Acute Radiation Proctitis Research Articles

Clinical Observation on Prevention and Treatment Effect of Thalidomide on Acute Radiation Proctitis

Clinical Observation on Prevention and Treatment Effect of Thalidomide on Acute Radiation Proctitis

Microbiota metabolite short chain fatty acids, GPCR, and inflammatory bowel diseases.

Gut microbiota has been well recognized in regulation of intestinal homeostasis and pathogenesis of inflammatory bowel diseases. However, the mechanisms involved are still not completely understood. Further, the components of the microbiota which are critically responsible for such effects are also largely unknown. Accumulating evidence suggests that, in addition to pathogen-associated molecular patterns, nutrition and bacterial metabolites might greatly impact the immune response in the gut and beyond. Short chain fatty acids (SCFA), which are metabolized by gut bacteria from otherwise indigestible fiber-rich diets, have been shown to ameliorate diseases in animal models of inflammatory bowel diseases (IBD) and allergic asthma. Although the exact mechanisms for the action of SCFA are still not completely clear, most notable among the SCFA targets is the mammalian G protein-coupled receptor pair of GPR41 and GPR43. In addition to the well-documented inhibition of histone deacetylases activity mainly by butyrate and propionate, which causes anti-inflammatory activities on IEC, macrophages, and dendritic cells, SCFA has recently been implicated in promoting development of Treg cells and possibly other T cells. In addition to animal models, the beneficial effects have also been reported from the clinical studies that used SCFA therapeutically in controlled trial settings in inflammatory disease, in that application of SCFA improved indices of IBD and therapeutic efficacy was demonstrated in acute radiation proctitis. In this review article, we will summarize recent progresses of SCFA in regulation of intestinal homeostasis as well as in pathogenesis of IBD.

Role of Colonoscopy in Patients with Hematochezia

Although colonoscopy is not indicated in patients with hematochezia, many surgeons, internists, and physicians are recommending colonoscopy for these patients in Korea. The aim of this study is to evaluate the diagnostic value of colonoscopy for patients with hematochezia. We retrospectively reviewed the data of colonoscopy between January 2010 and December 2010. A total of 321 patients among 3,038 colonoscopies (10.6%) underwent colonoscopy to evaluate the cause of hematochezia. The patients with previous colorectal surgery (2) or polypectomy (5) were excluded. We analyzed endoscopic diagnoses. Advanced neoplastic polyps were defined as adenomas with villous histology or high grade dysplasia, or adenomas more than 10 mm in diameter. Hemorrhoid was the most common diagnosis (217 cases, 67.6%). Polyps were detected in 93 patients (29.0%), but advanced neoplastic polyps were found in only 14 cases (4.4%). Colorectal cancers were diagnosed in 18 patients (5.6%) including 14 rectal cancers. There was no cancer located above sigmoid-descending junction. Diverticuli were detected in 41 patients (12.8%) but there was only one case of suspected diverticular bleeding. Colitis was diagnosed in 24 patients (7.5%). Other lesions included acute anal fissure, rectal tumor, stercoral ulcer, and radiation proctitis. The colonoscopy had little value in patients with hematochezia because the most pathologic lesions were located below sigmoid colon. The first choice of diagnosis in patients with hematochezia is sigmoidoscopy.

Postoperative external beam irradiation with and without brachytherapy in pelvic node-positive IB1-IIA2 cervical cancer patients: a retrospective clinical study.

BackgroundThis study assessed the survival outcomes and recurrent patterns in pelvic node-positive IB1-IIA2 cervical cancer patients treated with postoperative external beam irradiation with or without vaginal brachytherapy.MethodsThe records of 1149 cervical cancer patients received radical surgery between February 2008 and March 2010 were retrospectively reviewed. 126 stages IB1-IIA2 patients with positive pelvic lymph node (LN) were included and a total of 113 patients who received different postoperative radiation therapy were identified and analyzed. Of the enrolled patients, 55 patients received pelvic external beam radiotherapy (EBRT) without vaginal brachytherapy and 58 patients received pelvic EBRT with vaginal brachytherapy. Treatment-related toxicities were evaluated. Progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier estimates and statistical significance was determined using the log-rank test.ResultsWith a median follow-up of 47 months (range: 10–61 months), the group which had pelvic EBRT with brachytherapy had a significantly improved 5-year PFS rate (P = 0.044), but no significant difference in 5-year overall survival was found between the two groups (P = 0.437). In patients treated without brachytherapy, the most common site of relapse was the pelvis. No significant differences were found regards to acute and chronic radiation toxicities, including myelosuppression, dermatitis, enterocolitis, proctitis and cystitis (P = 0.485, 0.875, 0.671, 0.459 and 0.969 respectively) between the groups of pelvic EBRT with and without vaginal brachytherapy.ConclusionsTreated with pelvic EBRT in combination with vaginal brachytherapy, cervical cancer patients with positive pelvic lymph node had a reduced risk of locoregional recurrence without increased side effects compared with patients treated with pelvic EBRT without vaginal brachytherapy.

