Radiation esophagitis

Experimental study on radiational characteristics and nursing care of a novel radioisotope 188Re memory alloy esophageal stent

Radioactive esophageal stent, known for inhibiting tumor growth and delaying restenosis in malignant esophageal tumors, presents challenges due to potent radiation, leading to side effects. This study aims to support the clinical use of 188Re radioactive esophageal stent. The 188Re stent with 128 MBq initial activity was placed in a biomimetic esophageal membrane. Radiation absorption doses were measured by thermoluminescence and calculated using mathematical software. Under simulated positioning, the stent was implanted in the esophagus of an experimental pig, followed by the feeding of Kangfuxin solution and nursing care (KFX-RT). Non-implanted and implanted-only pigs served as normal (CR) and experimental (RT) controls. Blood samples collected on days 7 and 21 were analyzed for inflammatory factors (TGF-β1, TNF-α, IL-6) using enzyme-linked immunosorbent assay. Esophageal tissue cells were assessed for deoxyribonucleic acid index (DI) and subdiploid content through flow cytometry. Absorbed doses at 0.5 mm and 5 mm reference points were 223.91 cGy and 20.55 cGy, respectively, with 92.64% absorbed within a 1 mm thickness. Radiation dose significantly decreased at 6.5 mm, with only 4.72% absorbed at depths ≥6.5 mm. On days 7 and 21, levels of inflammatory factors, DI and subdiploid content were significantly increased in the KFX-RT and RT groups compared to the CR group, while all levels in the KFX-RT group were significantly lower than in the RT group. The 188Re esophageal stent exhibits high radiation absorption in superficial tissues and low absorption in deeper tissues. Kangfuxin solution combined with nursing care alleviates radiation-induced inflammatory damage.

Cerebral arterial air embolism after esophageal stenting for recurrence of gastroesophageal junction cancer: a case report

Cerebral arterial air embolism (CAE) is a rare complication after esophageal stenting, but it can be life-threatening. It is especially a concern for those with a history of previous gastrointestinal cancer therapies. We report a case of CAE after esophageal stenting in a patient with recurrent gastroesophageal junction cancer and a history of multiple cancer treatments. A 71 year-old man with a history of a proximal gastrectomy, resection of the lower esophagus, chemotherapy, and radiation presented to our hospital 2 weeks after stenting with epigastric and back pain. Mediastinitis was suspected and conservative treatment was begun. The patient suddenly developed altered mental status, left hemiplegia, and anisocoria after drinking water. A brain computed tomography (CT) revealed right-sided predominance of multifocal CAE. Chest and abdominal CT showed a hematoma in the gastric and duodenal wall and an intraluminal hematoma from the esophagus, around the stent, to the upper ileum. CAE was thought to be due to rupture of the recurrent tumor. Unfortunately, despite intensive care, the patient died about 5 h after the onset of neurological symptoms. It has been reported that prior treatments, such as chemotherapy and radiotherapy, increase the risk of life-threatening adverse events, including CAE after esophageal stenting. Clinicians should keep in mind the possibility of CAE after esophageal stenting in patients with a history of multiple cancer treatments.

Combined deep learning and radiomics in pretreatment radiation esophagitis prediction for patients with esophageal cancer underwent volumetric modulated arc therapy

PURPOSE

To develop a combined radiomics and deep learning (DL) model in predicting radiation esophagitis (RE) of a grade ≥ 2 for patients with esophageal cancer (EC) underwent volumetric modulated arc therapy (VMAT) based on computed tomography (CT) and radiation dose (RD) distribution images.

MATERIALS AND METHODS

A total of 273 EC patients underwent VMAT were retrospectively reviewed and enrolled from two centers and divided into training (n = 152), internal validation (n = 66), and external validation (n = 55) cohorts, respectively. Radiomic and dosiomic features along with DL features using convolutional neural networks were extracted and screened from CT and RD images to predict RE. The performance of these models was evaluated and compared using the area under curve (AUC) of the receiver operating characteristic curves (ROC).

RESULTS

There were 5 and 10 radiomic and dosiomic features were screened, respectively. XGBoost achieved a best AUC of 0.703, 0.694 and 0.801, 0.729 with radiomic and dosiomic features in the internal and external validation cohorts, respectively. ResNet34 achieved a best prediction AUC of 0.642, 0.657 and 0.762, 0.737 for radiomics based DL model (DLR) and RD based DL model (DLD) in the internal and external validation cohorts, respectively. Combined model of DLD + Dosiomics + clinical factors achieved a best AUC of 0.913, 0.821 and 0.805 in the training, internal, and external validation cohorts, respectively.

CONCLUSION

Although the dose was not responsible for the prediction accuracy, the combination of various feature extraction methods was a factor in improving the RE prediction accuracy. Combining DLD with dosiomic features was promising in the pretreatment prediction of RE for EC patients underwent VMAT.

The sparing effect of ultra-high dose rate irradiation on the esophagus

Background and purpose

Current studies have substantiated the sparing effect of ultra-high dose rate irradiation (FLASH) in various organs including the brain, lungs, and intestines. Whether this sparing effect extends to esophageal tissue remains unexplored. This study aims to compare the different responses of esophageal tissue in histological and protein expression levels following conventional dose rate irradiation (CONV) and FLASH irradiation to ascertain the presence of a sparing effect.

Methods and materials

C57 female mice were randomly divided into three groups: control, CONV, and FLASH groups. The chest region of the mice in the radiation groups was exposed to a prescribed dose of 20 Gy using a modified electron linear accelerator. The CONV group received an average dose rate of 0.1 Gy/s, while the FLASH group received an average dose rate of 125 Gy/s. On the 10th day after irradiation, the mice were euthanized and their esophagi were collected for histopathological analysis. Subsequently, label-free proteomic quantification analysis was performed on esophageal tissue. The validation process involved analyzing transmission electron microscopy images and utilizing the parallel reaction monitoring method.

Results

Histopathology results indicated a significantly lower extent of esophageal tissue damage in the FLASH group compared to the CONV group (p < 0.05). Label-free quantitative proteomic analysis revealed that the sparing effect observed in the FLASH group may be attributed to a reduction in radiation-induced protein damage associated with mitochondrial functions, including proteins involved in the tricarboxylic acid cycle and oxidative phosphorylation, as well as a decrease in acute inflammatory responses.

Conclusions

Compared with CONV irradiation, a sparing effect on esophageal tissue can be observed after FLASH irradiation. This sparing effect is associated with alleviated mitochondria damage and acute inflammation.

The clinical manifestations and molecular pathogenesis of radiation fibrosis

Advances in radiation techniques have enabled the precise delivery of higher doses of radiotherapy to tumours, while sparing surrounding healthy tissues. Consequently, the incidence of radiation toxicities has declined, and will likely continue to improve as radiotherapy further evolves. Nonetheless, ionizing radiation elicits tissue-specific toxicities that gradually develop into radiation-induced fibrosis, a common long-term side-effect of radiotherapy. Radiation fibrosis is characterized by an aberrant wound repair process, which promotes the deposition of extensive scar tissue, clinically manifesting as a loss of elasticity, tissue thickening, and organ-specific functional consequences. In addition to improving the existing technologies and guidelines directing the administration of radiotherapy, understanding the pathogenesis underlying radiation fibrosis is essential for the success of cancer treatments. This review integrates the principles for radiotherapy dosimetry to minimize off-target effects, the tissue-specific clinical manifestations, the key cellular and molecular drivers of radiation fibrosis, and emerging therapeutic opportunities for both prevention and treatment.

