Current concepts in radiation enteritis and implications for future clinical trials

Recent advances in intestinal fibrosis

Despite many progresses have been made in the treatment of inflammatory bowel disease, especially due to the increasing number of effective therapies, the development of tissue fibrosis is a very common occurrence along the natural history of this condition. To a certain extent, fibrogenesis is a physiological and necessary process in all those conditions characterised by chronic inflammation. However, the excessive deposition of extracellular matrix within the bowel wall will end up in the formation of strictures, with the consequent need for surgery. A number of mechanisms have been described in this process, but some of them are not yet clear. For sure, the main trigger is the presence of a persistent inflammatory status within the mucosa, which in turn favours the occurrence of a pro-fibrogenic environment. Among the main key players, myofibroblasts, fibroblasts, immune cells, growth factors and cytokines must be mentioned. Although there are no available therapies able to target fibrosis, the only way to prevent it is by controlling inflammation. In this review, we summarize the state of art of the mechanisms involved in gut fibrogenesis, how to diagnose it, and which potential targets could be druggable to tackle fibrosis.

Radiation Enterocolitis Featuring the Perforation of the Sigmoid Colon, Small Bowel, and Entero-Colonic Fistula: A Case Report

Radiation enteritis poses a treatment challenge for patients undergoing or completing radiation therapy. A significant issue has been the patient's and surgeon's lack of awareness of the condition and the radiotherapy or associated surgical treatments. A 66-year-old female presented with acute onset of diffuse abdominal pain and peritonitis for one day, status post radiation therapy following a diagnosis of cervical cancer. A review of systems was positive for diffuse sweating, chills, and nausea. The patient was diagnosed with an entero-colonic fistula with mesenteric edema. An entero-colonic fistula due to radiation enterocolitis is a rare but important complication that can occur after radiation therapy for abdominal or pelvic malignancies. With any patient who has a history of abdominal or pelvic cancer and has received radiotherapy and shows up with acute abdomen, bowel perforation should be considered in the differential diagnosis with the possible management of acute complications.

Higher radiation doses after partial laryngectomy may raise the incidence of pneumonia: A retrospective cohort study

Background

Currently, studies have shown that a high dose of radiotherapy to the throat have various harmful and adverse effects on the patients' laryngeal function, resulting in the development of pneumonia. This study aimed to explore how radiotherapy dose affected the probability of pneumonia following laryngeal cancer surgery.

Materials and methods

A retrospective analysis was done on patients diagnosed with laryngeal cancer between 2010 and 2020 and were treated surgically and with postoperative radiotherapy in the same institution. This study included 108 patients in total, 51 of who were in the low-dose group and 57 of whom were in the high-dose group. Age, gender, the location of laryngeal cancer, the presence or absence of lymph node metastasis, and other demographic and clinical characteristics were collected, and the prevalence of postoperative pneumonia was compared between the two groups.

Results

The total prevalence of postoperative pneumonia was 59.3%, but there was a significant difference between the two groups(high-dose group 71.9% VS low-dose group 45.1%; p=0.005). A total of 9.3% (10/108) of the patients had readmission due to severe pneumonia, and the rate of readmission due to pneumonia was significantly different between the two groups (high-dose group 15.8% VS low-dose group 2.0%, p=0.032). Additionally, the high-dose group's prevalence of Dysphagia was significantly higher than the low-dose group's. According to multivariate logistic modeling, high-dose radiation was a risk factor for pneumonia (OR=4.224, 95%CI =1.603-11.131, p=0.004).

Conclusion

Pneumonia risk could increase with radiotherapy doses > 50 Gy in the treatment of laryngeal cancer. Therefore, we recommend that when the radiation dose surpasses 50Gy, doctors should pay particular attention to the lung health of patients with laryngeal cancer.

Evaluation of Novel Tranexamic Acid/Montmorillonite Intercalation Composite, as a New Type of Hemostatic Material

Radiation enteritis-clinically manifested as diarrhea, intestinal bleeding, and so on-is frequently caused when the body is exposed to radiation or radiotherapy because the intestine is radiation-sensitive as an abdominal organ. Therefore, strategies to modulate intestinal hemostasis had inspired an important research trend in the process of preventing and treating radiation enteritis. Based on the structural characteristics of montmorillonite (MMT) and the hemostatic drug tranexamic acid (TXA) which was used clinically to treat enteritis, the tranexamic acid-montmorillonite composite material (TXA-MMT) was prepared through intercalation composite technology. According to the analysis of FTIR, XRD, TG-DTG, SEM, and XRF, the prepared TXA-MMT was verified that tranexamic acid could intercalate into layers of montmorillonite. To evaluate the biocompatibility, two experiments were conducted by in vitro hemolysis and in vitro cytotoxicity experiments and results showed that TXA-MMT exhibited good visible biocompatibility. Activated partial thromboplastin time, prothrombin time, and in vitro clotting time were adopted to determine the hemostatic effect of TXA-MMT. Compared with other groups, TXA-MMT revealed a significant decrease in clotting time variations, APTT, and PT. In addition, to investigate the preventive effect of TXA-MMT by the intervention of radiation enteritis mice, inflammatory factors IL-1β, IL-6, and TNF-α and the content of endotoxin in the serum of mice were detected. It demonstrated that TXA-MMT reduced the levels of these factors. Besides, the expression and the pathological changes of the small intestine tissue of mice were relieved. Our findings suggests that TXA-MMT as a promising intercalation composite has a great potential for application in the field of intestinal hemostasis.