Radiation proctopathy.

Radiation therapy is a widely utilized treatment modality for pelvic malignancies, including prostate cancer, rectal cancer, and cervical cancer. Given its fixed position in the pelvis, the rectum is at a high risk for injury secondary to ionizing radiation. Despite advances made in radiation science, up to 75% of the patients will suffer from acute radiation proctitis and up to 20% may experience chronic symptoms. Symptoms can be variable and include diarrhea, bleeding, incontinence, and fistulization. A multitude of treatment options exist. This article summarizes the latest knowledge relating to radiation proctopathy focusing on the vast array of treatment options.

Efficacy of Synbiotics to Reduce Acute Radiation Proctitis Symptoms and Improve Quality of Life: A Randomized, Double-Blind, Placebo-Controlled Pilot Trial

To evaluate whether the daily intake of synbiotics interferes in radiation-induced acute proctitis symptoms and in quality of life in patients with prostate cancer. Twenty patients who underwent 3-dimensional conformal radiation therapy for prostate cancer were randomized to intake either a synbiotic powder containing Lactobacillus reuteri 10(8) colony-forming units and 4.3 g of soluble fiber (Nestlé) or placebo. The questionnaire EORTC QLQ-PRT23 was applied before the beginning of radiation therapy and in every week for the first 4 weeks of treatment. The sum of both the complete (proctitis symptoms plus quality of life) and partial (proctitis symptoms) scores of the EORTC QLQ-PRT23 (European Organization for Research and Treatment of Cancer Quality of Life Module for Proctitis-23 items) questionnaire were the main endpoints. This pilot study showed that the complete questionnaire score (median [range]) was higher in the second (23 [21-30] vs 26.5 [22-34], P<.05) and third (23 [21-32] vs 27.5 [24-33], P<.01) weeks in the placebo group. Proctitis symptoms were highest scored in the placebo group in both the second (19.5 [16-25]) and third (19 [17-24]) weeks than in the synbiotic group (week 2: 16.5 [15-20], P<.05; week 3: 17 [15-23], P<.01). In both scores the placebo group had a significantly higher result (P<.01) than the synbiotic group (repeated-measures analysis of variance). Synbiotics reduce proctitis symptoms and improve quality of life in radiation-induced acute proctitis during radiation therapy for prostate cancer.

Daily Sodium Butyrate Enema for the Prevention of Radiation Proctitis in Prostate Cancer Patients Undergoing Radical Radiation Therapy: Results of a Multicenter Randomized Placebo-Controlled Dose-Finding Phase 2 Study

To evaluate the efficacy of sodium butyrate enemas (NABUREN) in prostate cancer radiation therapy (RT) in reducing the incidence, severity, and duration of acute RT-induced proctitis. 166 patients, randomly allocated to 1 of 4 groups (rectal sodium butyrate 1 g, 2 g, or 4 g daily or placebo), were treated with NABUREN during and 2 weeks after RT. The grade of proctitis was registered in a daily diary. The correlation between NABUREN and proctitis was investigated through χ(2) statistics. The toxicity endpoints considered were as follows: total number of days with grade ≥1 proctitis (≥G1); total number of days with grade ≥2 proctitis (≥G2); ≥G1 and ≥G2 proctitis lasting at least 3 and 5 consecutive days starting from week 4 (≥G1+3d, ≥G2+3d); damaging effects of RT on rectal mucosa as measured by endoscopy. The relationship between endpoints and pretreatment morbidities, hormonal therapy, presence of diabetes or hypertension, abdominal surgery, or hemorrhoids was investigated by univariate analysis. The patients were randomly allocated to the 4 arms. No difference in the distribution of comorbidities among the arms was observed (P>.09). The mean ≥G1 and ≥G2 proctitis were 7.8 and 4.9 for placebo and 8.9 and 4.7 for the NABUREN group, respectively. No favorable trend in reduction of incidence, severity, and duration of ≥G1 and ≥G2 proctitis was observed with NABUREN use. In univariate analysis, ≥G1+3d toxicity was found to be related to hemorrhoids (P=.008), and a slight correlation was found between ≥G2 proctitis and hormonal therapy (P=.06). The RT effects on rectal mucosa as based on endoscopic assessment were mainly related to diabetes (P<.01). Endoscopy data at 6 week showed no significant difference between the placebo and butyrate arms. The other investigated endpoints were not correlated with any of the clinical risk factors analyzed. There was no evidence of efficacy of NABUREN in reducing the incidence, severity, and duration of acute radiation proctitis. There was a correlation between some endpoints and clinical risk factors.