Surgical complications of oncological treatments: A narrative review

Gastrointestinal complications are common in patients undergoing various forms of cancer treatments, including chemotherapy, radiation therapy, and molecular-targeted therapies. Surgical complications of oncologic therapies can occur in the upper gastrointestinal tract, small bowel, colon, and rectum. The mechanisms of action of these therapies are different. Chemotherapy includes cytotoxic drugs, which block the activity of cancer cells by targeting intracellular DNA, RNA, or proteins. Gastrointestinal symptoms are very common during chemotherapy, due to a direct effect on the intestinal mucosa resulting in edema, inflammation, ulceration, and stricture. Serious adverse events have been described as complications of molecular targeted therapies, including bowel perforation, bleeding, and pneumatosis intestinalis, which may require surgical evaluation. Radiotherapy is a local anti-cancer therapy, which uses ionizing radiation to cause inhibition of cell division and ultimately lead to cell death. Complications related to radiotherapy can be both acute and chronic. Ablative therapies, including radiofrequency, laser, microwave, cryoablation, and chemical ablation with acetic acid or ethanol, can cause thermal or chemical injuries to the nearby structures. Treatment of the different gastrointestinal complications should be tailored to the individual patient and based on the underlying pathophysiology of the complication. Furthermore, it is important to know the stage and prognosis of the disease, and a multidisciplinary approach is necessary to personalize the surgical treatment. The purpose of this narrative review is to describe complications related to different oncologic therapies that may require surgical interventions.

Incidence of dysphagia requiring medical attention in various types of cancers: A nationwide population-based cohort study

PURPOSE

Most previous reports on dysphagia in cancer have focused on specific cancer types, particularly head and neck cancer. Therefore, we aimed to investigate the incidence of dysphagia in patients with various cancers using a nationwide database in South Korea.

METHODS

This was a retrospective cohort study using the National Health Insurance Service database. Claim codes were used for the selection criteria and operational definitions. The total population data from 2010 to 2015 were extracted. The crude incidence of dysphagia was calculated per 1,000 person-years. The multivariate adjusted Cox proportional hazards regression was used to determine the effects of different cancers on the incidence of dysphagia.

RESULTS

People with cancer had a lower income and suffered from a higher risk of comorbidities compared to people without cancer. The risk of dysphagia increased in all types of cancers, particularly in the oral cavity and pharynx (hazard ratio [HR]: 20.65, 95% confidence interval [CI]: 17.73-24.06), esophagus (HR: 18.25, 95% CI: 15.66-21.26), larynx (HR: 12.87, 95% CI: 10.33-16.02), and central nervous system (HR: 12.42, 95% CI: 10.33-14.94).

CONCLUSIONS

The risk of dysphagia was significantly higher in the cancer group than in the non-cancer group. As the survival of cancer patients is improving with the development of new treatments, more attention should be paid to dysphagia in the management of cancer. Prompt and appropriate multidisciplinary interventions for dysphagia are necessary to improve the recovery and quality of life in cancer patients.

Polyphenols as Potential Protectors against Radiation-Induced Adverse Effects in Patients with Thoracic Cancer

Radiotherapy is one of the standard treatment approaches used against thoracic cancers, occasionally combined with chemotherapy, immunotherapy and molecular targeted therapy. However, these cancers are often not highly sensitive to standard of care treatments, making the use of high dose radiotherapy necessary, which is linked with high rates of radiation-induced adverse effects in healthy tissues of the thorax. These tissues remain therefore dose-limiting factors in radiation oncology despite recent technological advances in treatment planning and delivery of irradiation. Polyphenols are metabolites found in plants that have been suggested to improve the therapeutic window by sensitizing the tumor to radiotherapy, while simultaneously protecting normal cells from therapy-induced damage by preventing DNA damage, as well as having anti-oxidant, anti-inflammatory or immunomodulatory properties. This review focuses on the radioprotective effect of polyphenols and the molecular mechanisms underlying these effects in the normal tissue, especially in the lung, heart and esophagus.

The Use of Hydrogel-Based Materials for Radioprotection

Major causes of the radiation-induced disease include nuclear accidents, war-related nuclear explosions, and clinical radiotherapy. While certain radioprotective drug or bioactive compounds have been utilized to protect against radiation-induced damage in preclinical and clinical settings, these strategies are hampered by poor efficacy and limited utilization. Hydrogel-based materials are effective carriers capable of enhancing the bioavailability of compounds loaded therein. As they exhibit tunable performance and excellent biocompatibility, hydrogels represent promising tools for the design of novel radioprotective therapeutic strategies. This review provides an overview of common approaches to radioprotective hydrogel preparation, followed by a discussion of the pathogenesis of radiation-induced disease and the current states of research focused on using hydrogels to protect against these diseases. These findings ultimately provide a foundation for discussions of the challenges and future prospects associated with the use of radioprotective hydrogels.

Multi-omics to predict acute radiation esophagitis in patients with lung cancer treated with intensity-modulated radiation therapy

PURPOSE

The study aimed to predict acute radiation esophagitis (ARE) with grade  ≥ 2 for patients with locally advanced lung cancer (LALC) treated with intensity-modulated radiation therapy (IMRT) using multi-omics features, including radiomics and dosiomics.

METHODS

161 patients with stage IIIA-IIIB LALC who received chemoradiotherapy (CRT) or radiotherapy by IMRT with a prescribed dose from 45 to 70 Gy from 2015 to 2019 were enrolled retrospectively. All the toxicity gradings were given following the Common Terminology Criteria for Adverse Events V4.0. Multi-omics features, including radiomics, dosiomics (including dose-volume histogram dosimetric parameters), were extracted based on the planning CT image and three-dimensional dose distribution. All data were randomly divided into training cohorts (N = 107) and testing cohorts (N = 54). In the training cohorts, features with reliably high outcome relevance and low redundancy were selected under random patient subsampling. Four classification models (using clinical factors (CF) only, using radiomics features (RFs) only, dosiomics features (DFs) only, and the hybrid features (HFs) containing clinical factors, radiomics and dosiomics) were constructed employing the Ridge classifier using two-thirds of randomly selected patients as the training cohort. The remaining patient was treated as the testing cohort. A series of models were built with 30 times training-testing splits. Their performances were assessed using the area under the ROC curve (AUC) and accuracy.

RESULTS

Among all patients, 51 developed ARE grade  ≥ 2, with an incidence of 31.7%. Next, 8990 radiomics and 213 dosiomics features were extracted, and 3, 6, 12, and 13 features remained after feature selection in the CF, DF, RF and DF models, respectively. The RF and HF models achieved similar classification performance, with the training and testing AUCs of 0.796 ± 0.023 (95% confidence interval (CI [0.79, 0.80])/0.744 ± 0.044 (95% CI [0.73, 0.76]) and 0.801 ± 0.022 (95% CI [0.79, 0.81]) (p = 0.74), respectively. The model performances using CF and DF features were poorer, with training and testing AUCs of 0.573 ± 0.026 (95% CI [0.56, 0.58])/ 0.509 ± 0.072 (95% CI [0.48, 0.53]) and 0.679 ± 0.027 (95% CI [0.67, 0.69])/0.604 ± 0.041 (95% CI [0.53, 0.63]) compared with the above two models (p < 0.001), respectively.

CONCLUSIONS

In LALC patients treated with CRT IMRT, the ARE grade  ≥ 2 can be predicted using the pretreatment radiotherapy image features. To predict ARE, the multi-omics features had similar predictability with radiomics features; however, the dosiomics features and clinical factors had a limited classification performance.

