Pathogenetic mechanisms in radiation fibrosis

Bacterial supplementation in mitigation of radiation-induced gastrointestinal damage

Pelvic irradiation, a crucial treatment for pelvic malignancies, is associated with the risk of gastrointestinal (GI) damage due to the high proliferation rate of epithelial cells. The radiosensitive gastrointestinal tract acts as a dose-limiting organ. High doses of ionizing radiation can cause inflammation and rupture of mucosal barriers and can also lead to intestinal fibrosis. Intestinal damage can cause acute to chronic complications, reducing patients' quality of life. The gut microbiota plays a vital role in maintaining gut health, and any changes in the gut microbial composition can worsen damage, emphasizing the importance of therapies that target and sustain the gut microbiota during radiotherapy. One potential strategy to prevent radiation-induced GI damage is to use bacterial supplements. Research suggests that probiotic supplementation may alleviate radiation-induced gastrointestinal damage, maintaining intestinal morphology and decreasing epithelial injury in cancer patients. The observed protective effects occur through various mechanisms, including antioxidant activities, modulation of the immune response, and preservation of gut barrier function. To optimize probiotic therapies, it is imperative to elucidate these mechanisms. The efficiency of probiotics as radioprotectors is highly dependent on the time and dose of administration, and their interaction with the host immune system is a key facet of their therapeutic potential. This review explores the potential benefits of bacterial supplementation in mitigating radiation-induced GI damage and the underlying mechanism. This highlights the need for further research to establish standardized protocols and refine probiotic supplementation strategies, underscoring the potential for enhancing therapeutic outcomes in patients undergoing pelvic radiotherapy.

Copper homeostasis and cuproptosis in radiation-induced injury

Radiation therapy for cancer treatment brings about a series of radiation injuries to normal tissues. In recent years, the discovery of copper-regulated cell death, cuproptosis, a novel form of programmed cell death, has attracted widespread attention and exploration in various biological functions and pathological mechanisms of copper metabolism and cuproptosis. Understanding its role in the process of radiation injury may open up new avenues and directions for exploration in radiation biology and radiation oncology, thereby improving tumor response and mitigating adverse reactions to radiotherapy. This review provides an overview of copper metabolism, the characteristics of cuproptosis, and their potential regulatory mechanisms in radiation injury.

Radiation-induced fibrosis: Mechanisms and therapeutic strategies from an immune microenvironment perspective

Radiation-induced fibrosis (RIF) is a severe chronic complication of radiotherapy (RT) manifested by excessive extracellular matrix (ECM) components deposition within the irradiated area. The lung, heart, skin, jaw, pelvic organs and so on may be affected by RIF, which hampers body functions and quality of life. There is accumulating evidence suggesting that the immune microenvironment may play a key regulatory role in RIF. This article discussed the synergetic or antagonistic effects of immune cells and mediators in regulating RIF's development. Several potential preventative and therapeutic strategies for RIF were proposed based on the immunological mechanisms to provide clinicians with improved cognition and clinical treatment guidance.

The Perioperative Effects of Preoperative Radiotherapy in Metastatic Spinal Tumor Patients

OBJECTIVE

Radiotherapy is one of the important treatment options for metastatic spinal tumors but is not the definite intervention in all cases, as there are patients who still require surgical treatment because of severe pain or neurologic events after this treatment. We evaluated the perioperative effects of preoperative radiotherapy in these cases as a future guide for surgeons on critical considerations in this period.

METHODS

We included 328 patients in this study who had undergone decompression and fusion surgery for metastatic spinal tumors. Patients who underwent surgery with preoperative radiotherapy were designated as the radiotherapy group (group RT, n = 81), and cases of surgery without preoperative radiotherapy were assigned to the non-radiotherapy group (group nRT, n = 247). We compared the demographic, intraoperative, and postoperative factors between these 2 groups.

RESULTS

In terms of intraoperative factors, statistically significant differences were evident in operation time, estimated blood loss, and transfusion (RT vs. nRT: 188.1 ± 80.7 minutes vs. 231.2 ± 106.1 minutes, 607.2 ± 532.7 mL vs. 830.1 ± 1324.7 mL, and 30.9% vs. 43.3%, P < 0.001, P < 0.031, and P < 0.048, respectively). With regard to postoperative factors, the incidence of infection, wound problems, and local recurrence were statistically higher in group RT (RT vs. nRT: 6.2% vs. 0.8%, 12.3% vs. 0.8%, 23.4% vs. 13.7%, P = 0.004, P < 0.001, and P = 0.038, respectively).

CONCLUSIONS

Preoperative radiotherapy has the intraoperative advantages of reducing bleeding and shortening the operating time, but postoperative caution is needed because of the possibility of infection, wound problems, and local recurrence increases.

Expected role of photodynamic therapy to relieve skin damage in nuclear or radiological emergency: Review

Nuclear and radiological accidents can occur due to poor management, in transportation, radiation therapy and nuclear wards in hospitals, leading to extreme radiation exposure and serious consequences for human health. Additionally, in many of previous radiological accidents, skin damage was observed in patients and survivors due to the high radiation exposure. However, as part of a medical countermeasures in a nuclear/radiological emergency, it is critical to plan for the treatment of radiation-induced skin damage. Hence, the new, non-invasive technology of photodynamic therapy (PDT) is projected to be more effectively used for treating skin damage caused by high-dose radiation. PDT plays an important role in treating, repairing skin damage and promoting wound healing as evidenced by research. This review, highlighted and recommended potential impacts of PDT to repair and decrease radiation-induced skin tissue damage. Moreover, we have suggested some photosensitizer (PS) agent as radio-mitigator drugs to decrease radiobiological effects.

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

A Novel TGFβ Receptor Inhibitor, IPW-5371, Prevents Diet-induced Hepatic Steatosis and Insulin Resistance in Irradiated Mice

As the number of cancer survivors increases and the risk of accidental radiation exposure rises, there is a pressing need to characterize the delayed effects of radiation exposure and develop medical countermeasures. Radiation has been shown to damage adipose progenitor cells and increase liver fibrosis, such that it predisposes patients to developing metabolic-associated fatty liver disease (MAFLD) and insulin resistance. The risk of developing these conditions is compounded by the global rise of diets rich in carbohydrates and fats. Radiation persistently increases the signaling cascade of transforming growth factor β (TGFβ), leading to heightened fibrosis as characteristic of the delayed effects of radiation exposure. We investigate here a potential radiation medical countermeasure, IPW-5371, a small molecule inhibitor of TGFβRI kinase (ALK5). We found that mice exposed to sub-lethal whole-body irradiation and chronic Western diet consumption but treated with IPW-5371 had a similar body weight, food consumption, and fat mass compared to control mice exposed to radiation. The IPW-5371 treated mice maintained lower fibrosis and fat accumulation in the liver, were more responsive to insulin and had lower circulating triglycerides and better muscle endurance. Future studies are needed to verify the improvement by IPW-5371 on the structure and function of other metabolically active tissues such as adipose and skeletal muscle, but these data demonstrate that IPW-5371 protects liver and whole-body health in rodents exposed to radiation and a Western diet, and there may be promise in using IPW-5371 to prevent the development of MAFLD.

Early Effects of Modern Radiotherapy for Lung Cancer on Endothelial Damage and Myocardial Fibrosis: A Prospective Single-Center Study

Radiotherapy (RT) may have a cardiotoxic effect on the heart and cardiovascular system. Postulated mechanisms mediating these complications include vascular endothelium damage and myocardial fibrosis. The aim of our study was to assess endothelial damage and myocardial fibrosis in the early period after RT on the basis of cardiac biomarkers and in relation to the radiation dose applied to individual heart structures in patients treated for non-small-cell lung cancer. This single-center prospective study included consecutive patients with lung cancer (LC) who were referred for treatment with radiochemotherapy (study group) or chemotherapy (control group). The study protocol included performing an echocardiographic examination, a standard ECG examination, and collecting blood samples for laboratory tests before starting treatment for lung cancer in the first week after completing RT (after four cycles of chemotherapy in the control group) and after 12 weeks from the end of treatment. The study included 23 patients in the study group and 20 patients in the control group. Compared to the baseline values, there was a significant increase in total cholesterol concentration in the study group immediately after the end of RT, which persisted for three months after the end of therapy. After taking into account the use of statins in the analysis, it was found that an increase in total cholesterol concentration after oncological treatment was observed only among patients who did not use statins. Taking into account the assessment of myocardial fibrosis markers, there were no significant changes in the concentration of matrix metallopeptidase 9 (MMP-9) and tissue inhibitors of metalloproteinases 1 (TIMP-1) in the study group. In patients treated with radiochemotherapy, there was a significant increase in the concentration of intercellular adhesion molecule 1 (ICAM-1) immediately after RT, when compared to the baseline. After taking into account the use of statins, an increase in ICAM-1 concentration immediately after RT was observed only in patients who did not use statins. There was also a significant correlation between the radiation dose received by the left anterior descending coronary artery (LAD) and left circumferential coronary artery, and vascular cell adhesion protein 1 (VCAM-1) concentration measured at three months after the end of RT. Immediately after completion of radiotherapy, a significant increase in the level of ICAM-1 is observed indicating endothelial damage. The radiation dose to coronary arteries should be minimized, as it correlates with the concentration of VCAM-1. The use of statins may prevent the increase in total cholesterol and ICAM-1 concentration after irradiation for lung cancer; however, further studies designed for this specific purpose are necessary to confirm the effectiveness of statins in this area.

