Radiation-Induced Skin Fibrosis: Pathogenesis, Current Treatment Options, and Emerging Therapeutics

Tumor necrosis factor-α-treated human adipose-derived stem cells enhance inherent radiation tolerance and alleviate in vivo radiation-induced capsular contracture

INTRODUCTION

Post-mastectomy radiotherapy plays a crucial role in breast cancer treatment but can lead to an inflammatory response causing soft tissue damage, particularly radiation-induced capsular contracture (RICC), impacting breast reconstruction outcomes. Adipose-derived stem cells (ADSCs), known for their regenerative potential via paracrine capacity, exhibit inherent radiotolerance. The influence of tumor necrosis factor-alpha (TNF-α) on ADSCs has been reported to enhance the paracrine effect of ADSCs, promoting wound healing by modulating inflammatory responses.

OBJECTIVE

This study investigates the potential of TNF-α-treated human ADSCs (T-hASCs) on silicone implants to alleviate RICC, hypothesizing to enhance suppressive effects on RICC by modulating inflammatory responses in a radiation-exposed environment.

METHODS

In vitro, T-hASCs were cultured on various surfaces to assess viability after exposure to radiation up to 20 Gy. In vivo, T-hASC and non-TNF-α-treated hASC (C-hASCs)-coated membranes were implanted in mice before radiation exposure, and an evaluation of the RICC mitigation took place 4 and 8 weeks after implantation. In addition, the growth factors released from T-hASCs were assessed.

RESULTS

In vitro, hASCs displayed significant radiotolerance, maintaining consistent viability after exposure to 10 Gy. TNF-α treatment further enhanced radiation tolerance, as evidenced by significantly higher viability than C-hASCs at 20 Gy. In vivo, T-hASC-coated implants effectively suppressed RICC, reducing capsule thickness. T-hASCs exhibited remarkable modulation of the inflammatory response, suppressing M1 macrophage polarization while enhancing M2 polarization. The elevated secretion of vascular endothelial growth factor from T-hASCs is believed to induce macrophage polarization, potentially reducing RICC.

CONCLUSION

This study establishes T-hASCs as a promising strategy for ameliorating the adverse effects experienced by breast reconstruction patients after mastectomy and radiation therapy. The observed radiotolerance, anti-fibrotic effects, and immune modulation suggest the possibility of enhancing patient outcomes and quality of life. Further research and clinical trials are warranted for broader clinical uses.

Hyaluronic acid-based injectable formulation developed to mitigate metastasis and radiation-induced skin fibrosis in breast cancer treatment

The standard treatment for early-stage breast cancer involves breast-conserving surgery followed by adjuvant radiotherapy. However, approximately 20 % of patients experience distant metastasis, and adjuvant radiotherapy often leads to radiation-induced skin fibrosis (RISF). In this study, we develop an on-site injectable formulation composed of selenocystamine (SeCA) and hyaluronic acid (HyA), referred to as SeCA cross-linked HyA (SCH) agent, and investigate its potential to mitigate metastasis and prevent RISF associated with breast cancer therapy. SCH agents are synthesized using the nanoprecipitation method to modulate cell-cell tight junctions and tissue inflammation. The toxicity assessments reveal that SCH agents with a higher Se content (Se payload 17.4 μg/mL) are well tolerated by L929 cells compared to SeCA (Se payload 3.2 μg/mL). In vitro, SCH agents significantly enhance cell-cell tight junctions and effectively mitigate migration and invasion of breast cancer cells (4T1). In vivo, SCH agents mitigate distant lung metastasis. Furthermore, in animal models, SCH agents reduce RISF and promote wound repair. These findings highlight the potential of SCH agents as a novel therapeutic formulation for effectively mitigating metastasis and reducing RISF. This holds great promise for improving clinical outcomes in breast cancer patients undergoing adjuvant radiotherapy.

Adjuvant Properties of Caffeic Acid in Cancer Treatment

Caffeic acid (CA) is a polyphenol belonging to the phenylpropanoid family, commonly found in plants and vegetables. It was first identified by Hlasiwetz in 1867 as a breakdown product of caffetannic acid. CA is biosynthesized from the amino acids tyrosine or phenylalanine through specific enzyme-catalyzed reactions. Extensive research since its discovery has revealed various health benefits associated with CA, including its antioxidant, anti-inflammatory, and anticancer properties. These effects are attributed to its ability to modulate several pathways, such as inhibiting NFkB, STAT3, and ERK1/2, thereby reducing inflammatory responses, and activating the Nrf2/ARE pathway to enhance antioxidant cell defenses. The consumption of CA has been linked to a reduced risk of certain cancers, mitigation of chemotherapy and radiotherapy-induced toxicity, and reversal of resistance to first-line chemotherapeutic agents. This suggests that CA could serve as a useful adjunct in cancer treatment. Studies have shown CA to be generally safe, with few adverse effects (such as back pain and headaches) reported. This review collates the latest information from Google Scholar, PubMed, the Phenol-Explorer database, and ClinicalTrials.gov, incorporating a total of 154 articles, to underscore the potential of CA in cancer prevention and overcoming chemoresistance.

Effects and Significance of Dicliptera chinensis Polysaccharide on the Expression of Transforming Growth Factor β1/Connective Tissue Growth Factor Pathway in the Masseter and Head and Neck Skin of Rats With Radiation-Induced Fibrosis

PURPOSE

To investigate whether Dicliptera chinensis polysaccharide (DCP) can alleviate radiation-induced fibrosis of masseter and head and neck skin.

METHODS

SD rats were divided into the control, the irradiation (IR), the IR + low dose DCP (200 mg/kg), and the IR + high dose DCP (400 mg/kg) groups. The head and neck of rats in the last 3 groups received a single dose of 18 Gy X-ray. At 1st, 2nd, 4th week (w) after radiation, haematoxylin and eosin staining were performed on masseter and skin to observe the histopathological changes; immunohistochemistry staining was performed to observe the pathological changes of the skin; Masson staining was performed on masseter and skin to observe the collagen deposition; western blot analysis was used on masseter to calculate the relative transforming growth factor β1 (TGF-β1), connective tissue growth factor (CTGF) expressions; ELISA was used to detect the contents of TGF-β1 and CTGF in skin and the contents of type I and type III collagens in masseter and skin.

RESULTS

In terms of skin, compared to the IR group, the IR + high-dose DCP group exhibited relatively smaller changes in skin structure, lower levels of TGF-β1 and CTGF; thinner skin thickness was observed at the 4th w after radiation; and the positive rates of collagen fibre and the optical densities of type I and type III collagens were lower at the 2nd and 4th w. For the masseter, compared to the IR group, the morphological changes were improved and the expression levels of TGF-β1 and CTGF proteins decreased in the 2 DCP dose groups at 2nd and 4th w.

CONCLUSION

DCP can reduce the formation and accumulation of type I and type III collagens after IR and ameliorate radiation-induced fibrosis of masseter and skin by down-regulating the expressions of TGF-β1 and CTGF.

Role of ferroptosis in radiation-induced soft tissue injury

Ionizing radiation has been pivotal in cancer therapy since its discovery. Despite its therapeutic benefits, IR causes significant acute and chronic complications due to DNA damage and the generation of reactive oxygen species, which harm nucleic acids, lipids, and proteins. While cancer cells are more vulnerable to ionizing radiation due to their inefficiency in repairing damage, healthy cells in the irradiated area also suffer. Various types of cell death occur, including apoptosis, necrosis, pyroptosis, autophagy-dependent cell death, immunogenic cell death, and ferroptosis. Ferroptosis, driven by iron-dependent lipid peroxide accumulation, has been recognized as crucial in radiation therapy's therapeutic effects and complications, with extensive research across various tissues. This review aims to summarize the pathways involved in radiation-related ferroptosis, findings in different organs, and drugs targeting ferroptosis to mitigate its harmful effects.

The current landscape of antifibrotic therapy across different organs: A systematic approach

Fibrosis is a common pathological process that can affect virtually all the organs, but there are hardly any effective therapeutic options. This has led to an intense search for antifibrotic therapies over the last decades, with a great number of clinical assays currently underway. We have systematically reviewed all current and recently finished clinical trials involved in the development of new antifibrotic drugs, and the preclinical studies analyzing the relevance of each of these pharmacological strategies in fibrotic processes affecting tissues beyond those being clinically studied. We analyze and discuss this information with the aim of determining the most promising options and the feasibility of extending their therapeutic value as antifibrotic agents to other fibrotic conditions.

