Radiation Fibrosis Syndrome: the Evergreen Menace of Radiation Therapy

Health Effects of Ionizing Radiation on the Human Body

Radioactivity is a process in which the nuclei of unstable atoms spontaneously decay, producing other nuclei and releasing energy in the form of ionizing radiation in the form of alpha (α) and beta (β) particles as well as the emission of gamma (γ) electromagnetic waves. People may be exposed to radiation in various forms, as casualties of nuclear accidents, workers in power plants, or while working and using different radiation sources in medicine and health care. Acute radiation syndrome (ARS) occurs in subjects exposed to a very high dose of radiation in a very short period of time. Each form of radiation has a unique pathophysiological effect. Unfortunately, higher organisms-human beings-in the course of evolution have not acquired receptors for the direct "capture" of radiation energy, which is transferred at the level of DNA, cells, tissues, and organs. Radiation in biological systems depends on the amount of absorbed energy and its spatial distribution, particularly depending on the linear energy transfer (LET). Photon radiation with low LET leads to homogeneous energy deposition in the entire tissue volume. On the other hand, radiation with a high LET produces a fast Bragg peak, which generates a low input dose, whereby the penetration depth into the tissue increases with the radiation energy. The consequences are mutations, apoptosis, the development of cancer, and cell death. The most sensitive cells are those that divide intensively-bone marrow cells, digestive tract cells, reproductive cells, and skin cells. The health care system and the public should raise awareness of the consequences of ionizing radiation. Therefore, our aim is to identify the consequences of ARS taking into account radiation damage to the respiratory system, nervous system, hematopoietic system, gastrointestinal tract, and skin.

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.

Challenges in Managing Post-Radiation TMJ Pseudoankylosis

This study demonstrates the outcomes of post-radiation temporomandibular joint (TMJ) pseudoankylosis management and its challenges. A rare maxillary squamous cell carcinoma was treated with subtotal maxillary resection. Subsequent radiation therapy, failure of free flap reconstruction, and 1 year of jaw hypomobility instigated TMJ pseudoankylosis with a maximal mouth opening (MMO) of less than 5 mm. Bilateral coronoidectomy was done simultaneously with maxillary reconstruction, followed up with buccal fibrosis release and extensive jaw exercises. At 16 months of follow-up, the patient's MMO was 20 mm. Although bilateral coronoidectomy released the attachment of the atrophic temporalis muscle, it did not correct the other causes of trismus, specifically the progressive fibrosis of masticatory muscles, loss of elasticity of the TMJ ligaments, and other soft tissue abnormalities. Radiotherapy-induced-trismus refractory to physical exercise may require further management to achieve satisfactory MMO.

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.

Overview of radiotherapy-induced chronic pain in childhood cancer survivors: A narrative review

Radiotherapy is an important aspect of oncological treatment in several childhood cancers. However, radiotherapy is known to have numerous side effects, including detrimental effects on growth, neurocognitive impairment, and the development of secondary malignancies. One less studied long-term side effect of pediatric radiotherapy treatment is chronic pain. While the short-term toxicities of radiotherapy resolve over a few weeks to months, the chronic pain caused by radiotherapy-induced tissue damage can significantly affect children's quality of life. As long-term childhood cancer survivors age into adulthood, they are typically followed up by a wide variety of doctors, not all of whom may be familiar with radiotherapy-induced chronic pain and its management. The aim of this review is to discuss the various common manifestations of radiotherapy-related pain in children, as well as ways to identify and manage these. Common radiotherapy-related side effects leading to chronic pain symptoms include radiation fibrosis, enteritis, dermatitis, lymphedema, neuropathic pain, and effects on bone development. The pathophysiology, evaluation and management of these are briefly summarized in this review. This is followed by an overview of radiotherapy techniques that allow greater sparing of normal tissue, minimizing future painful side effects. Finally, the assessment of pain in children is described, as well as strategies for management, and red flag symptoms that should prompt urgent specialist referral. In conclusion, a good understanding of the long-term side effects of radiotherapy treatment in children is essential for the various medical professionals that follow-up the child in the years after treatment. For young children, the evaluation of pain is in itself a challenge, and effects on growth, development, and learning are crucial. For older children, social and psychological factors become increasingly important. As radiation therapy techniques continue to advance, the spectrum and incidence of chronic pain syndromes may change over time.

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.

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.