Effects of ozonated olive oil on acute radiation proctitis in rats.

Acute radiation proctitis is a common complication of pelvic radiation and management of acute radiation proctitis is under evaluation. The beneficial effects of ozonated olive oil (OzOO) have already been shown in the treatment of chronic wounds. Thus, this study was designed to evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. To evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Animal experimentation. RATS WERE DIVIDED INTO THREE GROUPS: control; irradiation+saline (1 mL); and irradiation +OzOO (1 mL). A single fraction of 17.5 Gy was delivered to each rat. The OzOO was administered rectally each day after irradiation. Each rat was observed daily for signs of proctitis. Irradiated rats were euthanised on days 5 and 10. The mucosal changes were evaluated macroscopically and pathologically. According to the clinical findings, five rats in the irradiation+saline group showed Grade 4 symptoms on the 10(th) day. Macroscopic finding scores on the 10(th) day in the irradiation+saline and irradiation+OzOO groups were statistically significantly different. On pathological examination, radiation-induced mucosal damage was the most prominent 10 days after irradiation in saline-treated rats. On the 10(th) day, the irradiation+OzOO group showed mild inflammation and slight crypt change, which corresponded to Grade 1 pathological findings. OzOO attenuates macroscopic and pathological findings of acute radiation proctitis in rats.

Use of Anticoagulants Predict Late Rectal Bleeding Following Definitive External Beam Radiation Therapy for Prostate Cancer

To determine the relationship between hematologic modifying drugs and the risk of acute and late radiation proctitis in patients undergoing definitive external beam radiation therapy for prostate cancer.

Intensity-modulated Radiotherapy Combined with Endocrine Therapy for Intermediate and Advanced Prostate Cancer: Long-term Outcome of Chinese Patients

The aim of this study was to evaluate acute adverse events and efficacy of three-dimensional intensity- modulated radiotherapy (IMRT) combined with endocrine therapy for intermediate and advanced prostate cancer. Sixty-seven patients were treated with three-dimensional IMRT combined with maximum androgen blockade. The correlation between radiation-induced rectal injury and clinical factors was further analyzed. After treatment, 21 patients had complete remission (CR), 37 had partial remission (PR), and nine had stable disease (SD), with an overall response rate of 86.5%. The follow-up period ranged from 12.5 to 99.6 months. Thirty-nine patients had a follow-up time of ≥ five years. In this group, three-year and five-year overall survival rates were 89% and 89.5%, respectively; three-year and five-year progression-free survival rates were 72% and 63%. In univariate analyses, gross tumor volume was found to be prognostic for survival (χ2 = 5.70, P = 0.037). Rates of leucopenia and anemia were 91.1% and 89.5%, respectively. Two patients developed acute liver injury, and a majority of patients developed acute radiation proctitis and cystitis, mainly grade 1/2. Tumor volume before treatment was the only prognostic factor influencing the severity of acute radiation proctitis (P < 0.05). IMRT combined with endocrine therapy demonstrated promising efficacy and was well tolerated in patients with intermediate and advanced prostate cancer.

Early treatment and prevention of the radiation proctitis—composite enemas containing sodium butyrate

Early treatment and prevention of the radiation proctitis—composite enemas containing sodium butyrate

Superoxide dismutase mimic, MnTE-2-PyP5+ ameliorates acute and chronic proctitis following focal proton irradiation of the rat rectum