Application of Palliative Hemostatic Radiotherapy in Canine Unresectable Oral Melanoma: A Case Report

A 9-year-old castrated male Schnauzer dog, weighing 11.6 kg, presented with a persistent hemorrhagic oral mass. An oral examination revealed a right maxillary oral mass characterized by continuous bleeding, halitosis, and severe pain. A cytological examination led to a provisional diagnosis of malignant melanoma, and, despite the option of aggressive surgery, the owner declined. The blood analysis indicated severe hemorrhagic anemia (hematocrit, 18.2%) requiring a blood transfusion. The patient underwent volumetric modulated arc therapy (VMAT) as part of a palliative radiation protocol, receiving six fractions of 6 Gy weekly for hemostasis and clinical improvement. The hemorrhaging ceased after the second fraction, with a subsequent rise in the hematocrit levels and the resolution of the anemia. Additionally, the intake increased following the second fraction, and effective pain management was achieved in the fourth fraction. Following the last fraction, computed tomography revealed a 20% reduction in the tumor size. This case highlights the potential use of radiotherapy for hemostasis in cases of inoperable hemorrhagic oral melanoma and represents the first report on the application of hemostatic radiotherapy in dogs.

Study of late toxicity biomarkers of locally advanced head and neck cancer patients treated with radiotherapy plus cisplatin or cetuximab points to the relevance of skin macrophages (TOX-TTCC-2015-01)

PURPOSE

Radiotherapy (RT) with concomitant cisplatin (CRT) or cetuximab (ERT) are accepted treatment options for locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). Long-term adverse events (AEs) have a vast impact on patients' quality of life. This study explored tissue biomarkers which could help predict late toxicity.

METHODS/PATIENTS

Single-institution prospective study including patients aged ≥ 18 with histologically confirmed newly diagnosed LA-SCCHN treated with RT and either concomitant cisplatin q3w or weekly cetuximab, according to institutional protocols. All patients underwent pre- and post-treatment skin biopsies of neck regions included in the clinical target volume. Angiogenesis, macrophages, and extracellular matrix (ECM) markers were evaluated by immunohistochemistry (IHC).

RESULTS

From April 15, 2016, to December 11, 2017; 31 patients were evaluated [CRT = 12 (38.7%) and ERT = 19 (61.3%)]. 27 patients (87%) had received induction chemotherapy. All patients finished RT as planned. IHC expression of vasculature (CD34) and collagen (Masson's Trichrome) did not differ significantly between and within CRT and ERT arms. Conversely, an increased CD68 and CD163 macrophage infiltration expression was observed after treatment, without significant impact of treatment modality. Patients with higher late toxicity showed lower expression of macrophage markers in pre-treatment samples compared with those with lower late toxicity, with statistically significant differences for CD68.

CONCLUSIONS

Angiogenesis and ECM biomarkers did not differ significantly between CRT and ERT. Macrophage markers increased after both treatments and deserve further investigation as predictors of late toxicity in LA-SCCHN patients. [Protocol code: TOX-TTCC-2015-01/Spanish registry of clinical studies (REec): 2015-003012-21/Date of registration: 27/01/2016].

Outcomes of whole breast radiation therapy in Asian breast cancer patients with prior cosmetic implants

BACKGROUND

As breast augmentation has become more popular, an increasing number of women with augmented breasts require treatment for breast cancer. This study aimed to assess the outcomes of postoperative whole breast radiation therapy (WB-RT) in Asian patients with breast cancer who underwent prior cosmetic breast implantation.

METHODS

We retrospectively reviewed the medical records of 61 patients with breast cancer who had prior cosmetic breast implants (prior-CBI) and underwent breast-conserving surgery (BCS) and WB-RT between 2015 and 2020. The median implant volume was 238.8 cc, with a median interval of 84.7 months between the prior-CBI and BCS. WB-RT was administered with either conventional fractionation (CF-RT) at 50 Gy in 25 fractions (N = 36) or hypofractionation (HF-RT) at 42.6 Gy in 16 fractions (N = 25). The incidences of implant-related complications (IRC) and their contributing factors were analyzed.

RESULTS

After a median follow-up of 43.5 months, the 3-year cumulative incidences of IRC and implant loss were 17.2% and 4.9%, respectively. Among the four (6.6%) patients who opted for implant removal after RT, three were potentially related to RT-related capsular contracture. There was no difference in the 3-year cumulative IRC rates following CF-RT and HF-RT (12.2% and 26.7%, respectively; p = 0.120). The risk factors for IRC included a larger implant size (> 260 cc) and a higher ratio of breast tissue to implant volume.

CONCLUSIONS

This study demonstrated a favorable safety profile of WB-RT for treatment of breast cancer in Asian women with prior-CBI. The integration of HF-RT following BCS was thought to be a feasible approach.

Adipose-Derived Stromal Cell-Based Therapies for Radiation-Induced Fibrosis

Significance: Half of all cancer patients receive radiation therapy as a component of their treatment regimen, and the most common resulting complication is radiation-induced fibrosis (RIF) of the skin and soft tissue. This thickening of the dermis paired with decreased vascularity results in functional limitations and esthetic concerns and poses unique challenges when considering surgical exploration or reconstruction. Existing therapeutic options for RIF of the skin are limited both in scope and efficacy. Cell-based therapies have emerged as a promising means of utilizing regenerative cell populations to improve both functional and esthetic outcomes, and even as prophylaxis for RIF. Recent Advances: As one of the leading areas of cell-based therapy research, adipose-derived stromal cells (ADSCs) demonstrate significant therapeutic potential in the treatment of RIF. The introduction of the ADSC-augmented fat graft has shown clinical utility. Recent research dedicated to characterizing specific ADSC subpopulations points toward further granularity in understanding of the mechanisms driving the well-established clinical outcomes seen with fat grafting therapy. Critical Issues: Various animal models of RIF demonstrated improved clinical outcomes following treatment with cell-based therapies, but the cellular and molecular basis underlying these effects remains poorly understood. Future Directions: Recent literature has focused on improving the efficacy of cell-based therapies, most notably through (1) augmentation of fat grafts with platelet-rich plasma and (2) the modification of expressed RNA through epitranscriptomics. For the latter, new and promising gene targets continue to be identified which have the potential to reverse the effects of fibrosis by increasing angiogenesis, decreasing inflammation, and promoting adipogenesis.

Bromelain as a natural anti-inflammatory drug: a systematic review

Inflammation is a complex and necessary mechanism of an organ's response to biological, chemical and/or physical stimuli. In recent years, investigations on natural compounds with therapeutic actions for the treatment of different diseases have increased. Among these compounds, bromelain is highlighted, as a cysteine protease isolated from the Ananas comosus (pineapple) stem. This review aimed to evaluate the anti-inflammatory activity of bromelain, as well as its pathways on inflammatory mediators, through a systematic review with in vitro studies on different cell lines. The search was performed in PubMed, Science Direct, Scopus, Cochrane Library and Web of Science databases. Bromelain reduced IL-1β, IL-6 and TNF-α secretion when immune cells were already stimulated in an overproduction condition by proinflammatory cytokines, generating a modulation in the inflammatory response through prostaglandins reduction and activation of a cascade reactions that trigger neutrophils and macrophages, in addition to accelerating the healing process.

Does Prior Breast Irradiation Increase Complications of Subsequent Reduction Surgery in Breast Cancer Patients? A systematic Review and Meta-Analysis

BACKGROUND

Reduction mammoplasty and mastopexy are potentially complicated by prior breast irradiation as part of breast conserving therapy. Associated tissue changes with therapeutic irradiation have led to surgeons deciding the risks may outweigh potential benefit for those patients. A systematic review of the existing literature was performed to explore surgical outcomes of patients undergoing delayed bilateral reduction mammoplasty or mastopexy following unilateral breast irradiation as part of breast conserving therapy.

METHODS

Medline, PubMed and EMBASE were searched from 1990 to 2023 according to PRISMA guidelines. Studies were combined by the generic inverse variance method on the natural logarithms of rate ratios (RR) using a random effect model in Review manager 5.4.1.