Effects of Microbeam Irradiation on Rodent Esophageal Smooth Muscle Contraction

BACKGROUND

High-dose-rate radiotherapy has shown promising results with respect to normal tissue preservation. We developed an ex vivo model to study the physiological effects of experimental radiotherapy in the rodent esophageal smooth muscle.

METHODS

We assessed the physiological parameters of the esophageal function in ex vivo preparations of the proximal, middle, and distal segments in the organ bath. High-dose-rate synchrotron irradiation was conducted using both the microbeam irradiation (MBI) technique with peak doses greater than 200 Gy and broadbeam irradiation (BBI) with doses ranging between 3.5-4 Gy.

RESULTS

Neither MBI nor BBI affected the function of the contractile apparatus. While peak latency and maximal force change were not affected in the BBI group, and no changes were seen in the proximal esophagus segments after MBI, a significant increase in peak latency and a decrease in maximal force change was observed in the middle and distal esophageal segments.

CONCLUSION

No severe changes in physiological parameters of esophageal contraction were determined after high-dose-rate radiotherapy in our model, but our results indicate a delayed esophageal function. From the clinical perspective, the observed increase in peak latency and decreased maximal force change may indicate delayed esophageal transit.

Esophageal stenosis as an independent factor of poor prognosis in patients with ESCC treated with definitive chemoradiotherapy

Aim: To evaluate the clinical outcome and elucidate the prognostic factors in patients with esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy (CRT). Patients: Data for patients newly diagnosed with ESCC receiving definitive CRT at our institution between 2012 and 2018 were retrospectively reviewed. Results: A total of 201 patients were included. Severe stenosis after radiotherapy was an independent factor relevant to prognosis. Maximal esophageal wall thickness, short-term responses, severe stenosis at diagnosis and a high neutrophil-to-lymphocyte ratio were independent risk factors for the occurrence of severe stenosis after radiotherapy. Conclusion: Severe stenosis after radiotherapy is a useful predictive indicator in patients with ESCC receiving definitive CRT. Further studies are needed to verify these findings.

Transcriptome Profiling Unveils a Critical Role of IL-17 Signaling-Mediated Inflammation in Radiation-Induced Esophageal Injury in Rats

Elucidation of the molecular mechanisms involving the initiation and progression of radiation-induced esophageal injury (RIEI) is important for prevention and treatment. Despite ongoing advances, the underlying mechanisms controlling RIEI remain largely unknown. In the present study, RNA-seq was performed to characterize mRNA profiles of the irradiated rat esophagus exposed to 0, 25, or 35 Gy irradiation. Bioinformatics analyses including dose-dependent differentially expressed genes (DEGs), Gene Ontology (GO), Kyoto Encyclopedia of Gene and Genome (KEGG) pathway, protein-protein interaction (PPI) network, and immune infiltration were performed. 134 DEGs were screened out with a dose-dependent manner (35 Gy > 25 Gy > control, or 35 Gy < 25 Gy < control). GO and KEGG analyses showed that the most significant mechanism was IL-17 signaling-mediated inflammatory response. 5 hub genes, Ccl11, Cxcl3, Il17a, S100a8, and S100a9, were identified through the intersection of the DEGs involved in inflammatory response, IL-17 pathway, and PPI network. Additionally, immune infiltration analysis showed the activation of macrophages, monocytes, T cells, NKT cells, and neutrophils, among which macrophages, monocytes, and neutrophils might be the main sources of S100a8 and S100a9. Thus, these findings further our understanding on the molecular biology of RIEI and may help develop more effective therapeutic strategies.

Impact of Regional Lymph Node Irradiation on Reducing Lymph Node Recurrence in Esophageal Cancer Patients

BACKGROUND/AIM

To evaluate the preventive effects of regional lymph node irradiation on lymph node recurrence in esophageal cancer (EC).

PATIENTS AND METHODS

The study included 289 patients who received definitive radiotherapy for EC. The regional lymph node area of group 1 was determined as the area with the highest probability of lymph node metastasis and group 2 was determined as the area with the next highest probability of lymph node metastasis depending on the primary site of EC.

RESULTS

The patients in whom group 2 was completely included in the irradiated field had a significantly lower rate of recurrence of regional lymph node metastasis than those in whom group 2 was not or insufficiently included (p=0.0337). There was no significant difference in overall survival (p=0.4627) or disease-specific survival (p=0.6174) between the two groups.

CONCLUSION

Regional lymph node irradiation did not have survival-prolonging effects but significantly reduced regional lymph node recurrence.

Metabolic Profiling Implicates a Critical Role of Cyclooxygenase-2-Mediated Arachidonic Acid Metabolism in Radiation-Induced Esophageal Injury in Rats

Radiation-induced esophageal injury (RIEL) is a major dose-limiting complication of radiotherapy, especially for esophageal and thoracic cancers. RIEL is a multi-factorial and multi-step process, which is regulated by a complex network of DNA, RNA, protein and metabolite. However, it is unclear which esophageal metabolites are altered by ionizing radiation and how these changes affect RIEL progression. In this work, we established a rat model of RIEL with 0-40 Gy X-ray irradiation. Esophageal irradiation using ≥25 Gy induced significant changes to rats, such as body weight, food intake, water intake and esophageal structure. The metabolic changes and related pathways of rat esophageal metabolites were investigated by liquid chromatography-mass spectrometry (LC-MS). One hundred eighty metabolites showed an up-regulation in a dose-dependent manner (35 Gy ≥ 25 Gy > controls), and 199 metabolites were downregulated with increasing radiation dose (35 Gy ≤ 25 Gy < controls). The KEGG analysis showed that ionizing radiation seriously disrupted multiple metabolic pathways, and arachidonic acid metabolism was the most significantly enriched pathway. 20 metabolites were dysregulated in arachidonic acid metabolism, including up-regulation of five prostaglandins (PGA2, PGJ2, PGD2, PGH2, and PGI2) in 25 or 35 Gy groups. Cyclooxygenase-2 (COX-2), the key enzyme in catalyzing the biosynthesis of prostaglandins from arachidonic acid, was highly expressed in the esophagus of irradiated rats. Additionally, receiver operating characteristic (ROC) curve analysis revealed that PGJ2 may serve as a promising tissue biomarker for RIEL diagnosis. Taken together, these findings indicate that ionizing radiation induces esophageal metabolic alterations, which advance our understanding of the pathophysiology of RIEL from the perspective of metabolism.

Interferon-α exerts proinflammatory properties in experimental radiation-induced esophagitis: Possible involvement of plasmacytoid dendritic cells

AIMS

Radiation-induced esophagitis, experienced during radiation therapy for lung cancer and head and neck cancer, is a major dose-limiting side effect of the treatment. This study aimed to elucidate the role of interferon-α (IFN-α) in radiation-induced esophagitis.

MAIN METHODS

C57BL/6 mice were exposed to 10 and 25Gy of single thoracic irradiation. Esophageal mucosal damage and inflammatory reactions were assessed for 5 days after irradiation.