Radiation proctitis, an inflammation and damage to the lower part of colon, is a common adverse event of the radiotherapy of tumors in the abdominal and pelvic region (colon, prostate, cervical). Several Mn(III) porphyrin-based superoxide dismutase mimics have been synthesized and successfully evaluated in preclinical models as radioprotectants. Here we report for the first time the remarkable rectal radioprotection of frequently explored Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin, MnTE-2-PyP5+. A batch prepared in compliance with good manufacturing practice (GMP), which has good safety/toxicity profile, was used for this study. MnTE-2-PyP5+ was given subcutaneously at 5mg/kg, either 1h before or 1h after irradiation, with additional drug administered at weekly intervals thereafter. MnTE-2-PyP5+ ameliorated both acute and chronic radiation proctitis in male Sprague-Dawley rats irradiated with 20–30Gy protons delivered to 2.5cm span of rectum using spread-out Bragg peak of a proton treatment beam. Focal irradiation of the rectum produced acute proctitis, which healed, followed by chronic rectal dilation and symptomatic proctitis. MnTE-2-PyP5+ protected rectal mucosa from radiation-induced crypt loss measured 10 days post-irradiation. Significant effects were observed with both pre- and post-treatment regimens. However, only MnTE-2-PyP5+ pre-treatment, but not post-treatment, prevented the development of rectal dilation, indicating that proper dosing regimen is critical for radioprotection. The pre-treatment also prevented or delayed the development of chronic proctitis depending on the radiation dose. Further work aimed at developing MnTE-2-PyP5+ and similar drugs as adjunctive agents for radiotherapy of pelvic tumors is warranted. The present study substantiates the prospects of employing this and similar analogs in preserving normal tissue during cancer radiation as well as any other radiation exposure.

Role of Early Proctoscopy in Predicting Late Symptomatic Proctitis After External Radiation Therapy for Prostate Carcinoma

To determine whether acute radiation-proctitis, diagnosed by proctoscopy after radiation therapy for prostate cancer, can predict late clinical proctitis. A prospective study of 130 patients who underwent external radiation therapy (RT) for stage T1 to T4 prostate cancer between 1997 and 2008 was performed. Treatments were conventional (2-dimensional [2D]) in 61 patients and 3D conformal in 69, with a median target dose of 72 Gy (70-74 Gy). Within 1 week after RT, proctoscopy was performed to detect possible acute endoscopic proctitis (AEP). Acute clinical proctitis (ACP) and late clinical proctitis (LCP) were also evaluated. The median follow-up was 84 months (20-180 months). The influence of AEP and ACP on LCP occurrence was studied using the Cox model controlling for age, dose, prostatectomy, RT technique (2D vs 3D), and hormone therapy. AEP was detected in 15 patients (11.5%) and ACP in 67 (51.5%); in 13 cases (10%) AEP and ACP occurred simultaneously. Thirty-five cases of LCP were recorded. The 5-year probability of developing LCP was highest in patients with AEP and ACP (77%, 95% confidence interval [CI] 53%-94%) and lowest in asymptomatic patients (14%, 95% CI 7%-26%; P<.001). Compared to asymptomatic patients, the 5-year probability also was slightly increased in patients with ACP only (26%, 95% CI 16%-40%; P=.052). In multivariable analysis, the combination of AEP and ACP was the main predictor of LCP: compared to asymptomatic patients, the hazard ratio was 5.6 (2.1-15.2) in patients with AEP plus ACP (P=.001) and 2.1 (0.9-4.9) in those with ACP only (P=.103). In patients with AEP and ACP, the risk of LCP was more than 5-fold increased compared to those who were asymptomatic, while a much smaller increase in risk occurred in patients with ACP only. Early proctoscopy can provide valuable information regarding the likelihood of late proctitis.

1039 Functional Net Value (FNV): an Important Consideration in Clinical Evaluation of IBS Pharmacotherapy

Background: Radiation proctitis (RAP) is defined as damage to the rectal mucosa resulting from radiotherapy to adjacent pelvic organs. More than 50 % of patients undergoing radiotherapy for prostate cancer (PC) will encounter symptoms such as diarrhea, blood and mucus in stool and tenesms that might alter qualitiy of life and might be dose limiting. The symptoms of radiation proctitis can be quantified by the acute EORTC/RTOG lower GI toxicity or the RAP score . Material and Methods: Patients undergoing radiotherapy (XRT) for PC were randomised to rectal budesonide (BUD) or placebo (PLB) treatment over 8 weeks. EORTC/RTOG lower GI toxicity score, RAP score and quality of life scores were taken at baseline and after 2, 4, 8 and 14 weeks as well as after 1 year. Flexible rectoscopy and assessment of the Vienna rectoscopy score (VRS) was done at baseline, after 8 weeks, 14 weeks and 1 year. 17 patients were included (n=8 budesonide, n=9 placebo) into the study. Results: 6/8 BUD patients and 6/9 PLB patients developed clinical signs of acute radiation proctitis, i.e. acute EORT/RTOG lower GI toxicity ≥ 1 for at least 2 consecutive days, during 8 weeks of treatment (p=0.8167). However, BUD ameliorated the severity of RAP by significantly reducing stool frequency at week 14 and after 1 year and numerically the number of tenesms at week 8. The endoscopic score for late radiation proctitis was diminished in the budesonide group compared to placebo. Conclusions: Rectal treatment with budesonide did not significantly prevent acute radiation proctitis in this pilot study. However, clinical symptoms of proctitis could be significantly reduced and the appearance of late radiation proctitis was diminished. Therefore BUD deserves further evaluation in the context of high dose XRT with curative intent to prevent or to ameliorate side effects that might be dose limiting.