Single-cell transcriptional analysis of irradiated skin reveals changes in fibroblast subpopulations and variability in caveolin expression

BACKGROUND

Radiation-induced fibrosis (RIF) is an important late complication of radiation therapy, and the resulting damaging effects of RIF can significantly impact reconstructive outcomes. There is currently a paucity of effective treatment options available, likely due to the continuing knowledge gap surrounding the cellular mechanisms involved. In this study, detailed analyses of irradiated and non-irradiated human skin samples were performed incorporating histological and single-cell transcriptional analysis to identify novel features guiding development of skin fibrosis following radiation injury.

METHODS

Paired irradiated and contralateral non-irradiated skin samples were obtained from six female patients undergoing post-oncologic breast reconstruction. Skin samples underwent histological evaluation, immunohistochemistry, and biomechanical testing. Single-cell RNA sequencing was performed using the 10X single cell platform. Cells were separated into clusters using Seurat in R. The SingleR classifier was applied to ascribe cell type identities to each cluster. Differentially expressed genes characteristic to each cluster were then determined using non-parametric testing.

RESULTS

Comparing irradiated and non-irradiated skin, epidermal atrophy, dermal thickening, and evidence of thick, disorganized collagen deposition within the extracellular matrix of irradiated skin were readily appreciated on histology. These histologic features were associated with stiffness that was higher in irradiated skin. Single-cell RNA sequencing revealed six predominant cell types. Focusing on fibroblasts/stromal lineage cells, five distinct transcriptional clusters (Clusters 0-4) were identified. Interestingly, while all clusters were noted to express Cav1, Cluster 2 was the only one to also express Cav2. Immunohistochemistry demonstrated increased expression of Cav2 in irradiated skin, whereas Cav1 was more readily identified in non-irradiated skin, suggesting Cav1 and Cav2 may act antagonistically to modulate fibrotic cellular responses.

CONCLUSION

In response to radiation therapy, specific changes to fibroblast subpopulations and enhanced Cav2 expression may contribute to fibrosis. Altogether, this study introduces a novel pathway of caveolin involvement which may contribute to fibrotic development following radiation injury.

Perforator versus Non-Perforator Flap-Based Vulvoperineal Reconstruction-A Systematic Review and Meta-Analysis

BACKGROUND

Patients with advanced vulvoperineal cancer require a multidisciplinary treatment approach to ensure oncological safety, timely recovery, and the highest possible quality of life (QoL). Reconstructions in this region often lead to complications, affecting approximately 30% of patients. Flap design has evolved towards perforator-based approaches to reduce functional deficits and (donor site) complications, since they allow for the preservation of relevant anatomical structures. Next to their greater surgical challenge in elevation, their superiority over non-perforator-based approaches is still debated.

METHODS

To compare outcomes between perforator and non-perforator flaps in female vulvoperineal reconstruction, we conducted a systematic review of English-language studies published after 1980, including randomized controlled trials, cohort studies, and case series. Data on demographics and surgical outcomes were extracted and classified using the Clavien-Dindo classification. We used a random-effects meta-analysis to derive a pooled estimate of complication frequency (%) in patients who received at least one perforator flap and in patients who received non-perforator flaps.

RESULTS

Among 2576 screened studies, 49 met our inclusion criteria, encompassing 1840 patients. The overall short-term surgical complication rate was comparable in patients receiving a perforator (n = 276) or a non-perforator flap (n = 1564) reconstruction (p* > 0.05). There was a tendency towards fewer complications when using perforator flaps. The assessment of patients' QoL was scarce.

CONCLUSIONS

Vulvoperineal reconstruction using perforator flaps shows promising results compared with non-perforator flaps. There is a need for the assessment of its long-term outcomes and for a systematic evaluation of patient QoL to further demonstrate its benefit for affected patients.

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].

Application of Stem Cells Shows Antiinflammatory Effect in an Irradiated Random Pattern Flap Model

BACKGROUND

In reconstructive surgery, local flaps might develop tissue necrosis or partial flap loss especially after previous irradiation, which may be necessary in many tumor entities. The application of stem cells seems promising to improve flap perfusion and might be a possible solution to optimize flap survival.

METHODS

Twenty rats received harvesting of bilateral random pattern fasciocutaneous flaps. The right flaps received 20 Gy ionizing radiation 4 weeks prior to the surgery, while the left flaps served as the non-irradiated control. After flap harvest, four different stem cell mixtures (5 × 106 ASC, ASC-HUVEC, MSC, MSC-HUVEC) were applied under both right and left flaps using 1 mL fibrin glue as the delivery vehicle. Flap size and its necrotic area were examined clinically. Two weeks after the surgery, HE staining and immunohistochemical staining for CD68 and ERG, as well as PCR analysis (Interleukin 6, HIF-1α and VEGF), were performed.

RESULTS

Application of ASCs, ASCs-HUVECs and MSCs resulted in a lower number of CD68-stained cells compared to the no cell group. The expression of Hif1α was higher in the ASC group compared to those in the MSC and previously treated no cell groups. Treatment with MSCs and MSCs-HUVECs prevented shrinking of the flaps in this series.

CONCLUSION

Application of ASCs, MSCs and ASCs-HUVECs was shown to have an antiinflammatory effect. Treatment with MSCs and MSCs-HUVECs can prevent early shrinking of the flaps.

A New Convenient Incision Model of the Nipple-Sparing Mastectomy: Lateralized Parabolic Multiplanar Incision

BACKGROUND

In this study, a lateralized parabolic multiplanar incision was defined. It was aimed to reduce necrosis in the nipple-areola complex (NAC) and, in the long run, to prevent the scar from pulling the areola laterally by maintaining healthy skin tissue between the scar and the areola and preserving the natural round appearance of the areola. Moreover, we purposed the scar not to be visible from the anterior view.

METHODS

The study included 243 patients who underwent nipple-sparing mastectomy and immediate implant-based breast reconstruction. The incision was made 4-5 cm away from the lateral border of the NAC. The incision was completed after passing the anterior axillary line by drawing a parabolic curve in superolateral axis.

RESULTS

The mean follow-up period was 24.6 months, and the mean age of the patients was 42.3 years. Full-thickness necrosis of the NAC occurred in 3.6% of breasts. In long-term follow-ups, the incision scar measured an average length of 8.6 cm. None of the patients had lateral displacement of the NAC. The NAC preserved its round appearance, except for 12 breasts that had full-thickness NAC necrosis. Ten breasts had an unnatural breast appearance.

CONCLUSION

The lateralized parabolic multiplanar incision is an ideal incision model for nipple-sparing mastectomy, as it allows for the exposure and reconstruction of all breast quadrants. We maintain areolar circulation; there are no visible scars when viewed anteriorly. Furthermore, it prevents lateral displacement of the NAC, ensuring that the natural round form of the NAC is not distorted.

LEVEL OF EVIDENCE IV

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 .

Superoxide Dismutase Mimetic Avasopasem Manganese Enhances Radiation Therapy Effectiveness in Soft Tissue Sarcomas and Accelerates Wound Healing

Soft tissue sarcomas (STSs) are mesenchymal malignant lesions that develop in soft tissues. Despite current treatments, including radiation therapy (RT) and surgery, STSs can be associated with poor patient outcomes and metastatic recurrences. Neoadjuvant radiation therapy (nRT), while effective, is often accompanied by severe postoperative wound healing complications due to damage to the surrounding normal tissues. Thus, there is a need to develop therapeutic approaches to reduce nRT toxicities. Avasopasem manganese (AVA) is a selective superoxide dismutase mimetic that protects against IR-induced oral mucositis and lung fibrosis. We tested the efficacy of AVA in enhancing RT in STSs and in promoting wound healing. Using colony formation assays and alkaline comet assays, we report that AVA selectively enhanced the STS (liposarcoma, fibrosarcoma, leiomyosarcoma, and MPNST) cellular response to radiation compared to normal dermal fibroblasts (NDFs). AVA is believed to selectively enhance radiation therapy by targeting differential hydrogen peroxide clearance in tumor cells compared to non-malignant cells. STS cells demonstrated increased catalase protein levels and activity compared to normal fibroblasts. Additionally, NDFs showed significantly higher levels of GPx1 activity compared to STSs. The depletion of glutathione using buthionine sulfoximine (BSO) sensitized the NDF cells to AVA, suggesting that GPx1 may, in part, facilitate the selective toxicity of AVA. Finally, AVA significantly accelerated wound closure in a murine model of wound healing post RT. Our data suggest that AVA may be a promising combination strategy for nRT therapy in STSs.

