Radiobiological mechanisms of anti-inflammatory radiotherapy

Disease Modulation Versus Modification: A Call for Revised Outcome Metrics in the Treatment of Thyroid Eye Disease

PURPOSE

This perspective introduces the concepts of disease-modulating and -modifying therapy for thyroid eye disease and offers novel metrics for therapeutic outcomes.

METHODS

A focused literature review was performed.

RESULTS

Modulators are treatments that suppress disease symptoms whereas modifiers alter the natural history of a disease. Though many drugs are capable of exhibiting both effects, consideration of a drug's primary effect is useful when considering therapeutic options. For thyroid eye disease, corticosteroids and teprotumumab are effective at modulating many signs and symptoms of the disease, particularly those related to soft tissue inflammation. Orbital radiotherapy and rituximab have demonstrated effectiveness at durably modifying the natural history of thyroid eye disease.

CONCLUSIONS

Outcome metrics should reflect the unique therapeutic objectives associated with disease modulation and modification. This conceptual framework should guide treatment of thyroid eye disease.

Analgesic effects of low-dose radiotherapy in greater trochanteric pain syndrome: results in a clinical series of 155 patients with recurrent or refractory symptoms

PURPOSE

This prospective study assessed the effects of low-dose radiotherapy in patients diagnosed with greater trochanteric pain syndrome (GTPS) with recurrent symptoms or refractory to previous conservative measures.

METHODS

We evaluated a total of 155 patients (90.3% women, mean age 69 years). Most patients (n = 136) received 10 Gy (1 Gy/day/3 fractions per week on alternate days), but after recommendations of DEGRO guidelines published in 2015, the remaining 19 patients (12.2%) received 6 Gy (1 Gy/day/3 fractions per week on alternate days).

RESULTS

At the pre-treatment visit, the mean (standard deviation, SD) visual analog scale (VAS) score was 8), which decreased to 5 (SD 2.2) after 1 month of the end of treatment and to 4 (SD 2.3) after 4 months. An objective symptom response with increased mobility, better sleep quality, and reduction of analgesic medication was found in 56% of patients at 1 month. In 129 patients (83.2%), there was a decrease of at least 1 point in the VAS score, and in 49 patients (29.0%), the VAS score was lower than 3. The mean length of follow-up was 45 months. The probability of maintaining the analgesic response estimated by the Kaplan-Meier method was 53% at 5 years.

CONCLUSION

Low dose radiotherapy effectively improved pain in the trochanteric area in most patients with recurrent or refractory GTPS, allowing a reduction in the need for analgesic medications and, more, importantly, better functioning and mobility. Further randomized studies in selected populations of GTPS are needed to define the treatment position of low-dose radiotherapy in this clinical setting.

Stereotactic body radiation therapy for the treatment of localized prostate cancer in men with underlying inflammatory bowel disease

BACKGROUND

Historically, IBD has been thought to increase the underlying risk of radiation related toxicity in the treatment of prostate cancer. In the modern era, contemporary radiation planning and delivery may mitigate radiation-related toxicity in this theoretically high-risk cohort. This is the first manuscript to report clinical outcomes for men diagnosed with prostate cancer and underlying IBD curatively treated with stereotactic body radiation therapy (SBRT).

METHODS

A large institutional database of patients (n = 4245) treated with SBRT for adenocarcinoma of the prostate was interrogated to identify patients who were diagnosed with underlying IBD prior to treatment. All patients were treated with SBRT over five treatment fractions using a robotic radiosurgical platform and fiducial tracking. Baseline IBD characteristics including IBD subtype, pre-SBRT IBD medications, and EPIC bowel questionnaires were reviewed for the IBD cohort. Acute and late toxicity was evaluated using the CTCAE version 5.0.

RESULTS

A total of 31 patients were identified who had underlying IBD prior to SBRT for the curative treatment of prostate cancer. The majority (n = 18) were diagnosed with ulcerative colitis and were being treated with local steroid suppositories for IBD. No biochemical relapses were observed in the IBD cohort with early follow up. High-grade acute and late toxicities were rare (n = 1, grade 3 proctitis) with a median time to any GI toxicity of 22 months. Hemorrhoidal flare was the most common low-grade toxicity observed (n = 3).

CONCLUSION

To date, this is one of the largest groups of patients with IBD treated safely and effectively with radiation for prostate cancer and the only review of patients treated with SBRT. Caution is warranted when delivering therapeutic radiation to patients with IBD, however modern radiation techniques appear to have mitigated the risk of GI side effects.

All for one, though not one for all: team players in normal tissue radiobiology

PURPOSE

As part of the special issue on 'Women in Science', this review offers a perspective on past and ongoing work in the field of normal (non-cancer) tissue radiation biology, highlighting the work of many of the leading contributors to this field of research. We discuss some of the hypotheses that have guided investigations, with a focus on some of the critical organs considered dose-limiting with respect to radiation therapy, and speculate on where the field needs to go in the future.

