Radiation-induced small bowel disease: latest developments and clinical guidance

Small Bowel Lesions Mimicking Crohn's Disease

PURPOSE OF REVIEW

Not all injuries of the terminal ileum are Crohn's disease. It is the purpose of this review to consider the differential diagnosis of other acute and chronic ileal lesions.

RECENT FINDINGS

The recognition of a granulomatous disease of the terminal ileum, distinct from tuberculosis, dates back over 85 years and perhaps much farther, but over the past decades, many other clinical pathologic entities have been described that are neither tuberculosis nor Crohn's eponymous regional enteritis. In recent years, the catalog of lesions mimicking Crohn's disease of the small bowel and proposals for differential diagnosis and treatment have expanded to include newly reported appendiceal pathology, primary cancers and lymphomas of the intestine, unexpected metastases from distant organs, unusual infections, vasculitides and other ischemic conditions, Behçet's disease, endometriosis, and drug reactions. A diagnosis of Crohn's disease should not be a reflex action in the face of small bowel structural or inflammatory lesions without consideration of pathology in adjacent organs, primary and metastatic lesions of the small intestine, infections, vascular diseases, infiltrative diseases, drug injury, or other "idiopathic" conditions.

Malabsorption Syndromes

Malabsorption syndrome refers to the small intestines' inability to absorb certain nutrients and fluids. There are several common associated disorders, which may present with subtle and/or overt symptoms. With subtle symptoms, it is difficult to determine the cause, making diagnosis difficult or even inaccurate. Malabsorption can originate from an immune response, an inflammatory process, or alternation of the small intestines by surgical methods. This article reviews common malabsorption disease processes of the small bowel and the resulting pathophysiology. Diagnostic studies, treatment, and prognosis of various conditions within the malabsorption disease state are discussed.

Prone Positioning on a Belly Board Decreases Rectal and Bowel Doses in Pelvic Intensity-Modulated Radiation Therapy (IMRT) for Prostate Cancer

The presence of normal tissues in the irradiated volume limits dose escalation during pelvic radiotherapy (RT) for prostate cancer. Supine and prone positions on a belly board were compared by analyzing the exposure of organs at risk (OARs) using intensity modulated RT (IMRT). The prospective trial included 55 high risk, localized or locally advanced prostate cancer patients, receiving definitive image-guided RT. Computed tomography scanning for irradiation planning was carried out in both positions. Gross tumor volume, clinical and planning target volumes (PTV) and OARs were delineated, defining subprostatic and periprostatic rectal subsegments. At the height of the largest antero-posterior (AP) diameter of the prostate, rectal diameters and distance from the posterior prostate wall were measured. IMRT plans were generated. Normal tissue exposure and structure volumes were compared between supine and prone plans using paired t-test. In the volumes of the prostate, PTV, colon and small bowel, no significant differences were found. In prone position, all rectal volumes, diameters, and rectum-prostate distance were significantly higher, the irradiated colon and small bowel volume was lower in dose ranges of 20-40 Gy, and the exposure to all rectal segments was more favorable in 40-75 Gy dose ranges. No significant difference was found in the exposure of other OARs. Prone positioning on a belly board is an appropriate positioning method aiming rectum and bowel protection during pelvic IMRT of prostate cancer. The relative reduction in rectal exposure might be a consequence of the slight departure between the prostate and rectal wall.

Bowel morbidity following radiochemotherapy and image-guided adaptive brachytherapy for cervical cancer: Physician- and patient reported outcome from the EMBRACE study

BACKGROUND/PURPOSE

This study describes late bowel morbidity prospectively assessed in the multi-institutional EMBRACE study on MRI-guided adaptive brachytherapy in locally advanced cervical cancer (LACC).

MATERIALS/METHODS

A total of 1176 patients were analyzed. Physician reported morbidity (CTCAE v.3.0) and patient reported outcome (PRO) (EORTC QLQ C30/CX24) were assessed at baseline and at regular follow-up.

RESULTS

At 3/5 years the actuarial incidence of bowel morbidity grade 3-4 was 5.0%/5.9%, including incidence of stenosis/stricture/fistula of 2.0%/2.6%. Grade 1-2 morbidity was pronounced with prevalence rates of 28-33% during follow-up. Diarrhea and flatulence were most frequently reported, significantly increased after 3 months and remained elevated during follow-up. Incontinence gradually worsened with time. PRO revealed high prevalence rates. Diarrhea ≥"a little" increased from 26% to 37% at baseline to 3 months and remained elevated, difficulty in controlling bowel increased from 11% to 26% at baseline to 3 months gradually worsening with time. Constipation and abdominal cramps improved after treatment.

CONCLUSION

Bowel morbidity reported in this large cohort of LACC patients was limited regarding severe/life-threatening events. Mild-moderate diarrhea, flatulence and incontinence were prevalent after treatment with PROs indicating a considerable and clinically relevant burden. Critical knowledge based on the extent and manifestation pattern of treatment-related morbidity will serve future patient management.

Does the low FODMAP diet improve symptoms of radiation-induced enteropathy? A pilot study

RATIONALE

Patients with radiation-induced enteropathy (RE) after cancer treatment show similar symptoms as patients with irritable bowel syndrome (IBS). The low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet (LFD) is a widespread management strategy for IBS. We aimed to investigate if there may be a positive effect of LFD on symptoms and health-related quality of life (HRQOL) in patients with RE.

