Chronic GI Research Articles

S754 Difference in Healthcare Outcomes Between Patients With Chronic GI Conditions and Psychiatric Comorbidities

S754 Difference in Healthcare Outcomes Between Patients With Chronic GI Conditions and Psychiatric Comorbidities

Validation of a Hand-Held Point-of-Care Device to Measure Breath Hydrogen and Its Utility in Detecting Response to Antibiotic Treatment.

Breath testing for small intestinal bacterial overgrowth (SIBO) is typically performed using clinic-based equipment or single-use test kits. This study aimed to evaluate the utility of a portable, point-of-care breath analysis device (AIRE®, FoodMarble) in patients suspected to have SIBO. A technical assessment including a comparison to existing mail-in kits was first performed. Then, postprandial breath hydrogen levels of patients before and after antibiotic treatment were gathered and compared to levels seen in a healthy cohort. For the comparison, 50 patients suspected of having SIBO were provided with an AIRE device and performed concurrent LHBTs at-home with a mail-in breath test kit. For the postprandial analysis, twenty-four patients with chronic GI symptoms measured their postprandial hydrogen for 7days prior to antibiotic treatment and for 7days after treatment. 10 healthy controls also measured their postprandial hydrogen for 7days. Substantial agreement was demonstrated between AIRE and the mail-in kits for the performance of lactulose hydrogen breath tests (κ = 0.8). Prior to treatment, patients had significantly greater daily postprandial hydrogen than healthy controls (p < 0.001). The mean postprandial hydrogen of patients reduced significantly after treatment (p < 0.001). Measuring postprandial hydrogen shows potential as a means of differentiating patients with chronic GI symptoms from healthy controls and may be useful in monitoring patients before, during, and after treatment. Future studies could help determine if pre-treatment breath gas levels are predictive of response to antibiotic treatment.

Diagnostic Yield of Same Setting Oesophago-Gastro-Duodenoscopy (OGD)and Colonoscopy for Pediatric Patients with Chronic Diarrhea

Abstract Background In patients with unexplained chronic diarrhea colonoscopy and upper GI endoscopy are helpful in the diagnosis. It is the routine practice in Ain Shams University pediatric endoscopy unit to perform both procedures at same setting for patients with unexplained chronic diarrhea. Aim of the Work To find out whether doing Oesophago-gastro-duodenoscopy (OGD) and colonoscopy in patients with chronic diarrhea in one setting is essential for the diagnosis of all cases. Patients and Methods Fifty patients presenting with chronic unexplained diarrhea (&amp;gt;4 weeks duration) in Paediatric Gastroenterology Unit, Children’s Hospital, Ain-Shams University were enrolled. After full history taking, physical examination, both endoscopies were performed biopsy taken and histopathological recording for each sample. Results Of 50 patients with chronic diarrhea included in our study; 23 (46%) had positive endoscopic findings in the OGD. Most common findings in esophagus and stomach were inflammation and erythema. while most common findings in duodenum were edema and flattened mucosa. Colonoscopy findings were positive in 50% of patients including inflammation, nodularity, and edema mostly in the ileum. 50% of endoscopied patients reached final diagnosis based on endoscopy and histopathology. Definitive diagnosis reached through EGD alone in (12%) of cases, through colonoscopy alone in (28%) and through both techniques in (60%). There was no statistical significant agreement between endoscopy findings and predominant gastrointestinal manifestations including different types of diarrhea, fecal calprotectin with p-value =0.150, and 0.833 respectively. There was no statistical significant agreement between final diagnosis and suspected GIT part involvement on initial clinical evaluation with p- value=0.805. Conclusion Endoscopy for upper gastrointestinal tract and colonoscopy at same day may be helpful in diagnosis of cases with chronic diarrhea as we can't decide which one to perform based on clinical presentation.