CONCLUSIONS

The scope of work that makes up normal tissue radiation biology has and continues to play a pivotal role in the radiation sciences, ensuring the most effective application of radiation in imaging and therapy, as well as contributing to radiation protection efforts. However, despite the proven historical value of preclinical findings, recent decades have seen clinical practice move ahead with altered fractionation scheduling based on empirical observations, with little to no (or even negative) supporting scientific data. Given our current appreciation of the complexity of normal tissue radiation responses and their temporal variability, with tissue- and/or organ-specific mechanisms that include intra-, inter- and extracellular messaging, as well as contributions from systemic compartments, such as the immune system, the need to maintain a positive therapeutic ratio has never been more urgent. Importantly, mitigation and treatment strategies, whether for the clinic, emergency use following accidental or deliberate releases, or reducing occupational risk, will likely require multi-targeted approaches that involve both local and systemic intervention. From our personal perspective as five 'Women in Science', we would like to acknowledge and applaud the role that many female scientists have played in this field. We stand on the shoulders of those who have gone before, some of whom are fellow contributors to this special issue.

Medical, non-invasive, and minimally invasive treatment for Peyronie's disease: A systematic review

BACKGROUND

The treatment of Peyronie's disease (PD) remains a dilemma as the true pathogenesis of PD remains an enigma. Consequently, new molecules and therapies continue to evolve. The safety and efficacy of conservative treatment for PD have not yet established.

OBJECTIVES

To provide the available information of the status of conservative therapy for PD.

METHODS

A systematic literature search was conducted using PubMed, EMBASE, and the Cochrane Library for English-language journal articles between January 2000 and July 2019, using the terms "Conservative treatment for PD", "medical treatment for PD", "non-invasive therapies for PD" and "minimally invasive therapies for PD". This systematic review was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system. We also manually reviewed references from selected articles. The risk of bias in the included RCTs was assessed using the Cochrane Risk of Bias Assessment tool (RoB 2).

RESULTS

Conservative treatment is accepted as the initial treatment step in most of the cases. This kind of therapy includes various methods of treatment such as medical, non-invasive, and minimally invasive therapies. Ideal management of PD is not yet available. It is not possible to assess the value of treatment without well-designed, randomized, placebo-controlled, large-scale clinical studies.

CONCLUSION

Optimistically, in the near future, we may witness emergence of efficacious new agents and modalities to revolutionize medical, non-invasive, and minimally invasive treatment of this devastating condition.

Low-Dose Radiation Therapy (LDRT) for COVID-19: Benefits or Risks?

The limited impact of treatments for COVID-19 has stimulated several phase 1 clinical trials of whole-lung low-dose radiation therapy (LDRT; 0.3-1.5 Gy) that are now progressing to phase 2 randomized trials worldwide. This novel but unconventional use of radiation to treat COVID-19 prompted the National Cancer Institute, National Council on Radiation Protection and Measurements and National Institute of Allergy and Infectious Diseases to convene a workshop involving a diverse group of experts in radiation oncology, radiobiology, virology, immunology, radiation protection and public health policy. The workshop was held to discuss the mechanistic underpinnings, rationale, and preclinical and emerging clinical studies, and to develop a general framework for use in clinical studies. Without refuting or endorsing LDRT as a treatment for COVID-19, the purpose of the workshop and this review is to provide guidance to clinicians and researchers who plan to conduct preclinical and clinical studies, given the limited available evidence on its safety and efficacy.

The role of radiation treatment in the management of inflammatory musculoskeletal conditions: a revisit

Inflammatory musculoskeletal conditions are a common group of diseases among the elderly, worldwide. They are characterized by articular degenerative changes accompanied with often debilitating pain. Treatments often involve life-long analgesic therapy or joint replacement in extreme cases. The aim of this current review is to look at the role of radiation treatment with the hope of further study into the effectiveness of radiation treatment in reducing pain, eliminate or reduce the need for life-long analgesic therapy and thereby avoiding the analgesics’ side effects. Extensive literature search was done on PubMed and other available data base and the findings are presented and discussed. Literature showed that many countries in Europe, especially Germany use radiation routinely for the treatment of many degenerative disorders including osteoarthritis with good results and few side effects. A pilot study is therefore recommended with a view to establish the effectiveness or otherwise of this treatment method in patients.

Low-dose radiation therapy for coronavirus disease-2019 pneumonia: Is it time to look beyond apprehensions?

Coronavirus disease-2019 (COVID-19) has become a global health crisis. Mortality associated with COVID-19 is characterized mainly by acute respiratory distress syndrome (ARDS), sepsis, pneumonia, and respiratory failure. The pathogenesis of the disease is known to be associated with pro-inflammatory processes after virus infection. Hence, various therapeutic strategies are being developed to control the inflammation and cytokine storm in COVID-19 patients. Recently, low-dose radiation therapy (LDRT) has been suggested for the treatment of pneumonia/ADRS in COVID-19 patients through irradiation of lungs by gamma/X-ray. In this direction, a few clinical trials have also been initiated. However, a few recent publications have raised some concerns regarding LDRT, especially about possibilities of activation/aggressiveness of virus (severe acute respiratory syndrome coronavirus 2 in case of COVID-19), lung injury and risk of second cancer after low-dose therapy. The present manuscript is an attempt to analyze these apprehensions based on cited references and other available literature, including some from our laboratory. At this point, LDRT may be not the first line of therapy. However, based on existing anti-inflammatory evidence of LDRT, it needs encouragement as an adjuvant therapy and for more multi-centric clinical trials. In addition, it would be worth combining LDRT with other anti-inflammatory therapies, which would open avenues for multi-modal therapy of pneumonia/ARDS in COVID-19 patients. The mode of irradiation (local lung irradiation or whole-body irradiation) and the window period after infection of the virus, need to be optimized using suitable animal studies for effective clinical outcomes of LDRT. However, considering ample evidence, it is time to look beyond the apprehensions if a low dose of radiation could be exploited for better management of COVID-19 patients.