METHODS

In an open non-controlled pilot study, 11 patients (all female) with RE-related IBS symptoms were recruited largely based on own initiative. All followed LFD for four weeks. IBS Severity Scoring System (IBS-SSS) and IBS Symptom Questionnaire (IBS-SQ) were used to assess symptoms. Short Form Nepean Dyspepsia Index (SF-NDI) and 12-item Short Form Health Survey (SF-12) evaluated HRQOL. A three day food record was used to estimate baseline intake of FODMAPs and to reveal dietary changes.

RESULTS

FODMAP intake was successfully reduced, although LFD was found a burdensome intervention. IBS symptoms improved significantly based on mean total score of IBS-SSS and IBS-SQ, which changed from 310.2 ± 60.7 to 171.4 ± 107.2 (p = .001) and 27.4 ± 4.1 to 15.7 ± 10.1 (p = .002). HRQOL improved based on SF-NDI total score (30.5 ± 9.4 to 18.3 ± 8.2, p = .001) and based on mental (p = .047) and physical (p = .134) score of SF-12. Main additional dietary changes were reduced intake of energy, carbohydrates, and fiber.

CONCLUSION

Our findings from this small-scaled pilot study indicate that the LFD may alleviate symptoms and improve HRQOL in patients with RE. Further controlled studies with larger sample size should be conducted to verify our results and hopefully enable implementation of LFD as a future part of the management strategy for RE.

Gastrointestinal toxicity of immune checkpoint inhibitors: from mechanisms to management

Immune checkpoint inhibitor therapies are a novel group of monoclonal antibodies with proven effectiveness in a wide range of malignancies, including melanoma, renal cell carcinoma, non-small-cell lung cancer, urothelial carcinoma and Hodgkin lymphoma. Their use in a range of other indications, such as gastrointestinal and head and neck cancer, is currently under investigation. The number of agents included in this drug group is increasing, as is their use. Although they have the potential to improve the treatment of advanced malignancies, they are also associated with a substantial risk of immune-related adverse events. The incidence of gastrointestinal toxicity associated with their use is second only in frequency to dermatological toxicity. Thus, gastroenterologists can expect to be increasingly frequently consulted by oncologists as part of a multidisciplinary approach to managing toxicity. Here, we describe this novel group of agents and their mechanisms of action. We review the manifestations of gastrointestinal toxicity associated with their use so that it can be recognized early and diagnosed accurately. We also discuss the proposed mechanisms underlying this toxicity and describe an algorithmic and, wherever possible, evidence-based approach to its management.

Update on Bile Acid Malabsorption: Finally Ready for Prime Time?

PURPOSE OF REVIEW

To provide an update on the prevalence, pathophysiology, disease associations, and treatment options for bile acid malabsorption (BAM).

RECENT FINDINGS

•Molecular mechanisms-BAs prevent water reabsorption and increase water secretion by intracellular mediators, increasing aquaporin channels and intracellular permeability. •Inflammatory bowel disease-new molecular mechanisms of BAM are identified in patients without ileal disease, including changes in expression of ileal BA transporter and nuclear receptors involved in BA homeostasis. •Microscopic colitis-BAM is one of the mechanisms leading to microscopic colitis. •Diagnostic testing-new diagnostic tests have been launched in the USA (serum C4 and fecal 48-h BA excretion); stimulated FGF19 has higher detection of BAM compared to fasting sample alone. •Treatment-investigational FXR agonists may provide a daily, oral option for treatment of BAM instead of BA sequestrants. There is a greater appreciation of the biological role of bile acids across multiple fields of medicine, including gastrointestinal indications.

Interventions to reduce acute and late adverse gastrointestinal effects of pelvic radiotherapy for primary pelvic cancers

BACKGROUND

An increasing number of people survive cancer but a significant proportion have gastrointestinal side effects as a result of radiotherapy (RT), which impairs their quality of life (QoL).

OBJECTIVES

To determine which prophylactic interventions reduce the incidence, severity or both of adverse gastrointestinal effects among adults receiving radiotherapy to treat primary pelvic cancers.

SEARCH METHODS

We conducted searches of CENTRAL, MEDLINE, and Embase in September 2016 and updated them on 2 November 2017. We also searched clinical trial registries.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions to prevent adverse gastrointestinal effects of pelvic radiotherapy among adults receiving radiotherapy to treat primary pelvic cancers, including radiotherapy techniques, other aspects of radiotherapy delivery, pharmacological interventions and non-pharmacological interventions. Studies needed a sample size of 20 or more participants and needed to evaluate gastrointestinal toxicity outcomes. We excluded studies that evaluated dosimetric parameters only. We also excluded trials of interventions to treat acute gastrointestinal symptoms, trials of altered fractionation and dose escalation schedules, and trials of pre- versus postoperative radiotherapy regimens, to restrict the vast scope of the review.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We used the random-effects statistical model for all meta-analyses, and the GRADE system to rate the certainty of the evidence.