Early outcomes of MR-guided SBRT for patients with recurrent pancreatic adenocarcinoma

BackgroundLocal treatment options for locally recurrent pancreatic adenocarcinoma (LR-PAC) are limited, with median survival time (MST) of 9–13 months (mos) following recurrence. MRI-guided stereotactic body radiation therapy (MRgSBRT) provides the ability to dose escalate while sparing normal tissue. Here we report on the early outcomes of MRgSBRT for LR-PAC.MethodsPatients with prior resection of pancreatic adenocarcinoma with local recurrence treated with MRgSBRT at a single tertiary referral center from 5-2021 to 2-2023 were identified from our prospective database. MRgSBRT was delivered to 40–50 Gy in 4–5 fractions with target and OAR delineation per institutional standards. Endpoints included local control per RECIST v1.1, distant failure, overall survival (OS), and acute and chronic toxicities per Common Terminology Criteria for Adverse Events, v5.ResultsFifteen patients with LR-PAC were identified with median follow-up of 10.6 mos (2.8–26.5 mos) from MRgSBRT. There were 8 females and 7 males, with a median age of 69 years (50–83). One patient underwent neoadjuvant radiation for 50.4 Gy in 28 fractions followed by resection, and one underwent adjuvant radiation for 45 Gy in 25 fractions prior to recurrence. MRgSBRT was delivered a median of 18.8 mos (3.5–52.8 mos) following resection. OS following recurrence at 6 and 12 mos were 87% and 51%, respectively, with a median survival time of 14.1 mos (3.2–27.4 mos). Three patients experienced local failure at 5.9, 7.8, and 16.6 months from MgSBRT with local control of 92.3% and 83.9% at 6 and 12 months. 10 patients experienced distant failure at a median of 2.9 mos (0.3–6.7 mos). Grade 1–2 acute GI toxicity was noted in 47% of patients, and chronic GI toxicity in 31% of patients. No grade > 3 toxicities were noted.ConclusionsThis is the first report on toxicity and outcomes of MRgSBRT for LR-PAC in the literature. MRgSBRT is a safe, feasible treatment modality with the potential for improved local control in this vulnerable population. Future research is necessary to better identify which patients yield the most benefit from MRgSBRT, which should continue to be used with systemic therapy as tolerated.Trial Registration: Jefferson IRB#20976, approved 2/17/21.

21 Gy single fraction prostate HDR brachytherapy: 5-year results of a single institution prospective pilot study

PURPOSETo present the outcome and toxicity results of a prospective trial of 21 Gy single fraction high-dose-rate (HDR) brachytherapy for men with low- or intermediate-risk prostate cancer. METHODS AND MATERIALSPatients were treated according to an IRB-approved prospective study of single fraction HDR brachytherapy. Eligible patients had low- or intermediate-risk prostate cancer with tumor stage ≤ T2b, PSA ≤ 15, and Gleason score ≤ 7. Patients underwent trans-rectal ultrasound-guided trans-perineal implant of the prostate followed by single fraction HDR brachytherapy to a dose of 21 Gy. The primary endpoint was grade ≥ 2 urinary/GI toxicity rates. RESULTSTwenty-six patients were enrolled with a median follow up of 5.1 years and median age of 64 years. 88.5% of patients had T1 disease, 15.4% had Gleason score 6 (84.6% Gleason 7), and median pre-treatment PSA was 5.0 ng/mL. Acute and chronic grade ≥ 2 urinary toxicity rates were 38.5% and 38.5%, respectively. There were no grade ≥ 2 acute or chronic GI toxicities. Six (23.1%) patients experienced biochemical failure, six (23.1%) patients experienced radiographic local failure, and five (19.2%) patients had biopsy-proven local failure. No patients developed regional lymph node recurrence or distant metastasis. 5-year overall survival and cause-specific survival were 96.2% and 100%, respectively. CONCLUSIONS21 Gy single fraction HDR brachytherapy was associated with modestly higher-than-anticipated chronic urinary toxicity, as well as high biochemical and local failure rates. The results from this prospective pilot study do not support the use of this regimen in standard clinical practice.

A81 GASTROINTESTINAL (GI) FEATURES OF HYPERMOBILE EHLERS-DANLOS SYNDROME (HEDS) AND HYPERMOBILITY SPECTRUM DISORDER (HSD): A SCOPING REVIEW