Immunomodulation of salivary gland function due to cancer therapy

Functional salivary glands (SG) are essential for maintaining oral health, and salivary dysfunction is a persistent major clinical challenge. Several cancer therapies also have off-target effects leading to SG dysfunction. Recent advances highlight the role of SG immune populations in homeostasis, dysfunction and gland regeneration. Here, we review what is known about SG immune populations during development and postnatal homeostasis. We summarize recent findings of immune cell involvement in SG dysfunction following cancer treatments such as irradiation (IR) for head and neck cancers, immune transplant leading to graft-versus-host-disease (GVHD) and immune checkpoint inhibitor (ICI) treatment. The role of immune cells in SG in both homeostasis and disease, is an emerging field of research that may provide important clues to organ dysfunction and lead to novel therapeutic targets.

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.

Implications of Malignancy, Radiation, and Timing of Major Nasal Reconstruction

Owing to the complex, multilayered anatomy of the nose in the central face, major nasal reconstruction can pose a significant challenge for reconstructive surgeons. It is the responsibility of reconstructive surgeons to have an understanding of the most common cutaneous malignancies and excisional techniques that may lead to complex nasal defects. The purpose of this article is to discuss these malignancies, excisional techniques, and impacts of radiation on tissue that has implications for reconstructive surgeons.

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.

Risk Prediction Model for Radiation-induced Dermatitis in Patients with Cervical Carcinoma Undergoing Chemoradiotherapy

PURPOSE

Radiation-induced dermatitis (RD) is a common side-effect of therapeutic ionizing radiation that can severely affect patient quality of life. This study aimed to develop a risk prediction model for the occurrence of RD in patients with cervical carcinoma undergoing chemoradiotherapy using electronic medical records (EMRs).

METHODS

Using EMRs, the clinical data of patients who underwent simultaneous radiotherapy and chemotherapy at a tertiary cancer hospital between 2017 and 2022 were retrospectively collected, and the patients were divided into two groups: a training group and a validation group. A predictive model was constructed to predict the development of RD in patients who underwent concurrent radiotherapy and chemotherapy for cervical cancer. Finally, the model's efficacy was validated using a receiver operating characteristic curve.

RESULTS

The incidence of radiation dermatitis was 89.5% (560/626) in the entire cohort, 88.6% (388/438) in the training group, and 91.5% (172/188) in the experimental group. The nomogram was established based on the following factors: age, the days between the beginning and conclusion of radiotherapy, the serum albumin after chemoradiotherapy, the use of single or multiple drugs for concurrent chemotherapy, and the total dose of afterloading radiotherapy. Internal and external verification indicated that the model had good discriminatory ability. Overall, the model achieved an area under the receiver operating characteristic curve of .66.

CONCLUSIONS

The risk of RD in patients with cervical carcinoma undergoing chemoradiotherapy is high. A risk prediction model can be developed for RD in cervical carcinoma patients undergoing chemoradiotherapy, based on over 5 years of EMR data from a tertiary cancer hospital.

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.

Deferoxamine topical cream superior to patch in rescuing radiation-induced fibrosis of unwounded and wounded skin

Topical patch delivery of deferoxamine (DFO) has been studied as a treatment for this fibrotic transformation in irradiated tissue. Efficacy of a novel cream formulation of DFO was studied as a RIF therapeutic in unwounded and excisionally wounded irradiated skin. C57BL/6J mice underwent 30 Gy of radiation to the dorsum followed by 4 weeks of recovery. In a first experiment, mice were separated into six conditions: DFO 50 mg cream (D50), DFO 100 mg cream (D100), soluble DFO injections (DI), DFO 1 mg patch (DP), control cream (Vehicle), and irradiated untreated skin (IR). In a second experiment, excisional wounds were created on the irradiated dorsum of mice and then divided into four treatment groups: DFO 100 mg Cream (W-D100), DFO 1 mg patch (W-DP), control cream (W-Vehicle), and irradiated untreated wounds (W-IR). Laser Doppler perfusion scans, biomechanical testing, and histological analysis were performed. In irradiated skin, D100 improved perfusion compared to D50 or DP. Both D100 and DP enhanced dermal characteristics, including thickness, collagen density and 8-isoprostane staining compared to untreated irradiated skin. D100 outperformed DP in CD31 staining, indicating higher vascular density. Extracellular matrix features of D100 and DP resembled normal skin more closely than DI or control. In radiated excisional wounds, D100 facilitated faster wound healing and increased perfusion compared to DP. The 100 mg DFO cream formulation rescued RIF of unwounded irradiated skin and improved excisional wound healing in murine skin relative to patch delivery of DFO.

Incidence of Nonkeratinocyte Skin Cancer After Breast Cancer Radiation Therapy

Importance

Previous studies have suggested that radiation therapy may contribute to an increased risk of subsequent nonkeratinocyte (ie, not squamous and basal cell) skin cancers.

Objective

To test the hypothesis that radiation therapy for breast cancer increases the risk of subsequent nonkeratinocyte skin cancers, particularly when these cancers are localized to the skin of the breast or trunk.

Design, Setting, and Participants

This population-based cohort study used longitudinal data from the Surveillance, Epidemiology, and End Results (SEER) Program for January 1, 2000, to December 31, 2019. The SEER database includes population-based cohort data from 17 registries. Patients with newly diagnosed breast cancer were identified and were evaluated for subsequent nonkeratinocyte skin cancer development. Data analysis was performed from January to August 2023.

Exposures

Radiation therapy, chemotherapy, or surgery for breast cancer.

Main Outcomes and Measures

The primary outcomes were standardized incidence ratios (SIRs) for subsequent nonkeratinocyte skin cancer development from 2000 to 2019 based on treatment type (radiation therapy, chemotherapy, or surgery), skin cancer site on the body, and skin cancer subtype.

Results

Among the 875 880 patients with newly diagnosed breast cancer included in this study, 99.3% were women, 51.6% were aged older than 60 years, and 50.3% received radiation therapy. A total of 11.2% patients identified as Hispanic, 10.1% identified as non-Hispanic Black, and 69.5% identified as non-Hispanic White. From 2000 to 2019, there were 3839 patients with nonkeratinocyte skin cancer, including melanoma (3419 [89.1%]), Merkel cell carcinoma (121 [3.2%]), hemangiosarcoma (104 [2.7%]), and 32 other nonkeratinocyte skin cancers (195 [5.1%]), documented to occur after breast cancer treatment. The risk of nonkeratinocyte skin cancer diagnosis after breast cancer treatment with radiation was 57% higher (SIR, 1.57 [95% CI, 1.45-1.7]) than that of the general population when considering the most relevant site: the skin of the breast or trunk. When risk at this site was stratified by skin cancer subtype, the SIRs for melanoma and hemangiosarcoma were both statistically significant at 1.37 (95% CI, 1.25-1.49) and 27.11 (95% CI, 21.6-33.61), respectively. Receipt of radiation therapy was associated with a greater risk of nonkeratinocyte skin cancer compared with chemotherapy and surgical interventions.

Conclusions and Relevance

In this study of patients with breast cancer, an increased risk of melanoma and hemangiosarcoma after breast cancer treatment with radiation therapy was observed. Although occurrences of nonkeratinocyte skin cancers are rare, physicians should be aware of this elevated risk to help inform follow-up care.

Human Adipose-Derived Endothelial Progenitor Cells Accelerate Epithelialization of Radiation Ulcers in Nude Mice

BACKGROUND

Cotransplantation of adipose-derived stem cells (ASCs) and endothelial progenitor cells has shown superior angiogenic effects compared with ASCs alone in recent animal studies. However, endothelial progenitor cells could only be collected from blood vessels or bone marrow. Thus, the authors have established a method for purifying adipose-derived endothelial progenitor cells (AEPCs). The authors hypothesized that AEPCs would enhance the therapeutic effect of ASCs on radiation ulcers.