MAIN RESULTS

We included 92 RCTs involving more than 10,000 men and women undergoing pelvic radiotherapy. Trials involved 44 different interventions, including radiotherapy techniques (11 trials, 4 interventions/comparisons), other aspects of radiotherapy delivery (14 trials, 10 interventions), pharmacological interventions (38 trials, 16 interventions), and non-pharmacological interventions (29 trials, 13 interventions). Most studies (79/92) had design limitations. Thirteen studies had a low risk of bias, 50 studies had an unclear risk of bias and 29 studies had a high risk of bias. Main findings include the following:Radiotherapy techniques: Intensity-modulated radiotherapy (IMRT) versus 3D conformal RT (3DCRT) may reduce acute (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.26 to 0.88; participants = 444; studies = 4; I2 = 77%; low-certainty evidence) and late gastrointestinal (GI) toxicity grade 2+ (RR 0.37, 95% CI 0.21 to 0.65; participants = 332; studies = 2; I2 = 0%; low-certainty evidence). Conformal RT (3DCRT or IMRT) versus conventional RT reduces acute GI toxicity grade 2+ (RR 0.57, 95% CI 0.40 to 0.82; participants = 307; studies = 2; I2 = 0%; high-certainty evidence) and probably leads to less late GI toxicity grade 2+ (RR 0.49, 95% CI 0.22 to 1.09; participants = 517; studies = 3; I2 = 44%; moderate-certainty evidence). When brachytherapy (BT) is used instead of external beam radiotherapy (EBRT) in early endometrial cancer, evidence indicates that it reduces acute GI toxicity (grade 2+) (RR 0.02, 95% CI 0.00 to 0.18; participants = 423; studies = 1; high-certainty evidence).Other aspects of radiotherapy delivery: There is probably little or no difference in acute GI toxicity grade 2+ with reduced radiation dose volume (RR 1.21, 95% CI 0.81 to 1.81; participants = 211; studies = 1; moderate-certainty evidence) and maybe no difference in late GI toxicity grade 2+ (RR 1.02, 95% CI 0.15 to 6.97; participants = 107; studies = 1; low-certainty evidence). Evening delivery of RT may reduce acute GI toxicity (diarrhoea) grade 2+ during RT compared with morning delivery of RT (RR 0.51, 95% CI 0.34 to 0.76; participants = 294; studies = 2; I2 = 0%; low-certainty evidence). There may be no difference in acute (RR 2.22, 95% CI 0.62 to 7.93, participants = 110; studies = 1) and late GI toxicity grade 2+ (RR 0.44, 95% CI 0.12 to 1.65; participants = 81; studies = 1) between a bladder volume preparation of 1080 mls and that of 540 mls (low-certainty evidence). Low-certainty evidence on balloon and hydrogel spacers suggests that these interventions for prostate cancer RT may make little or no difference to GI outcomes.Pharmacological interventions: Evidence for any beneficial effects of aminosalicylates, sucralfate, amifostine, corticosteroid enemas, bile acid sequestrants, famotidine and selenium is of a low or very low certainty. However, evidence on certain aminosalicylates (mesalazine, olsalazine), misoprostol suppositories, oral magnesium oxide and octreotide injections suggests that these agents may worsen GI symptoms, such as diarrhoea or rectal bleeding.Non-pharmacological interventions: Low-certainty evidence suggests that protein supplements (RR 0.23, 95% CI 0.07 to 0.74; participants = 74; studies = 1), dietary counselling (RR 0.04, 95% CI 0.00 to 0.60; participants = 74; studies = 1) and probiotics (RR 0.43, 95% CI 0.22 to 0.82; participants = 923; studies = 5; I2 = 91%) may reduce acute RT-related diarrhoea (grade 2+). Dietary counselling may also reduce diarrhoeal symptoms in the long term (at five years, RR 0.05, 95% CI 0.00 to 0.78; participants = 61; studies = 1). Low-certainty evidence from one study (108 participants) suggests that a high-fibre diet may have a beneficial effect on GI symptoms (mean difference (MD) 6.10, 95% CI 1.71 to 10.49) and quality of life (MD 20.50, 95% CI 9.97 to 31.03) at one year. High-certainty evidence indicates that glutamine supplements do not prevent RT-induced diarrhoea. Evidence on various other non-pharmacological interventions, such as green tea tablets, is lacking.Quality of life was rarely and inconsistently reported across included studies, and the available data were seldom adequate for meta-analysis.

AUTHORS' CONCLUSIONS

Conformal radiotherapy techniques are an improvement on older radiotherapy techniques. IMRT may be better than 3DCRT in terms of GI toxicity, but the evidence to support this is uncertain. There is no high-quality evidence to support the use of any other prophylactic intervention evaluated. However, evidence on some potential interventions shows that they probably have no role to play in reducing RT-related GI toxicity. More RCTs are needed for interventions with limited evidence suggesting potential benefits.

A Time Course of Bevacizumab (Anti-VEGF) Effect on Rat Peritoneum: Relations Between Antiadhesive Action and Fibrin Regulation Enzymes

BACKGROUND

To investigate the early and late antiadhesive effect and any changes of fibrin matrix regulation enzymes on rat peritoneum, after local administration of bevacizumab.

METHODS

Rats were subjected to cecal abrasion. Bevacizumab (5 mg/kg) against placebo was given intraperitoneally. On the 2nd, 14th, and 28th postoperative days adhesions were scored, and tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), degree of fibrosis, and angiogenesis were measured in abrased cecum and in intact parietal peritoneum.

RESULTS

Bevacizumab significantly reduced adhesions up to 15% on the 2nd, 52.5% on the 14th, and 55% on the 28th postoperative day, and significantly increased tPA concentrations in peritoneum. PAI-1 was decreased, and a significantly higher tPA/PAI-1 ratio along with an increase of MMP-9 was measured at all time points. Fibrosis and angiogenesis were significantly lower on the 14th and 28th postoperative days.

CONCLUSIONS

Local bevacizumab administration has a strong early and late antiadhesive action on rat peritoneum, mediated by changes in the tPA/PAI-1 and MMP balance in favor of fibrinolysis up to 28 days after operations.

