CT scan (98% vs 92%, respectively)
      in diagnostic accuracy in its ability to detect the number of metastatic lesions in the liver
      and correctly diagnose the nature of the lesions .(Singh P etal.,2009) Endoscopic
      ultrasonography (EUS) has become an indispensable method for diagnosis and therapeutic
      procedures in gastroenterology and as experience with this technique is growing, new
      indications for EUS continue to emerge.

      (Saraireh HA .,2017) Furthermore, the use of on-site cytopathology interpretation has further
      improved the diagnostic yield of EUS-FNA by helping to ensure that the samples obtained are
      representative of the target organ and adequate for diagnostic purposes.

      Objectives: To assess the feasibility of EUS in detection of occult small hepatic focal
      lesions at the time of primary tumor staging, not seen by CT or MRI

      All the patients will be subjected to:

        1. Thorough history talking including;

             -  Age

             -  Sex

             -  Comorbidity

        2. Clinical general and local abdominal examination

        3. Abdominal US & CT abdomen

        4. laboratory investigations:

             1. complete blood count (CBC)

             2. Prothombin time ,INR

             3. Ceatinine , Urea

             4. Albumin

             5. ALT , AST

        5. Virological test for HIV, HCV and HBV

        6. CA-19-9 and alfa fetoproteins.

        7. EUS will be done to all patients. During EUS examination the liver will be examined
           thoroughly to detect hepatic focal lesions with possible EUS-FNA of any detected
           lesions.

      All EUS examination with be done by EUS linear array Echoendoscope, Pentax EG-3870UTK
      attached to Hitachi Avius US machine under Propofol deep sedation.

      The collected data will be organized and statistically analyzed.

      Data collection tool:

      Data including study design, participant demographics, stage and type of pancreatic and GI
      malignancy will be extracted and recorded on electronic data collection sheet. Data will be
      pooled for various arms in trials: Individual data for each outcome were entered into the
      Comprehensive analysis. Pooled effects with 95%CI will be reported. Data will be analyzed
      separately for each arm.
    

Intervention name(s): Endoscopic ultrasound ( EUS )
Intervention type(s): Diagnostic Test
Intervention description(s): - EUS will be done to all patients. During EUS examination the liver will be examined thoroughly to detect hepatic focal lesions with possible EUS-FNA of any detected lesions.
All EUS examination will being done by EUS linear array Echoendoscope, Pentax EG-3870UTK attached to Hitachi Avius US machine under Propofol deep sedation
Other intervention name(s): EUS-FNA ( fine needle aspiration )
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        400 pt , both male and female above 12 years All patients diagnosed with either pancreatic
        or gastrointestinal tumors and have undergone a CT scan of the abdomen with contrast or MRI
        before being referred for EUS for staging
      
Keywords: EUS; occult metastases