KEY FINDINGS

Irradiation induced esophagitis, characterized by reduction in the thickness of epithelial layer, upregulation of proinflammatory cytokines and chemokines, infiltration of inflammatory cells into the esophageal mucosa, and apoptosis of epithelial cells. Irradiation upregulated the level of gene expression for IFN-α in the esophageal tissue, and the neutralizing antibody against IFN-α ameliorated radiation-induced esophageal mucosal damage, while administration of IFN-α receptor agonist (RO8191) had an inverse effect. Depletion of plasmacytoid dendritic cells (pDCs) by anti-CD317 antibody or pharmacological inactivation with bortezomib suppressed radiation-induced mucosal inflammation and damage, accompanied by decrease in IFN-α expression level.

SIGNIFICANCE

These findings suggest that IFN-α and pDCs exert proinflammatory properties in the pathophysiology of radiation-induced esophagitis.

Gut Microbiota Characteristics Are Associated With Severity of Acute Radiation-Induced Esophagitis

BACKGROUND

Acute radiation-induced esophagitis (ARIE) is one of the most debilitating complications in patients who receive thoracic radiotherapy, especially those with esophageal cancer (EC). There is little known about the impact of the characteristics of gut microbiota on the initiation and severity of ARIE.

MATERIALS AND METHODS

Gut microbiota samples of EC patients undergoing radiotherapy (n = 7) or concurrent chemoradiotherapy (n = 42) were collected at the start, middle, and end of the radiotherapy regimen. Assessment of patient-reported ARIE was also performed. Based on 16S rRNA gene sequencing, changes of the gut microbial community during the treatment regimen and correlations of the gut microbiota characteristics with the severity of ARIE were investigated.

RESULTS

There were significant associations of several properties of the gut microbiota with the severity of ARIE. The relative abundance of several genera in the phylum Proteobacteria increased significantly as mucositis severity increased. The predominant genera had characteristic changes during the treatment regimen, such as an increase of opportunistic pathogenic bacteria including Streptococcus. Patients with severe ARIE had significantly lower alpha diversity and a higher abundance of Fusobacterium before radiotherapy, but patients with mild ARIE were enriched in Klebsiella, Roseburia, Veillonella, Prevotella_9, Megasphaera, and Ruminococcus_2. A model combining these genera had the best performance in prediction of severe ARIE (area under the curve: 0.907).

CONCLUSION

The characteristics of gut microbiota before radiotherapy were associated with subsequent ARIE severity. Microbiota-based strategies have potential use for the early prediction of subsequent ARIE and for the selection of interventions that may prevent severe ARIE.

Pharmacological Interventions for the Prevention and Treatment of Kidney Injury Induced by Radiotherapy: Molecular Mechanisms and Clinical Perspectives

More than half of cancer patients need radiotherapy during the course of their treatment. Despite the beneficial aspects, the destructive effects of radiation beams on normal tissues lead to oxidative stress, inflammation, and cell injury. Kidneys are affected during radiotherapy of abdominal malignancies. Radiation nephropathy eventually leads to the release of factors triggering systemic inflammation. Currently, there is no proven prophylactic or therapeutic intervention for the management of radiation-induced nephropathy. This article reviews the biomarkers involved in the pathophysiology of radiation-induced nephropathy and its underlying molecular mechanisms. The efficacy of compounds with potential radio-protective properties on amelioration of inflammation and oxidative stress is also discussed. By outlining the approaches for preventing and treating this critical side effect, we evaluate the potential treatment of radiation-induced nephropathy. Available preclinical and clinical studies on these compounds are also scrutinized.

Evaluation of Epigallocatechin-3-Gallate as a Radioprotective Agent During Radiotherapy of Lung Cancer Patients: A 5-Year Survival Analysis of a Phase 2 Study

Background

Previous analysis of the study (NCT02577393) had demonstrated the application of epigallocatechin-3-gallate (EGCG) could be safe and effective in the prevention and treatment of acute radiation esophagitis in patients with advanced lung cancer. EGCG seemed to improve the response rate of small cell lung cancer (SCLC) to radiotherapy in a subgroup analysis. This research continued to analyze the impact of EGCG application on cancer-radiation efficacy and patient survival.

Methods

All patients with SCLC in the NCT02577393 study were included. Patients were randomized into EGCG group or conventional therapy group as protocol. The primary endpoints of the study were radiation response rate and progression-free survival (PFS). Overall survival (OS) and the efficacy of EGCG in the treatment of esophagitis were assessed as secondary endpoints.

Results

A total of 83 patients with lung cancer in the NCT02577393 study were screened, and all 38 patients with SCLC were eligible for analysis. No significant differences with regard to baseline demographic and clinical characteristics were observed between the two groups. The objective response rate (ORR) was higher than that of conventionally treated patients (84.6 vs 50%, P = 0.045), while the median PFS and OS were not significantly prolonged. At data cut-off (1 January 2021), 5-year PFS was 33% with EGCG versus 9.3% with conventional treatment, and 5-year OS was 30.3% versus 33.3%, respectively. The mean adjusted esophagitis index and pain index of patients with EGCG application were lower than conventional treatment (5.15 ± 2.75 vs 7.17 ± 1.99, P = 0.030; 8.62 ± 5.04 vs 15.42 ± 5.04, P < 0.001).

Conclusion

The study indicates EGCG may alleviate some esophagitis-related indexes in SCLC patients exposed to ionizing radiation without reducing survival. However, this conclusion should be confirmed by further studies with large sample size.

Significance of radiation esophagitis: Conditional survival assessment in patients with non-small cell lung cancer

Purpose

This study aimed to examine the effect of radiation esophagitis (RE) and the dynamics of RE on subsequent survival in non-small cell lung cancer (NSCLC) patients who underwent radiotherapy.

Experimental Design

Patients with NSCLC treated with fractionated thoracic radiotherapy enrolled in prospective trials were eligible. RE was graded prospectively according to Common Terminology Criteria for Adverse Events (CTCAE) v3.0 per protocol requirement weekly during-RT and 1 month after RT. This study applied conditional survival assessment which has advantage over traditional survival analysis as it assesses the survival from the event instead of from the baseline. P-value less than 0.05 was considered to be significant. The primary endpoint is overall survival.

Results

A total of 177 patients were eligible, with a median follow-up of 5 years. The presence of RE, the maximum RE grade, the evolution of RE and the onset timing of RE events were all correlated with subsequent survival. At all conditional time points, patients first presented with RE grade1 (initial RE1) had significant inferior subsequent survival (multivariable HRs median: 1.63, all P-values<0.05); meanwhile those with RE progressed had significant inferior subsequent survival than those never develop RE (multivariable HRs median: 2.08, all P-values<0.05). Multivariable Cox proportional-hazards analysis showed significantly higher C-indexes for models with inclusion of RE events than those without (all P-values<0.05).

Conclusion

This study comprehensively evaluated the impact of RE with conditional survival assessment and demonstrated that RE is associated with inferior survival in NSCLC patients treated with RT.

A novel nomogram containing acute radiation esophagitis predicting radiation pneumonitis in thoracic cancer receiving radiotherapy

Background

Radiation-induced pneumonitis (RP) is a non-negligible and sometimes life-threatening complication among patients with thoracic radiation. We initially aimed to ascertain the predictive value of acute radiation-induced esophagitis (SARE, grade ≥ 2) to symptomatic RP (SRP, grade ≥ 2) among thoracic cancer patients receiving radiotherapy. Based on that, we established a novel nomogram model to provide individualized risk assessment for SRP.

Methods

Thoracic cancer patients who were treated with thoracic radiation from Jan 2018 to Jan 2019 in Shandong Cancer Hospital and Institute were enrolled prospectively. All patients were followed up during and after radiotherapy (RT) to observe the development of esophagitis as well as pneumonitis. Variables were analyzed by univariate and multivariate analysis using the logistic regression model, and a nomogram model was established to predict SRP by “R” version 3.6.0.