A Mnemonic for Pharmacists to Ensure Optimal Monitoring and Safety of Total Parenteral Nutrition: I AM FULL

Objective: To present a guideline-derived mnemonic that provides a systematic monitoring process to increase pharmacists’ confidence in total parenteral nutrition (TPN) monitoring and improve safety and efficacy of TPN use. Data Sources: The American Society for Parenteral and Enteral Nutrition (ASPEN) guidelines were reviewed. Additional resources included a literature search of PubMed (1980 to May 2016) using the search terms: total parenteral nutrition, mnemonic, indications, allergy, macronutrients, micronutrients, fluid, comorbidities, labs, peripheral line, and central line. Articles (English-language only) were evaluated for content, and additional references were identified from a review of literature citations. Study Selection and Data Extraction: All English-language observational studies, review articles, meta-analyses, guidelines, and randomized trials assessing monitoring parameters of TPN were evaluated. Data Synthesis: The ASPEN guidelines were referenced to develop key components of the mnemonic. Review articles, observational trials, meta-analyses, and randomized trials were reviewed in cases where guidelines did not adequately address these components. Conclusions: A guideline-derived mnemonic was developed to systematically and safely manage TPN therapy. The mnemonic combines 7 essential components of TPN use and monitoring: Indications, Allergies, Macro/Micro nutrients, Fluid, Underlying comorbidities, Labs, and Line type.

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.

Metabolomic Analysis of Mice Exposed to Gamma Radiation Reveals a Systemic Understanding of Total-Body Exposure

Diagnostic markers are needed for accidental or deliberate radiation exposure that could cause acute and chronic radiation toxicity. Biomarkers of temporal, dose-dependent, aging-attenuated and multiple radiation exposures have been previously described by others. However, the physiological origin and biochemical networks that generate these biomarkers and their association at the molecular level have yet to be explored. Hence, the discovery and identification of total-body-irradiation-induced tissue specific biomarkers remains an enormous challenge within radiation biodosimetry research. To determine the tissue level response of total-body exposure (6 Gy), metabolomics analysis was carried out on radiosensitive tissues bone marrow, ileum, liver, muscle and lung as well as serum and on urine within 12 h postirradiation. Differences in the metabolic signatures between the sham and gamma-irradiated groups were analyzed by hydrophilic interaction liquid chromatography (HILIC)-based ultra-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOFMS). A panel of 67 biomarkers identified in radiosensitive tissues and biofluids (serum and urine) at a 6 Gy dose. Among the identified biomarkers, 3-methylglutarylcarnitine (3-MGC) was found to be a novel metabolite in liver, serum and urine that could potentially be an early radiation response marker. The degree of metabolic changes among different tissues showed perturbations in pathways including DNA methylation, energy, nucleic acid, amino acid, glutathione and bile acid metabolism. These results highlight metabolomics as a potential novel approach to understand functional alterations in the metabolome that could be adapted for use in the rapid assessment of radiation exposure and triage protocols in the case of nuclear incidents.

Silk-elastinlike protein polymers enhance the efficacy of a therapeutic glycosaminoglycan for prophylactic treatment of radiation-induced proctitis

Radiation-induced proctitis (RIP) is the most common clinical adverse effect for patients receiving radiotherapy as part of the standard course of treatment for ovarian, prostate, colon, and bladder cancers. RIP limits radiation dosage, interrupts treatment, and lowers patients' quality of life. A prophylactic treatment that protects the gastrointestinal tract from deleterious effects of radiotherapy will significantly improve patient quality of life and may allow for higher and more regular doses of radiation therapy. Semi-synthetic glycosaminoglycan (GAG), generated from the sulfation of hyaluronic acid, are anti-inflammatory but have difficulty achieving therapeutic levels in many tissues. To enhance the delivery of GAG, we created an in situ gelling rectal delivery system using silk-elastinlike protein polymers (SELPs). Using solutions of SELP 815K (which contains 6 repeats of blocks comprised of 8 silk-like units, 15 elastin-like units, and 1 lysine-substituted elastin-like unit) with GAG GM-0111, we created an injectable delivery platform that transitioned in <5min from a liquid at room temperature to a hydrogel at body temperature. The hydrogels released 50% of their payload within 30min and enhanced the accumulation of GAG in the rectum compared to traditional enema-based delivery. Using a murine model of radiation-induced proctitis, the prophylactic delivery of a single dose of GAG from a SELP matrix administered prior to irradiation significantly reduced radiation-induced pain after 3, 7, and 21days by 53±4%, 47±10%, and 12±6%, respectively. Matrix-mediated delivery of GAG by SELP represents an innovative method for more effective treatment of RIP and promises to improve quality of life of cancer patients by allowing higher radiotherapy doses with improved safety.

The stratification of severity of acute radiation proctopathy after radiotherapy for cervical carcinoma using diffusion-weighted MRI

OBJECTIVE

To determine whether diffusion-weighted imaging (DWI) can be used for quantitatively evaluating severity of acute radiation proctopathy after radiotherapy for cervical carcinoma.

MATERIALS AND METHODS

One hundred and twenty-four patients with cervical carcinoma underwent MR examination including DWI before and after radiotherapy. Acute radiation proctopathy was classified into three groups (grade 0, grade I-II and grade III-IV) according to Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG). The pretreatment ADC (ADC_pre), ADC after treatment (ADC_post) and ADC change (ΔADC) were compared among three groups. In addition, acute radiation proctopathy was classified into good-prognosis group and poor-prognosis group. ADC_pre, ADC_post and ΔADC were compared between two groups. For DWI parameter that had significant difference, discriminatory capability of the parameter was determined using receiver operating characteristics (ROC) analysis.