METHODS

Seven-week-old male nude mice (BALB/cAJcl-nu/nu) were irradiated on the dorsal skin (total 40 Gy); 12 weeks later, 6-mm-diameter wounds were created. The mice were then treated with subcutaneous injection of human ASCs [1 × 10 5 ( n = 4)], human AEPCs [2 × 10 5 or 5 × 10 5 ( n = 5)], combinations of those [ASCs 1 × 10 5 plus AEPCs 2 × 10 5 ( n = 4) or 5 × 10 5 ( n = 5)], or only vehicle ( n = 7). The nonirradiated group was also prepared as a control ( n = 6). The days required for macroscopic epithelialization was compared, and immunostaining for human-derived cells and vascular endothelial cells was performed at day 28.

RESULTS

AEPC-ASC combination-treated groups healed faster than the ASC-treated group (14 ± 0 days versus 17 ± 2 days; P < 0.01). Engraftment of the injected cells could not be confirmed. Only the nonirradiated mice had significantly higher vascular density (0.988 ± 0.183 × 10 -5 /µm -2 versus 0.474 ± 0.092 × 10 -5 /µm 2 ; P = 0.02).

CONCLUSION

The results suggested therapeutic potentials of AEPCs and an enhanced effect of combination with ASCs. This study is a xenogenic transplantation model, and further validation in an autologous transplantation model is needed.

CLINICAL RELEVANCE STATEMENT

Human AEPCs and their combination with ASCs accelerated epithelialization of radiation ulcers in nude mice. The authors suggest that administration of humoral factors secreted from AEPCs (eg, treatment with culture-conditioned media) could be used for the same purpose.

Deciphering the fibrotic process: mechanism of chronic radiation skin injury fibrosis

This review explores the mechanisms of chronic radiation-induced skin injury fibrosis, focusing on the transition from acute radiation damage to a chronic fibrotic state. It reviewed the cellular and molecular responses of the skin to radiation, highlighting the role of myofibroblasts and the significant impact of Transforming Growth Factor-beta (TGF-β) in promoting fibroblast-to-myofibroblast transformation. The review delves into the epigenetic regulation of fibrotic gene expression, the contribution of extracellular matrix proteins to the fibrotic microenvironment, and the regulation of the immune system in the context of fibrosis. Additionally, it discusses the potential of biomaterials and artificial intelligence in medical research to advance the understanding and treatment of radiation-induced skin fibrosis, suggesting future directions involving bioinformatics and personalized therapeutic strategies to enhance patient quality of life.

Pharmaceutical management of acute radiation dermatitis in the German speaking radiation oncology community

BACKGROUND

Radiation dermatitis (RD) remains the most common side effect in radiation therapy (RT) with various pharmaceutical options available for prevention and treatment. We sought to determine pharmaceutical management patterns of radiation dermatitis among radiation oncology professionals.

METHODS

We conducted a survey on RD among the German-speaking community of radiation oncologists inquiring for their opinion on preventive and therapeutic pharmaceutical approaches for acute RD.

RESULTS

244 health professionals participated. Dexpanthenol lotion is the agent most widely used both for prevention (53.0%) and treatment (76.9%) of RD, followed by urea (29.8%) for prevention and corticosteroids (46.9%) for treatment. A wide range of substances is used by participants, though the overall experience with them is rather limited. 32.5% of participants do generally not recommend any preventative treatment. 53.4% of participants recommend alternative medicine for RD management. While seldomly used, corticosteroids were considered most effective in RD therapy, followed by dexpanthenol and low-level laser therapy. A majority of participants prefers moist over dry treatment of moist desquamation and 43.8% prescribe antiseptics.

CONCLUSIONS

Pharmaceutical management of RD in the German-speaking radiation oncology community remains controversial, inconsistent, and partially not supported by evidence-based medicine. Stronger evidence level and interdisciplinary consensus is required amongst practitioners to improve these care patterns.

Pharmazeutische Behandlung der akuten Radiodermatitis in der deutschsprachigen strahlentherapeutischen Gemeinschaft: Pharmaceutical management of acute radiation dermatitis in the German speaking radiation oncology community

Hintergrund

Die Radiodermatitis (RD) ist die häufigste Nebenwirkung der Strahlentherapie (RT), wobei verschiedene pharmazeutische Optionen zur Vorbeugung/Behandlung zur Verfügung stehen. Unser Ziel war, die pharmazeutischen Behandlungsmuster für die RD unter strahlentherapeutischen Fachleuten zu ermitteln.

Methodik

Wir haben eine Umfrage zum Thema RD in der deutschsprachigen radioonkologischen Gemeinschaft durchgeführt und ihre Meinung zu präventiven und therapeutischen pharmazeutischen Therapieansätzen betreffend die akute RD erfragt.

Ergebnisse

244 Angehörige zugehöriger Gesundheitsberufe nahmen teil. Dexpanthenol‐Lotion ist das am häufigsten verwendete Mittel sowohl zur Vorbeugung (53%) als auch zur Behandlung (76,9%) der RD, gefolgt von Harnstoff (29,8%) zur Vorbeugung und Kortikosteroiden (46,9%) zur Behandlung. Die Teilnehmer verwenden eine breite Palette an Substanzen, haben aber insgesamt wenig Erfahrung mit diesen. 32,5% der Teilnehmer empfehlen generell keine präventive Behandlung. 53,4% der Teilnehmer empfehlen Alternativmedizin. Obwohl selten eingesetzt, wurden Kortikosteroide als wirksamstes Behandlungsmittel angesehen, gefolgt von Dexpanthenol und Low‐Level‐Lasertherapie. Die Mehrheit der Teilnehmer bevorzugt die feuchte gegenüber der trockenen Behandlung der feuchten Desquamation und 43,8% verschreiben Antiseptika.

Schlussfolgerungen

Die pharmazeutische Behandlung der RD in der deutschsprachigen strahlentherapeutischen Fachwelt ist nach wie vor umstritten, sowie mitunter inkonsistent und nicht durch evidenzbasierte Medizin gestützt. Ein interdisziplinärer Konsens ist erforderlich, um die bestehenden Behandlungskonzepte zu verbessern.

Therapeutic Potential of Adipose-Derived Stem Cell-Conditioned Medium and Extracellular Vesicles in an In Vitro Radiation-Induced Skin Injury Model

Radiotherapy (RT) is one of three major treatments for malignant tumors, and one of its most common side effects is skin and soft tissue injury. However, the treatment of these remains challenging. Several studies have shown that mesenchymal stem cell (MSC) treatment enhances skin wound healing. In this study, we extracted human dermal fibroblasts (HDFs) and adipose-derived stem cells (ADSCs) from patients and generated an in vitro radiation-induced skin injury model with HDFs to verify the effect of conditioned medium derived from adipose-derived stem cells (ADSC-CM) and extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) on the healing of radiation-induced skin injury. The results showed that collagen synthesis was significantly increased in wounds treated with ADSC-CM or ADSC-EVs compared with the control group, which promoted the expression of collagen-related genes and suppressed the expression of inflammation-related genes. These findings indicated that treatment with ADSC-CM or ADSC-EVs suppressed inflammation and promoted extracellular matrix deposition; treatment with ADSC-EVs also promoted fibroblast proliferation. In conclusion, these results demonstrate the effectiveness of ADSC-CM and ADSC-EVs in the healing of radiation-induced skin injury.

Immunohistochemical and histochemical analysis of the rat skin after local electron irradiation

Background

Skin cancer is the most frequently diagnosed type of cancer among all malignant neoplasms. The decrease in mitotic activity and the death of intact keratinocytes arise due to the constantly renewing epithelium being highly sensitive to ionizing radiation.

Aim

The aim of the study is immunohistochemical evaluation of the proliferative-apoptotic balance of keratinocytes, the fibrous component of the skin, and the expression of pro-inflammatory and anti-inflammatory cytokines after single or fractional local electron irradiation.

Methods

Wistar rats (n = 80) were taken from the ITM&B Vivarium (Sechenov University) and divided into groups: I-control, which were injected with saline; and experimental groups, local electron irradiation at doses: II-8 Gy (single), III-40 Gy (single), IV-summary dose 78 Gy (fractional; 13 Gy per day for 6 days). We performed histological analysis, histochemical analysis using Masson, safranine, and picrosirius red staining, immunohistochemical (Ki-67, caspase-3, p53, types I and III collagens, IL-1, IL-6, IL-4, and IL-10) and morphometric analysis of skin fragments of the outer surface of the thigh, irradiated in accordance with the design of the experiment. The early and delayed effects of local electron irradiation at different doses were studied.