Abstract Background Ehlers-Danlos syndromes (EDS) are a varied group of hereditable connective tissue disorders (HCTD) typified by skin, joint and vascular features, along with less well-recognized features of chronic pain, immunological dysfunction and chronic GI symptoms. The latest EDS classification (2017) lists 13 EDS types and 19 genetic factors but there is no identified genetic basis for hEDS, the most common type and the most-commonly associated with GI symptoms. There is a need for robust data on the prevalence of GI symptoms and diagnoses in hEDS and HSD. Aims To investigate the extent of evidence on GI symptom prevalence and methods used to establish GI diagnoses in patients with hEDS and HSD. Methods Following the JBI (Joanna Briggs Institute) guide for scoping reviews, a systematic search of Ovid Medline, Embase and Cochrane Library retrieved scoping and systematic reviews, published in English (1974 – Sept 2023), reporting GI symptom prevalence, assessment and complications in EDS or HSD. Abstracts of identified papers were reviewed by NC &amp; DB and discrepancies resolved by YY &amp; DA. As a scoping review, it required no statistical comparisons. Results Duplicate screening of 410 abstracts yielded 10 papers that met inclusion criteria: 1 scoping and 9 systematic reviews. Four systematic reviews reported GI surgical issues related to vascular EDS; none was evaluated further. Two papers reported, specifically, on GI symptoms in patients with postural tachycardia syndrome or eating disorders, some of whom had hEDS or HSD and two papers reported on multiple GI and non-GI symptoms associated with fibromyalgia or functional somatic symptoms. The final 2 papers reported on multiple GI and non-GI symptoms in patients with HSD or multiple EDS types, limited in the latter case to papers published after the latest EDS classification (2017). In general, GI symptoms were characterised as IBS-like symptoms (Rome III or Rome IV) or as typical GI symptoms but without using a validated symptom questionnaire. Conclusions There are few data on GI symptom prevalence in hEDS or HSD and no standardised methods for identifying or characterizing GI symptoms or function in hEDS. The evaluation of GI function and symptoms in EDS is hampered by the absence of a definitive genetic or diagnostic test for hEDS or HSD and by changes in EDS classification over the last 50 years. There is a need for targeted systematic reviews of the prevalence of various GI symptoms in hEDS individuals and of relevant diagnostic methods, to guide further research into the causes of GI dysfunction in hEDS or HSD. Funding Agencies None

Arabic websites assessment of irritable bowel syndrome: How trustworthy are they? A cross-sectional study.

Irritable bowel syndrome (IBS) is a chronic GI disorder that affects people all over the world. Patients frequently look for information about their ailments online. Despite being widely and easily accessible, online information's quality and readability are under doubt. In this investigation, we assessed the effectiveness and usability of IBS Arabic websites found on significant search engines. IBS-related search terms in Arabic were entered into two search engines (Google and YouTube), and the first 30 websites per word from Google, and the first 20 websites per word from YouTube were assessed for eligibility. Eligible Google websites were assessed for quality and readability, while YouTube websites were assessed for quality. Quality was assessed using the DISCERN score and the JAMA Benchmark. Readability was assessed using the automatic Arabic readability index (AARI). Associations between quality, readability, types of websites (medical/nonmedical), and video length were analyzed. For Google: A total of 48 websites were evaluated, mean DISCERN score was 40.4 (SD = 10.28) indicating fair quality. The mean JAMA score was 1.6 (SD = 0.69), with the readability being worse the higher the quality. Medical websites had higher quality scores than nonmedical ones. For YouTube: A total of 34 YouTube videos were evaluated, mean DISCERN score was 34.7 (SD = 7.35), indicating poor quality. The mean JAMA score was 1.4 (SD = 0.72). Medical websites had higher quality scores than nonmedical ones. There was no association between the quality of the videos and their length. The majority of websites were of low to fair quality and required a high degree of readability. As a result, we advise (1) healthcare practitioners to offer helpful websites to their patients, and (2) the development of IBS-related websites under the guidance of experts, with the involvement of patients.

Burden and Treatment of Chronic Upper GI Symptoms and Diagnoses: A Nationwide Study

Chronic gastrointestinal (GI) symptoms are a common reason for seeking medical care. We aim to determine the rates of ambulatory care use and to characterize demographics, work-up, and treatment (pharmacologic and nonpharmacologic) for patients with chronic upper GI symptoms and conditions in the United States. Estimates of annual visits for the most common upper GI symptoms and diagnoses including gastroesophageal reflux disease, dyspepsia, nausea and vomiting, and gastroparesis were recorded from the 2007-2015 National Ambulatory Medical Care Surveys. Only chronic conditions, defined as >3 months, were included. We calculated the weighted proportion of ambulatory visits associated with pharmacologic, nonpharmacologic treatment (eg, diet, complementary and alternative medicine), or both. A total of 116,184,475 weighted ambulatory visits were identified between the years of 2007 and 2015 for adults (average of 12,909,386 annual visits) with chronic upper GI symptoms and diagnoses. Gastroesophageal reflux disease was the most common reason for an ambulatory visit (n= 11,200,193), followed by dyspepsia (n= 1,232,598), nausea and vomiting (n= 714,834), and gastroparesis (n= 140,312). Pharmacologic treatment was more common than nonpharmacologic treatment (44.7% vs 28.5%). A total of 37.6% of patients were not receiving treatment at the time of the visit. These treatment patterns did not significantly change over the time of our study. Upper endoscopies were the most ordered test, representing 7.5% of all investigated upper GI symptoms. Chronic upper GI symptoms and diagnoses account for a high number of annual health care visits, both in primary care and specialty care. Although there are several treatments, many of these patients are not on any treatments.