1041 Efficacy of Rifaximin for IBS Without Constipation in Men and Women

Background: Radiation proctitis (RAP) is defined as damage to the rectal mucosa resulting from radiotherapy to adjacent pelvic organs. More than 50 % of patients undergoing radiotherapy for prostate cancer (PC) will encounter symptoms such as diarrhea, blood and mucus in stool and tenesms that might alter qualitiy of life and might be dose limiting. The symptoms of radiation proctitis can be quantified by the acute EORTC/RTOG lower GI toxicity or the RAP score . Material and Methods: Patients undergoing radiotherapy (XRT) for PC were randomised to rectal budesonide (BUD) or placebo (PLB) treatment over 8 weeks. EORTC/RTOG lower GI toxicity score, RAP score and quality of life scores were taken at baseline and after 2, 4, 8 and 14 weeks as well as after 1 year. Flexible rectoscopy and assessment of the Vienna rectoscopy score (VRS) was done at baseline, after 8 weeks, 14 weeks and 1 year. 17 patients were included (n=8 budesonide, n=9 placebo) into the study. Results: 6/8 BUD patients and 6/9 PLB patients developed clinical signs of acute radiation proctitis, i.e. acute EORT/RTOG lower GI toxicity ≥ 1 for at least 2 consecutive days, during 8 weeks of treatment (p=0.8167). However, BUD ameliorated the severity of RAP by significantly reducing stool frequency at week 14 and after 1 year and numerically the number of tenesms at week 8. The endoscopic score for late radiation proctitis was diminished in the budesonide group compared to placebo. Conclusions: Rectal treatment with budesonide did not significantly prevent acute radiation proctitis in this pilot study. However, clinical symptoms of proctitis could be significantly reduced and the appearance of late radiation proctitis was diminished. Therefore BUD deserves further evaluation in the context of high dose XRT with curative intent to prevent or to ameliorate side effects that might be dose limiting.

1038 Randomised, Double-Blind, Placebo-Controlled Phase II Pilot Study on the Efficacy and Tolerability of an Rectal Treatment With Budesonide (2mg) or Placebo for the Prevention of Acute Radiation Proctitis

1038 Randomised, Double-Blind, Placebo-Controlled Phase II Pilot Study on the Efficacy and Tolerability of an Rectal Treatment With Budesonide (2mg) or Placebo for the Prevention of Acute Radiation Proctitis

Low-Dose Aspirin Therapy Does not Increase the Severity of Acute Radiation Proctitis.

BackgroundAlthough anticoagulation therapy is commonly used in the prostate cancer population, there are only a few studies about the correlation between radiation proctitis and anticoagulation therapy. The purpose of the present study was to determine whether low-dose aspirin increases the severity of acute radiation proctitis in an experimental animal model.MethodsWistar rats were used in the present study. The rats were administered either aspirin at doses of 5, 10, and 20 mg/kg, or saline, daily before and after irradiation. The rats were irradiated to the rectum as a single fraction of 25 Gy. The rectal mucosal changes of each rat were evaluated macroscopically and pathologically on the tenth day following irradiation. The findings of proctitis were graded from 0 to 4, and then were compared with regard to the status.ResultsNo apparent correlations were observed between the administration of aspirin and the severity of radiation proctitis in the macroscopic findings and in the morphological mucosal damage in the pathological examination. The proportion of rats with a severe degree of mucosal inflammation was 90.0%, 100.0%, 16.7% and 100.0% at 5 mg/kg, 10 mg/kg, and 20 mg/kg of aspirin, or saline, respectively. The rats receiving aspirin at the dose of 20 mg/kg showed significantly milder inflammation than the other groups (P < 0.05).ConclusionsIn the present study, low-dose aspirin did not increase the severity of acute radiation proctitis. In addition, aspirin might decrease the severity of radiation-induced mucosal inflammation in the rectum.