Results

A total of 123 patients were enrolled (64 esophageal cancer, 57 lung cancer and 2 mediastinal cancer) in this study prospectively. RP grades of 0, 1, 2, 3, 4 and 5 occurred in 29, 57, 31, 0, 3 and 3 patients, respectively. SRP appeared in 37 patients (30.1%). In univariate analysis, SARE was shown to be a significant predictive factor for SRP (P < 0.001), with the sensitivity 91.9% and the negative predictive value 93.5%. The incidence of SRP in different grades of ARE were as follows: Grade 0–1: 6.5%; Grade 2: 36.9%; Grade 3: 80.0%; Grade 4: 100%. Besides that, the dosimetric factors considering total lung mean dose, total lung V5, V20, ipsilateral lung mean dose, ipsilateral lung V5, and mean esophagus dose were correlated with SRP (all P < 0.05) by univariate analysis. The incidence of SRP was significantly higher in patients whose symptoms of RP appeared early. SARE, mean esophagus dose and ipsilateral mean lung dose were still significant in multivariate analysis, and they were included to build a predictive nomogram model for SRP.

Conclusions

As an early index that can reflect the tissue’s radiosensitivity visually, SARE can be used as a predictor for SRP in patients receiving thoracic radiation. And the nomogram containing SARE may be fully applied in future’s clinical work.

Update on the management of the gastrointestinal effects of radiation

Radiation therapy is a long-established and essential modality in the treatment of many cancers. It is well known that tissue within a field of radiation can suffer indiscriminate effects, leading to acute and chronic problems. The gastrointestinal tract may be adversely affected by radiation. From the mouth to the rectum, patients can experience troublesome symptoms that require the concerted input of specialist teams. Interventions range from nursing care, dietetic optimization, pharmacological management, and mechanical procedures through endoscopy and surgery. Quality evidence exists mainly for radiation induced effects in four distinct areas of the gastrointestinal tract: oral mucosa, esophagus, small bowel, and rectum. This review explores the experiences of oncology and gastrointestinal teams in managing the most common conditions and some of the different practices for radiation associated morbidity.

Salvage endoscopic resection after definitive chemoradiotherapy for esophageal cancer: a Western experience

BACKGROUND AND AIMS

Definitive chemoradiotherapy (CRT) is increasingly used as a nonsurgical treatment for esophageal cancer. In Japanese studies, salvage endoscopic resection (ER) has emerged as a promising strategy for local failure after definitive CRT. We aimed to evaluate the safety and efficacy of salvage ER in a Western setting.

METHODS

Gastroenterologists from Europe and the United States were invited to submit their experience with salvage endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) after definitive CRT. Participating gastroenterologists completed an anonymized database, including patient demographics, clinicopathologic variables, and follow-up on survival and recurrence.

RESULTS

Gastroenterologists from 10 endoscopic units in 6 European countries submitted information on 25 patients. A total of 35 salvage ER procedures were performed, of which 69% were ESD and 31% EMR. Most patients had squamous cell carcinoma (64%) of the middle or lower esophagus (68%) staged as cT2-3 (68%) and cN+ (52%) before definitive CRT. The median time from end of definitive CRT to ER was 22 months (interquartile range, 6-47). The en-bloc resection rate was 92% for ESD and 46% for EMR. During a median of 24 months (interquartile range, 12-59) of follow-up after salvage ER, 52% developed a recurrence (11 locoregional, 2 distant). The 5-year recurrence-free survival, overall survival, and disease-specific survival were 36%, 52%, and 79%, respectively. No major intra- or postprocedural adverse events, such as bleeding or perforation, were reported.

CONCLUSIONS

In carefully selected esophageal cancer patients, salvage ER is technically feasible after definitive CRT. Further prospective research is recommended to validate the safety and effectivity of salvage ER for the management of local failure.

Regeneration of irradiation-damaged esophagus by local delivery of mesenchymal stem-cell spheroids encapsulated in a hyaluronic-acid-based hydrogel

Radiation therapy (RT) is a typical treatment for head and neck cancers. Generally, prolonged irradiation of the esophagus causes esophageal fibrosis due to increased reactive oxygen species and proinflammatory cytokines. This study was designed to determine whether catechol-functionalized hyaluronic acid (HA-CA) hydrogel-encapsulated human mesenchymal stem-cell spheroids (MSC-SPs) could ameliorate damage to the esophagus in a mouse model of radiation-induced esophageal fibrosis. MSC-SPs were cultured in concave microwells 600 μm in diameter at a cell density of 1 × 10⁶ cells per mL. Most cells formed spheroids with a 100-300 μm size distribution in concave microwells. MSC-SPs were well maintained in the HA gel, and live-dead staining confirmed that most cells survived. The HA gel containing the MSC-SPs was then injected into the damaged esophageal layer. Inflammatory signs or adverse tissue reactions were not observed after esophageal injection of HA-gel-encapsulated MSC-SPs. Based on Masson's trichrome staining at 4 and 12 weeks postinjection, the inner esophageal layer (IEL) was significantly thinner in the MSC-SP + HA gel group compared to those in the other experimental groups. While the saline and HA gel treatments made the esophageal muscles loose and thick, the MSC-SP + HA gel group showed bundles of tightly packed esophageal muscles, as assayed by desmin immunostaining. qPCR analysis showed that epithelial genes tended to increase over time in the MSC-SP + HA gel group, and the expression of most fibrosis-related genes decreased. This study proposes the potential of using HA-CA-hydrogel-encapsulated MSC-SPs as a promising therapy against radiation-induced esophageal fibrosis.

Self-Expanding Metal Stent (SEMS) Placement to Treat Bleeding from Late Radiation Esophagitis

Radiation esophagitis is a serious complication occurring in patients receiving radiotherapy for head and neck cancers. Current treatment with proton pump inhibitors and mucosal protectants provides symptomatic relief with few studies showing improvement in erosive esophagitis or ulceration. Use of self-expandable metal stents (SEMS) in cases of erosive radiation esophagitis refractory to medical therapy has not been studied. We report a case of a patient presenting with recurrent hematemesis from late (chronic) radiation esophagitis with bleeding esophageal ulceration successfully treated with SEMS placement after failure of conservative medical management, proposing a possible utility for SEMS in this setting.

[Therapy of radiation-induced esophagits by oro-dispersible budesonide]

Radiation esophagitis is a common side effect of therapeutic radiotherapy. In this case report, we describe a patient with a complete remission of the esophagitis after therapy with an oro-dispersible budesonide formulation.

Plant Extracts as Possible Agents for Sequela of Cancer Therapies and Cachexia

Cancer is a leading cause of the death worldwide. Since the National Cancer Act in 1971, various cancer treatments were developed including chemotherapy, surgery, radiation therapy and so forth. However, sequela of such cancer therapies and cachexia are problem to the patients. The primary mechanism of cancer sequela and cachexia is closely related to reactive oxygen species (ROS) and inflammation. As antioxidant properties of numerous plant extracts have been widely reported, plant-derived drugs may have efficacy on managing the sequela and cachexia. In this study, recent seventy-four studies regarding plant extracts showing ability to manage the sequela and cachexia were reviewed. Some plant-derived antioxidants inhibited cancer proliferation and inflammation after surgery and others prevented chemotherapy-induced normal cell apoptosis. Also, there are plant extracts that suppressed radiation-induced oxidative stress and cell damage by elevation of glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and regulation of B-cell lymphoma 2 (BcL-2) and Bcl-2-associated X protein (Bax). Cachexia was also alleviated by inhibition of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) by plant extracts. This review focuses on the potential of plant extracts as great therapeutic agents by controlling oxidative stress and inflammation.