Radiation Fibrosis After Stereotactic Body Radiation Therapy for Osseous Metastases: A Case Report

Radiation-induced fibrosis is a potentially severe late complication after high-dose radiotherapy. Over the last decade, there has been increasing use of stereotactic body radiation therapy (SBRT) to treat both primary and metastatic malignancies. While there has been evolving evidence of appropriate dose constraints for certain organs receiving hypofractionated radiotherapy, the risk, and appropriate dose constraints to limit the risk of radiation-induced muscle fibrosis are poorly defined. In this report, two patients are presented who underwent SBRT for osseous oligometastatic renal cell carcinoma. While the treatment was well-tolerated with no acute toxicities and complete local control of the metastasis, both patients experienced late toxicity of radiation-induced fibrosis in the adjacent musculature. In both cases, toxicity was nonresponsive to medical interventions and was severe enough to require surgical resection of the affected tissue. Following surgery, both patients reported improved pain relief and mobility. Further studies are needed to explore the dose constraints that may reduce the risk of radiation-induced muscle fibrosis in five-fraction treatment.

Swallowing and communication outcomes following primary transoral robotic surgery for advanced or recurrent oropharyngeal cancer: Case series

Purpose: Transoral robotic surgery (TORS) is most commonly undertaken as a minimally invasive approach for early staged oropharyngeal cancers (OPC), with good expectations for a functional recovery. A small number of patients, however, require TORS for recurrent or advanced OPC tumours. Their prospects for longer term recovery of communication and swallowing are both unreported and hypothesised to be poorer than the majority of TORS cases. This case-series describes the recovery of swallowing and communication function post-TORS for this unique group of patients.Method: Consecutive recruitment was carried out prospectively at a quaternity oncology referral centre. Participants were aged 18 years and older, with reconstruction involving a free-flap and tracheostomy. Patients were assessed using Fibreoptic Endoscopic Evaluation of Swallowing, and clinician and patient-reported outcomes 12-months post-TORS. Their pre-operative baseline and three-month post-TORS FOIS scores were collated retrospectively.Result: Six participants were recruited over an 18-month period of which three patients underwent TORS for recurrent, and three for advanced OPC. Those with recurrent-OPC did not return to their baseline diet and demonstrated post-swallow silent aspiration of pharyngeal residue. Three of the six were rehabilitated back to their baseline intelligibility (100%).Conclusion: TORS in the recurrent OPC setting appears congruent with high rates of silent aspiration and prolonged reliance on a feeding tube due to oropharyngeal dysphagia, as well as compromised intelligibility. This is the first study that evaluates this instrumentally and provides clinically relevant evidence to inform practice.

Effects of Ultrafine Single-Nanometer Oxygen Bubbles on Radiation Sensitivity in a Tumor-Bearing Mouse Model

Radiation therapy against cancer cells often causes radiation resistance via accumulation of hypoxia-inducible factor 1 subunit alpha (HIF-1α) under hypoxic conditions and severe side effects. Radiation sensitizers without side effects are required to overcome hypoxia-induced radiation resistance and decrease radiation-related side effects in patients with refractory cancer. We previously developed oxygen nanobubble water (NBO₂ water) and demonstrated that it suppresses hypoxia-induced radiation resistance in cancer cell lines within the single-nanometer range. This study aimed to elucidate whether NBO₂ water could act as a radiosensitizer via regulation of HIF-1α in a tumor-bearing mouse model. Six-week-old female BALB/c mice subcutaneously injected with tumor cells received control water or NBO₂ water for 28 days, after which biochemical examinations and radiation treatment were performed. Hypoxic tumor regions were detected immunohistochemically. We found that NBO₂ water sensitized radiation reactivity in the xenografted tumors. Notably, NBO₂ water administration downregulated the accumulation of HIF-1α in xenografted tumors and did not affect the vital organs of healthy mice. The combination of radiation and single-nanometer NBO₂ water without severe side effects may be a promising therapeutic option to improve radiation sensitivity in cancer patients without tolerance to invasive treatments.

Spontaneous Tissue Expander Migration in an Irradiated Field: A Case Report

A 59-year-old woman with a history of bilateral breast cancer, bilateral mastectomy, and bilateral latissimus dorsi flap reconstruction with tissue expanders, before expansion, developed spontaneous unilateral tissue expander migration on the side that had been irradiated. During the operation to return the migrated tissue expander to the chest, the expander was found at the back with a seroma. The chest pocket had collapsed, and a subcutaneous tunnel inferior to the flap inset was encountered, indicating the path of migration. To our knowledge, this is the first case reported of spontaneous tissue expander dislodgement to the donor site. This case is unique in that the patient had bilateral procedures but developed tissue expander migration only on the irradiated side. This highlights the need during pocket creation to account for the fibrosis caused by radiation that can create a constricted pocket promoting migration.

Role of Manual Therapy for Neck Pain and Quality of Life in Head and Neck Cancer Survivors: A Systematic Review

Background:

Pain is the one the most dreadful side effects of head and neck cancers and cancer related treatments affecting patients during and after the treatment adding to the problems affecting their ability to speak, swallow, breath and feeding. Manual therapy is standard set of physiotherapy treatments used for alleviating neck pain. It has found to be effective in small subset of cancer patients for relieving pain.