Efficacy of Polaprezinc for Acute Radiation Proctitis in a Rat Model

The purpose of the present study was to standardize the experimental rat model of radiation proctitis and to examine the efficacy of polaprezinc on radiation proctitis. A total of 54 female Wistar rats (5 weeks old) were used. The rats were divided into three groups: those treated with polaprezinc (PZ+), those treated with base alone, exclusive of polaprezinc (PZ-), and those treated without any medication (control). All the rats were irradiated to the rectum. Polaprezinc was prepared as an ointment. The ointment was administered rectally each day after irradiation. All rats were killed on the 10th day after irradiation. The mucosal changes were evaluated endoscopically and pathologically. The results were graded from 0 to 4 and compared according to milder or more severe status, as applicable. According to the endoscopic findings, the proportion of mild changes in the PZ+, PZ-, and control group was 71.4%, 25.0%, and 14.3% respectively. On pathologic examination, the proportion of low-grade findings in the PZ+, PZ-, and control group was 80.0%, 58.3%, and 42.9% for mucosal damage, 85.0%, 41.7%, and 42.9% for a mild degree of inflammation, and 50.0%, 33.3%, and 4.8% for a shallow depth of inflammation, respectively. The PZ+ group tended to have milder mucosal damage than the other groups, according to all criteria used. In addition, significant differences were observed between the PZ+ and control groups regarding the endoscopic findings, degree of inflammation, and depth of inflammation. This model was confirmed to be a useful experimental rat model for radiation proctitis. The results of the present study have demonstrated the efficacy of polaprezinc against acute radiation-induced rectal disorders using the rat model.

Mast Cells Are an Essential Component of Human Radiation Proctitis and Contribute to Experimental Colorectal Damage in Mice

Radiation proctitis is characterized by mucosal inflammation followed by adverse chronic tissue remodeling and is associated with substantial morbidity and mortality. Mast cell hyperplasia has been associated with diseases characterized by pathological tissue remodeling and fibrosis. Rectal tissue from patients treated with radiotherapy shows mast cell hyperplasia and activation, suggesting that these cells play a role in the development of radiation-induced sequelae. To investigate the role of mast cells in radiation damage, experimental radiation proctitis was induced in a mast cell-deficient (W(sh)/W(sh)) mouse model. The colon and rectum of W(sh)/W(sh) and wild-type mice were exposed to 27-Gy single-dose irradiation and studied after 2 and 14 weeks. Irradiated rodent rectum showed mast cell hyperplasia. W(sh)/W(sh) mice developed less acute and chronic rectal radiation damage than their control littermates. Tissue protection was associated with increased tissue neutrophil influx and expression of several inflammatory mediators immediately after radiation exposure. It was further demonstrated that mast cell chymase, tryptase, and histamine could change human muscularis propria smooth muscle cells into a migrating/proliferating and proinflammatory phenotype. These data show that mast cells have deleterious effects on both acute and chronic radiation proctitis, possibly by limiting acute tissue neutrophil influx and by favoring phenotypic orientation of smooth muscle cells, thus making them active participants in the radiation-induced inflammatory process and dystrophy of the rectal wall.

Endoscopic Ultrasonographic Features of Subacute Radiation Proctitis

Endoscopic ultrasonography (EUS) is one of the most accurate methods for the assessment of rectal disorders, in particular for local staging of rectal adenocarcinomas. 1 The role of EUS in imaging benign inflammatory disorders of the rectum is less defined. 2-4 Radiation proctitis is a known complication of pelvic irradiation. Acute radiation proctitis occurring within the first 6 weeks is caused by direct mucosal damage by radiation and typically resolves with resolution of the radiation treatement. 5,6 Chronic radiation proctitis is a result of progressive epithelial atrophy, fibrosis, and obliterative endarteritits with mucosal ischemia. It manifests late (>1 year after radiation) in 5% to 20% of patients, with symptoms including rectal bleeding, pain, and urgency. 7 The risk of rectal adenocarcinoma is increased after pelvic radiation therapy; however, the rate does not increase for 10 to 20 years after therapy. 8 In this report, we present an unusual case of subacute radiation proctitis appearing as an ulcerated mass lesion and the use of EUS to help differentiate it from malignancy. To our knowledge, the EUS features of radiation proctitis have not been reported previously.