S625 Prevalence of Depression Is Higher in Irritable Bowel Syndrome Compared to Chronic GI and Non-GI Disorders

S625 Prevalence of Depression Is Higher in Irritable Bowel Syndrome Compared to Chronic GI and Non-GI Disorders

VMAT-IGRT Hypofractionated Radiotherapy for Locally Advanced Thyroid Cancer in Resource-Limited Settings: A Retrospective Report from Bolivia

This study evaluated the efficacy and safety of hypofractionated external beam irradiation with VMAT-IGRT in patients with locally advanced thyroid cancer (LATC) who are ineligible for surgery or I-131 in a resource-limited setting such as Bolivia. Thirty-three patients were treated with H-VMAT-IGRT between August 2018 and November 2022. Axial CT images were acquired every 3 mm from the base of the skull to the middle of the chest. GTV was determined based on contrast-enhanced tumor on T1 MRI or CT scans. CTV 55 Gy at 2.75 Gy was defined based on visible residual tumor and included dissected nodal stations with pathologically positive nodes. CTV 44 at 2.2 Gy for non-dissected nodal stations with low risk of recurrence, we escalated the dose up to 60 Gy at 3 Gy for small tumors up to 20 cc. PTVs were created by adding a 0.3 cm margin around CTVs, with a reduced margin of minus 3-5 mm for critical organs such as esophagus, pharynx, and brachial plexus. Equivalent dose in 2Gy (EQD2 10-3) was reported for tumor control and OAR constraints. Acute toxicity was reported according to RTOG criteria, and response to treatment was assessed at baseline, end of treatment, and every third month thereafter. The mean time since last follow-up was 24 months (r: 8-40). Patients were 80% female and 20% male. The mean age was 50 years (r: 29-72). Local recurrence was treated in 52% (13) of patients and LATC in 48% (12). Papillary carcinomas accounted for 68% of patients, followed by anaplastic (24%) and follicular (8%) carcinomas. Tumors were classified according to the AJCC classification. Of the patients treated for LATC, 25% were at stage II, 25% at stage III, 16.67% at stage IVA, and 33.33% at stage IVB. Among patients treated for local recurrence, the initial stage before progression was stage I in 61.5%, stage II in 30.8%, and stage IVA in 7.7%. The median PTV was 383.8 cc (r: 51.7 - 627.3) and the median CTV55 was 189.2 cc (r: 39.6 - 519.8). Grade 1 (10%), Grade 2 (90%) dysphagia, Grade 1 (40%), Grade 2 (60%) acute pharyngeal mucositis, and no Grade 3 acute toxicity were observed. No reports of chronic upper damage GI, 30% xerostomia G2. Two-year local control was 70% and overall survival was also 70%. We suggest that reducing treatment duration while maintaining efficacy is particularly beneficial in resource-limited areas with a shortage of trained personnel and overburdened treatment centers. We report good local control rates with no detrimental effects on quality of life with hypofractionation. No evidence of delayed damage, such as spinal cord dysfunction, mandibular osteoradionecrosis, or brachial plexopathy, was noted. We emphasize the importance of using VMAT with IGRT for reliable and accurate daily treatment of the target area, while minimizing side effects. However, these results should be confirmed with a larger sample of patients.