Reprint of: Deciphering and simulating models of radiation genotoxicity with CRISPR/Cas9 systems

This short review explores the utility and applications of CRISPR/Cas9 systems in radiobiology. Specifically, in the context of experimentally simulating genotoxic effects of Ionizing Radiation (IR) to determine the contributions from DNA targets and 'Complex Double-Stranded Breaks' (complex DSBs) to the IR response. To elucidate this objective, this review considers applications of CRISPR/Cas9 on nuclear DNA targets to recognize the respective 'nucleocentric' response. The article also highlights contributions from mitochondrial DNA (mtDNA) - an often under-recognized target in radiobiology. This objective requires accurate experimental simulation of IR-like effects and parameters with the CRISPR/Cas9 systems. Therefore, the role of anti-CRISPR proteins in modulating enzyme activity to simulate dose rate - an important factor in radiobiology experiments is an important topic of this review. The applications of auxiliary domains on the Cas9 nuclease to simulate oxidative base damage and multiple stressor experiments are also topics of discussion. Ultimately, incorporation of CRISPR/Cas9 experiments into computational parameters in radiobiology models of IR damage and shortcomings to the technology are discussed as well. Altogether, the simulation of IR parameters and lack of damage to non-DNA targets in the CRISPR/Cas9 system lends this rapidly emerging tool as an effective model of IR induced DNA damage. Therefore, this literature review ultimately considers the relevance of complex DSBs to radiobiology with respect to using the CRISPR/Cas9 system as an effective experimental tool in models of IR induced effects.

Local injection of a hexametaphosphate formulation reduces heterotopic ossification in vivo

Heterotopic ossification (HO), the pathological formation of ectopic bone, is a debilitating condition which can cause chronic pain, limit joint movement, and prevent prosthetic limb fitting. The prevalence of this condition has risen in the military population, due to increased survivorship following blast injuries. Current prophylaxes, which aim to target the complex upstream biological pathways, are inconsistently effective ​and have a range of side-effects that make them unsuitable for combat-injured personnel. As such, many patients must undergo further surgery to remove the formed ectopic bone. In this study, a non-toxic, U.S. Food and Drug Administration (FDA) -approved calcium chelator, hexametaphosphate (HMP), is explored as a novel treatment paradigm for this condition, which targets the chemical, rather that biological, ​bone formation pathways. This approach allows not only prevention of pathological bone formation ​but also uniquely facilitates reversal, which current drugs cannot achieve. Targeted, minimally invasive delivery is achieved by loading HMP into an injectable colloidal alginate. These formulations significantly reduce ​the length of the ectopic bone formed in a rodent model of HO, with no effect on the adjacent skeletal bone. This study demonstrates the potential of localized dissolution as a new treatment ​and an alternative to surgery ​for pathological ossification and calcification conditions.

Mitigating Coronavirus-Induced Acute Respiratory Distress Syndrome by Radiotherapy

The acute respiratory distress syndrome (ARDS) induced by SARS-CoV-2-mediated cytokine storm (CS) in lungs leads to the high mortality in COVID-19 patients. To reduce ARDS, an ideal approach is to diminish virus loading by activating immune cells for CS prevention or to suppress the overactive cytokine-releasing immune cells for CS inhibition. Here, a potential radiation-mediated CS regulation is raised by reevaluating the radiation-mediated pneumonia control in the 1920s, with the following latent advantages of lung radiotherapy (LR) in treatment of COVID-19: (1) radiation accesses poorly circulated tissue more efficiently than blood-delivered medications; (2) low-dose radiation (LDR)-mediated metabolic rewiring and immune cell activation inhibit virus loading; (3) pre-consumption of immune reserves by LDR decreases CS severity; (4) higherdose radiation (HDR) within lung-tolerable doses relieves CS by eliminating in situ overactive cytokine-releasing cells. Thus, LDR and HDR or combined with antiviral and life-supporting modalities may mitigate SARS-CoV-2 and other virus-mediated ARDS.