Permeable gastric ulcer caused by radioactive 125I seed implantation for adrenal metastasis: A case report and literatures review

Radioactive ¹²⁵I seed implantation as a means of radiotherapy for malignant tumors has been proved to be safe and effective. Although the effectiveness of ¹²⁵I seed implantation in the treatment of tumor metastases has been widely recognized, there is still no standard for the selection of radiation doses. Adrenal blood supply is abundant, and it is a common metastatic site for malignant tumors. CT-guided radioactive ¹²⁵I seed implantation is effective in treating adrenal metastases. However, it may cause certain damage to surrounding organs, especially the stomach. Clinically, for patients with left adrenal metastatic carcinoma and concurrent radioactive seed implantation, the occurrence of permeable gastric ulcer should not be neglected. In order to reduce the effect of radioactive particles on the normal tissue structure around the tumor, low-activity particles should be used.

Antioxidant Supplementation: A Linchpin in Radiation-Induced Enteritis

Radiation enteritis is one of the most feared complications of abdominal and pelvic regions. Thus, radiation to abdominal or pelvic malignancies unavoidably injures the intestine. Because of rapid cell turnover, the intestine is highly sensitive to radiation injury, which is the limiting factor in the permissible dosage of irradiation. Bowel injuries such as fistulas, strictures, and chronic malabsorption are potentially life-threatening complications and have an impact on patient quality of life. The incidence of radiation enteritis is increasing because of the current trend of combined chemotherapy and radiation. The consequences of radiation damage to the intestine may result in considerable morbidity and even mortality. The observed effects of ionizing radiation are mediated mainly by oxygen-free radicals that are generated by its action on water and are involved in several steps of signal transduction cascade, leading to apoptosis. The oxyradicals also induce DNA strand breaks and protein oxidation. An important line of defense against free radical damage is the presence of antioxidants. Therefore, administration of antioxidants may ameliorate the radiation-induced damage to the intestine.

Protected graft copolymer-formulated fibroblast growth factors mitigate the lethality of partial body irradiation injury

We evaluated the mitigating effects of fibroblast growth factor 4 and 7 (FGF4 and FGF7, respectively) in comparison with long acting protected graft copolymer (PGC)-formulated FGF4 and 7 (PF4 and PF7, respectively) administered to C57BL/6J mice a day after exposure to LD50/30 (15.7 Gy) partial body irradiation (PBI) which targeted the gastrointestinal (GI) system. The PGC that we developed increased the bioavailability of FGF4 and FGF7 by 5- and 250-fold compared to without PGC, respectively, and also sustained a 24 hr presence in the blood after a single subcutaneous administration. The dose levels tested for mitigating effects on radiation injury were 3 mg/kg for the PF4 and PF7 and 1.5 mg each for their combination (PF4/7). Amifostine administered prior to PBI was used as a positive control. The PF4, PF7, or PF4/7 mitigated the radiation lethality in mice. The mitigating effect of PF4 and PF7 was similar to the positive control and PF7 was better than other mitigators tested. The plasma citrulline levels and hematology parameters were early markers of recovery and survival. GI permeability function appeared to be a late or full recovery indicator. The villus length and crypt number correlated with plasma citrulline level, indicating that it can act as a surrogate marker for these histology evaluations. The IL-18 concentrations in jejunum as early as day 4 and TPO levels in colon on day 10 following PBI showed statistically significant changes in irradiated versus non-irradiated mice which makes them potential biomarkers of radiation exposure. Other colon and jejunum cytokine levels are potentially useful but require larger numbers of samples than in the present study before their full utility can be realized.

Long-Term Palliative Effect of Stenting in Gastric Outlet Obstruction Due to Transarterial Chemoembolization with Yttrium-90 in a Patient with Metastatic Neuroendocrine Tumor

Internal radioembolization with yttrium-90 is a promising treatment method, predominantly for liver tumors. However, the shifting of yttrium-90-loaded spherules into the arteries and veins that supply the duodenum and stomach, leading to ulceration, hemorrhage, perforation, and outlet obstruction of these organs, is one of the major undesirable consequences of this technique. We report a case of gastric outlet obstruction (GOO) due to antropyloric stenosis with ulceration, edema, and inflammation following transarterial yttrium-90 treatment for a metastatic neuroendocrine tumor in a 58-year-old man. Stenting was used for palliation in this case. GOO improved after stenting and recovery of oral intake was permanent after stent removal.

High-Dose Radiation-Induced Changes in Murine Small Intestinal Motility: Are the Changes in the Interstitial Cells of Cajal or in the Enteric Nervous System?

Murine small intestinal motility consists of phasic contraction from interstitial cells of Cajal (ICC) and migrating motor complexes (MMCs) from the enteric nervous system. The number of ICC is reduced in various gastrointestinal disorders, and this effect can be reversed once the disorder is resolved through cellular and tissue remodelling. Exposure to high-dose radiation can induce inflammation and alter intestinal motility. In this study, we investigated the changes in the small intestinal motility of 8- to 10-week-old male C3H/HeN mice after high-dose (13 Gy) irradiation. The aim of this study was to determine whether those changes are caused by changes in the ICC or enteric nervous system. After irradiation, the small intestine was dissected and stored in oxygenated Krebs-Ringer bicarbonate solution. The tension of contractions and intracellular membrane potentials were recorded at day 0, 1, 3 and 5 after irradiation and compared with those of sham-irradiated mice. Histological evaluation was performed by immunohistochemistry and apoptosis was evaluated. Quantitative real-time polymerase chain reaction (qPCR) for c-kit mRNA was also performed. Phasic contractions were not changed at day 0, 1, 3 and 5 after irradiation and did not significantly differ from those in the control mice. Slow waves were also sustained after irradiation. However, the frequency of migrating motor complexes (MMCs) was significantly higher at day 0 and 1 after exposure and the amplitude and area under the curve were significantly lower at day 3 after exposure compared with control mice. MMCs were recovered at day 5 with no difference from those of the control mice. ICC were detected after irradiation by immunohistochemistry for c-kit, and c-kit mRNA levels did not differ between sham-irradiated and irradiated mice. Histological evaluation showed that the most severe inflammation was detected at day 3 after irradiation, and apoptosis was detected only in the mucosa. Acetylcholine increased the contractility after irradiation, and tetrodotoxin decreased the number of MMCs in sham-irradiated and irradiated mice. N(w)-oxide-l-arginine (L-NA) increased the number of MMCs. MMCs were recovered after L-NA treatment at day 3 after irradiation. Sodium nitroprusside decreased the MMCs in sham-irradiated and irradiated mice. Exposure to high-dose radiation did not alter phasic contractions and slow waves in the small intestine of mice, which suggests that ICC and their functions may be sustained after high-dose irradiation. Mucosal inflammation was severe after irradiation and there were some changes in MMCs related to the enteric nervous system.

