Radiation in Gastroenterology

Chemotherapy-Induced Neuropathy Affecting the Gastrointestinal Tract

BACKGROUND

Cancer is a major global cause of morbidity and mortality. Survivorship is increasing, bringing new challenges. Cancer treatment, including chemotherapeutic drugs, immunotherapy, and radiotherapy, can have severe and impactful gastrointestinal side effects occurring shortly after treatment (acute toxicity) or persisting for years after treatment ends (late/chronic toxicity).

PURPOSE

The aim of this article is to review the neurotoxic effects of chemotherapy on the enteric nervous system (ENS) and the gut extrinsic innervation. These effects could contribute to the development of long-term gastrointestinal dysfunctions. Research, primarily conducted in animal models, indicates that antitumoral drugs can lead to chemotherapy-induced enteric neuropathy (CIEN). Studies, mainly performed in the myenteric plexus, show that CIEN is characterized by a reduced density of nerve cells and fibers, as well as an imbalanced representation of neuronal subpopulations or their markers, with enteric glial cells also affected. These alterations underlie changes in neuronal activity and gastrointestinal motor function. Although research on the submucosal plexus remains limited, evidence suggests that CIEN affects the entire ENS. Furthermore, scarce studies show that CIEN also occurs in humans. Moreover, emerging experimental data on chemotherapy-induced alterations in visceral sensitivity suggest that the extrinsic innervation of the gut is also affected, but this has received little attention thus far. Nevertheless, this could contribute to the development of chemotherapy-induced brain-gut axis (BGA) disorders in the long term. Cancer chemotherapy (and probably also immunotherapy and radiotherapy) seems to cause neuropathic effects on the intrinsic and extrinsic innervation of the gastrointestinal tract, with an important impact on gastrointestinal and BGA functions. This is a relatively neglected area deserving further investigation.

Interventions for Managing Late Gastrointestinal Symptoms Following Pelvic Radiotherapy: a Systematic Review and Meta-analysis

AIMS

Pelvic radiotherapy can induce gastrointestinal injury and symptoms, which can affect quality of life. We assessed interventions for managing these symptoms.

MATERIALS AND METHODS

A review of randomised controlled trials published between January 1990 and June 2023 from databases including MEDLINE, EMBASE, CENTRAL, CINAHL, clinicaltrials.gov, ISRCTN and grey literature sources was conducted. Meta-analyses were carried out using the DerSimonian and Laird random effects model to produce overall treatment differences with 95% confidence intervals.

RESULTS

Twenty-eight studies (2392 participants) of varying methodological quality were included. 4% formalin was superior to sucralfate for improving gastrointestinal symptom score (standardised mean difference [SMD] -1.07, 95% confidence interval -1.48 to -0.65). Argon plasma coagulation (APC) was inferior to sucralfate (SMD 1.22, 95% confidence interval 0.84 to 1.59). Counselling positively influenced symptom score (SMD -0.53, 95% confidence interval -0.76 to -0.29), whereas hyperbaric oxygen therapy showed conflicting results. Sucralfate combined with APC increased endoscopic markers of moderate-severe bleeding versus APC alone (risk ratio 2.26, 95% confidence interval 1.12 to 4.55). No definite conclusions on pain, incontinence, diarrhoea, tenesmus or quality of life interventions were confirmed.

CONCLUSIONS

Small study sizes, methodological quality and heterogeneity limit support of any individual intervention. APC and 4% formalin seem to be promising interventions, with further larger randomised controlled trials now warranted.

Concurrent rectal perforation and obstruction following neoadjuvant chemoradiation for locally advanced rectal cancer: A case report

INTRODUCTION

Locally advanced rectal cancer (LARC) is commonly managed with neoadjuvant chemoradiation (neoCRT) followed by surgery, though not without complications. The anatomical exposure of the colon and rectum and pelvic radiotherapy poses risk, with rectal perforation and bowel obstruction, though rare, carrying life-threatening potential.

PRESENTATION OF CASE

This case highlights an exceptionally rare occurrence of concurrent rectal perforation and rectal obstruction in a 77-year-old male with LARC, just two months post neoCRT. Initial symptoms included rectal bleeding, and diagnostic procedures confirmed rectal T1N3adenocarcinoma with no metastasis. Emergency admission, prompted by complete bowel obstruction symptoms, led to discovery of rectal perforation during laparotomy, sealed by the bladder. Pathological analysis attributed the cause to radiation proctitis, reporting complete response to neoCRT with no residual tumor.

DISCUSSION

The rarity of both bowel obstruction and perforation as neoCRT complications, particularly in the acute phase of radiation proctitis, is noteworthy in this case. The absence of tumoral cells at the affected sites emphasizes the exceptional nature of this case.