RESULTS

Fifteen studies reported outcomes in 188 patients who underwent breast reduction (BR) following unilateral breast conserving surgery and radiotherapy. The median age at BR was 51.5 years (range 39-60), and median time since radiotherapy was 48 months (range 11.7-86). We compared outcomes for irradiated breast (IB) versus non-irradiated breast (NIB). Pooled results showed higher rate of major complications in the IB (RR 2.52, 95%CI 0.96-6.63, p=0.06), but not statistically significant. However, rate of minor complications was significantly higher in the IB (RR 3.97 95%CI 1.86-8.50, p<0.0004). Incidence of fat necrosis as a discrete complication was 2× higher in IB (RR 2.14 95%CI 0.85-5.35, p-value 0.10) compared to the NIB, but not significant.

CONCLUSION

We found breast reduction to be safe with acceptable risk of major complications. However, the overall complication rate remains higher in IB compared to NIB.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of contents or the online Instructions to Authors www.springer.com/00266 .

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.

Molecular Changes in Breast Cancer Induced by Radiation Therapy

PURPOSE

Breast cancer treatments are based on prognostic clinicopathologic features that form the basis for therapeutic guidelines. Although the utilization of these guidelines has decreased breast cancer-associated mortality rates over the past three decades, they are not adequate for individualized therapy. Radiation therapy (RT) is the backbone of breast cancer treatment. Although a highly successful therapeutic modality clinically, from a biological perspective, preclinical studies have shown RT to have the potential to alter tumor cell phenotype, immunogenicity, and the surrounding microenvironment, potentially changing the behavior of cancer cells and resulting in a significant variation in RT response. This review presents the recent advances in revealing the complex molecular changes induced by RT in the treatment of breast cancer and highlights the complexities of translating this information into clinically relevant tools for improved prognostic insights and the revelation of novel approaches for optimizing RT.

METHODS AND MATERIALS

Current literature was reviewed with a focus on recent advances made in the elucidation of tumor-associated radiation-induced molecular changes across molecular, genetic, and proteomic bases. This review was structured with the aim of providing an up-to-date overview over the very broad and complex subject matter of radiation-induced molecular changes and radioresistance, familiarizing the reader with the broader issue at hand.

RESULTS

The subject of radiation-induced molecular changes in breast cancer has been broached from various physiological focal points including that of the immune system, immunogenicity and the abscopal effect, tumor hypoxia, breast cancer classification and subtyping, molecular heterogeneity, and molecular plasticity. It is becoming increasingly apparent that breast cancer clinical subtyping alone does not adequately account for variation in RT response or radioresistance. Multiple components of the tumor microenvironment and immune system, delivered RT dose and fractionation schedules, radiation-induced bystander effects, and intrinsic tumor physiology and heterogeneity all contribute to the resultant RT outcome.

CONCLUSIONS

Despite recent advances and improvements in anticancer therapies, tumor resistance remains a significant challenge. As new analytical techniques and technologies continue to provide crucial insight into the complex molecular mechanisms of breast cancer and its treatment responses, it is becoming more evident that personalized anticancer treatment regimens may be vital in overcoming radioresistance.

Mediastinal Radiotherapy-induced Early-onset Valvulopathy in a 6-Year-old Boy With Hodgkin Lymphoma

Mediastinal radiotherapy for childhood cancers, particularly Hodgkin disease, has numerous potential adverse effects, including coronary artery disease, pericarditis, cardiomyopathy, valvular disease, and conduction abnormalities. The prevalence of valvular stenosis is relatively low, and regurgitation is more common. Mediastinal radiotherapy-induced valvular disease develops more than 10 years after radiotherapy. Here, we present a case of a 6-year-old boy with moderate to significant mitral stenosis + moderate mitral regurgitation and mild aortic regurgitation that appeared 1.5 months after radiotherapy and showed a progressive course.

Worth of pan-immune-inflammation value in trismus prediction after concurrent chemoradiotherapy for nasopharyngeal carcinomas

OBJECTIVE

Radiation-induced trismus (RIT), one of the rare but serious side effects of concurrent chemoradiotherapy (C-CRT), is difficult to predict with high accuracy. We aimed to examine whether the pretreatment pan-immune-inflammation value (PIV) measures predict RIT in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) receiving C-CRT.

METHODS

Data of patients with LA-NPC who underwent C-CRT and had maximum mouth openings (MMO) > 35 mm were reviewed. Any MMO of 35 mm or less after C-CRT was considered RIT. All PIV values were computed using the complete blood count test results: PIV = (Platelets × Monocytes × Neutrophils) ÷ Lymphocytes. The receiver operating characteristic analysis was employed to dissect a possible association between pre-treatment PIV readings and RIT status. Confounding variables were tested for their independent relationship with the RIT rates using logistic regression analysis.

RESULTS

The research comprised 223 participants, and RIT was diagnosed in 46 (20.6%) at a median time from C-CRT to RIT of 10 months (range: 5-18 months). Pre-C-CRT PIV levels and RIT rates were analyzed using receiver operating characteristic curve analysis, with 830 being the optimal cutoff (area under the curve: 92.1%; sensitivity: 87.5%; specificity: 85.5%; Youden index: 0.730). RIT was significantly more prevalent in the PIV > 830 cohort than its PIV ≤ 830 counterpart (60.3% vs. 5%; hazard ratio 5.79; P < 0.001). Multivariate logistic regression analysis revealed that advanced T-stage (P = 0.004), masticatory apparatus dose V58Gy≥%32 (P = 0.003), and PIV > 830 (P < 0.001) were independently linked with significantly elevated rates of RIT.

CONCLUSION

The presence of elevated pre-C-CRT PIV is a unique biological marker that independently predicts increased RIT rates in LA-NPC undergoing C-CRT.

Endothelial Robo4 suppresses endothelial-to-mesenchymal transition induced by irradiation and improves hematopoietic reconstitution

Bone marrow ablation is routinely performed before hematopoietic stem cell transplantation (HSCT). Hematopoietic stem and progenitor cells (HSPCs) require a stable bone marrow microenvironment to expand and refill the peripheral blood cell pool after ablation. Roundabout guidance receptor 4 (Robo4) is a transmembrane protein exclusive to endothelial cells and is vital in preserving vascular integrity. Hence, the hypothesis is that Robo4 maintains the integrity of bone marrow endothelial cells following radiotherapy. We created an endothelial cell injury model with γ-radiation before Robo4 gene manipulation using lentiviral-mediated RNAi and gene overexpression techniques. We demonstrate that Robo4 and specific mesenchymal proteins (Fibronectin, Vimentin, αSma, and S100A4) are upregulated in endothelial cells exposed to irradiation (IR). We found that Robo4 depletion increases the expression of endoglin (CD105), an auxiliary receptor for the transforming growth factor (TGF-β) family of proteins, and promotes endothelial-to-mesenchymal transition (End-MT) through activation of both the canonical (Smad) and non-canonical (AKT/NF-κB) signaling pathways to facilitate Snail1 activation and its nuclear translocation. Endothelial Robo4 overexpression stimulates the expression of immunoglobulin-like adhesion molecules (ICAM-1 and VCAM-1) and alleviates irradiation-induced End-MT. Our coculture model showed that transcriptional downregulation of endothelial Robo4 reduces HSPC proliferation and increases HSC quiescence and apoptosis. However, Robo4 overexpression mitigated the damaged endothelium's suppressive effects on HSC proliferation and differentiation. These findings indicate that by controlling End-MT, Robo4 preserves microvascular integrity after radiation preconditioning, protects endothelial function, and lessens the inhibitory effect of damaged endothelium on hematopoietic reconstitution.

90Y-/166Ho- 'Radiation lobectomy' for liver tumors induces abnormal morphology and impaired drainage of peritumor lymphatics

Background & Aims

High-dose unilobar radioembolization, or 'radiation lobectomy' (RL), is an induction therapy that achieves contralateral future liver remnant hypertrophy while simultaneously irradiating the tumor. As such, it may prevent further growth, but it is unknown whether RL affects intrahepatic lymphatics, a major route via which liver tumors disseminate.

Methods

This was a case-control study conducted at University Medical Center Utrecht. The study compared lymph vessels in livers that had undergone RL (cases) with those in livers that had not undergone RL (controls). Histological samples were acquired from patients diagnosed with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) between 2017 and 2022. Lymph vessel morphology was analyzed by two researchers using podoplanin, a protein that is expressed in lymphatic endothelium. In vivo liver lymph drainage of radioembolized livers was assessed using intraoperative liver lymphangiography (ILL): during liver surgery, patent blue dye was injected into the liver parenchyma, followed by inspection for staining of perihepatic lymph structures. ILL results were compared to a previously published cohort.

Results

Immunohistochemical analysis on post-RL tumor tissues from ten patients with CRLM and nine patients with HCC revealed aberrant morphology of irradiated liver lymphatics when compared to controls (n = 3 per group). Irradiated lymphatics were tortuous (p <0.05), thickened (p <0.05) and discontinuous (p <0.05). Moreover, post-RL lymphatics had larger lumens (1.5-1.7x, p <0.0001), indicating lymph stasis. ILL revealed diminished lymphatic drainage to perihepatic lymph nodes and vessels in irradiated livers when compared to non-radioembolized controls (p = 1.0x10-4).