Research status of radiation induced gastroduodenal injury

With the development of modern radiotherapy techniques, such as three dimensional conformal radiotherapy, Gamma-knife treatment, and tomotherapy, patients who have abdominal tumors like liver cancer, pancreatic cancer, and colon cancer can live longer. The wide use of radiation therapy increases the incidence of gastroduodenal radioactive injury. This article reviews the pathogenesis and pathological characteristic of radiation induced gastroduodenal injury, factors influencing the injury, and the diagnosis and treatment of radiation induced gastroduodenal injury. Currently, there have been few studies on the mechanism of radiation induced gastroduodenal injury. The optimal timing of endoscopic examination after radiotherapy is still inconclusive. V25 for the stomach, V35 for the duodenum and aV55 Gy for the duodenum are predictive factors for gastroduodenal toxicity (>grade 2, CTCAE3.0). There has been no treatment standard for curing radiation induced gastroduodenitis. Traditional Chinese medicine has unique advantages in the prevention and control of radiation induced gastroduodenal injury.

Risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy

PURPOSE

Perineal wounds after complete proctectomy are at risk for failure, with dramatic consequences on patients' health and quality of life. This study is aimed at identifying risk factors for wound complications in patients undergoing primary closure of the perineal defect after total proctectomy.

METHODS

Data from 284 patients undergoing total proctectomy from 2002 to 2012 either at the University of Chicago Medical Center or the Catholic University of Rome Hospital were collected and analyzed.

RESULTS

Overall, the perineal wound complication rate was 21.8%. Successful conservative management was accomplished in 45.2% of cases. Complications occurred significantly more often in patients with a higher Charlson score index, with the diagnosis of rectal cancer, who had received preoperative radiation and who had a surgical drain placed at the time of initial surgery. Neoadjuvant radiation was the only significant risk factor at multivariate analysis (OR 4.40). In the rectal cancer subgroup, younger age, female gender, and preoperative radiation were predictors of wound complications. Based on that, a 3-point score (radiation, age, and gender (RAG)) was developed. Patients with a score of 3 had a 50% risk of developing a perineal wound complication.

CONCLUSIONS

Perineal wound complications are a common and burdensome problem after total proctectomy. Preoperative radiation is the single most significant and controllable risk factor predicting perineal wound failure. In the presence of multiple, non-modifiable risk factors, alternative approaches to primary closure should be considered in managing complex perineal defects.

Molecular mechanism of acute radiation enteritis revealed using proteomics and biological signaling network analysis in rats

BACKGROUND AND AIMS

Radiation enteritis (RE) has emerged as a significant complication that can progress to severe gastrointestinal disease and the mechanisms underlying its genesis remain poorly understood. The aim of this study was to identify temporal changes in protein expression potentially associated with acute inflammation and to elucidate the mechanism underlying radiation enteritis genesis.

METHODS

Male Sprague-Dawley rats were irradiated in the abdomen with a single dose of 10 Gy to establish an in vivo model of acute radiation enteritis. Two-dimensional fluorescence difference gel electrophoresis, matrix-assisted laser desorption/ionization time-of-flight spectrometer (MALDI-TOF) tandem mass spectrometry, and peptide mass fingerprinting were used to determine differentially expressed proteins between normal and inflamed intestinal mucosa. Additionally, differentially expressed proteins were evaluated by KO Based Annotation System to find the biological functions associated with acute radiation enteritis.

RESULTS

Intensity changes of 86 spots were detected with statistical significance (ratio ≥ 1.5 or ≤ 1.5, P < 0.05). Sixty one of the 86 spots were identified by MALDI-TOF/TOF tandem mass spectrometry. These radiation-induced proteins with biological functions showed that the FAS pathway and glycolysis signaling pathways were significantly altered using the KOBAS tool.

CONCLUSIONS

Our results reveal an underlying mechanism of radiation-induced acute enteritis, which may help clarify the pathogenesis of RE and point to potential targets for therapeutic interventions.

Significant fibrosis after radiation therapy in a patient with Marfan syndrome

Marfan syndrome is one of the collagen vascular diseases that theoretically predisposes patients to excessive radiation-induced fibrosis yet there is minimal published literature regarding this clinical scenario. We present a patient with a history of Marfan syndrome requiring radiation for a diagnosis of a right brachial plexus malignant nerve sheath tumor. It has been suggested that plasma transforming growth factor beta 1 (TGF-β1) can be monitored as a predictor of subsequent fibrosis in this population of high risk patients. We therefore monitored the patient's TGF-β1 level during and after treatment. Despite maintaining stable levels of plasma TGF-β1, our patient still developed extensive fibrosis resulting in impaired range of motion. Our case reports presents a review of the literature of patients with Marfan syndrome requiring radiation therapy and the limitations of serum markers on predicting long-term toxicity.

Gastrectomy for the treatment of refractory gastric ulceration after radioembolization with 90Y microspheres

Transcatheter arterial radioembolization (TARE) with Yttrium-90 ((90)Y)-labeled microspheres has an emerging role in treatment of patients with unresectable hepatocellular carcinoma. Although complication of TARE can be minimized by aggressive pre-evaluation angiography and preventive coiling of aberrant vessels, radioembolization-induced gastroduodenal ulcer can be irreversible and can be life-threatening. Treatment of radioembolization-induced gastric ulcer is challenging because there is a few reported cases and no consensus for management. We report a case of severe gastric ulceration with bleeding that eventually required surgery due to aberrant deposition of microspheres after TARE.