A case of cytomegalovirus esophagitis during topical steroid therapy for eosinophilic esophagitis

Systemic immune deficiency is a major cause of cytomegalovirus (CMV) esophagitis. We report a case of CMV esophagitis during topical steroid therapy of eosinophilic esophagitis (EoE) in a non-immunodeficient patient. An 85-year-old man with dysphagia was on a 6-year regimen of oral budesonide (1200 mcg daily) for EoE. He underwent right upper lobectomy and postoperative radiotherapy 25 years ago for lung squamous cell carcinoma. Esophageal cicatricial stenosis due to EoE or previous radiation therapy persisted. Esophagogastroduodenoscopy revealed ulcerating mucosa with a thick white coat originating from the fixed stenotic lesion to the oral side. Histopathological examinations revealed CMV esophagitis. All signs of CMV esophagitis rapidly disappeared after reducing the budesonide dose and initiating anti-viral treatment with ganciclovir and valganciclovir for 12 and 2 days, respectively. The patient continued topical budesonide 400 mcg daily after anti-viral therapy. The clinical course was uneventful and without CMV esophagitis recurrence. This suggests that topical steroid therapy, particularly the local stasis of steroids at stenotic lesions, may induce CMV esophagitis. This is the first report of CMV esophagitis complicating the local steroid therapy of EoE with a stenotic lesion. When EoE patients' clinical symptoms worsen with topical steroid therapy, CMV esophagitis should be considered.

Non gastro-esophageal reflux disease related esophagitis: an overview with a histologic diagnostic approach

Several pathological conditions, other than gastro-esophageal reflux disease and its complications, can affect the esophagus. While some of these can present with unspecific lesions (i.e. ulcers and epithelial damage) and require clinico-pathological correlation for diagnosis (i.e. drug-induced esophagitis and corrosive esophagitis) other conditions show distinctive histological lesions which enable the pathologist to reach the diagnosis (i.e. some specific infectious esophagites and Crohn's disease). In this context eosinophilic esophagitis is the condition which has been increasingly studied in the last two decades, while lymphocytic esophagitis, a relatively new entity, still represents an enigma. This overview will focus on and describe histologic lesions which allow pathologists to differentiate between these conditions.

Treatment-related complications in patients with esophageal cancer: A systematic review and network meta-analysis

BACKGROUND

The aim of this review was to compare the available treatments of esophageal cancer, in terms of pulmonary, cardiovascular complications, anastomotic leakage, and esophagitis after treatment in patients with esophageal squamous cell carcinoma (SCC).

METHODS

Medline, Web of Science, Scopus, the Cochrane Library and Embase were searched. The randomized controlled trials (RCT) that had compared the treatment -related complications of treatments for esophageal SCC were included. We included 39 randomized control trials in a network meta-analysis. The Chi2-test was used to assess of heterogeneity. The loop-specific and design-by-treatment interaction methods were used for assessment of consistency assumption. The risk ratio with 95% confidence interval (CI) was used to report the effect-sizes in the network meta-analysis.

RESULTS

The pulmonary complication, cardiac complication, anastomotic leakage, and esophagitis were reported in 31, 11, 17, and 15 RCTs respectively. Video-assisted thoracoscopy + laparoscopy (VATS) was rank as the first and second treatment in terms of lower risk for pulmonary complication and anastomotic leakage. There was no statistically significant difference between treatments in terms of lower risk of cardiovascular complications. However, Surgery + Cisplatin + Fluorouracil (SCF) was ranked as better treatment. 3-dimensional conformal radiotherapy + Docetaxel + Cisplatin (3DCRTDC) was the best treatment in terms of lower risk for esophagitis.

CONCLUSION

According to the results of this study, it seems the risk of pulmonary, cardiovascular, anastomotic leakage and esophagitis complications for VATS, SCF, surgery + radiotherapy (SRT), and 3DCRTDC was lower than other treatments respectively in the networks.

The Mexican consensus on non-cardiac chest pain

INTRODUCTION

Non-cardiac chest pain is defined as a clinical syndrome characterized by retrosternal pain similar to that of angina pectoris, but of non-cardiac origin and produced by esophageal, musculoskeletal, pulmonary, or psychiatric diseases.

AIM

To present a consensus review based on evidence regarding the definition, epidemiology, pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options for those patients.

METHODS

Three general coordinators carried out a literature review of all articles published in English and Spanish on the theme and formulated 38 initial statements, dividing them into 3 main categories: (i)definitions, epidemiology, and pathophysiology; (ii)diagnosis, and (iii)treatment. The statements underwent 3rounds of voting, utilizing the Delphi system. The final statements were those that reached >75% agreement, and they were rated utilizing the GRADE system.

RESULTS AND CONCLUSIONS

The final consensus included 29 statements. All patients presenting with chest pain should initially be evaluated by a cardiologist. The most common cause of non-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initial approach should be a therapeutic trial with a proton pump inhibitor for 2-4weeks. If dysphagia or alarm symptoms are present, endoscopy is recommended. High-resolution manometry is the best method for ruling out spastic motor disorders and achalasia and pH monitoring aids in demonstrating abnormal esophageal acid exposure. Treatment should be directed at the pathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/or smooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionally surgery or endoscopic therapy.

Esophageal Stricture Following Radiation, Concurrent Immunochemotherapy, Treated With Hyperbaric Oxygen and Dilation

Low-dose palliative radiation may offer symptomatic relief in patients with spinal metastases from primary renal cell cancer and is unlikely to result in radiation injury. Patients with advanced malignancy requiring palliative radiation are often also receiving chemotherapy. Synergistic adverse effects resulting from combined palliative radiation and novel antiprogrammed cell death-1 (anti-PD 1) and/or multityrosine kinase inhibitors are rare.

We report about a 60-year-old woman with metastatic clear-cell renal cancer, status post-left nephrectomy, with debilitating mid-back pain from metastatic tumor burden and foraminal nerve compression. Her chemotherapeutic regimen was repeatedly altered because of progression of disease until she was maintained on the anti-PD 1 checkpoint inhibitor, nivolumab. She received palliative radiation to her thoracic spine over a 2-week period, and nivolumab was then switched to cabozantinib midway through a course of palliative radiation. The patient rapidly developed severe esophagitis, progressing to esophageal stricture, and required placement of a percutaneous endoscopic gastrostomy tube. She was successfully treated with serial esophageal dilation and hyperbaric oxygen treatments to diminish inflammation and improve tissue vascularity. Concurrent use of anti-PD 1 and/or multityrosine kinase drugs may accelerate development of radiation injury regardless of radiation dosage. Radiation-induced esophageal stricture was managed successfully in this patient with serial esophageal dilation and adjuvant hyperbaric oxygen.

Low- vs. High-Dose Neoadjuvant Radiation in Trimodality Treatment of Locally Advanced Esophageal Cancer

BACKGROUND

The optimal dose of neoadjuvant radiation for locally advanced, resectable esophageal cancer remains controversial in the absence of randomized clinical trials, with conventional practice favoring the use of 50.4 vs. 41.4 Gy.

