Pathobiology, irradiation dosimetric parameters and therapy of radiation-induced gastric damage: a narrative review

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.

Clinical course and treatment of radiation-induced hemorrhagic gastritis: a case series study

Radiation-induced hemorrhagic gastritis is a relatively uncommon complication of irradiation that can be severe. However, appropriate treatment guidelines have not yet been established because of the small number of known cases. At our hospital, we encountered nine cases of radiation-induced hemorrhagic gastritis between July 2005 and July 2018. All patients initially underwent argon plasma coagulation (APC) for hemostasis. The treatment was highly effective, and hemostasis was successfully achieved in eight of the cases. Hemostasis could not be achieved in one case treated with APC; therefore, surgical resection was required. This patient had risk factors, such as liver cirrhosis and a history of abdominal surgery. Our case series suggests that APC is an effective hemostatic method that should be considered as the initial treatment option for radiation-induced hemorrhagic gastritis; however, surgical resection may be considered when the patient is at high risk for rebleeding.

Opaganib Protects against Radiation Toxicity: Implications for Homeland Security and Antitumor Radiotherapy

Exposure to ionizing radiation (IR) is a lingering threat from accidental or terroristic nuclear events, but is also widely used in cancer therapy. In both cases, host inflammatory responses to IR damage normal tissue causing morbidity and possibly mortality to the victim/patient. Opaganib, a first-in-class inhibitor of sphingolipid metabolism, has broad anti-inflammatory and anticancer activity. Opaganib elevates ceramide and reduces sphingosine 1-phosphate (S1P) in cells, conditions that increase the antitumor efficacy of radiation while concomitantly suppressing inflammatory damage to normal tissue. Therefore, opaganib may suppress toxicity from unintended IR exposure and improve patient response to chemoradiation. To test these hypotheses, we first examined the effects of opaganib on the toxicity and antitumor activity of radiation in mice exposed to total body irradiation (TBI) or IR with partial bone marrow shielding. Oral treatment with opaganib 2 h before TBI shifted the LD75 from 9.5 Gy to 11.5 Gy, and provided substantial protection against gastrointestinal damage associated with suppression of radiation-induced elevations of S1P and TNFα in the small intestines. In the partially shielded model, opaganib provided dose-dependent survival advantages when administered 4 h before or 24 h after radiation exposure, and was particularly effective when given both prior to and following radiation. Relevant to cancer radiotherapy, opaganib decreased the sensitivity of IEC6 (non-transformed mouse intestinal epithelial) cells to radiation, while sensitizing PAN02 cells to in vitro radiation. Next, the in vivo effects of opaganib in combination with radiation were examined in a syngeneic tumor model consisting of C57BL/6 mice bearing xenografts of PAN02 pancreatic cancer cells and a cross-species xenograft model consisting of nude mice bearing xenografts of human FaDu cells. Mice were treated with opaganib and/or IR (plus cisplatin in the case of FaDu tumors). In both tumor models, the optimal suppression of tumor growth was attained by the combination of opaganib with IR (± cisplatin). Overall, opaganib substantially protects normal tissue from radiation damage that may occur through unintended exposure or cancer radiotherapy.

Novel management of expected post-radiotherapy complications in hepatocellular carcinoma patients: a case report

In recent years, radiotherapy (RT) has been used to treat hepatocellular carcinoma (HCC) at each stage. This clinical trend has developed with the increasing improvement of RT techniques, which show clinical results comparable to those of other treatment modalities. Intensity-modulated radiotherapy uses a high radiation dose to improve treatment effectiveness. However, the associated radiation toxicity can damage adjacent organs. Radiation-induced gastric damage with gastric ulcers is a complication of RT. This report presents a novel management strategy for preventing post-RT gastric ulcers. We present the case of a 53-year-old male patient diagnosed with HCC, who experienced gastric ulcer after RT. Before the second round of RT, the patient was administered a gas-foaming agent, which was effective in preventing RT complications.

Palliative Radiotherapy for Bleeding from Unresectable Gastric Cancer Using Three-Dimensional Conformal Technique

Optimal regimens using recent radiotherapy (RT) equipment for bleeding gastric cancer (GC) have not been fully investigated yet. We retrospectively reviewed the clinical data of 20 patients who received RT for bleeding GC in our institution between 2016 and 2021. Three-dimensional conformal RT was performed. The effectiveness of RT was evaluated by the mean serum hemoglobin (Hb) level and the number of transfused red blood cell (RBC) units 1 month before and after RT. The median first radiation dose was a BED of 39.9 Gy. The treatment success rate was 95% and the rebleeding rate was 10.5%. There was a significant increase in the mean Hb level (8.0 ± 1.1 vs. 9.8 ± 1.3 g/dL, p = 0.01), and a significant decrease in the mean number of transfused RBC units (6.8 ± 3.3 vs. 0.6 ± 1.5 units, p < 0.01). Severe toxicity was observed in two patients (anorexia [n = 1] and gastrointestinal [GI] perforation [n = 1]). Reirradiation was attempted in three patients (for hemostasis [n = 2] and for mass reduction [n = 1]). The retreatment success rate for rebleeding was 100%. GI perforation occurred in two patients who had received hemostatic reirradiation. Palliative RT for bleeding GC using recent technology had excellent efficacy. However, it may be associated with a risk of GI perforation.