Radiation enteritis

Radiation enteritis continues to be a major health concern in recipients of radiation therapy. The incidence of radiation enteritis is expected to continue to rise during the coming years paralleling the unprecedented use of radiotherapy in pelvic cancers. Radiation enteritis can present as either an acute or chronic syndrome. The acute form presents within hours to days of radiation exposure and typically resolves within few weeks. The chronic form may present as early as 2 months or as long as 30 years after exposure. Risk factors can be divided into patient and treatment-related factors. Chronic radiation enteritis is characterized by progressive obliterative endarteritis with exaggerated submucosal fibrosis and can manifest by stricturing, formation of fistulae, local abscesses, perforation, and bleeding. In the right clinical context, diagnosis can be confirmed by cross-sectional imaging, flexible or video capsule endoscopy. Present treatment strategies are directed primarily towards symptom relief and management of emerging complications. Recently, however, there has been a shift towards rational drug design based on improved understanding of the molecular basis of disease in an effort to limit the fibrotic process and prevent organ damage.

Effect of antioxidant supplementation on digestive enzymes in radiation induced intestinal damage in rats

PURPOSE

Intestinal mucosa, a rapidly proliferating tissue, is highly sensitive to radiation and undergoes apoptosis as a consequence of over generation of oxidative free radicals and the lack of the antioxidants. Thus the present study was designed to investigate the intestinal damage induced by radiation and to study if supplementation of the diet with antioxidant vitamins could ameliorate the intestinal damage and its digestive activity, as determined by the expression of various border enzymes.

MATERIALS AND METHODS

Swiss Albino rats (150-200 g body weight) were divided into six groups. Group I: Control untreated; Group II: Irradiated; Group III: Irradiated + vitamin A; Group IV: Irradiated + vitamin C; Group V: Irradiated + vitamin E; and Group VI: Irradiated + lycopene. Animals were exposed to whole body γ-radiation from (60)Co at the rate of 8 Gy for 15 min/rat. Intestinal morphology and changes in various digestive enzymes together with, DNA damage was studied in six groups and each group consisted of 18 animals.

RESULTS

The gastrointestinal toxicity resulted in malabsorption, diarrhoea, weight loss, loss of appetite, abdominal haemorrhage and hair loss. The activities of sucrase and alkaline phosphatase were elevated and those of lactase, leucine aminopeptidase (LAP) and gamma-glutamyl transpeptidase or tranferase (γ-GTP) were markedly reduced. Antioxidant vitamin A, C or E supplementations prevented changes in brush border enzyme activities as compared to lycopene administration in rat intestine by radiation exposure. Intestinal histology showed that the vitamin supplementation to irradiated rats minimized the intestinal damage in rats.

CONCLUSION

These findings suggest that the epithelial lining of the intestine is highly sensitive to radiation exposure and supplementation of antioxidant vitamins is helpful in minimizing the intestinal damage and supplementation by vitamin E was most potent in ameliorating the intestinal aberrations.

Gastric or duodenal injury induced by radiotherapy for pancreatic carcinoma: An analysis of 31 cases

AIM: To observe gastric or duodenal mucosal injury induced by radiotherapy in patients with pancreatic carcinoma and to analyze possible influencing factors.

METHODS: Thirty-one patients with pancreatic carcinoma who underwent gastroscopy after radiotherapy were included. Their clinical symptoms were graded according to RTOG/EORTC. Gastroscopic findings were graded as I-IV. All patients underwent endoscopic biopsy for histopathological examination. Factors influencing radiotherapy-induced gastric or duodenal mucosal injury were analyzed.

RESULTS: Main clinical symptoms included abdominal distension, anorexia, acid reflux, nausea, vomiting, and abdominal pain. Endoscopic analysis indicated that 4 cases were classified as grade Ⅰ (no gastric or duodenal mucosa injury), 6 cases as grade Ⅱ (mild gastric or duodenal mucositis), 3 cases as grade Ⅲ (erosive gastritis), and 17 cases as grade Ⅳ ( including 6 with gastric ulcer, 1 with gastric ulcer and gastric antral deformation, 5 with duodenal ulcer, 1 with anastomotic ulcer, and 4 with duodenal ulcer and narrowing). Endoscopic biopsy and histopathological analysis proved that all cases had inflammatory or ulcerative changes. The rates of detection of gastric or duodenal mucosa injury by γ-ray, 3-D, TOMO or gastroscopy were: γ-ray therapy vs 3-D (80.0% vs 80.0%, P > 0.0167), γ-ray therapy vs TOMO (80.0% vs 72.7%, P > 0.0167), and 3-D vs TOMO (80.0% vs 72.7%, P > 0.0167). When γ-ray radiotheraphy dose was 51 Gy (10 cases), 48 Gy (3 cases) and 45 Gy (2 cases), the rates of gastric or duodenal mucosal injury were 90%, 100% and 100%, respectively. The rate of gastric or duodenal mucosal injury did not differ significantly between patients who underwent surgery (n = 16) and those who did not undergo (n = 15) (87.5% vs 66.7%, P > 0.05), between patients receiving concurrent chemoradiotherapy (n = 9) and those not receiving (n = 22) (66.7% vs 91.9%, P > 0.05), between those receiving amifostine during radiotherapy (n = 10) and not receiving (n = 15) (85.7% vs 82.4%, P > 0.05), or between patients having co-morbidities (e.g., diabetes mellitus, hypertension, or inflammatory bowel disease) (n = 14) and those not having (n = 17) (78.6% vs 76.5%, P > 0.05). In contrast, the rate of gastric or duodenal mucosal injury differed significantly between patients given gastrointestinal mucosal protective agents during radiotherapy (n = 16) and those not given (n = 15) (68.7% vs 100%, P < 0.05).