METHODS

Retrospective analysis of adults with non-metastatic esophageal cancer in the National Cancer Database (2004-2015) treated with neoadjuvant chemoradiotherapy. Outcomes were compared between patients undergoing 41.4, 45, or 50.4 Gy. Primary outcome was overall survival. Secondary outcomes included T and N downstaging and perioperative mortality adjusted for demographics, clinicopathologic factors, and facility volume.

RESULTS

Eight thousand eight hundred eighty-one patients were included: 439 (4.9%) received low-dose (41.4 Gy), 2194 (24.7%) received moderate-dose (45 Gy), and 6248 (70.4%) received high-dose (50.4 Gy) neoadjuvant radiation. Compared to high-dose, low-dose radiation was associated with superior median overall survival (52.6 vs. 40.7 months) and 5-year survival (48.3% vs. 40.2%), and lower unadjusted 90-day mortality (2.3% vs. 6.5%, all p ≤ 0.01). Multivariable proportional hazards models confirmed an increased hazard of death associated with high-dose radiation therapy (HR = 1.38, 95% CI 1.10-1.72, p = 0.005). There was no significant difference in T and/or N downstaging between low-dose vs. high-dose therapy (p > 0.1 for both). Patients receiving 45 Gy exhibited the lowest median overall survival (37.2 months) and 5-year survival (38.7%, log-rank p = 0.04).

CONCLUSIONS

Compared to 50.4 Gy, 41.4 Gy is associated with reduced perioperative mortality and superior overall survival with similar downstaging in locally advanced esophageal cancer. In the absence of randomized clinical data, our findings support the use of 41.4 Gy in patients with chemoradiation followed by esophagectomy. Prospective trials are warranted to further validate these results.

Clinical Characteristics and Associated Systemic Diseases in Patients With Esophageal "Absent Contractility"-A Clinical Algorithm

GOALS

This study was carried out to assess the clinical characteristics and associated systemic diseases seen in patients diagnosed with absent contractility as per the Chicago Classification version 3.0, allowing us to propose a diagnostic algorithm for their etiologic testing.

BACKGROUND

The Chicago Classification version 3.0 has redefined major and minor esophageal motility disorders using high-resolution esophageal manometry. There is a dearth of publications based on research on absent contractility, which historically has been associated with myopathic processes such as systemic sclerosis (SSc).

STUDY

We conducted a retrospective, multicenter study. Data of patients diagnosed with absent contractility were pooled from Cleveland Clinic, Cleveland, OH (January 2006 to July 2016) and Metrohealth Medical Center, Cleveland, OH (July 2014 to July 2016) and included: age, gender, associated medical conditions, surgical history, medications, and specific antibody testing.

RESULTS

A total of 207 patients, including 57 male individuals and 150 female individuals, with mean age of 56.1 and 60.0 years, respectively, were included. Disease distribution was as follows: SSc (diffuse or limited cutaneous) 132, overlap syndromes 7, systemic lupus erythematosus17, Sjögren syndrome 4, polymyositis 3, and dermatomyositis 3. Various other etiologies including gastroesophageal reflux disease, postradiation esophagitis, neuromuscular disorders, and surgical complications were seen in the remaining cohort.

CONCLUSIONS

Most practitioners use the term "absent contractility" interchangeably with "scleroderma esophagus"; however, only 63% of patients with absent contractility had SSc. Overall, 20% had another systemic autoimmune rheumatologic disease and 16% had a nonrheumatologic etiology for absent contractility. Therefore, alternate diagnosis must be sought in these patients. We propose an algorithm for their etiologic evaluation.

Oropharyngeal Dysphagia Evaluation Tools in Adults with Solid Malignancies Outside the Head and Neck and Upper GI Tract: A Systematic Review

Dysphagia is often associated with head and neck and upper gastrointestinal (GI) tract cancers. Evidence suggests that those with solid malignancies in other primary sites may also have swallowing difficulties. Timely and accurate identification of dysphagia is important given the impact it has on hydration, medical treatment, nutrition, prognosis, and quality of life. A systematic review was conducted to identify swallow screening, evaluation, and quality of life tools for those with solid malignancies outside the head and neck and upper GI tract. Ten electronic databases, one journal and two published conference proceedings were searched. Following deduplication, 7435 studies were examined for relevance. No tools were validated solely in this cancer population, though some included this group in larger cohorts. Comments are provided on the diagnostic properties and applicability of these tools. In the absence of appropriate diagnostic instruments, the exact prevalence of dysphagia and its impact on clinical and psychosocial well-being remain unknown. Accurate and adequate measurement of therapeutic intervention is also compromised. This review establishes the need for validated dysphagia evaluation tools for this clinical population.

Feasibility of using optical coherence tomography to detect acute radiation-induced esophageal damage in small animal models

Lung cancer survival is poor, and radiation therapy patients often suffer serious treatment side effects. The esophagus is particularly sensitive leading to acute radiation-induced esophageal damage (ARIED). We investigated the feasibility of optical coherence tomography (OCT) for minimally invasive imaging of the esophagus with high resolution (10  μm) to detect ARIED in mice. Thirty mice underwent cone-beam computed tomography imaging for initial setup assessment and dose planning followed by a single-dose delivery of 4.0, 10.0, 16.0, and 20.0 Gy on 5.0-mm spots, spaced 10.0 mm apart in the esophagus. They were repeatedly imaged using OCT up to three months postirradiation. We compared OCT findings with histopathology obtained three months postirradiation qualitatively and quantitatively using the contrast-to-background-noise ratio (CNR). Histopathology mostly showed inflammatory infiltration and edema at higher doses; OCT findings were in agreement with most of the histopathological reports. We were able to identify the ARIED on OCT as a change in tissue scattering and layer thickness. Our statistical analysis showed significant difference between the CNR values of healthy tissue, edema, and inflammatory infiltration. Overall, the average CNR for inflammatory infiltration and edema damages was 1.6-fold higher and 1.6-fold lower than for the healthy esophageal wall, respectively. Our results showed the potential role of OCT to detect and monitor the ARIED in mice, which may translate to humans.

PARP Inhibition Combined With Thoracic Irradiation Exacerbates Esophageal and Skin Toxicity in C57BL6 Mice

PURPOSE

Poly (ADP-ribose) polymerase (PARP) inhibitors have been shown to enhance the radiosensitivity of cancer cells in vitro in a replication-dependent manner. Their in vivo radiosensitizing effects have also been demonstrated in preclinical tumor models. However, whether PARP inhibition can enhance the response to radiation therapy in normal tissues has been largely neglected. We hypothesized that PARP inhibition might also potentiate the response of replicating normal tissues to radiation therapy. In this study, we examined the normal tissue response in mice treated with PARP inhibitors (BMN673 or AZD2281) in combination with thoracic irradiation.

METHODS AND MATERIALS

The antitumor effects of fractionated irradiation (5 Gy × 4) in combination with BMN673 were evaluated in nude mice bearing established Calu-6 human lung cancer xenografts. The normal tissue response was evaluated in C57BL6 mice that were treated with BMN673 or AZD2281 combined with fractionated irradiation, 5 Gy × 4, delivered to the whole thorax. Body weight and histology of the esophagus and skin in the field of irradiation were examined. The DNA damage response in the esophagus and skin was assessed by γH2AX immunohistochemistry.

RESULTS

While PARP inhibition enhanced irradiation-induced tumor growth inhibition in nude mice, it was also associated with significant body weight loss and increased damage to the esophagus and skin within the field of irradiation in C57BL6 mice. PARP inhibition compromised the repair of irradiation-induced DNA damage in the esophagus and skin.