Early Outcomes of MR-Guided SBRT for Patients with Recurrent Pancreatic Adenocarcinoma

Local treatment options for patients with locally recurrent pancreatic adenocarcinoma (L-PAC) are limited, with expected median survival time (MST) of 8-11 months (mo) following recurrence. MRI-guided radiation therapy (MRgRT) provides the ability to dose escalate while sparing normal tissue. The literature for MR-guided Stereotactic Body Radiotherapy (MRgSBRT) for L-PAC is sparse. Here we report on the early outcomes of MRgSBRT in patients with L-PAC. Patients with prior resection of pancreatic adenocarcinoma with post-operative chemotherapy as indicated followed by local recurrence of disease at prior surgical site and treated with MRgSBRT at a single tertiary referral center from 5-2021 to 8-2022 for L-PAC were identified from our prospective database. MRgSBRT was delivered to 40-50 Gy in 4-5 fractions with target and OAR delineation per institutional standards. Descriptive analysis of the patient, disease, and treatment characteristics were performed. Endpoints included local control, defined as absence of tumor progression per RECIST criteria, distant failure, overall survival (OS), and acute and chronic toxicities per Common Terminology Criteria for Adverse Events (CTCAE), version 5. Eleven patients with L-PAC were identified with median follow-up of 10.7 mo (3.2 - 22.3). Ten of those underwent surgical resection at the treating radiation facility and one patient underwent preoperative radiation for 50.4 Gy in 28 fractions followed by surgical resection at an outside hospital. MRgRT was delivered a median of 18.8 mo (3.5 - 48.0) following resection. There were 5 females and 6 males, with a median age of 72 years (52-83) and median KPS of 80 (60-100). OS rates following initial diagnosis at 12, 18 and 24 mo were 100%, 82%, and 61%, respectively, with an MST of 25.3 mo (12.4-53.1). OS rates following recurrence at 6 and 12 mo were 82% and 52%, respectively, with an MST of 10.7 mo (3.2 - 21.9). One patient experienced local failure at 7.8 mo, and 9 patients experienced distant failure at a median of 3.4 mo (0.3 - 21.9) following MRgSBRT. Five patients experienced distant failure less than 3 mo following radiation. Grade 1 or 2 acute GI toxicity was noted in 45% of patients and chronic GI toxicity, in 18% of patients. No Grade≥3 AEs were noted. MRgSBRT for recurrent pancreatic adenocarcinoma demonstrates good local control with acceptable acute and chronic toxicity as well as reasonable overall survival. Distant failure remains a substantial problem with a significant number of patients demonstrating metastases immediately following radiation, suggesting the presence of micro-metastatic disease prior to local therapy. Adequate patient selection for MRgSBRT, and proper integration of systemic therapy in this patient population remains a topic of discussion that requires further exploration.

Magnetic Resonance Imaging of the Gastrointestinal Tract: Current Role, Recent Advancements and Future Prospectives.

This review focuses on the role of magnetic resonance imaging (MRI) in the evaluation of the gastrointestinal tract (GI MRI), analyzing the major technical advances achieved in this field, such as diffusion-weighted imaging, molecular imaging, motility studies, and artificial intelligence. Today, MRI performed with the more advanced imaging techniques allows accurate assessment of many bowel diseases, particularly inflammatory bowel disease and rectal cancer; in most of these diseases, MRI is invaluable for diagnosis, staging, and disease monitoring under treatment. Several MRI parameters are currently considered activity biomarkers for inflammation and neoplastic disease. Furthermore, in younger patients with acute or chronic GI disease, MRI can be safely used for short-term follow-up studies in many critical clinical situations because it is radiation-free. MRI assessment of functional gastro-esophageal and small bowel disorders is still in its infancy but very promising, while it is well established and widely used for dynamic assessment of anorectal and pelvic floor dysfunction; MRI motility biomarkers have also been described. There are still some limitations to GI MRI related to high cost and limited accessibility. However, technical advances are expected, such as faster sequences, more specific intestinal contrast agents, AI analysis of MRI data, and possibly increased accessibility to GI MRI studies. Clinical interest in the evaluation of bowel disease using MRI is already very high, but is expected to increase significantly in the coming years.

COLON TARGETED DELIVERY AND STABILIZATION OF MONOCLONAL ANTIBODIES FOR LOCAL TREATMENT OF INFLAMMATORY BOWEL DISEASES

In the era of biologics where IBD treatment has been transformed by potent antibody-based therapeutics, a key challenge still remains, to develop orally administered antibody medicines for chronic GI inflammation. This is primarily due to the challenges in accurate oral targeted delivery of drugs to the lower GI tract and the inherent enzymatic instability of antibodies in these harsh luminal environment. As a result, all antibody therapeutics in clinical development and on the market are available only as an injection leading to undesired adverse effects due to high systemic exposure and suboptimal therapeutic response due to insufficient antibody levels at the inflamed tissue.

