Rectal Markers Research Articles

Biomarkers of Colorectal Cancer Risk Decrease 6\xa0months After Roux-en-Y Gastric Bypass Surgery

PurposeThe impact of weight loss on obesity-related colorectal cancer (CRC) risk is not well defined. Previous studies have suggested that Roux-en-Y gastric bypass (RYGB) surgery may have an unexpected adverse impact on CRC risk. This study aimed to investigate the impact of RYGB on biomarkers of CRC risk.Materials and methodsRectal mucosal biopsies and blood were obtained from patients undergoing RYGB (n = 22) and non-obese control participants (n = 20) at baseline and at a median of 6.5 months after surgery. Markers of systemic inflammation and glucose homeostasis were measured. Expression of pro-inflammatory genes and proto-oncogenes in the rectal mucosa was quantified using qPCR. Crypt cell proliferation state of the rectal mucosa was assessed by counting mitotic figures in whole micro-dissected crypts.ResultsAt 6.5 months post-surgery, participants had lost 29 kg body mass and showed improvements in markers of glucose homeostasis and in systemic inflammation. Expression of pro-inflammatory genes in the rectal mucosa did not increase and COX-1 expression fell significantly (P = 0.019). The mean number of mitoses per crypt decreased from 6.5 to 4.3 (P = 0.028) after RYGB.ConclusionRYGB in obese adults led to lower rectal crypt cell proliferation, reduced systemic and mucosal markers of inflammation and improvements in glucose regulation. These consistent findings of reduced markers of tumourigenic potential suggest that surgically induced weight loss may lower CRC risk.

Sa1578 Race and Gender Predilection for Spectroscopic Rectal Microvascular Markers in Colonic Field Carcinogenesis Detection: Implications for Colorectal Cancer Screening

Sa1578 Race and Gender Predilection for Spectroscopic Rectal Microvascular Markers in Colonic Field Carcinogenesis Detection: Implications for Colorectal Cancer Screening

Su2086 A Pilot Study of Mesalazine Treatment in IBS, Evaluating the Tolerance and Usefulness of the Mucosal Patch Technique for Measurement of Rectal Inflammatory Markers

Su2086 A Pilot Study of Mesalazine Treatment in IBS, Evaluating the Tolerance and Usefulness of the Mucosal Patch Technique for Measurement of Rectal Inflammatory Markers

Systemic folate status, rectal mucosal folate concentration and dietary intake in patients at differential risk of bowel cancer (The FAB2 Study)

Folate has been strongly implicated in the aetiology of colorectal cancer. However, the relationship between dietary folate intake, rectal mucosal folate status and colorectal cancer risk is uncertain. The study aimed to estimate nutrient intakes and measure systemic folate status and rectal mucosal folate concentration in people at differential risk of developing colorectal cancer. Two hundred and twenty-eight individuals were recruited from gastroenterology clinics and subdivided into three patient groups: untreated colorectal cancer (n = 43), adenomatous polyps (n = 90) or normal bowel (n = 95). Biopsies from macroscopically normal rectal mucosa and blood were collected and used for the measurement of rectal mucosal 5-methyltetrahydrofolate (5-MeTHF) and systemic markers of folate status, respectively. Nutrient intake was estimated using a validated food frequency questionnaire. Dietary intake variables, plasma 5-MeTHF and red cell folate and plasma homocysteine concentrations were similar in all three subject groups and 95% CI fell within normal range for each variable. Rectal mucosal 5-MeTHF concentration was higher in the normal mucosa of adenomatous polyp patients than in normal subjects (P = 0.055). Rectal mucosal 5-MeTHF was associated significantly with plasma folate (P < 0.001, r = 0.294), red cell folate (P = 0.014, r = 0.305), plasma homocysteine (P = 0.017, r = -0.163) and dietary folate intake (P = 0.036, r = 0.152). This study demonstrates adequate folate status of patients attending gastroenterology clinics for the investigation of bowel symptoms, with no significant difference in dietary intakes or systemic folate status indices according to diagnosis. Rectal mucosal 5-MeTHF concentrations were elevated in adenomatous polyp patients, but failed to reach significance. Further studies are required to determine the biological significance of this observation.