Objectives:

To highlight the use of various manual therapy techniques focusing in decreasing neck pain and improving quality of life in Head and Neck Cancer survivors that may suggest its safe utilisation in oncology rehabilitation.

Materials and Methods:

Electronic search was conducted in PubMed, Google Scholar, CINAHL, Pedro, and COCHRANE databases. Reference lists of the included studies and relevant reviews were manually searched. Studies that met the inclusion criteria were evaluated using McMaster critical review form for quantitative studies. A descriptive synthesis was undertaken due to the heterogeneity of the included studies.

Results:

Seven studies were assessed for risk of bias that comprised of three clinical trials, one case series and three case reports that applied Maitland’s mobilisation, Myofascial release, Muscle Energy Techniques to head and neck cancer survivors in various clinical settings. The outcomes highlighted decrease in pain, improvement in cervical range of motion and quality of life.

Conclusion:

This review recommends application of manual therapy to head and neck cancer survivors. However, authors caution application of manual therapy in terms of choosing a particular technique. Further, well designed larger sample size with randomisation and double blinding would help to generate better evidence for head and neck cancer survivors.

The Effects of Ionising and Non-Ionising Electromagnetic Radiation on Extracellular Matrix Proteins

Exposure to sub-lethal doses of ionising and non-ionising electromagnetic radiation can impact human health and well-being as a consequence of, for example, the side effects of radiotherapy (therapeutic X-ray exposure) and accelerated skin ageing (chronic exposure to ultraviolet radiation: UVR). Whilst attention has focused primarily on the interaction of electromagnetic radiation with cells and cellular components, radiation-induced damage to long-lived extracellular matrix (ECM) proteins has the potential to profoundly affect tissue structure, composition and function. This review focuses on the current understanding of the biological effects of ionising and non-ionising radiation on the ECM of breast stroma and skin dermis, respectively. Although there is some experimental evidence for radiation-induced damage to ECM proteins, compared with the well-characterised impact of radiation exposure on cell biology, the structural, functional, and ultimately clinical consequences of ECM irradiation remain poorly defined.

The Impact of Smoking, Alcohol Use, Recurrent Disease, and Age on the Development of Neck Fibrosis in Head and Neck Cancer Patients Following Radiation Therapy

There is a paucity of information regarding the demographic factors associated with the development of neck fibrosis in head and neck cancer (HNC) patients following radiotherapy. A retrospective review of all patients being treated for HNC at a tertiary care center between 2013 and 2017 was performed. Chi-squared and Mann-Whitney U tests were used to identify differences in incidence and grade of fibrosis, respectively, between populations. A total of 90 patients aged 19 to 99 years were included. Factors associated with an increased incidence of fibrosis included smoking during radiotherapy (p < 0.001), alcohol use (p = 0.026), recurrent disease (p = 0.042), and age less than 60 (p < 0.001) on univariate analysis. Factors associated with increased grade of fibrosis in HNC patients included recurrent HNC (p = 0.033), alcohol use (p = 0.013), patient age younger than 60 years (p = 0.018), smoking during radiotherapy (p < 0.001), and non-Caucasian race (p = 0.012). Identification and intervention directed at patients that possess risk factors associated with fibrosis prior to treatment has the potential to improve the long-term quality of life for HNC patients.

Transplantation of the Stromal Vascular Fraction (SVF) Mitigates Severe Radiation-Induced Skin Injury

Severe radiation-induced skin injury is a complication of tumor radiotherapy and nuclear accidents. Cell therapy is a potential treatment for radiation-induced skin injury. The stromal vascular fraction (SVF) is a newer material in stem cell therapy that is made up of stem cells harvested from adipose tissue, which has been shown to promote the healing of refractory wounds of different causes. In this study, SVF was isolated from patients with radiation-induced skin injury. Adipose-derived stem cells (ADSCs) accounted for approximately 10% of the SVF by flow cytometry. Compared with the control group of rats, administration with SVF attenuated the skin injury induced by electron beam radiation. The effect of SVF on the human skin fibroblast microenvironment was determined by proteomic profiling of secreted proteins in SVF-co-cultured human skin fibroblast WS1 cells. Results revealed 293 upregulated and 1,481 downregulated proteins in the supernatant of SVF-co-cultured WS1 cells. WS1 co-culture with SVF induced secretion of multiple proteins including collagen and MMP-1. In the clinic, five patients with radiation-induced skin injury were recruited to receive SVF transfer-based therapy, either alone or combined with flap transplantation. Autogenous SVF was isolated and introduced into a multi-needle precision electronic injection device, which automatically and aseptically distributed the SVF to the exact layer of the wound in an accurate amount. After SVF transfer, wound healing clearly improved and pain was significantly relieved. The patients' skin showed satisfactory texture and shape with no further wound recurrence. Our findings suggest that transplantation of SVF could be an effective countermeasure against severe radiation-induced skin injury.