Deciphering and simulating models of radiation genotoxicity with CRISPR/Cas9 systems

This short review explores the utility and applications of CRISPR/Cas9 systems in radiobiology. Specifically, in the context of experimentally simulating genotoxic effects of Ionizing Radiation (IR) to determine the contributions from DNA targets and 'Complex Double-Stranded Breaks' (complex DSBs) to the IR response. To elucidate this objective, this review considers applications of CRISPR/Cas9 on nuclear DNA targets to recognize the respective 'nucleocentric' response. The article also highlights contributions from mitochondrial DNA (mtDNA) - an often under-recognized target in radiobiology. This objective requires accurate experimental simulation of IR-like effects and parameters with the CRISPR/Cas9 systems. Therefore, the role of anti-CRISPR proteins in modulating enzyme activity to simulate dose rate - an important factor in radiobiology experiments is an important topic of this review. The applications of auxiliary domains on the Cas9 nuclease to simulate oxidative base damage and multiple stressor experiments are also topics of discussion. Ultimately, incorporation of CRISPR/Cas9 experiments into computational parameters in radiobiology models of IR damage and shortcomings to the technology are discussed as well. Altogether, the simulation of IR parameters and lack of damage to non-DNA targets in the CRISPR/Cas9 system lends this rapidly emerging tool as an effective model of IR induced DNA damage. Therefore, this literature review ultimately considers the relevance of complex DSBs to radiobiology with respect to using the CRISPR/Cas9 system as an effective experimental tool in models of IR induced effects.

Minimally invasive therapies for Peyronie's disease: the current state of the art

Peyronie's disease (PD) is a relatively common condition that can result in significant penile deformity, sexual dysfunction, and psychological bother. Surgical straightening offers the highest probability of success during the stable phase of the disease. However, for men in the acute phase of PD or for those with less severe deformity who elect to avoid surgery, a variety of non-surgical treatment options are available. Oral therapies, including L-citrulline and pentoxifylline, are most useful as part of a combination regimen rather than as monotherapy. Intralesional therapy with IFN-α2b, verapamil, and collagenase clostridium histolyticum (CCH) can cause significant reduction in penile curvature, yet these results may not be clinically significant for men with more severe curvature. Further investigation into the timing of administration and optimal patient characteristics is required. Penile traction therapy offers a clinically significant improvement in penile length and curvature. However, this has traditionally required hours of daily therapy. Overall, a combination of oral, topical, injection and traction therapies may provide the most significant benefit among the non-surgical modalities for PD.

Noninvasive Treatment Options for Peyronie's Disease

INTRODUCTION

Evidence for noninvasive management of Peyronie's disease contains many options with varying levels of evidence for each. Many first-line treatments recommended by urologists lack strong evidence for their use.

AIM

We summarize the noninvasive (oral medications, topical medications, traction, vacuum erection devices, extracorporeal shock wave therapy, intracavernosal injections and electromotive therapy) treatment options for Peyronie's disease and provide the levels of evidence for each.

METHODS

A literature search of PubMed, EMBASE, Cochrane Library, and ClinicalKey databases was conducted, current up to April 2019.

MAIN OUTCOME MEASURE

For each treatment modality, we measured level of evidence, change in penile curvature, change in erectile function, the percentage of patients with improved angulation, and pain scores.

RESULTS

There is weak evidence to support the use of oral or topical medications. Higher levels of evidence exist for intracavernosal injections and extracorporeal shock wave therapy and may be helpful in certain patient populations.

CONCLUSION

The mechanisms behind Peyronie's disease are not fully understood. Penile injections provide the highest quality of evidence for noninvasive treatment. Ory J, MacDonald L, Langille G. Noninvasive Treatment Options for Peyronie's Disease. Sex Med Rev 2020;8:603-614.

TLI in pediatric patients

PURPOSE

Hematopoietic progenitor cell transplantation (HSCT) is a procedure used in different hematological diseases as part of the curative treatment, so the investigators propose a system of conditioning of reduced intensity based on total lymphoid irradiation (TLI) as an alternative to the classic total body irradiation (TBI) followed by haploidentical transplantation in patients compatible with a single HLA haplotype, as an alternative to patients who do not have an HLA compatible donor.

MATERIALS AND METHODS

A cohort of 25 patients with hematological disease underwent haploidentical HSCT from February 2015 to May 2018, conditioned with TLI from day - 10 (2-4 days of treatment) followed by thiotepa (5 mg/kg/12 h) and melphalan (70 mg/m²/day) prior to HSCT and prophylaxis with ciclosporin (1.5 mg/kg/12 h). 2 Gy/fraction was administered to complete 8 Gy with IMRT and VMAT technique.

RESULTS

12% rejection of the transplant was obtained with acute GVHD < II (48%) and chronic GVHD 12%. No acute toxicity was recorded in irradiated patients and 56% survival of patients at the end of follow-up.

CONCLUSION

Conditioning the haploidentical transplant with TLI, IMRT, and VMAT techniques compared with TBI and RT3D-C techniques is a feasible technique that helps inducing the necessary immunosuppression in patients with a high risk of graft rejection, minimal adverse effects, low incidence of GVHD, and high survival rate.

Quantitative analysis of extraocular muscle volume and exophthalmos reduction after radiation therapy to treat Graves' ophthalmopathy: A pilot study

PURPOSE

The aim of this study was to provide radiological information on the inherent response of Graves' ophthalmopathy after radiation therapy.

METHODS

Quantitative analysis of extraocular muscle volume was performed on 96 involved extraocular muscles in a total of 16 patients. A total of 48 computed tomography images were analyzed. Exophthalmos was also measured. The percentage reductions in extraocular muscle volume and exophthalmos length were determined and compared to the pre-radiation therapy values at 6-, 12-, and 24-month follow-up.