RESULTS

ADC_post and ΔADC were higher in grade I-II group than in grade 0 group (p<0.05), yielding a sensitivity of 79.3% and specificity of 69.4% for ADC_post, and 85.1%, 72.3% for ΔADC for discrimination between two groups. ADC_post and ΔADC were higher in grade III-IV group than in grade I-II group (p<0.05), yielding a sensitivity of 80.3% and specificity of 72.5% for ADC_post, and 84.1%, 74.5% for ΔADC for discrimination between two groups. ADC_post and ΔADC were higher in poor-prognosis group than in good-prognosis group (p<0.05), yielding a sensitivity of 79.5% and specificity of 73.4% for ADC_post, and 87.2%, 78.3% for ΔADC for discrimination between two groups.

CONCLUSION

Diffusion-weighted MRI can be used for quantitative stratification of severity of acute radiation proctopathy, which serves as an important basis for appropriate timely adjustment of radiotherapy for cervical carcinoma in order to maximally reduce the radiation injury of rectum.

Adult Survivors of Childhood Cancer Have Poor Adherence to Dietary Guidelines

BACKGROUND

Poor nutritional intake can exacerbate the chronic disease burden in childhood cancer survivors, whereas a healthful diet serves a protective function. Few studies have provided detailed evaluations of the diet of childhood cancer survivors.

OBJECTIVES

This study aimed to evaluate diet quality and dietary intakes of key food groups and nutrients in a large cohort of childhood cancer survivors and whether cancer and treatment characteristics have an impact on survivors' long-term intake.

METHODS

Diet was assessed in 2570 adult survivors of childhood cancer enrolled in the St. Jude Lifetime cohort (mean age = 32.3 y) by using the Block food-frequency questionnaire. The Healthy Eating Index-2010 (HEI-2010) was calculated to quantify diet quality. Cancer diagnosis and treatment exposure were abstracted from medical records. Differences in HEI-2010 by patient characteristics and treatment exposure were examined by using ANCOVA.

RESULTS

The mean ± SD HEI-2010 in childhood cancer survivors was 57.9 ± 12.4 of a maximum score of 100. Referenced to Dietary Reference Intakes, survivors consumed inadequate amounts of vitamin D, vitamin E, potassium, fiber, magnesium, and calcium (27%, 54%, 58%, 59%, 84%, and 90% of the recommended intakes) but excessive amounts of sodium and saturated fat (155% and 115% of the recommended intakes) from foods. Survivors diagnosed when <5 y of age had a lower diet quality than did those diagnosed when ≥5 y of age (mean HEI-2010 score: 56.9 compared with 58.2; P = 0.046). Survivors who received higher radiation doses to the abdomen had a lower diet quality than those who received lower doses (mean HEI-2010 scores = 58.9, 57.2, 56.7, and 56.1 for doses of 0, 1-19.9, 20-29.9, and ≥30 Gy, respectively; P = 0.02).

CONCLUSIONS

Long-term childhood cancer survivors have poor adherence to the 2010 Dietary Guidelines for Americans. Findings reinforce the need to incorporate nutrition into cancer care to improve diet quality and to reduce morbidities.

An amino acid-based oral rehydration solution (AA-ORS) enhanced intestinal epithelial proliferation in mice exposed to radiation

Destruction of clonogenic cells in the crypt following irradiation are thought to cause altered gastrointestinal function. Previously, we found that an amino acid-based oral rehydration solution (AA-ORS) improved gastrointestinal function in irradiated mice. However, the exact mechanisms were unknown. Electrophysiology, immunohistochemistry, qPCR, and Western blot analysis were used to determine that AA-ORS increased proliferation, maturation, and differentiation and improved electrolyte and nutrient absorption in irradiated mice. A single-hit, multi-target crypt survival curve showed a significant increase in crypt progenitors in irradiated mice treated with AA-ORS for six days (8.8 ± 0.4) compared to the saline-treated group (6.1 ± 0.3; P < 0.001) without a change in D₀ (4.8 ± 0.1 Gy). The D_q values increased from 8.8 ± 0.4 Gy to 10.5 ± 0.5 Gy with AA-ORS treatment (P < 0.01), indicating an increased radiation tolerance of 1.7 Gy. We also found that AA-ORS treatment (1) increased Lgr5⁺, without altering Bmi1 positive cells; (2) increased levels of proliferation markers (Ki-67, p-Erk, p-Akt and PCNA); (3) decreased apoptosis markers, such as cleaved caspase-3 and Bcl-2; and (4) increased expression and protein levels of NHE3 and SGLT1 in the brush border membrane. This study shows that AA-ORS increased villus height and improved electrolyte and nutrient absorption.

Time-varying SMART design and data analysis methods for evaluating adaptive intervention effects

BACKGROUND

In a standard two-stage SMART design, the intermediate response to the first-stage intervention is measured at a fixed time point for all participants. Subsequently, responders and non-responders are re-randomized and the final outcome of interest is measured at the end of the study. To reduce the side effects and costs associated with first-stage interventions in a SMART design, we proposed a novel time-varying SMART design in which individuals are re-randomized to the second-stage interventions as soon as a pre-fixed intermediate response is observed. With this strategy, the duration of the first-stage intervention will vary.