Conclusions

Radioembolization impairs peritumoral lymph vessel function. Further research is needed to evaluate if radioembolization impairs tumor dissemination via this route.

Impact and implications

Unilobar radioembolization can serve as an alternative to portal venous embolization for patients who are considered unresectable due to an insufficient future liver remnant. This research suggests that radioembolization impairs the function of peritumoral liver lymph vessels, potentially hindering dissemination via this route. These findings provide support for considering unilobar radioembolization over standard portal venous embolization.

Incidence and Risk Assessment of Capsular Contracture in Breast Cancer Patients following Post-Mastectomy Radiotherapy and Implant-Based Reconstruction

Our study aims to identify the risk factors and dosimetry characteristics associated with capsular contracture.

METHODS

We retrospectively analyzed 118 women with breast cancer who underwent PMRT following an IBR between 2010 and 2022. Patients were treated with PMRT of 50.0-50.4 Gy in 25-28 fractions. Capsular contracture was categorized according to the Baker Classification for Reconstructed Breasts.

RESULTS

After a median follow-up of 22 months, the incidence of clinically relevant capsular contracture (Baker III-IV) was 22.9%. Overall, capsular contracture (Baker I-IV) occurred in 56 patients (47.5%) after a median of 9 months after PMRT. The rate of reconstruction failure/implant loss was 25.4%. In the univariate analysis, postoperative complications (prolonged pain, prolonged wound healing, seroma and swelling) and regional nodal involvement were associated with higher rates of capsular contracture (p = 0.017, OR: 2.5, 95% CI: 1.2-5.3 and p = 0.031, respectively). None of the analyzed dosimetric factors or the implant position were associated with a higher risk for capsular contracture.

CONCLUSION

Postoperative complications and regional nodal involvement were associated with an increased risk of capsular contracture following breast reconstruction and PMRT, while none of the analyzed dosimetric factors were linked to a higher incidence. Additional studies are needed to identify further potential risk factors.

The Preventive Effect of Endostar on Radiation-induced Pulmonary Fibrosis

BACKGROUND

Radiation-induced pulmonary fibrosis (RIPF) is a long-term complication of thoracic radiotherapy without effective treatment available.

OBJECTIVE

This study aimed to establish a RIPF mouse model and explore the therapeutic effects and mechanisms of recombinant human endostatin (Endostar).

METHODS

C57BL/6 mice received a 16-Gy dose of X-rays to the whole thorax with or without the administration of Endostar for 24 weeks.

RESULTS

Radiation-induced body weight loss was partially attenuated by Endostar (P<0.05). Endostar significantly reduced alveolar inflammation (P<0.05) and pulmonary fibrosis (P<0.001), as indicated by a decrease in the expression levels of collagen I and collagen IV in lung tissue (both P<0.001). Angiogenesis (as shown by CD31 immunohistochemistry) was also decreased (P<0.01). In irradiated mice, Endostar inhibited the transforming growth factor-β1 (TGF-β1)/drosophila mothers against the decapentaplegic 3 (Smad3)/extracellular regulated protein kinases (ERK) signaling pathway (all P<0.05). In vitro, Endostar treatment decreased the radiation-induced expression of TGF-β1, vascular endothelial growth factor (VEGF), p-Smad3, and p-ERK in alveolar epithelial cells and vascular endothelial cells (all P<0.05).

CONCLUSION

Endostar could alleviate RIPF through decreased antiangiogenic activity and inhibition of the TGF-β1/Smad3/ERK pathway.

A Survey of Manual Therapy Techniques and Protocols Used to Prevent or Treat Dysphagia in Head and Neck Cancer Patients During and after Radiation Therapy

Background

Authoritative research demonstrating efficacy of traditional dysphagia therapy for Head & Neck Cancer (HNC) patients is limited. A 2019 survey reported speech-language-pathologists (SLPs) have started using Manual Therapy (MT) to prevent or rehabilitate dysphagia in HNC patients. This application of MT is supported theoretically but no research has established efficacy. Further, specific contents of MT protocols employed in this setting remain unknown.

Objectives

In the absence of HNC dysphagia specific MT protocols, this study aimed to better understand MT protocols employed by SLPs to prevent and treat dysphagia in HNC patients during and after Radiation Therapy (RT).

Methods

An internet-based questionnaire for SLPs who use MT with HNC patients was developed and tested for face/content validity. It was sent to SLPs practicing in the USA, twice, through three national listservs (ASHA-SIG13, ASHA-SIG3, University of Iowa Voiceserv).

Results

Of 64 respondents, 44 completed the survey. Of the 44, 15(34%) provided proactive MT during RT, 37(84%) provided proactive MT after RT (to prevent dysphagia), and 44(100%) provided reactive MT after RT (to treat dysphagia). 40(91%) were trained in MT through a CE course and 25(57%) had HNC-specific MT training. The most common MT techniques were laryngeal manipulation (LM) and myofascial release (MFR). During RT, MT protocols are gentler and highly tailored, with simple home programs of mild intensity. After RT, protocols are more regimented and aggressive, but still highly customized, with more diverse home programs of at least moderate intensity.

Conclusion

MT for HNC patients lacks a standard protocol or approach, but MFR and LM, or components of those techniques, are used most frequently. Given the frequency with which MFR and LM are employed to treat dysphagia during and post-RT, and the lack of empirical evidence supporting or refuting their use, a collaboratively designed RCT is warranted to establish the safety and efficacy of MT for HNC patients.

Diabetic Pneumopathy- A Novel Diabetes-associated Complication: Pathophysiology, the Underlying Mechanism and Combination Medication

BACKGROUND

The "diabetic lung" has been identified as a possible target organ in diabetes, with abnormalities in ventilation control, bronchomotor tone, lung volume, pulmonary diffusing capacity, and neuroadrenergic bronchial innervation.

OBJECTIVE

This review summarizes studies related to diabetic pneumopathy, pathophysiology and a number of pulmonary disorders including type 1 and type 2 diabetes.

METHODS

Electronic searches were conducted on databases such as Pub Med, Wiley Online Library (WOL), Scopus, Elsevier, ScienceDirect, and Google Scholar using standard keywords "diabetes," "diabetes Pneumopathy," "Pathophysiology," "Lung diseases," "lung infection" for review articles published between 1978 to 2023 very few previous review articles based their focus on diabetic pneumopathy and its pathophysiology.

RESULTS

Globally, the incidence of diabetes mellitus has been rising. It is a chronic, progressive metabolic disease. The "diabetic lung" may serve as a model of accelerated ageing since diabetics' rate of respiratory function deterioration is two to three-times higher than that of normal, non-smoking people.

CONCLUSION

Diabetes-induced pulmonary dysfunction has not gained the attention it deserves due to a lack of proven causality and changes in cellular properties. The mechanism underlying a particular lung illness can still only be partially activated by diabetes but there is evidence that hyperglycemia is linked to pulmonary fibrosis in diabetic people.

Hemostatic radiotherapy in clinically significant tumor-related bleeding: excellent palliative results in a retrospective analysis of 77 patients

BACKGROUND

Significant bleeding of tumor sites is a dreaded complication in oncological diseases and often results in clinical emergencies. Besides basic local and interventional procedures, an urgent radiotherapeutic approach can either achieve a bleeding reduction or a bleeding stop in a vast majority of patients. In spite of being used regularly in clinical practice, data reporting results to this therapy approach is still scarce.

METHODS

We retrospectively analyzed 77 patients treated for significant tumor-related bleeding at our clinic between 2000 and 2021, evaluating treatment response rate, hemoglobin levels, hemoglobin transfusion necessity, administered radiotherapy dose and overall survival.

RESULTS

Response rate in terms of bleeding stop was 88.3% (68/77) in all patients and 95.2% (60/63) in the subgroup, wherein radiotherapy (RT) was completed as intended. Hemoglobin transfusions decreased during treatment in a further subgroup analysis. Median overall survival (OS) was 3.3 months. Patients with primary tumors (PT) of the cervix (carcinoma of the cervix, CC) or endometrium (endometrioid carcinoma, EDC) and patients receiving the full intended RT dose showed statistically significant better OS in a multivariable cox regression model. Median administered dose was 39 Gy, treatment related acute toxicity was considerably low.

CONCLUSIONS

Our data show an excellent response rate with a low toxicity profile when administering urgent radiotherapy for tumor related clinically significant bleeding complications. Nonetheless, treatment decisions should be highly individual due to the low median overall survival of this patient group.