Results

After local electron irradiation, dose-dependent morphological changes in the skin of the experimental groups were observed: violation of the histoarchitectonics of the skin confirmed by morphological and morphometric analysis, the proliferation of connective tissue according to the results of histochemical and immunohistochemical studies with signs of the radiation-induced skin fibrosis development, an increase in the levels of pro- and anti-inflammatory cytokines. We observed the most pronounced signs of radiation-induced skin damage in the group of fractional irradiation after 3 months.

Conclusion

8 Gy and 40 Gy single local electron irradiation leads to a shift in the proliferative-apoptotic balance of keratinocytes toward their apoptosis, which activity is directly correlated with the dose of ionizing radiation, and 78 Gy in fractions leads to partial desquamation of the epithelium and inflammatory infiltration. In addition, after 3 months a significant increase in the expression of type I and III collagen fibers and the development of radiation-induced skin fibrosis takes place against the background of 78 Gy fractional local electron irradiation.

Effect of radiation therapy during surgery on postoperative wound complications after breast reconstruction in patients with breast cancer: A meta-analysis

Breast remodelling is a major therapeutic choice in radical mastectomy. Breast reconstruction is regarded as a promising option for the treatment of breast cancer. The purpose of this meta-analysis was to investigate the effect of Post mastectomy radiotherapy (PMRT) on postoperative wound complications in breast carcinoma. A comprehensive review of documents was conducted between the date of establishment and the 28th of August 2023. In all of the trials, patients were treated with breast cancer. The researchers chose 11 publications out of 8068 related studies. Two researchers examined these publications to satisfy the inclusion criteria. Among the 516 patients who had received radiation therapy in the course of the operation, 1772 had not received radiation therapy. The impact of radiation therapy and non-radiation therapy in breast cancer patients after breast reconstruction was reported in 8 studies, and the incidence of postoperative wound infection in non-radiation group was significantly lower (OR, 1.95; 95% CI, 1.26-3.02 p = 0.003). In nine studies, There is not considered to have achieved statistical significance between radiation therapy and non-radiation treatment for post-operation wound dehiscence in breast cancer patients who had received chemotherapy (OR, 1.61; 95% CI, 0.70-3.72 p = 0.27). The results of six trials demonstrated that radiation therapy and non-radiation therapy had no statistical significance on post-operation haemorrhage in breast cancer patients (OR, 1.02; 95% CI, 0.42-2.47 p = 0.96). The results of 7 trials demonstrated that radiation therapy and non-radiation therapy had no significant impact on the post-operation of skin necrosis (OR, 1.22; 95% CI, 0.66-2.28 p = 0.53). Two trials demonstrated that those without radiation therapy were less likely than those who received radiation therapy in skin contracture in patients (OR, 7.24; 95% CI, 1.80-29.10 p = 0.005). Regarding the incidence of wound infection and cutaneous contraction was higher in the radiation group.

Topical Iron Chelator Therapy: Current Status and Future Prospects

Systemic iron chelation therapy has long been used for iron overload, providing a role in returning iron levels to proper homeostatic concentrations. Recently, topical iron chelation therapy has emerged as a potential strategy for treating skin damage. This narrative review explores the current status and future prospects of topical iron chelation therapy for treating ultraviolet (UV) and non-UV skin damage, as well as its potential application in wound healing. The review was conducted through a literature search across PubMed, Web of Science, and EMBASE databases, spanning publications from 1990 to 2023. The selection of articles was focused on primary research studies, either experimental or clinical, that explored the implications and formulations of topical iron chelators used alone or in conjunction with another therapeutic agent. The search strategy employed a combination of terms, including "topical iron chelation", "topical deferoxamine", "UV", "wound healing", "skin inflammation", "radiation-induced fibrosis", and "skin cancer". Relevant studies, including methods, intervention strategies, measured outcomes, and findings, are summarized. The review also considered the potential challenges in translating research findings into clinical practice. Results indicate that topical iron chelators, such as deferoxamine, are effective in mitigating UV-induced skin damage, reducing tumorigenesis, and decreasing oxidative damage. In addition, the use of these agents in radiation-induced fibrosis has been shown to significantly increase skin elasticity and reduce dermal fibrosis. Several studies also highlight the use of topical iron chelators in difficult-to-treat chronic wounds, such as diabetic neuropathic ulcers and sickle cell ulcers. In conclusion, topical iron chelation therapy represents a novel and promising approach for skin protection and wound healing. Its potential makes it a promising area of future research.

Risk assessment, surveillance, and nonpharmaceutical prevention of acute radiation dermatitis: results of a multicentric survey among the German-speaking radiation oncology community

PURPOSE

Radiation dermatitis (RD) represents one of the most frequent side effects in radiotherapy (RT). Despite technical progress, mild and moderate RD still affects major subsets of patients and identification and management of patients with a high risk of severe RD is essential. We sought to characterize surveillance and nonpharmaceutical preventive management of RD in German-speaking hospitals and private centers.

METHODS

We conducted a survey on RD among German-speaking radiation oncologists inquiring for their evaluation of risk factors, assessment methods, and nonpharmaceutical preventive management of RD.

RESULTS

A total of 244 health professionals from public and private institutions in Germany, Austria, and Switzerland participated in the survey. RT-dependent factors were deemed most relevant for RD onset followed by lifestyle factors, emphasizing the impact of treatment conceptualization and patient education. While a broad majority of 92.8% assess RD at least once during RT, 59.0% of participants report RD at least partially arbitrarily and 17.4% stated to classify RD severity solely arbitrarily. 83.7% of all participants were unaware of patient-reported outcomes (PROs). Consensus exists on some lifestyle recommendations like avoidance of sun exposure (98.7%), hot baths (95.1%), and mechanical irritation (91.8%) under RT, while deodorant use (63.4% not at all, 22.1% with restrictions) or application of skin lotion (15.1% disapproval) remain controversial and are not recommended by guidelines or evidence-based practices.

CONCLUSION

Identification of patients at an increased risk of RD and subsequent implementation of adequate preventive measures remain relevant and challenging aspects of clinical routines. Consensus exists on several risk factors and nonpharmaceutical prevention recommendations, while RT-dependent risk factors, e.g., the fractionation scheme, or hygienic measures like deodorant use remain controversial. Surveillance is widely lacking methodology and objectivity. Intensifying outreach in the radiation oncology community is needed to improve practice patterns.

ADM-Assisted Direct-to-Implant Prepectoral Breast Reconstruction in Postmastectomy Radiation Therapy Setting: Long-Term Results

BACKGROUND

Postmastectomy radiotherapy (PMRT) on immediate breast reconstruction historically involved a marked increase in complication rate (up to 50%). Prepectoral breast reconstruction (PPBR) has shown promising early postoperative results. This study aims to evaluate PPBR long-term results in PMRT setting.

MATERIALS AND METHODS

This is a retrospective monocentric analysis of 485 PPBR (439 patients) undergoing Acellular-Dermal-Matrix assisted direct-to-implant reconstruction (46 bilateral procedures) between January 2015 and December 2020 (mean FU:35.6 months). Group 1 comprised 401 PPBR not submitted to PMRT, and 84 reconstructions receiving PMRT in Group 2. Patients' characteristics, postoperative complication and revisional surgery rate were examined. PMRT characteristics and subcutaneous tissue thickness, measured in Group 2 by CT scan, were also evaluated.

RESULTS

Long-term complication rate was 11.2% in Group 1 vs. 21.4% in Group 2 (P-value = .019). Capsular contracture represented the only complication associated to a statistically significant difference between the 2 groups (P-value < .001). In Group 2, only 4.8% implant loss and 8.3% severe capsular contracture rate was found. In patients who underwent PMRT, 38.9% of complications settled with no consequences, and only 4.8% of patients needed revisional surgery in the long-term FU. According to multivariate analysis, drug intake and PMRT were significantly associated with postoperative complications. In Group 2, a thinner subcutaneous tissue was linked to a higher complication risk.

CONCLUSION

In our series, patients treated with PPBR who underwent PMRT, presented a low complication rate and minimal need for revisional surgery in the long-term follow-up, suggesting that this technique is feasible and safe also in PMRT context.