CONCLUSIONS

Although PARP inhibition enhanced the antitumor response to fractionated irradiation, it also enhanced the irradiation response in replicating normal tissues. Therefore, our study suggests that additional caution may be warranted in the clinical development of combination therapies using PARP inhibitors and radiation therapy, in particular where the field of irradiation includes the esophagus.

Subjective Global Assessment (SGA) Score Could Be a Predictive Factor for Radiation Pneumonitis in Lung Cancer Patients With Normal Pulmonary Function Treated by Intensity-Modulated Radiation Therapy and Concurrent Chemotherapy

INTRODUCTION

To investigate the relationship between malnutrition and the severity of radiation pneumonitis (RP) in patients with lung cancer with normal baseline pulmonary function and lungs' V20 < 35% treated by intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy.

MATERIALS AND METHODS

A total of 150 patients with lung cancer who received definitive IMRT (≥ 60 Gy) and concurrent chemotherapy were enrolled. In the condition of normal baseline pulmonary function and strict constraints of the irradiation dose to normal lung tissues, we recorded Eastern Cooperative Oncology Group score; concurrent chemotherapy; clinical stage; the level of albumin (ALB), hemoglobin, and C-reactive protein; Subjective Global Assessment (SGA) scores; radiation esophagitis grade; V20 of lungs; and mean lung dose. These factors were correlated with RP using univariate and multivariate regression analyses.

RESULTS

Of 150 patients, 12 patients (8.0%) developed Grade 3 to 5 RP, 37 (24.6%) patients developed grade 3 to 5 esophageal toxicity. In univariate analysis, ALB level (P = .002), radiation esophagitis (P < .001), and SGA score (P < .001) were significantly associated with RP. Multivariate analysis revealed that SGA (P < .001) was the independent predictor of RP.

CONCLUSIONS

SGA could be a predictor for RP in patients with lung cancer treated with definitive IMRT and concurrent chemotherapy.

Acute radiation oesophagitis associated with 2-deoxy-2-[18F]fluoro-d-glucose uptake on positron emission tomography/CT during chemo-radiation therapy in patients with non-small-cell lung cancer

INTRODUCTION

Acute radiation oesophagitis (ARO) is frequently experienced by patients receiving concurrent chemo-radiation therapy (cCRT) for non-small-cell lung cancer (NSCLC). We investigated ARO symptoms (CTCAE v3.0), radiation dose and oesophageal FDG PET/CT uptake.

METHOD

Candidates received cCRT (60 Gy, 2 Gy/fx) and sequential FDG PET/CT (baseline FDG₀ , FDG_wk2 and FDG_wk4 ). Mean and maximum standardized uptake value (SUVmean and SUVmax) and radiation dose (O_mean and O_max ) were calculated within the whole oesophagus and seven sub-regions (5-60 Gy).

RESULTS

Forty-four patients underwent FDG₀ and FDG_wk2 , and 41 (93%) received FDG_wk4 , resulting in 129 PET/CT scans for analysis. Of 29 (66%) patients with ≥ grade 2 ARO, SUVmax (mean ± SD) increased from FDG₀ to FDG_wk4 (3.06 ± 0.69 to 3.83 ± 1.27, P = 0.0019) and FDG_wk2 to FDG_wk4 (3.10 ± 0.75 to 3.83 ± 1.27, P = 0.0046). Radiation dose (mean ± SD) was higher in grade ≥2 patients; O_mean (47.5 ± 20 vs 53.9 ± 10.2, P = 0.0061), O_max (13.7 ± 9.6 vs 20.1 ± 10.6, P = 0.0009) and V40 Gy (8.0 ± 8.2 vs 11.9 ± 7.3, P = 0.0185).

CONCLUSIONS

FDG_wk4 SUVmax and radiation dose were associated with ≥ grade 2 ARO. Compared to subjective assessments, future interim FDG PET/CT acquired for disease response assessment may also be utilized to objectively characterize ARO severity and image-guided oesophageal dose constraints.

Radiation-induced esophagitis in lung cancer

Radiation-induced esophagitis is the most common local acute toxicity of radiotherapy (RT) delivered for the curative or palliative intent treatment of lung cancer. Although concurrent chemotherapy and higher RT dose are associated with increased esophagitis risk, advancements in RT techniques as well as adherence to esophageal dosimetric constraints may reduce the incidence and severity. Mild acute esophagitis symptoms are generally self-limited, and supportive management options include analgesics, acid suppression, diet modification, treatment for candidiasis, and maintenance of adequate nutrition. Esophageal stricture is the most common late sequela from esophageal irradiation and can be addressed with endoscopic dilatation. Approaches to prevent or mitigate these toxicities are also discussed.

Imaging after radiation therapy of thoracic tumors

Radiation-induced lung disease (RILD) is frequent after therapeutic irradiation of thoracic malignancies. Many technique-, treatment-, tumor- and patient-related factors influence the degree of injury sustained by the lung after irradiation. Based on the time interval after the completion of the treatment RILD presents as early and late features characterized by inflammatory and fibrotic changes, respectively. They are usually confined to the radiation port. Though the typical pattern of RILD is easily recognized after conventional two-dimensional radiation therapy (RT), RILD may present with atypical patterns after more recent types of three- or four-dimensional RT treatment. Three atypical patterns are reported: the modified conventional, the mass-like and the scar-like patterns. Knowledge of the various features and patterns of RILD is important for correct diagnosis and appropriate treatment. RILD should be differentiated from recurrent tumoral disease, infection and radiation-induced tumors. Due to RILD, the follow-up after RT may be difficult as response evaluation criteria in solid tumours (RECIST) criteria may be unreliable to assess tumor control particularly after stereotactic ablation RT (SABR). Long-term follow-up should be based on clinical examination and morphological and/or functional investigations including CT, PET-CT, pulmonary functional tests, MRI and PET-MRI.

Radiation-Induced Esophagitis is Mitigated by Soy Isoflavones

Introduction

Lung cancer patients receiving radiotherapy present with acute esophagitis and chronic fibrosis, as a result of radiation injury to esophageal tissues. We have shown that soy isoflavones alleviate pneumonitis and fibrosis caused by radiation toxicity to normal lung. The effect of soy isoflavones on esophagitis histopathological changes induced by radiation was investigated.

Methods

C57BL/6 mice were treated with 10 Gy or 25 Gy single thoracic irradiation and soy isoflavones for up to 16 weeks. Damage to esophageal tissues was assessed by hematoxylin–eosin, Masson’s Trichrome and Ki-67 staining at 1, 4, 10, and 16 weeks after radiation. The effects on smooth muscle cells and leukocyte infiltration were determined by immunohistochemistry using anti-αSMA and anti-CD45, respectively.

Results

Radiation caused thickening of esophageal tissue layers that was significantly reduced by soy isoflavones. Major radiation alterations included hypertrophy of basal cells in mucosal epithelium and damage to smooth muscle cells in muscularis mucosae as well as disruption of collagen fibers in lamina propria connective tissue with leukocyte infiltration. These effects were observed as early as 1 week after radiation and were more pronounced with a higher dose of 25 Gy. Soy isoflavones limited the extent of tissue damage induced by radiation both at 10 and 25 Gy.

Conclusion

Soy isoflavones have a radioprotective effect on the esophagus, mitigating the early and late effects of radiation injury in several esophagus tissue layers. Soy could be administered with radiotherapy to decrease the incidence and severity of esophagitis in lung cancer patients receiving thoracic radiation therapy.