TANGO1 Dances to Export of Procollagen from the Endoplasmic Reticulum

The endoplasmic reticulum (ER) to Golgi secretory pathway is an elegantly complex process whereby protein cargoes are manufactured, folded, and distributed from the ER to the cisternal layers of the Golgi stack before they are delivered to their final destinations. The export of large bulky cargoes such as procollagen and its trafficking to the Golgi is a sophisticated mechanism requiring TANGO1 (Transport ANd Golgi Organization protein 1. It is also called MIA3 (Melanoma Inhibitory Activity protein 3). TANGO1 has two prominent isoforms, TANGO1-Long and TANGO1-Short, and each isoform has specific functions. On the luminal side, TANGO1-Long has an HSP47 recruitment domain and uses this protein to collect collagen. It can also tether its paralog isoforms cTAGE5 and TALI and along with these proteins enlarges the vesicle to accommodate procollagen. Recent studies show that TANGO1-Long combines retrograde membrane flow with anterograde cargo transport. This complex mechanism is highly activated in fibrosis and promotes the excessive deposition of collagen in the tissues. The therapeutic targeting of TANGO1 may prove successful in the control of fibrotic disorders. This review focuses on TANGO1 and its complex interaction with other procollagen export factors that modulate increased vesicle size to accommodate the export of procollagen.

Outcomes Following Recent and Distant Neoadjuvant Radiation in Rectal Cancer: An Institutional Retrospective Review and Analysis of NSQIP

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) is the standard of care in locally advanced rectal cancer (LARC). However, radiation therapy is thought to increase operative difficulty due to induction of fibrosis. Total neoadjuvant therapy (TNT) protocols increase the time between completion of radiation and surgical resection which may lead to increased operative difficulty and complications.

METHODS

A single institution retrospective review of patients ≥18 years with LARC undergoing nCRT from 2015 to 2022. Patients were dichotomized in 2 cohorts: <90 days from radiation to surgery (recent radiation), and ≥90 days from radiation to surgery (distant radiation). Institutional data was compared to National Surgical Quality Improvement Program (NSQIP) rectal cancer data from 2016 to 2020. Outcomes included intraoperative complications, 30-day morbidity, and oncologic outcomes.

RESULTS

One hundred forty-six institutional patients included, 120 had recent radiation, 26 had distant radiation. Thirty-day morbidity and intraoperative complications did not differ. There was greater radial margin positivity (7% vs. 24%), fewer lymph nodes harvested (17 ± 5 vs. 15 ± 6), and a lower rate of complete mesorectal dissection (88% vs. 65%,) in distant radiation patients 3059 patients were included in NSQIP analysis, 2029 completed radiation <90 days before surgery and 1030 without radiation 90 days before surgery. Patients without radiation 90 days preoperatively had more radial margin positivity (9.2% vs. 4.6%), organ space infection (8.6% vs. 6.4%), and pneumonia (2.2% vs. 0.9%).

CONCLUSION

The present study suggests that increased time between radiation and surgery results in more challenging dissection with less complete mesorectal dissection and increased radial margin positivity without increasing technical complications.

DTPA clearance test: a sensitive method for detecting radiation-induced lung fibrosis in lung cancer patients

OBJECTIVE

The aim of this study is to analyze the frequency of lung injury and the sensitivity of the diethylenetriamine penta-acetic acid (DTPA) clearance test in detecting lung injury in patients undergoing radiotherapy (RT) to the thorax.

MATERIAL AND METHOD

Twenty individuals scheduled for RT for lung cancer were included as the patient group. The healthy control group consisted of 20 age and gender-matched individuals who were nonsmokers with no history of comorbidities. We conducted follow-up with patients at 0-1-6 months, performing carbon monoxide diffusion test (DLCO), DTPA clearance test (excluding the first month), and high-resolution computed tomography of the thorax. The control group was followed up with DLCO between the baseline and 6th months.

RESULTS

Ninety percent of the patient group was male, and the median age was 62 years. Seventy percent of the patients had squamous cell carcinoma and adenocarcinoma. Pneumonitis was detected in the patient group in the first month (100%) and fibrosis in the sixth month (%100) Both at the beginning and in the sixth month, the DLCO values of patients who received RT were lower than those of the control group ( P  = 0.001 and P  < 0.001, respectively). While DTPA clearance was similar between irradiated and non-radiated lungs at the beginning, there was a substantial decrease in the irradiated lung in the sixth month( P  = 0.001). There was no significant correlation between malignancy type, RT dose, and tumor size( P  > 0.05).

CONCLUSION

The DTPA clearance test could be an alternative method for demonstrating radiation injury in patients receiving RT.

Bone marrow mesenchymal stem cell transplantation alleviates radiation-induced myocardial fibrosis through inhibition of the TGF-β1/Smad2/3 signaling pathway in rabbit model

Background

and purpose: Radiotherapy (RT) is an effective treatment for most malignant chest tumors. However, radiation-induced myocardial fibrosis (RIMF) is a serious side effect of RT. Currently, due to the mechanism of RIMF has not been fully elucidated, there is a lack of effective therapeutic approach. In this study, we aimed to investigate the role and possible mechanisms of bone marrow mesenchymal stem cells (BMSCs) in the therapy of RIMF.

Materials and methods

Twenty-four New Zealand white rabbits were allotted into four groups (n = 6). Rabbits in the Control group received neither irradiation nor treatment. A single dose of 20 Gy heart X-irradiation was applied to the RT group, RT + PBS group and RT + BMSCs group. Rabbits in the RT + PBS group and RT + BMSCs group were injected with 200 μL PBS or 2 × 10⁶ cells via pericardium puncture 24 h following irradiation, respectively. Echocardiography was used to test the cardiac function; Then the heart samples were collected, and processed for histopathological, Western blot and immunohistochemistry investigations.

Results

It was observed that BMSCs have therapeutic effect on RIMF. Compared with the Control group, inflammatory mediators, oxidative stress and apoptosis were significantly increased, meanwhile, cardiac function was remarkably decreased in the RT group and RT + PBS group. However, in the BMSCs group, BMSCs significantly improved cardiac function, decreased inflammatory mediators, oxidative stress and apoptosis. Furthermore, BMSCs remarkably reduced the expression level of TGF-β1 and the phosphorylated-Smad2/3.

Conclusions

In conclusion, our research indicates BMSCs have the potential to alleviate RIMF through TGF-β1/Smad2/3 and would be a new therapeutic approach for patients with myocardial fibrosis.

Radiation-associated secondary malignancies: a novel opportunity for applying immunotherapies

Radiation is commonly used as a treatment intended to cure or palliate cancer patients. Despite remarkable advances in the precision of radiotherapy delivery, even the most advanced forms inevitably expose some healthy tissues surrounding the target site to radiation. On rare occasions, this results in the development of radiation-associated secondary malignancies (RASM). RASM are typically high-grade and carry a poorer prognosis than their non-radiated counterparts. RASM are characterized by a high mutation burden, increased T cell infiltration, and a microenvironment that bears unique inflammatory signatures of prior radiation, including increased expression of various cytokines (e.g., TGF-β, TNF-α, IL4, and IL10). Interestingly, these cytokines have been shown to up-regulate the expression of PD-1 and/or PD-L1-an immune checkpoint receptor/ligand pair that is commonly targeted by immune checkpoint blocking immunotherapies. Here, we review the current understanding of the tumor-immune interactions in RASM, highlight the distinct clinical and molecular characteristics of RASM that may render them immunologically "hot," and propose a rationale for the formal testing of immune checkpoint blockade as a treatment approach for patients with RASM.

Reflecting on the cardiac toxicity in non-small cell lung cancer in the era of immune checkpoint inhibitors therapy combined with thoracic radiotherapy

In recent years, immune checkpoint inhibitors (ICIs) have become a widely used treatment for non-small cell lung cancer (NSCLC), and the combination with traditional radiotherapy (RT) has shown significant potential in prolonging patient survival. However, both thoracic RT and ICIs can lead to cardiac toxicity, including radiation-induced heart damage (RIHD) and immunotherapy-related heart damage (IRHD). It still remains uncertain whether the combination of thoracic RT and immunotherapy will exacerbate acute or late cardiovascular (CV) toxicity and incidence. In this review, we summarize safety data from relevant clinical studies regarding CV toxicity for the combination therapy in NSCLC patients, explore the underlying synergetic mechanisms and common risk factors, and proposed treatment and management strategies. We hope to increase emphasis on the long-term assessment of CV toxicity risks associated with the combination therapy, and reduce the incidence of CV deaths resulting from such regimens.

The Influence of Different Irradiation Regimens on Inflammation and Vascularization in a Random-Pattern Flap Model

BACKGROUND

Irradiation plays an important role in the oncological treatment of various tumor entities. The aim of the study was to investigate the influence of different irradiation regimens on random-pattern flaps at the molecular and histopathological levels.