Predictive Factors of Non-Response to Vismodegib in Locally Advanced Basal-Cell Carcinoma

BACKGROUND

Vismodegib has shown clinical efficacy in the management of locally advanced basal cell carcinomas (laBCC). However, non-response to vismodegib is observed in 2-13.5% of patients in clinical studies. The purpose of this study was to identify factors associated with non-response to vismodegib in patients with laBCC.

METHODS

We carried out a retrospective multicenter study, including patients with laBCC treated with vismodegib, from July 2011 to May 2019. Response to treatment was assessed according to the RECIST 1.1 criteria. Patients were categorized as responders with a complete response or a partial response or non-responders with a stable disease or a progressive disease according to what has been observed during follow-up. Patient demographics, tumor profile, and treatment modalities were compared in responders and non-responders.

RESULTS

Eighty-three patients with laBCC were included in the study. Twenty-five (30.1%) were non-responders to vismodegib. History of treatment with radiotherapy, presence of muscle involvement and intermittent treatment with vismodegib were significantly associated with a non-response (p < 0.001, p = 0.025, p < 0.001). Bone involvement (p = 0.2) and morpheaform IaBCC subtype (p = 0.056) were more frequent in non-responders without reaching statistical significance.

CONCLUSION

In this study, non-response of laBCC to vismodegib therapy was associated with muscle involvement. Previous radiotherapy and intermittent use of vismodegib have been identified as causes favoring non-response to vismodegib. Due to the low numbers of patients included in the study, it is difficult to draw firm conclusions. Further studies are needed to confirm these data.

Sonographic Pearls for Imaging the Brachial Plexus and Its Pathologies

The brachial plexus (BP) is a complicated neural network, which may be affected by trauma, irradiation, neoplasm, infection, and autoimmune inflammatory diseases. Magnetic Resonance Imaging is the preferred diagnostic modality; however, it has the limitations of high cost and lack of portability. High-resolution ultrasound has recently emerged as an unparalleled diagnostic tool for diagnosing postganglionic lesions of the BP. Existing literature describes the technical skills needed for prompt ultrasound imaging and guided injections for the BP. However, it remains particularly challenging for beginners to navigate easily while scanning its different parts. To address this, we share several “clinical pearls” for the sonographic examination of the BP as well as its common pathologies.

Autotaxin and Breast Cancer: Towards Overcoming Treatment Barriers and Sequelae

After a decade of intense preclinical investigations, the first in-class autotaxin inhibitor, GLPG1690, has entered Phase III clinical trials for idiopathic pulmonary fibrosis. In the intervening time, a deeper understanding of the role of the autotaxin–lysophosphatidate (LPA)–lipid phosphate phosphatase axis in breast cancer progression and treatment resistance has emerged. Concordantly, appreciation of the tumor microenvironment and chronic inflammation in cancer biology has matured. The role of LPA as a central mediator behind these concepts has been exemplified within the breast cancer field. In this review, we will summarize current challenges in breast cancer therapy and delineate how blocking LPA signaling could provide novel adjuvant therapeutic options for overcoming therapy resistance and adverse side effects, including radiation-induced fibrosis. The advent of autotaxin inhibitors in clinical practice could herald their applications as adjuvant therapies to improve the therapeutic indexes of existing treatments for breast and other cancers.

Chondroradionecrosis of the larynx

PURPOSE OF REVIEW

Purpose of the present review is to revise the literature of the last 18 months, looking for novelties or new trends in diagnosis and therapeutical approaches to a very uncommon complicaton.

RECENT FINDINGS

Some comorbidities as well as prior surgical laryngeal treatment and lifestyle factors are known to increase tissue susceptibility to radiation injury and to complications due to endotracheal intubation.

SUMMARY

Chondroradionecrosis (CRN) of the larynx is a rare and severe complication of radiotherapy and endotracheal intubation which can be fatal if not managed promptly. In recent years, the trend in oncological surgery is organ preservation even in the advanced stage of laryngeal malignancies. However, in certain stages of squamous cell carcinomas, radiotherapy is necessary as a first or second line of treatment. Endotracheal intubation has also been associated with chondronecrosis and it is thought to be secondary to excessive pressure of the endotracheal tube or its cuff on the cartilage itself. Clinical diagnosis of CRN is extremely difficult and should be placed in differential diagnosis with postradiation outcomes and cancer recurrence. PET is useful, but biopsy is still required to confirm the diagnosis. The use of the laryngeal mask airway should prevent this complication and is a reasonable choice through which to administer general anesthesia in selected patients.