METHODS

We developed a time-varying mixed effects model and a joint model that allows for modeling the outcomes of interest (intermediate and final) and the random durations of the first-stage interventions simultaneously. The joint model borrows strength from the survival sub-model in which the duration of the first-stage intervention (i.e., time to response to the first-stage intervention) is modeled. We performed a simulation study to evaluate the statistical properties of these models.

RESULTS

Our simulation results showed that the two modeling approaches were both able to provide good estimations of the means of the final outcomes of all the embedded interventions in a SMART. However, the joint modeling approach was more accurate for estimating the coefficients of first-stage interventions and time of the intervention.

CONCLUSION

We conclude that the joint modeling approach provides more accurate parameter estimates and a higher estimated coverage probability than the single time-varying mixed effects model, and we recommend the joint model for analyzing data generated from time-varying SMART designs. In addition, we showed that the proposed time-varying SMART design is cost-efficient and equally effective in selecting the optimal embedded adaptive intervention as the standard SMART design.

Associations between body composition and nutritional assessments and biochemical markers in patients with chronic radiation enteritis: a case-control study

Background

Chronic radiation enteritis (CRE) is defined as loss of absorptive capacity after irradiation due to chronic inflammation and damage of intestinal mucosa, which may lead to varying degrees of malnutrition. The aim of this study was to evaluate the potential correlation between the nutritional status and systemic inflammation in patients with CRE.

Methods

Medical records of 92 patients with CRE and 184 age- and sex-matched controls in a single center from January 2010 to October 2015 were retrospectively reviewed. All enrolled subjects underwent nutritional status analysis, including three different nutritional indices: Nutritional Risk Screening-2002 (NRS-2002), Patient-generated Subjective Global Assessment (PG-SGA) and Controlling Nutritional Status (CONUT), bioelectrical impedance spectroscopy (BIS), and biochemical markers, within 24 h of admission.

Results

The results showed that NRS-2002, PG-SGA and CONUT were all positively correlated with neutrophil/lymphocyte ratio (NLR) (r = 0.304, 0.384 and 0.425, all p < 0.001) and C-reactive protein (CRP) (r = 0.357, 0.479 and 0.230, all p < 0.001), while negatively correlated with albumin (r = −0.612, −0.727 and −0.792, all p < 0.001) and total cholesterol (TC) (r = −0.485, −0.545 and −0.473, all p < 0.001) in patients with CRE, respectively. Body cell mass (BCM) has been deemed a key body composition parameter. It was positively correlated with albumin (r = 0.489, p < 0.001) and TC (r = 0.237, p < 0.001), while negatively correlated with NLR (r = −0.140, p = 0.02) and CRP (r = −0.215, p < 0.001). A multivariate linear regression analysis showed that values of intracellular water (β coefficient = 0.760, p < 0.001), extracellular water (β coefficient = 0.006, p = 0.011), protein (β coefficient = 0.235, p < 0.001) and CRP (β coefficient = 0.001, p = 0.009) were independent determinants of BCM.

Conclusion

This study revealed that BIS combined with nutritional assessments and biochemical markers were appropriate methods to assess the nutritional and inflammatory status in patients with CRE. Furthermore, the nutritional status was verified to be significantly correlated with systemic inflammation.

Optimization of re-irradiation using deformable registration: a case study

Re-irradiation is frequently performed in radiotherapy (RT) departments. We present an optimization methodology that takes the previous irradiation into account. A 68-year-old female patient suffering from rectal adenocarcinoma, who had previously undergone RT for metastases to the right iliac bone, presented with a recurrence of metastasis to the L5 and the left sacroiliac joint. Re-irradiation was performed using volumetric modulated arc therapy (VMAT). We proceeded to a registration of the previous RT planning CT and RT doses to the new planning CT. Virtual volumes corresponding to the intersection of the small bowel (SB) and each isodose structure were created. We calculated the maximal dose (D_max) that each virtual structure could receive and considered them as constraints. We called this technique modified VMAT. We compared this technique with a standard VMAT plan and a three-dimensional RT plan. Using the modified VMAT technique, a total dose of 20 Gy in five fractions of 4 Gy was delivered to the planning target volume without any acute toxicity. A composite dosimetry was realized with each technique to compare the dose given to the already irradiated SB. We calculated the D_max received by the already irradiated SB in equivalent dose of 2 Gy fractions. The Dmax was 46.8, 60 and 52 Gy for modified VMAT, standard VMAT and three-dimensional RT, respectively. Dose deformation was used to create new constraint structures to optimize the dose delivered to surrounding tissues. This methodology is readily feasible in clinical routine to optimize the re-irradiation process.

Clinical application of precise radiotherapy in rectal cancer

Precise radiotherapy plays an important role in the comprehensive multidisciplinary therapy of rectal cancer. The mainstream technology is the intensity modulated radiation therapy (IMRT). The technique of repetitive body positioning and the filling of the bladder and rectum are the important factors influencing the accuracy and efficacy of radiotherapy for rectal cancer. The quality of life for patients with rectal cancer is highly affected by side effects associated with radiotherapy. The application of precise positioning technique and image guided radiotherapy (IGRT) can significantly contribute to the accurate delivery of radiotherapy to the region of rectal cancer to improve the local tumor control and reduce unnecessary exposure of normal tissues to irradiation. In this paper, the clinical application of precise positioning technique and the improvement of accurate delivery of radiotherapy are comprehensively reviewed.

Is the irradiated small bowel volume still a predictor for acute lower gastrointestinal toxicity during preoperative concurrent chemo-radiotherapy for rectal cancer when using intensity-modulated radiation therapy?