RESULTS

The median follow-up time was 21.5 months (range: 7.2-29.4 months). The mean reduction in relative tumor volume compared to the pre-radiation therapy extraocular muscle volume was 46.1% (range: 33.3%-58.8%). The mean relative extraocular muscle volumes were 71.5% at 6 months, 59.2% at 12 months, and 54.3% at 24 months after radiation therapy. The volume of the involved extraocular muscles decreased rapidly within the first 12 months of follow-up. The mean pre-radiation therapy length of exophthalmos was 21.7 mm (range: 17.6-26.1 mm). The mean percentages of exophthalmos length by comparison with the pre-radiation therapy length were 96.7% at 6 months, 92.3% at 12 months, and 88.5% at 24 months after radiation therapy. Exophthalmos decreased slowly and steadily during the follow-up period.

CONCLUSION

Quantitative volumetric analysis of the pattern of extraocular muscle volume reduction and exophthalmos length reduction in response to radiation therapy will allow clinicians to better understand the effect of radiotherapy on Graves' ophthalmopathy.

Temporarily increased TGFβ following radon spa correlates with reduced pain while serum IL-18 is a general predictive marker for pain sensitivity

Sustained pain relief following radon spa therapy in patients suffering from chronic painful diseases has been well described. But still, the underlying mechanisms are not fully understood. We conducted the prospective and explorative RAD-ON01 study which included 103 patients who suffered from chronic painful musculoskeletal disorders of the spine and/or joints and present here the data of the examination of pro- and anti-inflammatory cytokines in the serum of the patients before and at weeks 6, 12 and 30 after therapy. While TNFα, IL-1β, IFNγ, IL-1Ra and IL-10 were not altered, TGFβ was temporarily significantly (p = 0.013) elevated 6 weeks after therapy. Importantly, this elevation positively correlated with lowered pain sensitivity (r = 0.41). Further, the amount of IL-18 in the serum positively correlated with lowered pain sensitivity. Therefore, IL-18 can be considered as predictive marker for pain sensitivity of radon spa patients. We conclude that alterations in TGFβ and general IL-18 levels in serum have prognostic and predictive value in situations of lowered pain by exposure of patients to very low-doses of radiation as it is the case in radon spa.

Pathological effects of ionizing radiation: endothelial activation and dysfunction

The endothelium, a tissue that forms a single layer of cells lining various organs and cavities of the body, especially the heart and blood as well as lymphatic vessels, plays a complex role in vascular biology. It contributes to key aspects of vascular homeostasis and is also involved in pathophysiological processes, such as thrombosis, inflammation, and hypertension. Epidemiological data show that high doses of ionizing radiation lead to cardiovascular disease over time. The aim of this review is to summarize the current knowledge on endothelial cell activation and dysfunction after ionizing radiation exposure as a central feature preceding the development of cardiovascular diseases.

Minimizing Risk of Cancer Therapeutics

Cancer treatments continue to advance the management and survival of patients. However, use of these regimens can lead to significant side effects both temporary and permanent. Neuromuscular side effects include chemotherapy-induced peripheral neuropathy and radiation fibrosis syndrome. At this time, the only way to resolve the neurotoxicity is reduction or discontinuation of the offending agent. In an attempt to limit interference with a patient's chemotherapy regimen and mitigate chronic disability, efforts for early detection through subjective clinical evaluations and objective measurement with electrodiagnostics can help to improve symptom management and minimize alteration in treatment.

Radiotherapy for Active Thyroid Eye Disease

PURPOSE

To critically review the published literature on orbital radiotherapy as a treatment modality for thyroid eye disease (TED).

METHODS

A systematic review and analysis of the relevant published literature was performed.

RESULTS

Thyroid eye disease is an autoimmune condition that is amenable to treatments that modulate the immune response, including orbital radiotherapy (ORT). Ideal candidates for ORT are patients in the early, active phase of TED with moderate to severe, or rapidly progressive, disease, including patients with significant motility deficits and compressive optic neuropathy. Patients with progressive strabismus may also benefit. Patients with mild or inactive disease will not benefit from ORT when compared with the natural history of the disease. Orbital radiotherapy should generally be used in conjunction with corticosteroid therapy, with response to corticosteroids demonstrating the immunomodulatory therapeutic potential of ORT. When treating TED-compressive optic neuropathy, ORT may help obviate the need for urgent surgical decompression, or postpone it until the stable, inactive phase of the disease. Orbital radiotherapy treatment doses should approach 20 Gy in most cases, but lower doses may be considered in younger patients without significant dysmotility. The safety profile of ORT is well established, and side effects are minimal in appropriately selected patients.

CONCLUSIONS

Radiotherapy is a safe and effective treatment for active TED in appropriately selected patients.

