EUS-guided Fine Needle Biopsy With a New Core Histology Needle Versus Conventional Fine Needle Aspiration
EUS-guided Fine Needle Biopsy With a New Core Histology Needle Versus Conventional Fine Needle Aspiration
Endoscopic ultrasound (EUS) is a well-established tool for the diagnosis and staging of many
 gastrointestinal conditions, including but not limited to, malignant and pre-malignant
 neoplasms of the pancreas, esophagus, rectum, and submucosal tumors developing along the
 gastrointestinal tract. EUS is the most sensitive test for the detection of focal lesions
 within the pancreas and is the most accurate method for diagnosing pancreas cancer. A biopsy
 method for tissue sampling via EUS called fine needle aspiration (FNA) was developed that
 enables a small needle to be passed into the lesion of interest under ultrasound guidance,
 obtaining cellular material for cytology. EUS-FNA is currently recommended for the diagnosis
 of cystic and solid mass lesions within and adjacent to the gastrointestinal tract. Yet in
 certain clinical circumstances, it is more desirable and sometimes necessary to obtain a core
 tissue biopsy for histology rather than the cellular material for cytology obtained with
 EUS-FNA. Furthermore, histology may generally increase the diagnostic yield of EUS-FNA
 compared to cytology. It is with these aims in mind that a new type of needle, the fine
 needle biopsy (EUS-FNB) device was developed to enable core tissue sampling. Since a
 comparison of these to methods has yet to be made, the aim of this study is to perform a
 direct comparison of the sampling adequacy and diagnostic yield of the new EUS-FNB needle
 with the conventional EUS-FNA needle.
Background:

 Endoscopic ultrasound (EUS) is a well-established tool for the diagnosis and staging of many
 gastrointestinal conditions, including but not limited to, malignant and pre-malignant
 neoplasms of the pancreas, esophagus, rectum, and submucosal tumors developing along the
 gastrointestinal tract. EUS provides endoscopic video imaging within the lumen of the
 gastrointestinal tract combined with ultrasound images via a transducer positioned at the tip
 of the endoscope. This diagnostic ability is enhanced by a biopsy method called fine needle
 aspiration (FNA). FNA via EUS (EUS-FNA) enables a small needle to be passed into a lesion of
 interest under ultrasound guidance, obtaining cellular material for cytology analysis.
 EUS-FNA is currently recommended for the confirmation of locally advanced pancreas
 adenocarcinoma, for the diagnosis of pancreatic cystic neoplasms and neuroendocrine tumors as
 well as autoimmune pancreatitis, for the characterization of submucosal tumors of the GI
 tract, and for the determination of malignant lymph node status in the staging of various
 cancers.

 While EUS-FNA has an impressive technical success rate between 90-95%, the diagnostic
 accuracy is less robust for mass lesions, and in particular for pancreatic masses, for which
 the sensitivity and specificity is 75% and 100% respectively, translating into a negative
 predictive value of only 72%. And in the setting of chronic pancreatitis, a condition that is
 itself a major risk factor for the development of cancer and in which focal, non-malignant
 nodules often develop that may mimic tumors, the sensitivity of EUS-FNA may only be 54-74%.
 The diagnostic accuracy of EUS-FNA is of particular importance for pancreas adenocarcinoma
 and pancreatic neuroendocrine tumors because the 5-year survival rates are only 5% and 32%
 respectively. Thus, it is crucial that patients found to have a focal mass lesion have a
 reliable test that effectively excludes malignancy. Currently, EUS-FNA does not have the
 necessary negative predictive value in order to do so because the sensitivity of the test is
 too low. This means that a positive result on FNA confirms malignancy but that a negative
 result is unable to exclude it with confidence. This conundrum tends to leave the patient in
 the unfortunate position of having to often return for multiple investigations to perform
 repeat EUS-FNA when the clinical suspicion for a mass lesion remains high but the cytology
 result is thought to be falsely negative.

 In order to overcome the current limitations of EUS-FNA cytology, the new EchoTip® ProCore™
 fine needle biopsy (FNB) needle was developed in order obtain core tissue samples for both
 histology and cytology. This is important because histology is expected to increase the
 diagnostic yield of EUS-guided biopsy compared to cytology. In addition, in certain clinical
 circumstances it is more desirable and sometimes necessary to obtain a core tissue biopsy for
 histology rather than cellular material for cytology obtained with EUS-FNA.