BACKGROUND

The small bowel (SB) represents the most important dose-limiting structure in pelvic radiotherapy (RT). However, we observed that the majority of rectal cancer patients who received preoperative pelvic intensity modulated RT (IMRT) developed acute tenesmus without watery diarrhea. The objective of this study is to determine if the RT dose to SB affects the acute lower gastrointestinal toxicity (ALGIT) in rectal cancer patients who received neoadjuvant concurrent chemotherapy-IMRT. We will also evaluate if patient and tumor factors affect the ALGIT.

METHODS

We retrospectively analyzed 63 rectal cancer patients that consecutively received preoperative IMRT (45 Gy for pelvis and 50 Gy for gross tumor in 25 fractions) with concurrent chemotherapy (oxaliplatin 130 mg/m(2) on day 1 and capecitabine 825 mg/m(2), twice per day from day 1 to day 14, week 1 and 4) between May 2012 and May 2013. The ALGIT was assessed with Common Terminology Criteria for Adverse Events version 3. The patients were stratified into two groups (with and without grade ≥2 ALGIT). The effect of SB volume receiving 5 to 40 Gy (V5 to V40) at a 5 Gy interval dose level on grade ≥2 ALGIT was evaluated. The volume of small bowel is defined as the volume of the small bowel loop. Other factors evaluated include patient's age and gender, tumor size and location and preexisting number of daily bowel movements.

RESULTS

Overall, grade ≥2 ALGIT occurred in 57 % (36/63) patients. There was no significant difference between the two groups of patients (with and without grade ≥2 ALGIT) in SB V5 to V40, patient's age and gender, tumor location and preexisting number of daily bowel movements. There was a significant difference between the two groups of patients in tumor volume (with grade ≥2 ALGIT: 115.5 ± 85.5 cm(3) versus without grade ≥2 ALGIT: 58.5 ± 25.2 cm(3), p = 0.0001). Multivariate analysis revealed no association between the dose SB received (V5 to V40) and the grade ≥2 ALGIT after adjusting for the tumor volume.

CONCLUSIONS

With IMRT technique used in rectal cancer patients undergoing preoperative chemo-radiotherapy, the acute lower GI toxicity is not associated with small bowel V5 to V40; instead it is associated with rectal tumor size.

Growth Hormone Protects the Intestine Preserving Radiotherapy Efficacy on Tumors: A Short-Term Study

The efficacy of radiotherapy on tumors is hampered by its devastating adverse effects on healthy tissue, particularly that of the gastrointestinal tract. These effects cause acute symptoms that are so disruptive to patients that they can lead to interruption of the radiotherapy program. These adverse effects could limit the intensity of radiation received by the patient, resulting in a sublethal dose to the tumor, thus increasing the risk of tumor resistance. The lack of an effective treatment to protect the bowel during radiation therapy to allow higher radiation doses that are lethal to the tumor has become a barrier to implementing effective therapy. In this study, we present a comparative analysis of both intestinal and tumor tissue in regard to the efficacy and the preventive impact of a short-term growth hormone (GH) treatment in tumor-bearing rats as a protective agent during radiotherapy. Our data show that the exogenous administration of GH improved intestinal recovery after radiation treatment while preserving the therapeutic effect against the tumor. GH significantly increased proliferation in the irradiated intestine but not in the irradiated tumors, as assessed by Positron Emission Tomography and the proliferative markers Ki67, cyclin D3, and Proliferating Cell Nuclear Antigen. This proliferative effect was consistent with a significant increase in irradiated intestinal villi and crypt length. Furthermore, GH significantly decreased caspase-3 activity in the intestine, whereas GH did not produce this effect in the irradiated tumors. In conclusion, short-term GH treatment protects the bowel, inducing proliferation while reducing apoptosis in healthy intestinal tissue and preserving radiotherapy efficacy on tumors.

Pelvic radiation therapy: Between delight and disaster

In the last few decades radiotherapy was established as one of the best and most widely used treatment modalities for certain tumours. Unfortunately that came with a price. As more people with cancer survive longer an ever increasing number of patients are living with the complications of radiotherapy and have become, in certain cases, difficult to manage. Pelvic radiation disease (PRD) can result from ionising radiation-induced damage to surrounding non-cancerous tissues resulting in disruption of normal physiological functions and symptoms such as diarrhoea, tenesmus, incontinence and rectal bleeding. The burden of PRD-related symptoms, which impact on a patient's quality of life, has been under appreciated and sub-optimally managed. This article serves to promote awareness of PRD and the vast potential there is to improve current service provision and research activities.

Increased Expression of Connective Tissue Growth Factor (CTGF) in Multiple Organs After Exposure of Non-Human Primates (NHP) to Lethal Doses of Radiation

Exposure to sufficiently high doses of ionizing radiation is known to cause fibrosis in many different organs and tissues. Connective tissue growth factor (CTGF/CCN2), a member of the CCN family of matricellular proteins, plays an important role in the development of fibrosis in multiple organs. The aim of the present study was to quantify the gene and protein expression of CTGF in a variety of organs from non-human primates (NHP) that were previously exposed to potentially lethal doses of radiation. Tissues from non-irradiated NHP and NHP exposed to whole thoracic lung irradiation (WTLI) or partial-body irradiation with 5% bone marrow sparing (PBI/BM5) were examined by real-time quantitative reverse transcription PCR, western blot, and immunohistochemistry. Expression of CTGF was elevated in the lung tissues of NHP exposed to WTLI relative to the lung tissues of the non-irradiated NHP. Increased expression of CTGF was also observed in multiple organs from NHP exposed to PBI/BM5 compared to non-irradiated NHP; these included the lung, kidney, spleen, thymus, and liver. These irradiated organs also exhibited histological evidence of increased collagen deposition compared to the control tissues. There was significant correlation of CTGF expression with collagen deposition in the lung and spleen of NHP exposed to PBI/BM5. Significant correlations were observed between spleen and multiple organs on CTGF expression and collagen deposition, respectively, suggesting possible crosstalk between spleen and other organs. These data suggest that CTGF levels are increased in multiple organs after radiation exposure and that inflammatory cell infiltration may contribute to the elevated levels of CTGF in multiple organs.