METHODS

Twenty-five rats underwent harvesting of bilateral random-pattern fasciocutaneous flaps. The right flaps received irradiation, while the left flaps served as non-irradiated intraindividual controls. Five rats served as a non-irradiated control group. Four different irradiation regimens with give rats each were tested: 20 Gy postoperatively, 3 × 12 Gy postoperatively, 20 Gy preoperatively, and 3 × 12 Gy preoperatively. Two weeks after surgery, HE staining and immunohistochemical staining for CD68 and ERG, as well as PCR analysis to detect Interleukin 6, HIF-1α, and VEGF, were performed.

RESULTS

A postoperative cumulative higher dose of irradiation appeared to result in an increase in necrosis, especially in the superficial layers of the flap compared to preoperative or single-stage irradiation. In addition, we observed increased expression of VEGF and HIF-1α in all irradiation groups.

CONCLUSION

Even though no statistically significant differences were found between the different groups, there was a tendency for fractional postoperative irradiation with a higher total dose to have a more harmful effect compared to preoperative or single-dose irradiation.

Tissue fibrosis induced by radiotherapy: current understanding of the molecular mechanisms, diagnosis and therapeutic advances

Cancer remains the leading cause of death around the world. In cancer treatment, over 50% of cancer patients receive radiotherapy alone or in multimodal combinations with other therapies. One of the adverse consequences after radiation exposure is the occurrence of radiation-induced tissue fibrosis (RIF), which is characterized by the abnormal activation of myofibroblasts and the excessive accumulation of extracellular matrix. This phenotype can manifest in multiple organs, such as lung, skin, liver and kidney. In-depth studies on the mechanisms of radiation-induced fibrosis have shown that a variety of extracellular signals such as immune cells and abnormal release of cytokines, and intracellular signals such as cGAS/STING, oxidative stress response, metabolic reprogramming and proteasome pathway activation are involved in the activation of myofibroblasts. Tissue fibrosis is extremely harmful to patients' health and requires early diagnosis. In addition to traditional serum markers, histologic and imaging tests, the diagnostic potential of nuclear medicine techniques is emerging. Anti-inflammatory and antioxidant therapies are the traditional treatments for radiation-induced fibrosis. Recently, some promising therapeutic strategies have emerged, such as stem cell therapy and targeted therapies. However, incomplete knowledge of the mechanisms hinders the treatment of this disease. Here, we also highlight the potential mechanistic, diagnostic and therapeutic directions of radiation-induced fibrosis.

Radiomic Assessment of Radiation-Induced Alterations of Skeletal Muscle Composition in Head and Neck Squamous Cell Carcinoma within the Currently Clinically Defined Optimal Time Window for Salvage Surgery-A Pilot Study

Patients with locally advanced head and neck squamous cell carcinoma (HNSCC) frequently require primary radiochemotherapy (RCT). Despite intensity modulation, the desired radiation-induced effects observed in HNSCC may also be observed as side effects in healthy tissue, e.g., the sternocleidomastoid muscle (SCM). These side effects (e.g., tissue fibrosis) depend on the interval between the completion of RCT and restaging CT. For salvage surgery, the optimal time window for surgery is currently clinically postulated at between 6 and 12 weeks after completion of RCT. Thus, no extensive tissue fibrosis is to be expected. This interval is based on clinical studies exploring surgical complications. Studies directly exploring radiation-induced changes of the SCM in HNSCC patients are sparse. The present study quantified tissue alterations in the SCM and paravertebral musculature (PVM) after RCT, applying radiomics to determine the optimal time window for salvage surgery. Three radiomic key parameters, (1) volume, (2) mean positivity of pixels (MPP), and (3) uniformity, were extracted with mint LesionTM in the staging CTs and restaging CTs of 98 HNSCC patients. Of these, 25 were female, the mean age was 62 (±9.6) years, and 80.9% were UICC Stage IV. The mean restaging interval was 55 (±28; range 29-229) days. Only the mean volume significantly decreased after RCT, from 9.0 to 8.4 and 96.5 to 91.9 mL for the SCM and PVM, respectively (both p = 0.007, both Cohen's d = 0.28). In addition, the mean body mass index (BMI) decreased from 23.9 (±4.2) to 21.0 (±3.6) kg/m² (p < 0.001; Cohen's d = 0.9). The mean BMI decreased significantly and was correlated with the volume decrease for the SCM (r = 0.27; p = 0.007) and PVM (r = 0.41; p < 0.001). If t-test p-values were adjusted for the BMI decrease, no significant change in volumes for the SCM and PVM was observed (both p > 0.05). The present data support the clinically postulated optimal interval for salvage surgery of 6 to 12 weeks.

Reconstruction of Moderately and Severely Atrophic Scalp-A Multicentric Experience in Surgical Treatment of Patients Irradiated for Tinea Capitis in Childhood and Surgical Algorithm

Background and Objectives: Before the introduction of griseofluvin, the use of X-ray radiation was the treatment of choice for tinea capitis. More than half a century later various types of tumors have been found to be associated with childhood irradiation due to tinea capitis, most commonly cancers of the head and neck, as well as brain tumors. The often unusually aggressive and recurrent nature of these tumors necessitates the need for repeated surgeries, while the atrophic skin with an impaired vascular supply due to radiation often poses an additional challenge for defect reconstruction. We present our experience in the surgical treatment of such patients. Materials and Methods: This is a retrospective cohort study. In this study, 37 patients treated for acquired defects of the scalp with a history of irradiation therapy due to tinea capitis in childhood were included in this study, 24 male and 13 female patients. The mean age at the first appointment was 60.6 ± 7.8, with the youngest included patient being 46 and the oldest being 75 years old. Patients' characteristics, surgical treatment, and complications were analyzed and a reconstructive algorithm was developed. Results: Local flaps were used for reconstruction in 34 patients, direct sutures were used in 10 patients and 20 patients received split-thickness skin grafts for coverage of both primary and secondary defects for reconstruction of flap donor sites. One regional flap and one dermal substitute covered by an autologous skin graft were also used for reconstruction. Complications occurred in 43.2% of patients and were significantly associated with the presence of comorbidities (p = 0.001), aseptic bone necrosis (p = 0.001), as well as skin atrophy in frontal, occipital, and parietal region (p = 0.001, p = 0.042 and p = 0.001, respectively). A significant correlation between major complications and moderate skin atrophy was found only in the parietal region (p = 0.026). Conclusions: Unfortunately, many protocols developed for scalp reconstruction are not applicable in the setting of severe or diffuse scalp skin atrophy associated with high tumor recurrence rate and radiation-induced vascular impairment, such as in tinea capitis patients in Serbia. An algorithm has been developed based on the authors' experience in managing these patients.

Targeted Radiation Exposure Induces Accelerated Aortic Valve Remodeling in ApoE-/- Mice

Thoracic radiation therapy may result in accelerated atherosclerosis and in late aortic valve stenosis (AS). In this study, we assessed the feasibility of inducing radiation-induced AS using a targeted aortic valve irradiation (10 or 20 Grays) in two groups of C57Bl6/J (WT) and ApoE-/- mice compared to a control (no irradiation). Peak aortic jet velocity was evaluated by echocardiography to characterize AS. T2*-weighted magnetic resonance imaging after injection of MPIO-αVCAM-1 was used to examine aortic inflammation resulting from irradiation. A T2* signal void on valve leaflets and aortic sinus was considered positive. Valve remodeling and mineralization were assessed using von Kossa staining. Finally, the impact of radiation on cell viability and cycle from aortic human valvular interstitial cells (hVICs) was also assessed. The targeted aortic valve irradiation in ApoE-/- mice resulted in an AS characterized by an increase in peak aortic jet velocity associated with valve leaflet and aortic sinus remodeling, including mineralization process, at the 3-month follow-up. There was a linear correlation between histological findings and peak aortic jet velocity (r = 0.57, p < 0.01). In addition, irradiation was associated with aortic root inflammation, evidenced by molecular MR imaging (p < 0.01). No significant effect of radiation exposure was detected on WT animals. Radiation exposure did not affect hVICs viability and cell cycle. We conclude that targeted radiation exposure of the aortic valve in mice results in ApoE-/-, but not in WT, mice in an aortic valve remodeling mimicking the human lesions. This preclinical model could be a useful tool for future assessment of therapeutic interventions.

Exploration of molecular mechanism underlying protective effect of astragaloside IV against radiation-induced lung injury by suppressing ferroptosis

In this study, we aimed to investigate the pharmacological effects and underlying mechanisms of astragaloside IV (AS IV) against radiation-induced lung injury. We established experimental models of radiation-induced lung injury and observed the effect of AS IV on cell viability, cell death, inflammatory responses and ferroptosis. Accordingly, we found that AS IV restored the suppressed cell viability and promoted cell death induced by X-ray irradiation. Moreover, radiation-induced up-regulation of lactate dehydrogenase (LDH) release, ferroptosis, reactive oxygen species (ROS) and inflammatory responses were also restored by AS IV in a dose-dependent manner. Besides, in radiation-induced lung injury C57BL/6 mice, AS IV evidently alleviated lung injury and promoted the survival rate of lung-injured mice. And the ferroptosis level in mice lung tissues were also alleviated by the administration of AS IV in a dose-dependent manner. As a conclusion, by comparing the changes of ferroptosis, ROS and inflammatory responses in the experimental models, we validated that AS IV could inhibit inflammatory responses and cell injury in the treatment of radiation-induced lung injury by suppressing ferroptosis. This finding not only find potentially effective treatments to mitigate radiation-induced lung injury, but also provides supporting evidence for clinical application of AS IV to improve the management of radiation-treated patients and minimize the associated lung complications or other adverse effects. Moreover, as inflammation and ROS are key contributors to tissue damage in various diseases, our study suggested the potential application of AS IV in the treatments for other diseases.