Obesity and functional gastrointestinal disorders: What is the link?

Obesity and functional gastrointestinal disorders: What is the link?

COLON TARGETED DELIVERY AND STABILIZATION OF MONOCLONAL ANTIBODIES FOR LOCAL TREATMENT OF INFLAMMATORY BOWEL DISEASES

Abstract In the era of biologics where IBD treatment has been transformed by potent antibody-based therapeutics, a key challenge still remains, to develop orally administered antibody medicines for chronic GI inflammation. This is primarily due to the challenges in accurate oral targeted delivery of drugs to the lower GI tract and the inherent enzymatic instability of antibodies in these harsh luminal environment. As a result, all antibody therapeutics in clinical development and on the market are available only as an injection leading to undesired adverse effects due to high systemic exposure and suboptimal therapeutic response due to insufficient antibody levels at the inflamed tissue. We have developed a suite of delivery technologies that are designed to bypass the harsher stomach and small intestinal conditions of the GI tract and achieve accurate targeted release and enzymatic stabilization of the antibody therapeutics in the colon. The delivery platform comprises of a film coating which is applied on the outside of the pill. The coating is a clinically validated polymer coating comprising of a combination of pH sensitive polymer and polysaccharide that is designed to start releasing drugs only when exposed to the correct pH and/or colonic bacteria, dramatically improving on the inconsistent colonic release profiles of solely pH-based coatings. The second component is in the core of the pill, a cocktail of amino acid-based excipients that are mixed together with the antibody and protects the drug from pancreatic and bacterial origin protease enzymes, allowing high luminal antibody concentration build-up that leads to inflamed tissue/systemic uptake through a combination of active and passive diffusion. We demonstrated in an acute DSS mouse model of colitis the effective colonic delivery and stabilization of an anti-IL6 antibody leading to superior uptake into the tissue compared IP injection. The superior tissue level demonstrated higher downregulation of target IL6. We are working to leverage the delivery technology for oral delivery of a variety of anti-inflammatory and epithelial wound healing protein modalities such as monoclonal antibodies, fusion proteins, cytokines, VHHs and peptides to allow for broad therapeutic interventions in indications such as Crohn’s disease, ulcerative colitis, pouchitis and celiac disease. Mechanism of oral colon targeted delivery of therapeutic antibodies in local treatment of inflammatory bowel disease. In-vivo PK of anti-IL6 antibody in acute DSS colitis mouse model. A. Impact of stabilization on antibody levels in the colon lumen compared to naked antibody and injected antibody. B. Impact of stabilization on colon tissue uptake. C. Effect of tissue conc. on colon tissue IL6 target downregulation.

PP05 Presentation Time: 9:40 AM: 21 Gy Single Fraction Prostate HDR Brachytherapy: Mature Results of a Single Institution Prospective Study.

<h3>Purpose</h3> To present the outcome and toxicity results of a prospective trial of 21 Gy single fraction high-dose-rate (HDR) brachytherapy for men with low- or intermediate-risk prostate cancer. <h3>Materials and Methods</h3> Patients were treated according to an IRB-approved prospective study of single fraction HDR brachytherapy. All patients had low- or intermediate-risk prostate cancer with tumor stage ≤ T2b, PSA ≤ 15, and Gleason score ≤ 7. Patients with prostate volumes > 50 cc or <12 cc, taking alpha-blockers for urinary symptoms, or with baseline American Urologic Association (AUA) symptom scores > 12 were ineligible. Patients underwent trans-rectal ultrasound (TRUS)-guided trans-perineal implant of the prostate followed by single fraction HDR brachytherapy. Treatment was delivered via Ir-192 to a dose of 21 Gy, prescribed to the prostate with no additional margin applied. Treatment planning was TRUS-based with constraints as follows: prostate V100 > 95%; urethral V115 < 1%; rectal V72 ≤ 1% prescription dose. <h3>Results</h3> A total of 26 patients were enrolled. Median follow up was 4.0 years (range 0.6-5.7 years). Median age was 64 years. Median gland volume at the time of treatment was 41 cc. 88.5% of patients had T1 disease, 15.4% had Gleason score 6, 84.6% Gleason score 7, and median pre-treatment PSA was 5.0 (range 2.7-12.2) ng/mL. Acute and chronic grade 2 GU toxicity rates were 26.9% and 38.5%, respectively. Acute grade 3 GU toxicity rate was 11.5%. There were no chronic grade 3 GU toxicities. There were no grade 2+ acute or chronic GI toxicities. The 5-year biochemical failure rate was 35.1%. The 5-year radiographic local failure rate was 32.4%. Biopsy-proven local failure at 5-years was 15.3%. Two patients underwent salvage treatment after experiencing radiographic local failure, without an attempted biopsy of the prostate. No patients developed biopsy proven or radiographic regional lymph node recurrence or distant metastasis. 5-year overall survival was 96.2%. The single patient death was a result of a myocardial infarction approximately 7 months after protocol treatment. Cause-specific survival at 5 years was 100%. <h3>Conclusions</h3> Despite being well-tolerated, 21 Gy single fraction HDR brachytherapy is associated with high biochemical and local failure rates. The results from this prospective pilot study do not support continued investigation of this dosing regimen in subsequent investigation.