The small bowel in its hammock: how to avoid irradiation thanks to the sigmoid

BACKGROUND

High-dose irradiation is the cornerstone treatment of bone cancers of the pelvic rim. To protect the small bowel from irradiation and following consequences, we described the laparoscopic use of the sigmoid to perform a hammock.

MATERIALS AND METHODS

Three patients were diagnosed with metastatic Ewing's sarcoma, localized malignant peripheral nerve sheath tumor, and localized BCOR-CCNB3 (Ewing-like) sarcoma of the pelvic rim at 13.1, 5.7, and 12.9 years, respectively. After neoadjuvant chemotherapy, the 2 female patients underwent a hemisacrectomy under S2 only by the posterior approach, whereas no orthopedic surgery was required for the male patient because of excellent local response to chemotherapy. A 54-Gy intensity-modulated radiotherapy of the posterior part of the pelvis was intended for all patients.

RESULTS

The laparoscopic procedure consisted in the fixation of the sigmoid loop to the anterior parietal wall on a transverse line just below the umbilicus, associated with a colostomy in the right iliac fossa. The anterior transposition of the two ovaries, uterus, and rectum and the dissection of left iliac vessels to move them anteriorly were added in female patients. Stomas were closed around 6 months after completion of the radiotherapy course, associated with the repositioning of the uterus, ovaries, and colon. With a mean follow-up of 22 months, all patients are alive without any recurrences or radiation-related symptoms.

CONCLUSIONS

The laparoscopic "hammock technique" both protects the small bowel from irradiation and secures the orthopedic procedure by displacing the abdominal organs forward.

Radiation persistently promoted oxidative stress, activated mTOR via PI3K/Akt, and downregulated autophagy pathway in mouse intestine

While acute effects of toxic radiation doses on intestine are well established, we are yet to acquire a complete spectrum of sub-lethal radiation-induced chronic intestinal perturbations at the molecular level. We investigated persistent effects of a radiation dose (2 Gy) commonly used as a daily fraction in radiotherapy on oxidants and anti-oxidants, and autophagy pathways, which are interlinked processes affecting intestinal homeostasis. Six to eight weeks old C57BL/6J mice (n=10) were exposed to 2 Gy γ-ray. Mice were euthanized two or twelve months after radiation, intestine surgically removed, and flushed using sterile PBS. Parts of the intestine from jejunal-ilial region were fixed, frozen, or used for intestinal epithelial cell (IEC) isolation. While oxidant levels and mitochondrial status were assessed in isolated IEC, autophagy and oxidative stress related signaling pathways were probed in frozen and fixed samples using PCR-based expression arrays and immunoprobing. Radiation exposure caused significant alterations in the expression level of 26 autophagy and 17 oxidative stress related genes. Immunoblot results showed decreased Beclin1 and LC3-II and increased p62, PI3K/Akt, and mTOR. Flow cytometry data showed increased oxidant production and compromised mitochondrial integrity in irradiated samples. Immunoprobing of intestinal sections showed increased 8-oxo-dG and nuclear PCNA, and decreased autophagosome marker LC3-II in IEC after irradiation. We show that sub-lethal radiation could persistently downregulate anti-oxidants and autophagy signaling, and upregulate oxidant production and proliferative signaling. Radiation-induced promotion of oxidative stress and downregulation of autophagy could work in tandem to alter intestinal functions and have implications for post-radiation chronic gastrointestinal diseases.

Prophylactic and therapeutic effects of oral budesonide for acute radiation-induced enteritis and colitis in rats

No satisfactory means has been found to control the symptoms of diarrhea and weight loss caused by radiation-induced enteritis and colitis. As a glucocorticoid, budesonide has multiple effects, and this study aimed to test whether it could be effective in treating these symptoms. Twenty-eight male Wistar albino rats were randomly allocated into 4 groups. Group I received 0.1 mg/kg/day budesonide at 8-h intervals for 5 days and did not undergo radiation. Group II received 0.1 mg/kg/day budesonide at 8-h intervals for 1 day before radiation treatment and 4 days after irradiation. Group III received 0.1 mg/kg/day budesonide at 8-h intervals for 4 days after irradiation. Group IV received only radiation treatment. On the fifth day after radiation treatment, the rats underwent laparotomy. The rats were weighed before irradiation and before laparotomy. Because of diarrhea, all rats lost weight except group I, which showed weight gain. Weight loss was statistically significant only in group IV. Group I rats exhibited a normal jejunum, ileum, and colon. The other groups showed varying degrees of damage. We conclude that, particularly when given before irradiation, budesonide decreased the side effects of radiation-induced enteritis and colitis both clinically and morphologically. Future pathophysiological and clinical studies will be needed to support this result.