Radiotherapy-induced Pathology of the Ear

Acute radiotherapy (RT)-induced external ear soft tissue changes start with erythema and dry desquamation and may progress to moist desquamation and epidermal ulceration. Chronic RT-induced changes include epithelial atrophy and subcutaneous fibrosis. Although RT-induced radiation dermatitis has been well studied, interventions for soft tissue disease involving the external auditory canal (EAC) warrant investigation. Medical management includes topical steroid treatment for EAC radiation dermatitis and topical antibiotic therapy for suppurative otitis externa. Hyperbaric oxygen and pentoxifylline-vitamin E therapy have shown promise for other applications, but their clinical effect on soft tissue EAC disease is currently undefined.

Microwave-induced thermoacoustic microscopy based on short-pulse microwave and high-frequency point-focused ultrasonic transducer

BACKGROUND

As an emerging hybrid imaging modality, microwave-induced thermoacoustic imaging (MITAI) provides high contrast and deep tissue penetration, and has been extensively applied in cancer diagnosis, arthritis detection, and brain research. However, the previous studies had a limited spatial resolution of about 0.45-1.5 mm.

PURPOSE

Here, we describe a microwave-induced thermoacoustic microscopy (MITAM) system to help overcome the resolution limitation of current MITAI to image more subtle tissue features. On this basis, this paper applies MITAM to the thin skin and to demonstrate the potential of MITAM in detecting scleroderma.

METHODS

To achieve high resolution, short pulse width microwave (pulse width: 70 ns) and high-frequency ultrasonic point-focused transducer (center frequency: 25 MHz) were used to build the MITAM system. Two parallel copper wires with a diameter of 90 μm in the X/Y plane and Y/Z plane were imaged to estimate X/Y/Z resolution. Nine Balb/c mice were randomly divided into three groups and injected with different concentrations of bleomycin to induce scleroderma models. Their ex vivo skins were then imaged by our MITAM system. Visual observations were performed on the 3-dimensional skins MITAM images. And the mean value, Standard deviation, quartile distance, and signal-to-noise ratio were calculated to verify the results of the qualitative observations. Hematoxylin-Eosin (HE) and Masson staining were used to validate the findings of the MITAM.

RESULTS

The thickness of each imaged skin was measured to be about 450 μm. As an organ composed of multiple layers of tissues, the skin needs to be imaged at high resolution for the detection of related diseases. The results obtained showed that the improved resolution (68 μm in the Z-axis and 135 μm in the X-axis/Y-axis) of MITAM over conventional MITAI allowed us to differentiate scleroderma skins from normal skins and to identify the severity of scleroderma skins, consistent with the pathological findings of these skins.

CONCLUSIONS

The preliminary results obtained indicate that the MITAM can relieve the resolution limitation of traditional MITAI and has the potential to detection scleroderma. However, the transmission-type MITAM mentioned in this paper is difficult to image in vivo due to the narrow area between the antenna and the transducer. In the future, a reflective scanning MITAM will be constructed to detect scleroderma in vivo.

RISREAC Study: Assessment of Cutaneous Radiation Injury Through Clinical Documentation

OBJECTIVE

Radiation dermatitis (RD) occurs in 95% of patients receiving radiation therapy (RT) for cancer treatment, affecting 800 million patients annually. We aimed to demonstrate the feasibility of developing a historical RD cohort, Radiation Induced Skin Reactions (RISREAC) cohort.

METHODS

This retrospective study evaluated RD-related clinical documentation for 245 breast cancer patients who received RT at the University of Rochester Medical Center, to understand the RD progression, scoring, and management. All statistical analyses were performed at 0.05 level of significance.

RESULTS

Clinician-documented RD severity was observed for 169 (69%) patients with a mean severity of 1.57 [1.46, 1.68]. The mean descriptor-based severity score of 2.31 [2.18, 2.45] moderately correlated (r = 0.532, P < 0.0001) with documented RD grade. Most patients (91.8%) received skin care treatment during RT, with 66.7% receiving more than 2 modalities.

CONCLUSIONS

The RISREAC cohort is the first retrospective cohort established from clinical documentation of radiation-induced skin changes for the study of RD and cutaneous radiation injury (CRI). RD symptom descriptors were more reliably documented and suitable for all skin types compared to Radiation Therapy Oncology Group (RTOG) or Common Toxicity Criteria for Adverse Events (CTCAE) grades. A new descriptor-based scoring tool would be useful for RD and CRI.

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.

Unraveling White Adipose Tissue Heterogeneity and Obesity by Adipose Stem/Stromal Cell Biology and 3D Culture Models

The immune and endocrine dysfunctions of white adipose tissue are a hallmark of metabolic disorders such as obesity and type 2 diabetes. In humans, white adipose tissue comprises distinct depots broadly distributed under the skin (hypodermis) and as internal depots (visceral). Depot-specific ASCs could account for visceral and subcutaneous adipose tissue properties, by regulating adipogenesis and immunomodulation. More importantly, visceral and subcutaneous depots account for distinct contributions to obesity and its metabolic comorbidities. Recently, distinct ASCs subpopulations were also described in subcutaneous adipose tissue. Interestingly, the superficial layer closer to the dermis shows hyperplastic and angiogenic capacities, whereas the deep layer is considered as having inflammatory properties similar to visceral. The aim of this focus review is to bring the light of recent discoveries into white adipose tissue heterogeneity together with the biology of distinct ASCs subpopulations and to explore adipose tissue 3D models revealing their advantages, disadvantages, and contributions to elucidate the role of ASCs in obesity development. Recent advances in adipose tissue organoids opened an avenue of possibilities to recreate the main cellular and molecular events of obesity leading to a deep understanding of this inflammatory disease besides contributing to drug discovery. Furthermore, 3D organ-on-a-chip will add reproducibility to these adipose tissue models contributing to their translation to the pharmaceutical industry.

Management of Radiation-induced Tissue Injuries: A Review of Current Treatment Strategies

Although radiation therapy remains an integral component in cancer treatment, the sequela of tissue damage can result in long-term morbidity and mortality for patients. This article aimed to perform a comprehensive review of the current literature for both nonsurgical and surgical management strategies for radiation-induced injuries.

Methods

A literature search was performed on PubMed to review the current described management and treatment options for radiation-induced injuries. Patient demographics, medical diagnoses, complications, strategies of management care, and outcomes were reviewed.

Results

The most commonly described management options and reconstructive techniques of radiation wounds were analyzed and reported.

Conclusions

Consideration of current techniques and outcomes in the management of radiation-induced wounds demonstrates that impaired wound healing remains a major problem. This literature review provides a detailed overview of the most frequently used therapies with recommendations for surgeons.

Broken Dermal Filler Cannula in Post-Radiated Décolleté

We present a case of 72-year-old that arrived at our emergency department following breaking of a dermal cannula used to inject a poly-L-lactic acid (PLLA) to the décolleté by an aesthetic practitioner. She had a history of previous radiation to the breast after a lumpectomy. The cannula was removed using fluoroscopy guidance. This case emphasizes several key messages. First is the extreme caution needed when using a cannula to inject dermal fillers in a previously radiated area. Second, the importance of properly trained practitioners. Last, one should consider the use of bio-stimulants in a previously cancerous area. Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Yoav Yechezkel] Last name [Pikkel], Author 1 Given name: [Assaf Aviram] Last name [Zeltzer] Also, kindly confirm the details in the metadata are correct.confirmedPlease check and confirm the organization division and organization name is correctly identified for the affiliation 2.yesLevel of Evidence V 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 .

Current perspectives on cell-assisted lipotransfer for breast cancer patients after radiotherapy

BACKGROUND

Cell-assisted lipotransfer (CAL), a technique of autologous adipose transplantation enriched with adipose-derived stem cells (ADSCs), has the potential to improve cosmetic outcomes at irradiated sites. However, many concerns have been raised about the possibility of ADSCs increasing oncological risk in cancer patients. With the increasing demand for CAL reconstruction, there is an urgent need to determine whether CAL treatment could compromise oncological safety after radiotherapy, as well as to evaluate its efficacy in guiding clinical decisions.

METHODS

A PRISMA-compliant systematic review of the safety and efficacy of CAL in breast cancer patients after radiotherapy was conducted. The PubMed, Ovid, Cochrane Library, and ClinicalTrials.gov databases were comprehensively searched from inception to 31 December 2021.