Megavoltage Radiotherapy for the Treatment of Degenerative Joint Disease in Dogs: Results of a Preliminary Experience in an Italian Radiotherapy Centre

The aim of the study was to evaluate the efficacy and toxicity of a low-dose radiotherapy treatment in dogs with osteoarthritis (OA). Inclusion criteria were dogs affected by OA of one or multiple joints, with lameness, previously treated with medical therapy and referred for radiotherapy because of chronic unresponsive pain. After suspension of medical therapy, dogs underwent external beam radiotherapy treatments delivered in three fractions of 2 Gy each. Four of these dogs had one (three dogs) to four (one dog) additional courses of radiation. Medical records were reviewed and follow-up information was collected by clinical recheck and owners interview. Twenty-five dogs matched the inclusion criteria; among them, 21 had one course of RT and 4 underwent multiple treatments, respectively 218, 266, 39, and 1,384 days after the first treatment. Clinical improvement was observed in 92% of patients with median benefit duration of 356 days after the first treatment, and 418 days after the second treatment. No side effects were recorded. In this group of patients, radiotherapy was effective, well tolerated, and repeatable, leading to an improvement of quality of life in dogs with degenerative joint disease unresponsive to medical treatments.

Modeling DNA damage-induced pneumopathy in mice: insight from danger signaling cascades

Radiation-induced pneumonitis and fibrosis represent severe and dose-limiting side effects in the radiotherapy of thorax-associated neoplasms leading to decreased quality of life or - as a consequence of treatment with suboptimal radiation doses - to fatal outcomes by local recurrence or metastatic disease. It is assumed that the initial radiation-induced damage to the resident cells triggers a multifaceted damage-signalling cascade in irradiated normal tissues including a multifactorial secretory program. The resulting pro-inflammatory and pro-angiogenic microenvironment triggers a cascade of events that can lead within weeks to a pronounced lung inflammation (pneumonitis) or after months to excessive deposition of extracellular matrix molecules and tissue scarring (pulmonary fibrosis).The use of preclinical in vivo models of DNA damage-induced pneumopathy in genetically modified mice has helped to substantially advance our understanding of molecular mechanisms and signalling molecules that participate in the pathogenesis of radiation-induced adverse late effects in the lung. Herein, murine models of whole thorax irradiation or hemithorax irradiation nicely reproduce the pathogenesis of the human disease with respect to the time course and the clinical symptoms. Alternatively, treatment with the radiomimetic DNA damaging chemotherapeutic drug Bleomycin (BLM) has frequently been used as a surrogate model of radiation-induced lung disease. The advantage of the BLM model is that the symptoms of pneumonitis and fibrosis develop within 1 month.Here we summarize and discuss published data about the role of danger signalling in the response of the lung tissue to DNA damage and its cross-talk with the innate and adaptive immune systems obtained in preclinical studies using immune-deficient inbred mouse strains and genetically modified mice. Interestingly we observed differences in the role of molecules involved in damage sensing (TOLL-like receptors), damage signalling (MyD88) and immune regulation (cytokines, CD73, lymphocytes) for the pathogenesis and progression of DNA damage-induced pneumopathy between the models of pneumopathy induced by whole thorax irradiation or treatment with the radiomimetic drug BLM. These findings underline the importance to pursue studies in the radiation model(s) if we are to unravel the mechanisms driving radiation-induced adverse late effects.A better understanding of the cross-talk of danger perception and signalling with immune activation and repair mechanisms may allow a modulation of these processes to prevent or treat radiation-induced adverse effects. Vice-versa an improved knowledge of the normal tissue response to injury is also particularly important in view of the increasing interest in combining radiotherapy with immune checkpoint blockade or immunotherapies to avoid exacerbation of radiation-induced normal tissue toxicity.

The effect of orbital radiation therapy on thyroid-associated orbitopathy complicated with dysthyroid optic neuropathy

Thyroid-associated orbitopathy (TAO) is an inflammatory autoimmune disorder. The most serious complication of TAO is dysthyroid optic neuropathy (DON), which can lead to permanent vision loss because of volume expansion in the orbital apex. Orbital radiation therapy (ORT) is an anti-inflammatory treatment used in the treatment of active TAO. Clinical studies support radiotherapy as having a modest effect on DON, and early radiotherapy may protect against disease progression to DON. Current studies suggest that radiotherapy is generally safe. However, risks still exist in some cases. The possible effects of radiotherapy on TAO, especially complicated with DON, are reviewed. The effects of radiotherapy on DON are not completely known, and evidence from standardized, prospective, and multicenter clinical trials is still lacking.

Radiotherapy for Pertussis: An Historical Assessment

X-ray therapy was used to treat pertussis/whooping cough during a 13-year period from 1923 to 1936 in North America and Europe. Twenty studies from clinicians in the United States reported that approximately 1500 cases of pertussis were treated by X-ray therapy usually with less than 0.5 erythema dose. Young children (<3 years) comprised about 70% to 80% of the cases, with the age of cases ranging from as young as 1 month to 50 years. In general, symptoms of severe coughing, vomiting episodes, and spasms were significantly relieved in about 85% of cases following up to 3 treatments, while about 15% of the cases showed nearly full relief after only 1 treatment. The X-ray therapy was also associated with a marked reduction in mortality of young (<3 years) children by over 90%. Despite such reported clinical success from a wide range of experienced researchers, the use of X-rays for the treatment of pertussis in young children was controversial, principally due to concerns of exposure to the thymus and thyroid even with the availability of lead shielding. By the mid-1930s, the treatment of pertussis cases via vaccine therapy came to dominate the therapeutic arena, and the brief era of a radiotherapy option for the treatment of pertussis ended.