CONCLUSION: Gastroscopy is a preferred modality for the detection of gastric or duodenal injury induced by radiotherapy in patients with pancreatic carcinoma. High radiation dose is associated with a higher incidence of gastric or duodenal mucosal injury. The use of gastric or duodenal mucosal protective agents is a favorable factor for radiotherapy-induced gastric or duodenal mucosal injury. Radiotherapy techniques, amifostine, abdominal surgery or chronic complications have no significant impact on gastric or duodenum injury induced by radiation.

Aspiration in head and neck cancer patients: a single centre experience of clinical profile, bacterial isolates and antibiotic sensitivity pattern

Most patients with head and neck cancer have dysphagia and are at increased risk of having aspiration and subsequent pneumonia. It can cause prolonged hospitalization, treatment delay and/or interruption and mortality in cancer patients. The treatment of these infections often relies on empirical antibiotics based on local microbiology and antibiotic sensitivity patterns. The aim of present study is to analyse respiratory tract pathogens isolated by sputum culture in head and neck cancer patients undergoing treatment at a tertiary cancer centre in South India who presented with features of aspiration. The study is carried out to establish empirical antibiotic policy for head and neck cancer patients who present with features of aspiration. This was a retrospective study. The study included sputum samples sent for culture and sensitivity from January 2011 to December 2012. Analysis of microbiologic species isolated in sputum specimen and the antibiotic sensitivity pattern of the bacterial isolates was performed. A detailed study of case files of all patients was done to find out which is the most common site prone for producing aspiration. There were 47 (31.54 %) gram positive isolates and 102 (68.45 %) gram negative isolates. The most common bacterial isolates were Klebsiella pneumoniae (25.50 %), Pseudomonas aeruginosa (16.77 %) and Haemophilus influenzae (15.43 %). Levofloxacin was the most effective antibiotic with excellent activity against both gram positive and gram negative isolates. Most patients with aspiration had laryngeal cancer (34.89 %). Aspiration pneumonia was present in 14 (9.39 %) patients. Gram negative bacteria are common etiologic agents in head and neck cancer patients presenting with features of aspiration. Levofloxacin should be started as empirical antibiotic in these patients while awaiting sputum culture sensitivity report. As aspiration in head and neck cancer is an underreported event such institutional antibiotic sensitivity studies should be encouraged for prompt initiation of antibiotic that is most likely to be effective against etiologic pathogens.

Radiation fibrosis of the vocal fold: from man to mouse

OBJECTIVES/HYPOTHESIS

To characterize fundamental late tissue effects in the human vocal fold following radiation therapy. To develop a murine model of radiation fibrosis in order to ultimately develop both treatment and prevention paradigms.

DESIGN

Translational study using archived human and fresh murine irradiated vocal fold tissue.

METHODS

1) Irradiated vocal fold tissue from patients undergoing laryngectomy for loss of function from radiation fibrosis was identified from pathology archives. Histomorphometry, immunohistochemistry, and whole-genome microarray, as well as real-time transcriptional analyses, were performed. 2) Focused radiation to the head and neck was delivered to mice in a survival fashion. One month following radiation, vocal fold tissue was analyzed with histomorphometry, immunohistochemistry, and real-time PCR transcriptional analysis for selected markers of fibrosis.

RESULTS

Human irradiated vocal folds demonstrated increased collagen transcription, with increased deposition and disorganization of collagen in both the thyroarytenoid muscle and the superficial lamina propria. Fibronectin were increased in the superficial lamina propria. Laminin decreased in the thyroarytenoid muscle. Whole genome microarray analysis demonstrated increased transcription of markers for fibrosis, oxidative stress, inflammation, glycosaminoglycan production, and apoptosis. Irradiated murine vocal folds demonstrated increases in collagen and fibronectin transcription and deposition in the lamina propria. Transforming growth factor (TGF)-β increased in the lamina propria.

CONCLUSION

Human irradiated vocal folds demonstrate molecular changes leading to fibrosis that underlie loss of vocal fold pliability occurring in patients following laryngeal irradiation. The irradiated murine tissue demonstrates similar findings, and this mouse model may have utility in creating prevention and treatment strategies for vocal fold radiation fibrosis.

A mechanism for abnormal angiogenesis in human radiation proctitis: analysis of expression profile for angiogenic factors

BACKGROUND

Radiation proctitis is an increasingly prevalent problem, with many patients being treated with radiotherapy for pelvic cancers. However, the mechanisms by which radiation proctitis develops in humans are not well understood. In this study, the expression profiles of angiogenic factors were analyzed to clarify their role in the etiology of radiation proctitis.

METHODS

Rectal biopsies were taken from 8 patients with radiation proctitis and 8 normal subjects. Protein lysates of the tissues were applied to an antibody array for angiogenesis-related factors. The mRNA level of each factor was evaluated by Taqman real-time PCR. Immunohistochemistry was performed using the labeled streptavidin biotin method.

RESULTS

Antibody array analysis revealed 2.12- to 7.31-fold higher expression levels of angiogenin, fibroblast growth factor 1 (FGF1), endoglin, matrix metalloproteinase (MMP)-8, urokinase-type plasminogen activator (uPA) and maspin in radiation proctitis tissues compared with normal rectal mucosa. The mRNA level of each factor in radiation proctitis tissue was significantly higher than in normal rectal mucosa, suggesting their transcriptional activation. Immunohistochemical staining showed strong expression of angiogenin and maspin in rectal epithelia, MMP-8 and uPA in infiltrating lymphocytes, FGF1 in fibroblasts and endoglin in endothelial cells. The expression of VEGF was not evident.