A Subset of Breg Cells, B10, Contributes to the Development of Radiation-Induced Pulmonary Fibrosis

PURPOSE

Radiation-induced pulmonary fibrosis (RIPF) is a serious side effect of radiation therapy, but the underlying mechanisms are unknown. B10 cells, as negative B regulatory cells, play important roles in regulating inflammation and autoimmunity. However, the role of B10 cells in RIPF progression is unclear. The aim of this study was to determine the role of B10 cells in aggravating RIPF and the underlying mechanism.

METHODS AND MATERIALS

The role of B10 cells in RIPF was studied by constructing mouse models of RIPF and depleting B10 cells with an anti-CD22 antibody. The mechanism of B10 cells in RIPF was further explored through cocultivation of B10 cells and MLE-12 or NIH3T3 cells and administration of an interleukin (IL)-10 antibody to block IL-10.

RESULTS

B10 cell numbers increased significantly during the early stage in the RIPF mouse models compared with the controls. In addition, depleting B10 cells with the anti-CD22 antibody attenuated the development of lung fibrosis in mice. Subsequently, we confirmed that B10 cells induced epithelial-mesenchymal transition and the transformation of myofibroblasts via activation of STAT3 signaling in vitro. After blockade of IL-10, it was verified that IL-10 secreted by B10 cells mediates the epithelial-mesenchymal transition of myofibroblasts, thereby promoting RIPF.

CONCLUSIONS

Our study uncovers a novel role for IL-10-secreting B10 cells that could be a new target of research for relieving RIPF.

Accelerated Atherosclerosis and Cardiovascular Toxicity Induced by Radiotherapy in Breast Cancer

The number of patients diagnosed with breast cancer and cardiovascular disease is continuously rising. Treatment options for breast cancer have greatly evolved, but radiotherapy (RT) still has a key role in it. Despite many advances in RT techniques, cardiotoxicity is one of the most important side effects. The new cardio-oncology guidelines recommend a baseline evaluation, risk stratification and follow-up of these patients. Cardiotoxicity induced by RT can be represented by almost all forms of cardiovascular disease, with atherosclerosis being the most frequent. An interdisciplinary team should manage these patients, in order to have maximum therapeutic effect and minimum cardiovascular toxicity. This review will summarize the current incidence, risk factors, mechanisms and follow-up of RT-induced cardiovascular toxicity.

Deconstructing Fat to Reverse Radiation Induced Soft Tissue Fibrosis

Adipose tissue is composed of a collection of cells with valuable structural and regenerative function. Taken as an autologous graft, these cells can be used to address soft tissue defects and irregularities, while also providing a reparative effect on the surrounding tissues. Adipose-derived stem or stromal cells are primarily responsible for this regenerative effect through direct differentiation into native cells and via secretion of numerous growth factors and cytokines that stimulate angiogenesis and disrupt pro-inflammatory pathways. Separating adipose tissue into its component parts, i.e., cells, scaffolds and proteins, has provided new regenerative therapies for skin and soft tissue pathology, including that resulting from radiation. Recent studies in both animal models and clinical trials have demonstrated the ability of autologous fat grafting to reverse radiation induced skin fibrosis. An improved understanding of the complex pathologic mechanism of RIF has allowed researchers to harness the specific function of the ASCs to engineer enriched fat graft constructs to improve the therapeutic effect of AFG.

Cardio-oncology for Pediatric and Adolescent/Young Adult Patients

OPINION STATEMENT

As chemotherapy continues to improve the lives of patients with cancer, understanding the effects of these drugs on other organ systems, and the cardiovascular system in particular, has become increasingly important. The effects of chemotherapy on the cardiovascular system are a major determinant of morbidity and mortality in these survivors. Although echocardiography continues to be the most widely used modality for assessing cardiotoxicity, newer imaging modalities and biomarker concentrations may detect subclinical cardiotoxicity earlier. Dexrazoxane continues to be the most effective therapy for preventing anthracycline-induced cardiomyopathy. Neurohormonal modulating drugs have not prevented cardiotoxicity, so their widespread, long-term use for all patients is currently not recommended. Advanced cardiac therapies, including heart transplant, have been successful in cancer survivors with end-stage HF and should be considered for these patients. Research on new targets, especially genetic associations, may produce treatments that help reduce cardiovascular morbidity and mortality.

Injured Endothelial Cell: A Risk Factor for Pulmonary Fibrosis

The pathological features of pulmonary fibrosis (PF) are the abnormal activation and proliferation of myofibroblasts and the extraordinary deposition of the extracellular matrix (ECM). However, the pathogenesis of PF is still indistinct. In recent years, many researchers have realized that endothelial cells had a crucial role in the development of PF. Studies have demonstrated that about 16% of the fibroblasts in the lung tissue of fibrotic mice were derived from endothelial cells. Endothelial cells transdifferentiated into mesenchymal cells via the endothelial-mesenchymal transition (E(nd)MT), leading to the excessive proliferation of endothelial-derived mesenchymal cells and the accumulation of fibroblasts and ECM. This suggested that endothelial cells, a significant component of the vascular barrier, played an essential role in PF. Herein, this review discusses E(nd)MT and its contribution to the activation of other cells in PF, which could provide new ideas for further understanding the source and activation mechanism of fibroblasts and the pathogenesis of PF.

The impact of tumor characteristics on cardiovascular disease death in breast cancer patients with CT or RT: a population-based study

Background

Previous studies focused on the impact of cardiovascular diseases (CVD) risk factors in breast cancer patients with chemotherapy (CT) or radiotherapy (RT). This study aimed to identify the impact of tumor characteristics on CVD death in these patients.

Methods

Data of female breast cancer patients with CT or RT between 2004 and 2016 were included. The risk factors of CVD death were identified using Cox regression analyses. A nomogram was constructed to evaluate the predicted value of tumor characteristics, and then validated by the concordance indexes (C-index) and calibration curves.

Result

A total of 28,539 patients were included with an average follow-up of 6.1 years. Tumor size > 45 mm (adjusted HR = 1.431, 95% CI = 1.116-1.836, P = 0.005), regional (adjusted HR = 1.278, 95% CI = 1.048-1.560, P = 0.015) and distant stage (adjusted HR = 2.240, 95% CI = 1.444-3.474, P < 0.001) were risk factors of CVD death for breast cancer patients with CT or RT. The prediction nomogram of tumor characteristics (tumor size and stage) on CVD survival was established. The C-index of internal and external validation were 0.780 (95% Cl = 0.751-0.809), and 0.809 (95% Cl = 0.768-0.850), respectively. The calibration curves showed consistency between the actual observation and nomogram. The risk stratification was also significant distinction (P < 0.05).

Conclusion

Tumor size and stage were related to the risk of CVD death for breast cancer patients with CT or RT. The management of CVD death risk in breast cancer patients with CT or RT should focus not only on CVD risk factors but also on tumor size and stage.