Endobronchial Aspergilloma (EBA) - An Enigma in Itself

Abstract SESSION TYPE: Infectious Disease Case Report Posters IIPRESENTED ON: Tuesday, October 23, 2012 at 01:30 PM - 02:30 PMINTRODUCTION: Endobronchial aspergilloma is a rare disease entity with pulmonary involvement of aspergillus. Definition of this entity is not well described in the literature and is not usually classified with other pulmonary aspergillosis. This is an unusual form of a fungus ball, found inside of the bronchus with or without a parenchymal lesion and/or cavity. Few cases of endobronchial aspergillosis associated with tumors have been reported in the literature.CASE PRESENTATION: A 49 year old, non smoker male with prior history of rectal cancer treated with surgery and chemo-radiation 6 years back and in remission presented with three weeks of dry cough and occasional hemoptysis. Patient was still symptomatic after a course of antibiotics. Chest X ray demonstrated left upper lobe (LUL) infiltrate and Computed Tomography (CT) of chest demonstrated LUL mass with adjoining atelectasis. Bronchoscopy revealed a pearly white lesion in LUL bronchus which was biopsied and pathology was consistent with necrotic tissue with surrounding Aspergillus species without local tissue invasion. CT guided biopsy of LUL mass showed Metastatic Adenocarcinoma positive for rectal tumor markers. Positron Emission Tomography revealed no other metabolically active lesion except the LUL mass. Our patient was treated with itraconazole for 3 months along with chemotherapy with significant improvement in clinical and radiographical findings.DISCUSSION: EBA is a rare disease entity with involvement of Pulmonary bronchus with Aspergillus species. It is hard to differentiate true EBA with colonization of Aspergillus with underlying cancer. 50 % of the patients are immunocompromised. Clinically patient exhibit symptoms of cough, fever, wheezing or hemoptysis. Radiographically, CT chest shows endobronchial lesion with lobar or segmental atelectasis. Bronchoscopy with endobronchial biopsy is diagnostic of EBA. Bronchoscopic findings vary from yellowish-white necrotic material-plaques to whitish nodules. Optimal treatment of EBA has not yet been established. Duration of therapy vary between 1 and 48 months in different case series based on disease severity. Treatment options include Amphotericin B, Voriconazole, Itraconazole or Capsofungin. Invasive procedures including debridement, surgical resection, stent placement and Nd-YAG laser has limited role in literature.CONCLUSIONS: EBA is a rare pulmonary manifestation of Aspergillus species. Treatment of EBA is a challenge since there is limited literature on the ideal duration and type of treatment.1) Endobronchial Aspergilloma: Report of 10 Cases and Literature Review- Yonsei Med J. 2011 September 1; 52(5)2) Endobronchial Aspergilloma in a 30-year-old Man- Journal of Bronchology: July 2007 - Volume 14 - Issue 33) Endobronchial Fungal Disease: An Under-Recognized Entity- Respiration 2007DISCLOSURE: The following authors have nothing to disclose: Aman Sethi, Nitesh Jain, Hasnain Bawaadam, Puja Sethi, Nisha Jain, Fazila Barodawala, Sivashankar SivaramanNo Product/Research Disclosure InformationChicago Medical School/Rosalind Franklin University of Health a Science, North Chicago, IL.

Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

851 Field Carcinogenesis Detection By Rectal Spectral Markers Accurately Identifies Patients Harboring Proximal Advanced Adenomas

851 Field Carcinogenesis Detection By Rectal Spectral Markers Accurately Identifies Patients Harboring Proximal Advanced Adenomas

MO-D-AUD B-07: Analysis of Rectal Dose Variability Due to Inter-Fractional Variations of Rectal Marker Positioning in Film-Based HDR Cervical Brachytherapy