CONCLUSIONS

Our results suggest that in radiation proctitis, MMP-8 and uPA cooperatively degrade the extracellular matrix and basement membrane to provide space for angiogenesis. Simultaneously, angiogenin and FGF1 promote endothelial cell proliferation, and endoglin induces vessel formation, culminating in angiogenesis. Inhibitors of angiogenic factors such as angiogenin and FGF1 may be effective for treating radiation proctitis.

Management of chronic radiation enteritis with intestinal obstruction

AIM: To evaluate the effect of various treatment methods for chronic radiation enteritis with concurrent intestinal obstruction.

METHODS: The clinical data for 21 patients with chronic radiation enteritis and intestinal obstruction was retrospectively analyzed.

RESULTS: Five of seven patients who received conservative treatment experienced relapse, and the cure rate was only 28.6%. Fourteen patients who underwent surgical treatment (of them ten patients underwent intestinal resection and anastomosis) had satisfactory outcome, and the cure rate was as high as 90.0%. One patient developed intestinal fistula, and re-operation confirmed that it was caused by residual radiation enteritis.

CONCLUSION: Surgical treatment is the best way for treatment of chronic radiation enteritis with intestinal obstruction. All intestinal lesions should be surgically removed to avoid intestinal fistula.

[Therapy of radiation enteritis--current challenges]

Radiation enteritis is one of the most feared complications after abdominal and pelvic radiation therapy. The incidence varies from 0.5 to 5%. It is not rare that the slowly progressing condition will be fatal. During a period of 13 years 24 patients were operated due to the complication of radiation enteritis. Despite different types of surgery repeated operation was required in 25% of cases and finally 4 patients died. Analyzing these cases predisposing factors and different therapeutic options of this condition are discussed. Treatment options of radiation induced enteritis are limited; however, targeted therapy significantly improves the outcome. Cooperation between oncologist, gastroenterologist and surgeon is required to establish adequate therapeutic plan.

Symptoms, diagnosis and treatment of radiation-induced enteritis

A daganatos betegségek ellátása során végzett sugárkezelések száma világszerte növekszik. A kismedencei és a hasüregi daganatok sugárkezelése során a legnagyobb gondosság ellenére is előfordulhatnak különböző súlyosságú bélgyulladások. A kismedence sugárkezelése közben vagy után megközelítőleg a kezelések felében lép fel a kezeléssel összefüggésbe hozható akut, az esetek egynegyedében krónikus, elhúzódó vékonybél-, illetve vastagbélgyulladás. A sugárterápiát követő krónikus enteritis számos diagnosztikai és terápiás problémát vet fel, amelyek megoldásához a társszakmák összefogása szükséges. A szerzők a sugárkezelés után kialakult bélgyulladások kezelésével kapcsolatban adnak rövid áttekintést.

Gastroduodenal ulceration associated with radioembolization for the treatment of hepatic tumors: an institutional experience and review of the literature

BACKGROUND

Microsphere radioembolization is a method of delivering radiation therapy directly to tumors, thereby minimizing toxicity to adjacent structures. Despite the relatively high precision of this modality, numerous adverse effects have been recognized. One particularly untoward complication is the development of severe gastroduodenal ulceration.

METHODS

In order to further characterize gastroduodenal ulceration associated with radioembolization, our institutional experience as well as the reported literature were reviewed.

RESULTS

The current evidence suggests that radioembolization-associated gastroduodenal ulceration results from inadvertent delivery of microspheres to the microvasculature of the gastrointestinal tract, leading to direct radiation toxicity. The reported incidence of this entity ranges between 2.9% and 4.8%. Most patients with this complication present with abdominal pain, often associated with nausea, vomiting, and anorexia. Symptoms can arise from hours to months after radioembolization treatment; diagnosis is made by endoscopic biopsy and histopathologic evaluation of the ulcer specimen. Radiation-induced ulcers have proven to be extremely difficult to treat. Current therapy based on acid suppression has had limited success, and the evidence for the addition of antioxidants and anti-inflammatory agents is still sparse.

CONCLUSIONS

The increasing utilization of radioembolization will lead to adverse events including gastroduodenal ulceration. This entity must be considered in any patient treated with radioactive microspheres presenting with symptoms of dyspepsia. Accurate diagnosis and aggressive treatment are necessary to improve patient outcomes.

Recombinant human epidermal growth factor (rhEGF) protects radiation-induced intestine injury in murine system

This study was to investigate whether rhEGF protects radiation induced intestine injury without compromising antitumor effect of radiation in murine system. A radiation induced intestinal injury model was established in mice by whole body irradiation. Using this model, 4 groups were set; control, rhEGF (100 µg/kg intraperitoneally), radiation (10 Gy), and a combination (rhEGF and radiation). The level of apoptosis and proliferation were analyzed by TUNEL assay and proliferation cell nuclear antigen (PCNA) immunohistochemical staining, respectively, as well as observation of survival and body weight change. A tumor growth delay assay was performed using murine syngeneic tumors; one radioresistant tumor, HCa-I and one radiosensitive tumor, MCa-K. In the radiation induced intestinal injury model, the 10 Gy group had significantly more weight loss with less number of crypt cells and higher apoptosis than the 8 Gy group. Using 10 Gy model, radioprotective effect of rhEGF was tested. Addition of rhEGF improved not only the body weight loss but also survival following radiation. It also induced suppression of apoptosis as well as increase of PCNA expression and recovery of villi. rhEGF did not enhance the tumor growth after radiation exposure in the tested tumors. These findings suggest that combination of exogenous rhEGF and radiation can be a new anticancer strategy by protecting radiation-induced intestinal injury without alleviating antitumor effect of radiation.