Further Characterization of Multi-Organ DEARE and Protection by 16,16 Dimethyl Prostaglandin E2 in a Mouse Model of the Hematopoietic Acute Radiation Syndrome

Survivors of acute radiation exposure suffer from the delayed effects of acute radiation exposure (DEARE), a chronic condition affecting multiple organs, including lung, kidney, heart, gastrointestinal tract, eyes, and brain, and often causing cancer. While effective medical countermeasures (MCM) for the hematopoietic-acute radiation syndrome (H-ARS) have been identified and approved by the FDA, development of MCM for DEARE has not yet been successful. We previously documented residual bone marrow damage (RBMD) and progressive renal and cardiovascular DEARE in murine survivors of H-ARS, and significant survival efficacy of 16,16-dimethyl prostaglandin E2 (dmPGE2) given as a radioprotectant or radiomitigator for H-ARS. We now describe additional DEARE (physiological and neural function, progressive fur graying, ocular inflammation, and malignancy) developing after sub-threshold doses in our H-ARS model, and detailed analysis of the effects of dmPGE2 administered before (PGE-pre) or after (PGE-post) lethal total-body irradiation (TBI) on these DEARE. Administration of PGE-pre normalized the twofold reduction of white blood cells (WBC) and lymphocytes seen in vehicle-treated survivors (Veh), and increased the number of bone marrow (BM) cells, splenocytes, thymocytes, and phenotypically defined hematopoietic progenitor cells (HPC) and hematopoietic stem cells (HSC) to levels equivalent to those in non-irradiated age-matched controls. PGE-pre significantly protected HPC colony formation ex vivo by >twofold, long term-HSC in vivo engraftment potential up to ninefold, and significantly blunted TBI-induced myeloid skewing. Secondary transplantation documented continued production of LT-HSC with normal lineage differentiation. PGE-pre reduced development of DEARE cardiovascular pathologies and renal damage; prevented coronary artery rarefication, blunted progressive loss of coronary artery endothelia, reduced inflammation and coronary early senescence, and blunted radiation-induced increase in blood urea nitrogen (BUN). Ocular monocytes were significantly lower in PGE-pre mice, as was TBI-induced fur graying. Increased body weight and decreased frailty in male mice, and reduced incidence of thymic lymphoma were documented in PGE-pre mice. In assays measuring behavioral and cognitive functions, PGE-pre reduced anxiety in females, significantly blunted shock flinch response, and increased exploratory behavior in males. No effect of TBI was observed on memory in any group. PGE-post, despite significantly increasing 30-day survival in H-ARS and WBC and hematopoietic recovery, was not effective in reducing TBI-induced RBMD or any other DEARE. In summary, dmPGE2 administered as an H-ARS MCM before lethal TBI significantly increased 30-day survival and ameliorated RBMD and multi-organ and cognitive/behavioral DEARE to at least 12 months after TBI, whereas given after TBI, dmPGE2 enhances survival from H-ARS but has little impact on RBMD or other DEARE.

Comparison of Myocardial Perfusion Scintigraphy and Coronary Angiography Results in Breast Cancer Patients Treated with Radiotherapy

Breast cancer is the most common type of malignancy in women and radiotherapy (RT) is an important part of treatment. Although it reduces cancer recurrence, it has been shown to cause accerelerated athnerosclerosis. This study aimed to compare the results of myocardial perfusion scintigraphy (MPS) for ischemia investigation with coronary angiography (CAG) findings and to investigate the effect of RT on the development of coronary artery disease in breast cancer patients who underwent RT. The results of 660 patients were analyzed and compared with each other in terms of clinical, demographic, laboratory parameters and MPS results. The mean age was 57.5 years and all of them were female. When the groups were compared, the Gensini score and marking of the left anterior descending artery (LAD) area as ischemic area localization were found more, but angiographically, the rate of severe stenosis in the area indicated by MPS was found to be lower in the RT group (p < 0.001). While the sensitivity of MPS in the RT group was 67.5% and non-RT group was 88.5% (p < 0.001), the result of our study shows that the sensitivity of the MPS test is significantly lower in the patient group receiving RT.

Differences in radiation-induced heart dysfunction in male versus female rats

PURPOSE

Radiation therapy remains part of the standard of care for breast, lung, and esophageal cancers. While radiotherapy improves local control and survival, radiation-induced heart dysfunction is a common side effect of thoracic radiotherapy. Cardiovascular dysfunction can also result from non-therapeutic total body radiation exposures. Numerous studies have evaluated the relationship between radiation dose to the heart and cardiotoxicity, but relatively little is known about whether there are differences based on biological sex in radiation-induced heart dysfunction (RIHD).

MATERIALS AND METHODS

We evaluated whether male and female inbred Dahl SS rats display differences in RIHD following delivery of 24 Gy in a single fraction to the whole heart using a 1.5 cm beam size (collimater). We also compared the 2.0 cm vs. 1.5 cm collimator in males. Pleural and pericardial effusions and normalized heart weights were measured, and echocardiograms were performed.

RESULTS

Female SS rats displayed more severe RIHD relative to age-matched SS male rats. Normalized heart weight was significantly increased in females, but not in males. A total of 94% (15/16) of males and 55% (6/11) of females survived 5 months after completion of radiotherapy (p < .01). Among surviving rats, 100% of females and 14% of males developed moderate-to-severe pericardial effusions at 5 months. Females demonstrated increased pleural effusions, with the mean normalized pleural fluid volume for females and males being 56.6 mL/kg ± 12.1 and 10.96 mL/kg ± 6.4 in males (p = .001), respectively. Echocardiogram findings showed evidence of heart failure, which was more pronounced in females. Because age-matched female rats have smaller lungs, a higher percentage of the total lung was treated with radiation in females than males using the same beam size. After using a larger 2 cm beam in males which results in higher lung exposure, there was not a significant difference between males and females in terms of the development of moderate-to-severe pericardial effusions or pleural effusions. Treatment of males with a 2 cm beam resulted in comparable increases in LV mass and reductions in stroke volume to female rats treated with a 1.5 cm beam.

CONCLUSION

Together, these results illustrate that there are differences in radiation-induced cardiotoxicity between male and female SS rats and add to the data that lung radiation doses, in addition to other factors, may play an important role in cardiac dysfunction following heart radiation exposure. These factors may be important to factor into future mitigation studies of radiation-induced cardiotoxicity.

Methods to assess radiation-induced fibrosis in mice

Therapeutic radiation is used to treat a variety of cancers in organs and tissues throughout the body. Exposure of benign normal tissue to radiation can result in late injury in a subset of patients. Radiation induced fibrosis is one chronic, progressive late toxicity of radiation exposure that can occur in many organs and tissues, including skin and lung. Radiation fibrosis has few effective treatments. The process of radiation fibrosis is known to involve many mitogenic and immunomodulatory cytokines, inflammatory programs, and processes such as stem cell senescence. Murine models of radiation fibrosis can be used to evaluate agents that may prevent, mitigate, or treat this injury. Here, we provide a detailed protocol for the development of radiation induced dermal and pulmonary fibrosis in mice and describe protocols for the measurement of this injury in treated tissue.

CD73: Friend or Foe in Lung Injury

Ecto-5′-nucleotidase (CD73) plays a strategic role in calibrating the magnitude and chemical nature of purinergic signals that are delivered to immune cells. Its primary function is to convert extracellular ATP to adenosine in concert with ectonucleoside triphosphate diphosphohydrolase-1 (CD39) in normal tissues to limit an excessive immune response in many pathophysiological events, such as lung injury induced by a variety of contributing factors. Multiple lines of evidence suggest that the location of CD73, in proximity to adenosine receptor subtypes, indirectly determines its positive or negative effect in a variety of organs and tissues and that its action is affected by the transfer of nucleoside to subtype-specific adenosine receptors. Nonetheless, the bidirectional nature of CD73 as an emerging immune checkpoint in the pathogenesis of lung injury is still unknown. In this review, we explore the relationship between CD73 and the onset and progression of lung injury, highlighting the potential value of this molecule as a drug target for the treatment of pulmonary disease.

Emerging Role of Immunomonitoring to Predict the Clinical Outcome of Patients With Malignant Pleural Mesothelioma Treated With Radical Radiation Therapy

PURPOSE

The present study aimed at evaluating the baseline immune profile and the immunomodulating effects of radical hemithoracic radiation therapy (RT) in patients affected by malignant pleural mesothelioma (MPM) to identify potential predictive biomarkers of therapy response, toxicity development, and eligibility for further immunotherapeutic treatments.

METHODS AND MATERIALS

Blood samples were collected from 55 patients with MPM, enrolled in a phase 3 trial comparing radical hemithoracic RT (interventional arm, n = 28) with local palliative RT (control arm, n = 27). Immunomonitoring was performed before RT, at the end of treatment, and 1 month after therapy, characterizing natural killer cells, B and T lymphocytes, activated CD4 and CD8 T cells, interferon-γ- and tumor necrosis factor-α-producing T helper (Th) 1 cells, regulatory T cells, and Th17 and Th22 lymphocytes, through flow cytometry. Serum levels of interleukin (IL)-6, -8, -10 and mesothelin were quantified through Enzyme-Linked Immunosorbent Assay (ELISA) assays at the same time points. Variations in the immune parameters were investigated by Friedman test and Wilcoxon signed rank post hoc test with Bonferroni correction for multiple testing, while the prognostic effect of immune biomarkers was evaluated through Kaplan-Meier method and Spearman's correlation analysis.

RESULTS

Major immune variations were noticed after radical RT compared with palliative treatment, in particular an improvement in activated T cells and in interferon-γ-producing Th1 cells after RT. In the interventional arm, baseline high levels of Th22 and IL-10 and an increase in T cells were associated with an improved survival, whereas a fold increase in serum mesothelin correlated with the development of severe toxicity. An improvement of immunosuppressive regulatory T cells was observed in both arms of treatment.

CONCLUSIONS

The immunomonitoring performed in patients with MPM revealed potential prognostic biomarkers for radical hemithoracic RT treatment and identified specific immune signatures induced by RT immunomodulation, which could suggest a synergistic effect with an immunotherapeutic treatment.