A Century of Radiation Therapy and Adaptive Immunity

The coming of age for immunotherapy (IT) as a genuine treatment option for cancer patients through the development of new and effective agents, in particular immune checkpoint inhibitors, has led to a huge renaissance of an old idea, namely to harness the power of the immune system to that of radiation therapy (RT). It is not an overstatement to say that the combination of RT with IT has provided a new conceptual platform that has re-energized the field of radiation oncology as a whole. One only has to look at the immense rise in sessions at professional conferences and in grant applications dealing with this topic to see its emergence as a force, while the number of published reviews on the topic is staggering. At the time of writing, over 97 clinical trials have been registered using checkpoint inhibitors with RT to treat almost 7,000 patients, driven in part by strong competition between pharmaceutical products eager to find their market niche. Yet, for the most part, this enthusiasm is based on relatively limited recent data, and on the clinical success of immune checkpoint inhibitors as single agents. A few preclinical studies on RT-IT combinations have added real value to our understanding of these complex interactions, but many assumptions remain. It seems therefore appropriate to go back in time and pull together what actually has been a long history of investigations into radiation and the immune system (Figure 1) in an effort to provide context for this interesting combination of cancer therapies.

Beyond checkpoint inhibition - Immunotherapeutical strategies in combination with radiation

The revival of cancer immunotherapy has taken place with the clinical success of immune checkpoint inhibition. However, the spectrum of immunotherapeutic approaches is much broader encompassing T cell engaging strategies, tumour-specific vaccination, antibodies or immunocytokines. This review focuses on the immunological effects of irradiation and the evidence available on combination strategies with immunotherapy. The available data suggest great potential of combined treatments, yet also poses questions about dose, fractionation, timing and most promising multimodal strategies.

Long term clinical toxicity of radiation therapy in prostate cancer patients with Inflammatory Bowel Disease

AIM

The study's aim was to examine the clinical impact of radiation therapy (RT) on GI toxicity in Inflammatory Bowel Disease (IBD) patients.

BACKGROUND

IBD has long been considered a risk factor for increased bowel toxicity from RT; however, minimal evidence exists on patients with prostate cancer (PC) and IBD.

MATERIALS AND METHODS

The tumor registry was queried for patients with IBD and PC from the years 1990-2013. A retrospective review was conducted for patients who received RT. Radiation treatment and toxicity data were collected.

RESULTS

Average length of follow-up was 12 years (median 9.54, range 0.42-19.9). The majority had well controlled baseline bowel function on medical management. Prior to radiation, 60% of patients (9/15) and 40% (6/15) reported grade 0 (G0) and grade (G1) diarrhea at baseline, respectively. No baseline proctitis existed. Following radiation treatment, 78% (14/18) of patients experienced G0 diarrhea while 22% (4/18) reported G1 diarrhea. No patients suffered from greater than G1 diarrhea. Sixty-six percent (12/18), 17% (3/18) and 17% (3/18) of patients experienced G0, G1, and G2 proctitis, respectively. No patients suffered post-radiation stricture formation, and all patients with G2 proctitis received 3dCRT.

CONCLUSIONS

Limited published data is available exploring RT for patients with PC and IBD. This analysis offers valuable insight into appropriate counseling for a rare patient subset. Radiation improved late G1 diarrhea rates. Grade 2 proctitis was only encountered in 3dCRT patients. No post-radiation complications occurred. Our findings suggest that IBD patients experience minimal toxicity in the era of IMRT based RT.

Is anti-inflammatory radiotherapy an effective treatment in trochanteritis?

OBJECTIVE

To evaluate the analgesic efficacy of low-dose radiotherapy in refractory cases of trochanteritis.

METHODS

We evaluated a total of 60 consecutive patients who received low-dose radiotherapy to achieve an anti-inflammatory and analgesic effect for recurrent trochanteritis following scarce response to conventional therapy. All patients were evaluated at baseline (prior to radiotherapy) and at 1 and 4 months after radiotherapy and then yearly thereafter for pain assessment using a visual analogue scale (VAS) and to determine the administration of analgesic treatment.

RESULTS

An improvement in the symptomatology was observed in 62% of the patients with a significant reduction in the VAS (8 ± 2 vs 4 ± 2; p < 0.0001), which was largely maintained until the second evaluation at 4 months. In the cases responding to radiotherapy, the probability of maintaining improvement beyond 24 months was 70%.

CONCLUSION

Low-dose anti-inflammatory radiation may be used in the treatment of the recurrent cases of relapse or no response of trochanteritis to conventional treatments, with a high probability of remission of pain. These preliminary results indicate the need for evaluating the use of radiotherapy in patients with trochanteritis refractory to conventional treatment in a long-term controlled study. Advances in knowledge: Radiotherapy provides effective analgesic treatment for patients refractory to standard treatment for trochanteritis.