Sigmoidectomy for radiation-induced sigmoid colonic dysplasia 35 years after radiotherapy for cervical cancer

Although radiation-induced colonic cancer is thought to arise from dysplasia, no guidelines exist for the treatment of such dysplasia. Therefore, clinicians must make treatment decisions for this condition on a case-by-case basis. Especially when the operative procedure is being decided, it is necessary to consider postoperative quality of life for advanced age. We report a patient who underwent sigmoidectomy for sigmoid colonic dysplasia that developed 35 years after radiation therapy. A 73-year-old woman who had undergone total hysterectomy and chemoradiotherapy for cervical cancer 35 years previously presented following a positive fecal occult blood test. Colonoscopy revealed sigmoid colonic dysplasia. To ensure reliable removal of the lesion, we elected to perform surgical resection. Given the patient's age, we performed sigmoidectomy rather than resecting the entire irradiated intestinal tract. The diagnosis of dysplasia was confirmed based on pathological findings, which included duct proliferation with partial structural atypia.

Punica granatum peel extract protects against ionizing radiation-induced enteritis and leukocyte apoptosis in rats

Radiation-induced enteritis is a well-recognized sequel of therapeutic irradiation. Therefore we examined the radioprotective properties of Punica granatum peel extract (PPE) on the oxidative damage in the ileum. Rats were exposed to a single whole-body X-ray irradiation of 800 cGy. Irradiated rats were pretreated orally with saline or PPE (50 mg/kg/day) for 10 days before irradiation and the following 10 days, while control rats received saline or PPE but no irradiation. Then plasma and ileum samples were obtained. Irradiation caused a decrease in glutathione and total antioxidant capacity, which was accompanied by increases in malondialdehyde levels, myeloperoxidase activity, collagen content of the tissue with a concomitant increase 8-hydroxy-2'-deoxyguanosine (an index of oxidative DNA damage). Similarly, pro-inflammatory cytokines (TNF-alpha, IL-1beta and IL-6) and lactate dehydrogenase were elevated in irradiated groups as compared to control. PPE treatment reversed all these biochemical indices, as well as histopathological alterations induced by irradiation. Furthermore, flow cytometric measurements revealed that leukocyte apoptosis and cell death were increased in irradiated animals, while PPE reversed these effects. PPE supplementation reduced oxidative damage in the ileal tissues, probably by a mechanism that is associated with the decreased production of reactive oxygen metabolites and enhancement of antioxidant mechanisms. Adjuvant therapy of PPE may have a potential to support a successful radiotherapy by protecting against radiation-induced enteritis.

Normal small bowel wall characteristics on MR enterography

PURPOSE

To assess the normal small bowel parameters, namely bowel diameter, bowel wall thickness, number of folds (valvulae connivientes) per 2.5 cm (in.), fold thickness and interfold distance per small bowel segment (duodenum, jejunum, proximal ileum, distal ileum and terminal ileum) on MR enterography.

MATERIALS AND METHODS

Between September 2003 and January 2008, 280 MR enterography examinations were performed for investigation of known or suspected small bowel pathology. 120 of these examinations were normal. Sixty-five (m=29, f=36, mean age=34 years, range=17-73 years) of 120 examinations without a prior small bowel diagnosis, with no prior or subsequent abnormal radiology or endoscopy examinations, no prior small bowel surgery and with a minimum 3 years follow-up demonstrating normality were retrospectively evaluated for the described small bowel parameters.

RESULTS

We found the mean diameter of the duodenum to be 24.8mm (S.D.=4.5mm), jejunum to be 24.5mm (S.D.=4.2mm), proximal ileum to be 19.5mm (S.D.=3.6mm), distal ileum to be 18.9 mm (S.D.=4.2mm) and terminal ileum to be 18.7 mm (S.D.=3.6mm). The number of folds per 2.5 cm varied from 4.6 in the jejunum to 1.5 in the terminal ileum. The fold thickness varied from 2.1mm in the duodenum to 1.8mm in the terminal ileum. The small bowel parameters gradually decreased in size from the duodenum to the smallest measurements which were in the terminal ileum. The bowel wall is similar in size throughout the small bowel measuring 1.5+/-0.5mm.

CONCLUSION

These results provide the mean, range of normality and standard deviation of the small bowel parameters per segment on the current population on MR enterography. From our experience, knowledge of these parameters is extremely helpful and essential in the everyday assessment of MR enterography studies.

Recent advances in the management of radiation colitis

Radiation colitis, an insidious, progressive disease of increasing frequency, develops 6 mo to 5 years after regional radiotherapy for malignancy, owing to the deleterious effects of the latter on the colon and the small intestine. When dealing with radiation colitis and its complications, the most conservative modality should be employed because the areas of intestinal injury do not tend to heal. Acute radiation colitis is mostly self-limited, and usually, only supportive management is required. Chronic radiation colitis, a poorly predictable progressive disease, is considered as a precancerous lesion; radiation-associated malignancy has a tendency to be diagnosed at an advanced stage and to bear a dismal prognosis. Therefore, management of chronic radiation colitis remains a major challenge owing to the progressive evolution of the disease, including development of fibrosis, endarteritis, edema, fragility, perforation, partial obstruction, and cancer. Patients are commonly managed conservatively. Surgical intervention is difficult to perform because of the extension of fibrosis and alterations in the gut and mesentery, and should be reserved for intestinal obstruction, perforation, fistulas, and severe bleeding. Owing to the difficulty in managing the complications of acute and chronic radiation colitis, particular attention should be focused onto the prevention strategies. Uncovering the fibrosis mechanisms and the molecular events underlying radiation bowel disease could lead to the introduction of new therapeutic and/or preventive approaches. A variety of novel, mostly experimental, agents have been used mainly as a prophylaxis, and improvements have been made in radiotherapy delivery, including techniques to reduce the amount of exposed intestine in the radiation field, as a critical strategy for prevention.

Recombinant human epidermal growth factor accelerates recovery of mouse small intestinal mucosa after radiation damage

PURPOSE

To determine whether systemically administered recombinant human epidermal growth factor (rhEGF) accelerates the recovery of mouse small intestinal mucosa after irradiation.