RESULTS

The search initially yielded 1185 unique studies. Ultimately, seven studies were eligible. Based on the limited outcome evidence, CAL did not increase recurrence risk in breast cancer patients but presented aesthetic improvement and higher volumetric persistence in a long-term follow-up. Although breast reconstruction with CAL also had oncological safety after radiotherapy, these patients needed more adipose tissue and had relatively lower fat graft retention than the non-irradiated patients (P < 0.05).

CONCLUSIONS

CAL has oncological safety and does not increase recurrence risk in irradiated patients. Since CAL doubles the amount of adipose required without significantly improving volumetric persistence, clinical decisions for irradiated patients should be made more cautiously to account for the potential costs and aesthetic outcomes. There is limited evidence at present; thus, higher-quality, evidence-based studies are required to establish a consensus on breast reconstruction with CAL after radiotherapy.

Breast Reconstruction Trends in the Setting of Postmastectomy Radiation Therapy: Analysis of Practices among Plastic Surgeons in the United States

Radiation is an integral part of breast cancer therapy. The ideal type and timing of breast reconstruction with relation to radiation delivery are not well established. The study aimed to identify reconstructive practices among American plastic surgeons in the setting of pre- and postmastectomy radiation.

Methods

A cross-sectional survey of members of the American Society of Plastic Surgery was performed. Practice/demographic information and breast reconstruction protocols were queried. Univariate descriptive statistics were calculated, and outcomes were compared across cohorts with χ² and Fischer exact tests.

Results

Overall, 477 plastic surgeons averaging 16.3 years in practice were surveyed. With respect to types of reconstruction, all options were well represented, although nearly 60% preferred autologous reconstruction with prior radiation and 55% preferred tissue expansion followed by implant/autologous reconstruction in the setting of unknown postoperative radiation. There was little consensus on the optimal timing of reconstruction in the setting of possible postoperative radiation. Most respondents wait 4-6 or 7-12 months between the end of radiation and stage 2 implant-based or autologous reconstruction. Common concerns regarding the effect of radiation on reconstructive outcomes included mastectomy flap necrosis, wound dehiscence, capsular contracture, tissue fibrosis, and donor vessel complications.

Conclusions

Despite considerable research, there is little consensus on the ideal type and timing of reconstruction in the setting of pre- and postoperative radiation. Understanding how the current body of knowledge is translated into clinical practice by different populations of surgeons allows us to forge a path forward toward more robust, evidence-based guidelines for patient care.

An updated narrative review on the management of the most common oncological and hematological emergencies

Oncological emergencies are defined as an acute life-threatening event in a patient with a tumor occurring as part of their complex treatment regimen or secondarily to their underlying malignancy. These events can occur at any time from the initial diagnosis of their cancer to end-stage disease. These oncological emergencies are broadly classified into four major categories; metabolic, structural, hematological and treatment-related causes; and can be encountered in any clinical setting, ranging from primary care physician and emergency department visits to a variety of subspecialty environments. This study aims to cover an in-depth review of the underlying pathogenesis, clinical presentation, and updated management protocol of most common emergencies belonging to the above-mentioned categories. An all-language literature search was conducted on 15th October 2021 and 10th March 2022, limited to 5 years on PubMed database using the following search strings: oncological emergencies, malignant spinal cord compression, febrile neutropenia, hyperviscosity syndrome, superior vena cava syndrome, immune related adverse events, tumor lysis syndrome, hypercalcemia of malignancy, corrected calcium, malignant pericardial effusion and chemotherapy extravasation.

The Therapeutic Application of Stem Cells and Their Derived Exosomes in the Treatment of Radiation-Induced Skin Injury

Radiation-induced skin injury (RISI) is a serious concern for nuclear accidents and cancer radiotherapy, which seriously affects the quality of life of patients. This injury differs from traditional wounds due to impaired healing and the propensity to recurrence and is divided into acute and chronic phases on the basis of the injury time. Unfortunately, there are few effective therapies for preventing or mitigating this injury. Over the last few decades, various studies have focused on the effects of stem cell-based therapies to address the tissue repair and regeneration of irradiated skin. These stem cells modulate inflammation and instigate tissue repair by differentiating into specific kinds of cells or releasing paracrine factors. Stem cell-based therapies, including bone marrow-derived stem cells (BMSCs), adipose-derived stem cells (ADSCs) and stromal vascular fraction (SVF), have been reported to facilitate wound healing after radiation exposure. Moreover, stem cell-derived exosomes have recently been suggested as an effective and cell-free approach to support skin regeneration, circumventing the concerns respecting direct application of stem cells. Based on the literature on stem cell-based therapies for radiation-induced skin injury, we summarize the characteristics of different stem cells and describe their latest animal and clinical applications, as well as potential mechanisms. The promise of stem-cell based therapies against radiation-induced skin injury contribute to our response to nuclear events and smooth progress of cancer radiotherapy.

Chelating the valley of death: Deferoxamine's path from bench to wound clinic

There is undisputable benefit in translating basic science research concretely into clinical practice, and yet, the vast majority of therapies and treatments fail to achieve approval. The rift between basic research and approved treatment continues to grow, and in cases where a drug is granted approval, the average time from initiation of human trials to regulatory marketing authorization spans almost a decade. Albeit with these hurdles, recent research with deferoxamine (DFO) bodes significant promise as a potential treatment for chronic, radiation-induced soft tissue injury. DFO was originally approved by the Food and Drug Administration (FDA) in 1968 for the treatment of iron overload. However, investigators more recently have posited that its angiogenic and antioxidant properties could be beneficial in treating the hypovascular and reactive-oxygen species-rich tissues seen in chronic wounds and radiation-induced fibrosis (RIF). Small animal experiments of various chronic wound and RIF models confirmed that treatment with DFO improved blood flow and collagen ultrastructure. With a well-established safety profile, and now a strong foundation of basic scientific research that supports its potential use in chronic wounds and RIF, we believe that the next steps required for DFO to achieve FDA marketing approval will include large animal studies and, if those prove successful, human clinical trials. Though these milestones remain, the extensive research thus far leaves hope for DFO to bridge the gap between bench and wound clinic in the near future.

The Impact of Postmastectomy Radiation Therapy on the Outcomes of Prepectoral Implant-Based Breast Reconstruction: A Systematic Review and Meta-Analysis

BACKGROUND

Breast reconstruction is the mainstay treatment choice for patients subjected to a mastectomy. Prepectoral implant-based breast reconstruction (IBBR) is deemed to be a promising alternative to subpectoral reconstruction. Postmastectomy radiation therapy (PMRT) is necessary for locoregional recurrence control and to improve the disease-free survival rate in locally advanced breast cancer. This systematic review and meta-analysis study was designed to reveal the surgical, aesthetic, and oncological outcomes of prepectoral IBBR after PMRT.

METHODS

An extensive literature search was performed from inception to March 28, 2022. All clinical studies that included patients who were subjected to prepectoral IBBR and PMRT were included. Studies that included patients who received radiation therapy before prepectoral IBBR were excluded.

RESULTS

This systematic review included six articles encompassing 1234 reconstructed breasts. Of them, 391 breasts were subjected to PMRT, while 843 breasts were not subjected. Irradiated breasts were more susceptible to develop wound infection (RR 2.49; 95% 1.43, 4.35; P = 0.001) and capsular contracture (RR 5.17; 95% 1.93, 13.80; P = 0.001) than the non-irradiated breasts. Furthermore, irradiated breasts were more vulnerable to losing implants (RR 2.89; 95% 1.30, 6.39; P = 0.009) than the non-irradiated breast. There was no significant difference between both groups regarding the risk of implant extrusion (RR 1.88; 95% 0.20, 17.63; P = 0.58).

CONCLUSIONS

Patients with prepectorally IBBR and PMRT were more vulnerable to developing poor outcomes. This included a higher risk of breast-related and implant-related adverse events.