Purpose: In film-based intracavitary brachytherapy for cervical cancer, rectal dose is usually computed using rectal markers. Position of the markers may not accurately represent the anterior rectal wall. The study is to retrospectively analyze the variability of rectal dose due to variations of marker placement in a multi-fractionated HDR treatment regimen. Method and Materials: A cohort of five patients, total 18 applications, treated with multiple-fraction tandem/ovoid HDR brachytherapy was studied. To correlate the rectal points from different fractions to the same coordinate system, the cervical os point and the orientation of the applicators were manually matched. With the applicator matching, rectal points obtained from other fractions were input into the original treatment plan for each application. A rectal dose was then calculated from all the possible rectal points. The fractional rectal doses were summed as the new cumulative rectal dose for each patient, which was compared with the original cumulative rectal dose. The reproducibility of the results was also analyzed by repeating the matching procedure. Results: The maximum inter-fractional variation of distances between rectal dose points and the closest source positions was 1.1 cm and the corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.1%, 16.4%, 25.7%, 18.9%, 12.2%, respectively. Overall reproducibility of the results was within 1.8%. Conclusion: Our results show underestimation of the rectal dose caused by variations of rectal marker positioning relative to the anterior rectal wall, which should be taken into consideration in film-based HDR cervical brachytherapy. By manually matching the rectal points into the same treatment plan, one may minimize the possibility of underestimating the rectal dose. We will also anticipate a more accurate approach for evaluating rectal doses in HDR intracavitary brachytherapy with the emerging 3-D volume imaging based treatment planning.

SU‐FF‐T‐445: Variations of Rectal Dose Estimation Using Rectal Markers in HDR Cervical Brachytherapy

Purpose: In the treatment of cervical cancer using high‐dose‐rate (HDR) brachytherapy, high rectal dose often limits the tumorcidal dose. In film based brachytherapy, rectal dose is usually computed using rectal markers. However, positions of these markers can vary relative to the anterior rectal wall. This retrospective study analyzes the potential inaccuracy in rectal dose estimation due to variations of marker placement in a multi‐fractionated HDR treatment regimen. Method and Materials: Five Patients treated with multiple‐fraction tandem and ovoid HDR brachytherapy were selected. By adequate packing the vagina, there was little inter‐fractional variation of the actual rectum position. Therefore, variations of rectal makers were due to their locations relative to the wall. For each patient (with 3–4 fractions), the plan of the first fraction was selected as the reference plan. Simulation films of all the other fractions were matched with the films of the reference plan based on bony anatomies. Rectal dose points specified based upon the rectal markers of all different fractions were then digitized into the reference plan after film matching. Dose prescription and dwell weights in the reference plan were set to be identical to the original treatment plan. The rectal doses within each group of rectal points were then analyzed. Results: Our results have shown that inter‐fractional variations of rectal marker locations to specify the rectal dose are up to 0.5–0.8 cm. The resulting differences in rectal dose values are 42.4%, 23.3%, 25.6%, 6.8% and 50.4% for each patient, respectively. Conclusion: Care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. Positions of the markers inside the rectum relative to the wall can vary and cause underestimation of the dose to the rectum. The true rectal dose should be determined by the most anterior point among all fractions.

Colonic distribution of oral and rectal markers in IBD

Colonic distribution of oral and rectal markers in IBD

Colonic distribution of oral and rectal markers in IBD

Colonic distribution of oral and rectal markers in IBD

Distribution of oral and rectal markers in active Crohn's colitis: Implications for therapy

Distribution of oral and rectal markers in active Crohn's colitis: Implications for therapy

A simple device for prostate and rectal localization in radiation therapy

A simple device for prostate and rectum localization in radiation therapy may be constructed as follows: first, dental wax is used to make up a shape of the rectal probe. Second, dental stone is used to make a two-piece mold by molding the dental wax probe. Third, using the mold, the rectal probe is made from a mixture of silicone and barium. The final step involves the attachment of the “plug”, which is made of aluminum. From the simulation films for the prostate setup, the location of the anterior wall of the rectum, anal sphincter, and anal verge can easily be identified, such that the appropriate regions are shielded accordingly. A CT scan with the probe in the rectum did not give too much artifacts from the barium/silicone mixture. The rectal probe with the plug is useful for localizing the prostate more accurately, compared with using the other rectal localization techniques such as barium injection or some rectal markers.