 In addition to the assessment of mass lesions in the pancreas, there are several other
 clinical areas in which the acquisition of core tissue samples for histology may prove
 superior to cytology from conventional EUS-FNA. For instance, EUS is part of the
 standard-of-care for the staging of esophageal cancer and histology may improve the
 sensitivity of EUS-biopsies for the determination of lymph node metastases. Also, although
 EUS is the preferred method for the work-up of submucosal lesions in the gastrointestinal
 tract, the value of EUS-FNA for differentiating the various subtypes of lesions is often
 limited, typically because FNA provides insufficient cellular material to reliably do so.
 Finally, it is clear that cytology from EUS-FNA is inadequate for the diagnosis of autoimmune
 pancreatitis and that a core biopsy sample for histology is needed. We expect the new
 EchoTip® ProCore™ FNB needle to potentially prove superior to FNA in all of these areas.

 Study Objectives The purpose of this study is to determine if the new EchoTip® ProCore™
 needle (FNB for histology) is superior to the current standard EchoTip® Ultra™ needle (FNA
 for cytology) for the diagnosis of focal, solid lesions for which biopsy sampling during EUS
 is clinically indicated. In particular, the objective is to compare the sampling adequacy of
 FNB with that of FNA for solid mass lesions within the pancreas, for submucosal lesions in
 the gastrointestinal tract and for the malignant status of lymph nodes as part of esophageal
 cancer staging. The sampling adequacy will be determined according to the ability of the
 pathologist to provide a definitive diagnostic interpretation based on the sample provided.

 Study Design This is a prospective, comparative trial examining the use of the new EchoTip®
 ProCore™ FNB needle with the existing EchoTip® Ultra™ FNA needle stratified by lesion type
 (solid pancreas lesion, intra-abdominal mass, submucosal tumor, suspected metastatic lymph
 node). Both the FNB and FNA needle will be used in each lesion with randomization to needle
 type for first pass, alternating subsequent passes; thus each lesion will serve as its own
 internal control.

 Methods Consecutive patients referred for EUS assessment of a solid lesion requiring FNA will
 be approached regarding study enrollment. Only those patients for whom EUS-FNA is clinically
 necessary will be selected. Consenting patients will undergo the standard EUS examination as
 indicated based on their lesion subtype, which will not differ from the EUS exam they would
 receive if they choose to not participate. Participating patients who have a lesion
 visualized during EUS that is technically amenable to FNA will then have their lesion
 biopsied by both FNB and FNA needles. The choice of needle size (19g or 22g) will be left to
 the clinical discretion of the endoscopist. However, the same needle size must be used for
 both the FNB and FNA needles.

 Patients will be randomized to the type of needle used for the first pass into the lesion,
 with subsequent passes alternating between needle types. For the EchoTip® ProCore™ FNB
 needle, if a good sample is obtained (as assessed by the endoscopist performing the EUS
 examination) with the first pass, no further passes will be made. If the sample obtained with
 the first pass is considered likely insufficient or if no tissue was acquired, a second pass
 will then be performed. Regardless of what is obtained after the second needle pass, no
 additional passes will be made using the FNB. The core tissue obtained by the FNB needle will
 be placed in formalin and sent for histology analysis.

 For the conventional EchoTip® Ultra™ FNA needle, a minimum of 2 passes will be performed. In
 cases in which a cytotechnologist is present, no feedback will be given to the endoscopist
 until after the 2nd pass. In cases where no cytotechnologist is present, up to 4 separate
 passes will be made, or fewer if the endoscopist is satisfied with the sample obtained. The
 sample obtained with the FNA needle will be placed on slides and also in cytology media
 (according to our standard clinical protocols).

 The histology and cytology specimens will be sent to the pathology department at each site
 where the interpretation of samples will be done in the usual fashion as per standard
 clinical care. The pathologist will first describe the biopsy specimen in terms of the
 "adequacy of the sample for pathologist interpretation" - i.e. the ability of the pathologist
 to provide a definitive diagnostic interpretation based on the sample provided. Next, the
 pathologist will provide the diagnostic interpretation itself.
Inclusion Criteria:

 -  Adult patient 18 years or older

 -  Able to read and write English

 -  Undergoing EUS for the evaluation of: i) pancreas mass ii) intra-abdominal mass iii)
 suspected submucosal tumor iv) esophageal cancer staging v) other lymph node
 assessment

 Exclusion Criteria:

 -  No detectable lesion

 -  lesion inaccessible to EUS guided biopsy

 -  Lesion determined to not require tissue sampling

 -  Pancreas lesion is predominantly cystic

 -  coagulopathy with a known clotting factor deficiency or an uncorrectable INR > 1.5,
 PTT > 40, platelet count < 50,000