METHODS AND MATERIALS

A mouse mucosal damage model was established by administering radiation to male BALB/c mice with a single dose of 15 Gy applied to the abdomen. After irradiation, rhEGF was administered subcutaneously at various doses (0.04, 0.2, 1.0, and 5.0 mg/kg/day) eight times at 2- to 3-day intervals. The evaluation methods included histologic changes of small intestinal mucosa, change in body weight, frequency of diarrhea, and survival rate.

RESULTS

The recovery of small intestinal mucosa after irradiation was significantly improved in the mice treated with a high dose of rhEGF. In the mice that underwent irradiation without rhEGF treatment, intestinal mucosal ulceration, mucosal layer damage, and severe inflammation occurred. The regeneration of villi was noticeable in mice treated with more than 0.2 mg/kg rhEGF, and the villi recovered fully in mice given more than 1 mg/kg rhEGF. The frequency of diarrhea persisting for more than 3 days was significantly greater in the radiation control group than in the rhEGF-treated groups.

CONCLUSIONS

Systemic administration of rhEGF accelerates recovery from mucosal damage induced by irradiation. We suggest that rhEGF treatment shows promise for the reduction of small intestinal damage after irradiation.

Emerging role of intensity-modulated radiation therapy in anorectal cancer

Although radiation therapy has an established role to play in the management of rectal and anal tumors, there are often treatment-related morbidities that negatively impact on patients. There is a long-standing interest in radiation oncology on maximizing treatment efficacy while minimizing treatment-related toxicities, which can be pronounced in the treatment of pelvic malignancies. Intensity-modulated radiation therapy is a recently introduced technology that has the potential to increase the efficacy:toxicity ratio. It has been implemented in the treatment of prostate and head and neck tumors with success. This article reviews the rationale for its use in treating anorectal tumors and discusses early clinical data supporting its continued investigation.

Ume (Japanese apricot)-induced small bowel obstruction with chronic radiation enteritis

Stricture formation is recognized as one of the complications of chronic radiation enteritis. Here, we present a case of a 73-year-old woman who presented with small bowel obstruction 16 years after pelvic irradiation for uterine cancer. Computed tomographic (CT) scan of the abdomen demonstrated a 1-cm foreign body in the terminal ileum. Laparotomy revealed a stone of ume (Japanese apricot) stuck in an ileal stricture, leading to complete impaction and perforation. She was successfully treated with ileocecal resection and ileocolic anastomosis without any complication. Pathological study revealed that the low compliance caused by fibrosis of the bowel wall prevented the small ume stone from passing through the irradiated ileum. Our case implies the specific risk of food-induced small bowel obstruction in patients with a history of pelvic irradiation.

Advanced radiation therapy technologies in the treatment of rectal and anal cancer: intensity-modulated photon therapy and proton therapy

Intensity-modulated photon radiation therapy (RT; IMRT) and proton therapy are advanced radiation technologies that permit improved conformation of radiation dose to target structures while limiting irradiation of surrounding normal tissues. Application of these technologies in the treatment of rectal and anal cancer is attractive, based on the potential reduction in radiation treatment toxicities that are frequently incurred in the pelvis and perineum. Furthermore, conformal RT might also allow for dose escalation to target areas, leading to improved tumor control. This review discusses the underlying principles of IMRT. In addition, the rationale and clinical data regarding the efficacy of radiation dose escalation for rectal and anal cancer will be highlighted, as well as tolerance of pelvic organs to RT and chemotherapy. Finally, preliminary results of IMRT in the treatment of lower gastrointestinal tract cancers will be reviewed. The potential and rationale for proton therapy in treatment of these malignancies are also discussed.

Concurrent chemoradiation for locally advanced oropharyngeal cancer

PURPOSE

The aim of this study was to assess the survival, pattern of failure, morbidity, and prognostic factors of concurrent chemoradiation for locally advanced oropharyngeal cancer.

MATERIALS AND METHODS

A retrospective survey of patients who underwent chemotherapy and radiation for locally advanced oropharyngeal carcinoma at the Veteran Affairs North Texas Health Care System, Dallas, Tex.

RESULTS

Between December 1999 and September 2004, 48 patients with locally advanced oropharyngeal cancer underwent concurrent chemotherapy and radiation. At a median follow-up of 23 months, the 3- and 5-year survival for the whole group were, respectively, 52% and 41%. Seventeen patients (35%) developed recurrences. There were 12 (25%) locoregional failures (6 local failures alone and 6 local and regional failures). Distant metastases developed in 8 patients (5 alone, 3 associated with locoregional failures). Four patients (8%) developed second primaries. No difference was observed in survival between base of tongue and tonsillar carcinoma (P = .32). The 5-year survival for T1-T2 and T3-T4 tumors was, respectively, 84% and 27% (P = .01). No patient with T1-T2 tumors developed distant metastases (P = .04). Forty-five patients (94%) developed toxicity grade 3 to 4 (40 mucositis and 26 hematological). The median weight loss was 18 lb (range, 0-47 lb). Eight patients (16%) developed aspiration pneumonia during and after treatment. Five patients (10%) died of aspiration (2 during and 3 post treatment). Four patients (8%) developed esophageal strictures requiring repeated dilatations post treatment. Two patients had radionecrosis (1 soft tissue and 1 bone) requiring hyperbaric oxygen. Eighteen patients (37%) had prolonged tube feedings (>3 months) after treatments because of severe dysphagia or aspiration.

CONCLUSION

Concurrent chemoradiation provided good locoregional control for locally advanced oropharyngeal carcinoma. Patients with small tumors (T1-T2) had excellent survival. The poor prognosis associated with large tumors may be due to the risk of developing distant metastases. Acute and late toxicities remained significant. Aspiration pneumonia and severe dysphagia were the most prevalent complications of the combined modality approach.