CONCLUSION

This case underscores the importance of recognizing acute post neoCRT injuries as potentially life-threatening complications, emphasizing the need for heightened awareness and consideration in clinical management.

Comparative Characterisation of Proliferation and Apoptosis of Colonic Epithelium after Electron Irradiation with 2 GY and 25 GY

Development of new techniques for multimodal treatment and diagnostics of various neoplasms and the improvement of current techniques can significantly increase the life expectancy of patients with carcinomas of the colon and abdominal-cavity organs, since prevention of various side effects of radiation therapy is one of the main problems of oncological care. Electron irradiation is one of the most promising types of radiation therapy. There are no data on proliferation and apoptosis of the colon epithelium after irradiation with electrons, especially in different modes (single and summary). Morphological evaluation of apoptosis and proliferation of colonic epithelium after local irradiation with electrons were conducted at doses of 2 Gy (Gray) and 25 Gy. Colon fragments from sexually mature Wistar rats (n = 50, body weight 200 ± 10 g) were divided into three groups: I-control (n = 10); II-experimental group (n = 20; local single electron irradiation at a dose of 2 Gy); III-experimental group (n = 30) with local fractional irradiation with electrons at a total dose of 25 Gy. They were studied using light microscopy using hematoxylin and eosin staining and immunohistochemical reactions with antibodies to Ki-67 and caspase-3 (Cas3). Morphological disorders were accompanied by increased expression of pro-apoptotic molecules (caspase-3), and the period of regeneration by proliferative marker (Ki-67). Colon electron irradiation led to disturbances in the histoarchitecture of varying severity, and an increase in cell apoptosis was observed (increased expression of caspase-3 and decrease in Ki-67). In addition, modulation of the PI3K/AKT and MAPK/ERK signalling pathways was detected. The most pronounced destructive changes were observed in the group of 25 Gy fractionated electron irradiation.

Recurrent Upper Gastrointestinal Bleeding due to Radiation-Induced Hemorrhagic Gastroduodenal Ectasia: A Review of Current Treatment Options for Radiation-Induced Gastric Injury

Introduction

Acute upper gastrointestinal bleeding is one of the most common medical emergencies that present to the hospital, and delineating the underlying etiology is essential to provide adequate definitive treatment. The purpose of this case report was to review the diagnosis and treatment of a rare complication known as radiation-induced hemorrhagic gastritis (RIHG) that can occur in patients with prior radiation exposure. The motivation for this study arose from the identification of a case within our institution.

Case Presentation

The study involved a review of the diagnosis and management of a patient who presented with anemia and recurrent episodes of gastrointestinal bleeding at our institution after undergoing treatment for metastatic biliary adenocarcinoma. With the advent of new therapies, we aimed to investigate the various techniques utilized to manage these patients and highlight the importance of maintaining a high index of suspicion for RIHG as a potential etiology of gastrointestinal bleeding in patients with a relevant medical history of radiation exposure. Despite the literature review, we found that there is a lack of guidelines in the approach to the management of these patients.

Conclusion

This case report underscores the rarity of radiation-induced gastritis and the complications that may arise from its diagnosis, including recurrent GI bleeding. Further investigation into identifying definitive treatment and creating guidelines for its management is desperately needed.

Ionizing Radiation, Antioxidant Response and Oxidative Damage: Radiomodulators

Ionizing radiation (IR) is the energy released by atoms in the form of electromagnetic waves (e [...].

The gut microbiota as a booster for radiotherapy: novel insights into radio-protection and radiation injury

Approximately 60-80% of cancer patients treated with abdominopelvic radiotherapy suffer post-radiotherapy toxicities including radiation enteropathy and myelosuppression. Effective preventive and therapeutic strategies are lacking for such radiation injury. The gut microbiota holds high investigational value for deepening our understanding of the pathogenesis of radiation injury, especially radiation enteropathy which resembles inflammatory bowel disease pathophysiology and for facilitating personalized medicine by providing safer therapies tailored for cancer patients. Preclinical and clinical data consistently support that gut microbiota components including lactate-producers, SCFA-producers, indole compound-producers and Akkermansia impose intestinal and hematopoietic radio-protection. These features serve as potential predictive biomarkers for radiation injury, together with the microbial diversity which robustly predicts milder post-radiotherapy toxicities in multiple types of cancer. The accordingly developed manipulation strategies including selective microbiota transplantation, probiotics, purified functional metabolites and ligands to microbe-host interactive pathways are promising radio-protectors and radio-mitigators that merit extensive validation in clinical trials. With massive mechanistic investigations and pilot clinical trials reinforcing its translational value the gut microbiota may boost the prediction, prevention and mitigation of radiation injury. In this review, we summarize the state-of-the-art landmark researches related with radio-protection to provide illuminating insights for oncologists, gastroenterologists and laboratory scientists interested in this overlooked complexed disorder.