S1902 A Rare Case of Lipomatous Pseudohypertrophy of the Pancreas Diagnosed With EUS-FNA

Introduction: Lipomatous pseudohypertrophy (LPH) of the pancreas is a rare benign entity of undetermined pathogenesis characterized by the enlargement of the pancreas due to replacement of exocrine parenchyma with adipose tissue in patients without obesity, diabetes, or pancreatitis. Adipose infiltration may be local or diffuse and forms a pseudotumor that mimics pancreatic malignancies, which has led to unnecessary resections. Endoscopic ultrasound with biopsy (EUS- FNA) has improved the ability to diagnose LPH and rule out malignancy. LPH is typically asymptomatic, however, abdominal pain may be a presenting symptom with steatorrhea due to exocrine insufficiency or jaundice due to mass effect seen in late stages. Case Description/Methods: 48-year-old female with history of hypothyroidism and migraines presented with epigastric pain, poor oral intake due to postprandial vomiting, and non-bloody mucoid diarrhea. Prior to admission, she had been having chronic GI symptoms and recent MRI demonstrated near complete fatty replacement of an enlarged pancreas causing mass effect with only a small amount of normal parenchyma remaining. She had been diagnosed with exocrine pancreatic deficiency and started on replacement therapy. Surgery was consulted for potential resection of the body and tail of the pancreas due to compressive symptoms. Due to concern for other malignant process including liposarcoma, EUS-FNA was pursued (Figure). The body and tail of the pancreas appeared diffusely hyperechoic and homogeneous, consistent with fatty replacement. Biopsies showed bland pancreatic islets in a background of mature adipose tissue consistent with fatty replacement of the pancreas. These pathology findings in conjunction with pancreatic hypertrophy and compression on surrounding organs without a history of obesity, diabetes, or pancreatitis, supported the diagnosis of LPH of the pancreas. She was ultimately treated conservatively with monitoring and pancreatic enzyme replacement therapy with improvement in symptoms. Discussion: LPH is a rare, benign disorder typically managed with enzyme therapy when symptoms develop. The mass formed by LPH mimics that of malignant disease which has led to unnecessary resections. The use of EUS-FNA to observe histological features and confirm diagnosis has led to a decrease in resections and differentiation from other causes of pancreatic fat infiltration. The pathogenesis remains unknown but is distinct from pancreatic steatosis commonly seen in metabolic syndromes or inflammation.Figure 1.: EUS showing pancreatic parenchymal abnormalities consisting of diffuse echogenicity with homogenous appearance in the Neck (A), Body (B), and Tail (C) of the pancreas. These findings consistent with fatty replacement of the pancreas. There is no focal mass noted, the pancreatic duct was not visualized.