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 effects of mechanical force on fibroblast behavior in cutaneous injury

Wound healing results in the formation of scar tissue which can be associated with functional impairment, psychological stress, and significant socioeconomic cost which exceeds 20 billion dollars annually in the United States alone. Pathologic scarring is often associated with exaggerated action of fibroblasts and subsequent excessive accumulation of extracellular matrix proteins which results in fibrotic thickening of the dermis. In skin wounds, fibroblasts transition to myofibroblasts which contract the wound and contribute to remodeling of the extracellular matrix. Mechanical stress on wounds has long been clinically observed to result in increased pathologic scar formation, and studies over the past decade have begun to uncover the cellular mechanisms that underly this phenomenon. In this article, we will review the investigations which have identified proteins involved in mechano-sensing, such as focal adhesion kinase, as well as other important pathway components that relay the transcriptional effects of mechanical forces, such as RhoA/ROCK, the hippo pathway, YAP/TAZ, and Piezo1. Additionally, we will discuss findings in animal models which show the inhibition of these pathways to promote wound healing, reduce contracture, mitigate scar formation, and restore normal extracellular matrix architecture. Recent advances in single cell RNA sequencing and spatial transcriptomics and the resulting ability to further characterize mechanoresponsive fibroblast subpopulations and the genes that define them will be summarized. Given the importance of mechanical signaling in scar formation, several clinical treatments focused on reducing tension on the wound have been developed and are described here. Finally, we will look toward future research which may reveal novel cellular pathways and deepen our understanding of the pathogenesis of pathologic scarring. The past decade of scientific inquiry has drawn many lines connecting these cellular mechanisms that may lead to a map for the development of transitional treatments for patients on the path to scarless healing.

The Normal, the Radiosensitive, and the Ataxic in the Era of Precision Radiotherapy: A Narrative Review

(1) Background: radiotherapy is a cornerstone of cancer treatment. When delivering a tumoricidal dose, the risk of severe late toxicities is usually kept below 5% using dose-volume constraints. However, individual radiation sensitivity (iRS) is responsible (with other technical factors) for unexpected toxicities after exposure to a dose that induces no toxicity in the general population. Diagnosing iRS before radiotherapy could avoid unnecessary toxicities in patients with a grossly normal phenotype. Thus, we reviewed iRS diagnostic data and their impact on decision-making processes and the RT workflow; (2) Methods: following a description of radiation toxicities, we conducted a critical review of the current state of the knowledge on individual determinants of cellular/tissue radiation; (3) Results: tremendous advances in technology now allow minimally-invasive genomic, epigenetic and functional testing and a better understanding of iRS. Ongoing large translational studies implement various tests and enriched NTCP models designed to improve the prediction of toxicities. iRS testing could better support informed radiotherapy decisions for individuals with a normal phenotype who experience unusual toxicities. Ethics of medical decisions with an accurate prediction of personalized radiotherapy's risk/benefits and its health economics impact are at stake; (4) Conclusions: iRS testing represents a critical unmet need to design personalized radiotherapy protocols relying on extended NTCP models integrating iRS.

Topical natural-origin polynucleotides in radiation-induced skin and mucosal toxicity

Seventy to 90 percent of patients who have received radiation treatment struggle with radiation skin and mucosal toxicity. The inflicted damage to progenitor cells and local microcirculation makes it more likely that wounds, infections, and fibrosis may occur; lesions of variable severity often co-exist. Acute erythema, hyperpigmentation, and mild desquamation usually wane in weeks and require only minor treatment. Conversely, the management of persistent radiation dermatitis and telangiectasia remains unsatisfactory; chronic lesions may progress to tissue atrophy and disfiguring fibrosis.

The therapeutic effect of adipose-derived stem cells on soft tissue injury after radiotherapy and their value for breast reconstruction

Background

Postmastectomy radiotherapy is considered to be a necessary treatment in the therapy of breast cancer, while it will cause soft tissue damage and complications, which are closely related to the success rate and effectiveness of breast reconstruction. After radiotherapy, cutaneous tissue becomes thin and brittle, and its compliance decreases. Component fat grafting and adipose-derived stem cell therapy are considered to have great potential in treating radiation damage and improving skin compliance after radiotherapy.

Main body

In this paper, the basic types and pathological mechanisms of skin and soft tissue damage to breast skin caused by radiation therapy are described. The 2015–2021 studies related to stem cell therapy in PubMed were also reviewed. Studies suggest that adipose-derived stem cells exert their biological effects mainly through cargoes carried in extracellular vesicles and soluble secreted factors. Compared to traditional fat graft breast reconstruction, ADSC therapy amplifies the effects of stem cells in it. In order to obtain a more purposeful therapeutic effect, proper stem cell pretreatment may achieve more ideal and safe results.

Conclusion

Recent research works about ADSCs and other MSCs mainly focus on curative effects in the acute phase of radiation injury, and there is little research about treatment of chronic phase complications. The efficacy of stem cell therapy on alleviating skin fibrosis and its underlying mechanism require further research.

Deferoxamine to Minimize Fibrosis During Radiation Therapy

Significance: By 2030, there will be >4 million radiation-treated cancer survivors living in the United States. Irradiation triggers inflammation, fibroblast activation, and extracellular matrix deposition in addition to reactive oxygen species generation, leading to a chronic inflammatory response. Radiation-induced fibrosis (RIF) is a progressive pathology resulting in skin pigmentation, reduced elasticity, ulceration and dermal thickening, cosmetic deformity, pain, and the need for reconstructive surgery. Recent Advances: Deferoxamine (DFO) is a U.S. Food and Drug Administration (FDA)-approved iron chelator for blood dyscrasia management, which has been found to be proangiogenic, to decrease free radical formation, and reduce cell death. DFO has shown great promise in the treatment and prophylaxis of RIF in preclinical studies. Critical Issues: Systemic DFO has a short half-life and is cumbersome to deliver to patients intravenously. Transdermal DFO delivery is complicated by its high atomic mass and hydrophilicity, preventing stratum corneum penetration. A transdermal drug delivery system was developed to address these challenges, in addition to a strategy for topical administration. Future Directions: DFO has great potential to translate from bench to bedside. An important step in translation of DFO for RIF prophylaxis is to ensure that DFO treatment does not affect the efficacy of radiation therapy. Furthermore, after an initial plethora of studies reporting DFO treatment by intravenous and subcutaneous routes, a significant advantage of recent studies is the success of transdermal and topical delivery. Given the strong foundation of basic scientific research supporting the use of DFO treatment on RIF, clinicians will be closely following the results of the ongoing human studies.

Promoting repair of highly purified stromal vascular fraction gel combined with advanced platelet-rich fibrin extract for irradiated skin and soft tissue injury

Background

To evaluate the effect of highly purified stromal vascular fraction gel (SVFG) combined with advanced platelet-rich fibrin extract (APRFE) in treatment of irradiated skin and soft tissue injury.

Methods

The subcutaneous fat and whole blood of 4 rabbits were collected to isolate the SVFG and APRFE, respectively. Forty-eight rabbits were divided into 4 groups to prepare irradiated skin injury models with 25 Gy for 24 hours; corresponding dose were performed subcutaneously injected into wounds. In group A, the rabbits were treated with 0.3 mL APRFE combined with 1 mL SVFG. In group B, the rabbits were treated with 1 mL SVFG. In group C, the rabbits were treated with 0.3 mL APRFE, and group D was treated with 1 mL normal saline. The wound healing was detected on the 2, 5, 9 and 14 d after intervention. The wounds tissue was cut for hematoxylin and eosin (HE) staining to observe the structure and Masson staining to observe the collagen content. The expression of CD31 in each group was detected by immunohistochemistry (IHC), the protein and mRNA levels of K19, hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), interleukin 8 (IL-8) and interleukin 10 (IL-10) were detected respectively by Western blot (WB) and reverse transcription-polymerase chain reaction (RT-PCR) on 7, 14 and 28 d after intervention.

Results

It is revealed that wound healing rates from 5 to 14 d in group A was significantly higher than that of control. The wounds healing rates in group B and C were significantly higher than that of control after 12 d. Masson staining results showed that the collagen content in group A was significantly higher than that of the other 3 groups on the 7, 14 and 28 d. The results of IHC showed that the expression of CD31 in group A was significantly higher than that of the other 3 groups on 7, 14 and 28 d. WB and RT-PCR results showed that relative expression levels of K19, HIF-1α, VEGF, IL-10 in group A were significantly higher than that of the other 3 groups on 7, 14 and 28 d. However, the relative expression levels of IL-8 in group A was significantly lower than that of the other 3 groups on 7, 14 and 28 d.

Conclusions

SVFG combined with APRFE can promote the repair of irradiated skin and soft tissue injury by accelerating angiogenesis, promoting collagen synthesis and reducing inflammation.