Chronic GI Bleeding as the Only Presenting Sign of AML in an Elderly Patient

Chronic GI Bleeding as the Only Presenting Sign of AML in an Elderly Patient

Incidence, Characteristics, Clinical Course, and Risk Factors of Ulcerative Colitis-related Lung Diseases

Ulcerative colitis (UC) is a chronic GI inflammatory disorder involving various extraintestinal organs, including the lungs. Although UC-related lung diseases (UC-LDs) have been widely recognized, much remains unclear. What are the incidence, characteristics, clinical course, and risk factors of UC-LD? This study retrospectively identified and classified UC-LDs by reviewing the medical records of consecutive patients with UC. The incidence, characteristics, and clinical course of each UC-LD type were investigated, and the clinical characteristics of patients with and without each UC-LD type were compared. Among 563 patients with UC, 28 (5.0%) developed UC-LD during a mean follow-up period of 77months. A majority of them displayed airway disease (AD) (n= 13 [2.3%]) or organizing pneumonia (OP) (n= 10 [1.8%]); there were six cases of interstitial pneumonias other than OP (IP) (0.8%) and one of pleuritis (0.2%). All 13 patients with AD responded favorably to inhaled or systemic corticosteroids, although five experienced frequent exacerbations. Older age and a history of colectomy were identified as the risk factors for developing AD. Nine of the 10 cases of OP were possibly due to drug-induced pathogenesis. Only one case showed recurrence, and all cases of OP exhibited a favorable clinical course with discontinuation of the suspicious drug and/or initiation of corticosteroid. The clinical course of IP depended on the existence of fibrosis, and IP with fibrosis was associated with gradual deterioration. Older age was associated with the development of IP. A nonnegligible number of patients with UC may develop UC-LD. AD, OP, and IP without fibrosis show good prognosis following steroid therapy along with the specific management for each UC-LD type, whereas IP with fibrosis shows gradual deterioration with poor prognosis. Our results provide cues to establish better management of UC-LDs.

A243 HISTAMINE H1-RECEPTOR ANTAGONISTS SUPPRESS THE HYPEREXCITABILITY OF NOCICEPTIVE NEURONS EXPOSED TO IBS-C PATIENT STOOL SUPERNATANTS

Abstract Background Abdominal pain is the primary cause of morbidity in many chronic GI disorders such as IBS, but the molecular mechanisms contributing to pain signaling are unclear. Stool supernatants from patients with diarrhea-predominant IBS increase the excitability of DRG neurons compared to supernatants from healthy controls, suggesting that mediators in the stool may sensitize nociceptors. Additionally, histamine has been implicated as a mediator of hypersensitivity in IBS patients. However, it is unclear if stool supernatants from constipation-predominant IBS (IBS-C) patients affect the excitability of DRG neurons. Furthermore, it is unknown if specific neuro-mediators in stool such as histamine impact the excitability of nociceptive neurons in this subgroup of IBS patients. Aims To evaluate whether IBS-C stool supernatants induce nociceptive signaling in DRG neurons compared to healthy control (HC) stool supernatants. If so, to evaluate the role of histamine 1 (H1) receptors in DRG neuron nociceptive signaling initiated by mediators in IBS-C stool supernatants. Methods IBS-C (n=5) and HC (n=2) patient stool was collected, filtered, and dissolved with Krebs solution in a 1:8 (g/v) dilution. Dorsal root ganglion (DRG) neurons from C57BL/6 mice were incubated with HC or IBS-C stool supernatant for 30 minutes. To evaluate whether histamine in stool supernatants can sensitize H1 receptors on nociceptors, DRG neurons were pre-incubated with the H1-receptor antagonist pyrilamine (1μM, 30 min) before stool supernatants. Changes in DRG neuronal excitability were recorded using perforated patch-clamp techniques to measure the rheobase (minimum input current needed to elicit an action potential) and the resting membrane potential (RMP). Results In neurons incubated with IBS-C stool supernatants (n=28) the rheobase decreased (63%) compared to healthy controls (78 ± 13.7 pA; n=6). This effect was reversed in DRG neurons pre-incubated with the H1 receptor antagonist, pyrilamine, (n=26) (77 ± 5.9 pA, p&amp;lt;0.001) compared to neurons incubated with IBS-C supernatant alone (50 ± 5.13 pA; n=28). No changes were found in the RMP. The data were analyzed with the non-parametric Kruskal-Wallis test. Conclusions IBS-C stool supernatants increase the excitability of DRG neurons compared to HC. Furthermore, the H1-receptor antagonist pyrilamine inhibits the neuronal hyperexcitability evoked by mediators in IBS-C patient stool. These findings suggest that the neuroactive metabolite histamine may contribute to visceral pain experienced by patients with IBS-C. Further studies are needed to examine whether similar signaling to nociceptive neurons by stool supernatants occurs in other subtypes of IBS. Funding Agencies CAG, CIHR