Cardiovascular diseases related to ionizing radiation: The risk of low-dose exposure (Review)

Traditionally, non-cancer diseases are not considered as health risks following exposure to low doses of ionizing radiation. Indeed, non-cancer diseases are classified as deterministic tissue reactions, which are characterized by a threshold dose. It is judged that below an absorbed dose of 100 mGy, no clinically relevant tissue damage occurs, forming the basis for the current radiation protection system concerning non-cancer effects. Recent epidemiological findings point, however, to an excess risk of non-cancer diseases following exposure to lower doses of ionizing radiation than was previously thought. The evidence is the most sound for cardiovascular disease (CVD) and cataract. Due to limited statistical power, the dose-risk relationship is undetermined below 0.5 Gy; however, if this relationship proves to be without a threshold, it may have considerable impact on current low-dose health risk estimates. In this review, we describe the CVD risk related to low doses of ionizing radiation, the clinical manifestation and the pathology of radiation-induced CVD, as well as the importance of the endothelium models in CVD research as a way forward to complement the epidemiological data with the underlying biological and molecular mechanisms.

Orbital Radiation Therapy in Thyroid Eye Disease

PURPOSE

To review the current literature summarizing the state of knowledge on the use of orbital radiation therapy (ORT) in thyroid eye disease.

METHODS

A systematic review and analysis of the literature were performed. MEDLINE/PubMed, Cochrane Library databases, SCOPUS, and recent relevant journal articles were searched.

RESULTS

Thyroid eye disease is an autoimmune disorder that has the propensity to affect multiple orbital tissues and can cause permanent vision loss. In moderate to severe disease, treatment may be warranted and can include multiple therapeutic modalities. Orbital radiation therapy is frequently used in this setting and may act to break the inflammatory cycle of glycosaminoglycan production and deposition. There has been a wealth of data regarding the effectiveness of ORT in thyroid eye disease resulting in the publication of treatment algorithms and management guidelines; however, there continues to be a lack of conformity among experts on the exact role of ORT in thyroid eye disease.

CONCLUSION

The multiple different thyroid eye disease classification schemes and the concurrent use of other therapeutic modalities challenge the interpretation of studies evaluating the effectiveness of thyroid eye disease. Despite these limitations, the current literature indicates that ORT is generally safe and well tolerated. Orbital radiation therapy may have a modest effect on motility and proptosis early in the disease process. It is unclear whether ORT leads to improved quality of life. There are some data to support the use of ORT to prevent compressive optic neuropathy.

Effect of single dose radiation therapy on weight-bearing lameness in dogs with elbow osteoarthritis

OBJECTIVES

To determine if a single low dose of radiation therapy in dogs with osteoarthritis of the elbow joint was associated with a detectable improvement in their lameness and pain as documented by force platform gait analysis.

METHODS

In this cohort longitudinal observational study, five Labrador Retrievers with lameness due to elbow osteoarthritis that was unresponsive to medical treatment were removed from all non-steroidal anti-inflammatory and analgesic medications. A single treatment of radiation therapy delivering 10 Gray was performed on the affected elbow joint(s). Force platform gait analysis was used to assess the ground reaction forces of a limb affected with elbow osteoarthritis both before and after radiation therapy.

RESULTS

Significant differences occurred in the weight-bearing on an affected limb with elbow osteoarthritis after radiation therapy at weeks six and 14. Change due to treatment was particularly apparent in dogs with unilateral elbow osteoarthritis.

CLINICAL SIGNIFICANCE

Administering a single low dose of radiation therapy may have a short-term benefit in dogs with elbow osteoarthritis, which is similar to the evidence supporting the use of radiation therapy in horses with orthopaedic disease.

Painful plantar heel spur treatment with Co-60 teletherapy: factors influencing treatment outcome

Background

Painful plantar heel spur (PPHS) is a benign disorder with painful heels as a result of plantar calcaneal bone spur. Exact etiological factors are still unclear. Treatment typically consists of osteoarthritis tretment schedules and surgical techniques. External radiotherapy is another treatment option. This study is aimed to determine effectiveness and treatment outcomes of external radiotherapy in patients with PPHS.

Methods

Sixty-two patients with PPHS were analysed for radiotherapy success and other possible prognostic factors. All patients were treated with Co-60 units from parallel opposed lateral portals, to a total dose of 8 Gy. Responses to radiotherapy was assessed by visual analogue scale (VAS) of pain. Follow-up completed in December 2012 with 28 months median duration (range 22 to 35 months). Age, sex, patient number, spur settlement site, prior treatments, time interval between diagnosis and radiotherapy, pain scores (before and after radiotherapy), plantar fat-pillow thickness (PFPT; thickness of the plantar fat pad) and Böhler’s angle estimations were analysed.

Results

Study included 53 female and 9 male patients with median age 57 (range 43–70). Time interval between PPHS diagnosis and radiotherapy were median 33 months (range10-60). Radiotherapy response time interval were 6 months (range 3–10 months). Responses to radiotherapy were no response in 13 patients (21%), partial response in 13 patients (21%)- pain relief below 50% and complete response - no pain in 36 patients (58%) respectively. Median PFPT of patients were 3.5 cm (range 1.20–4.50 cm). Complete response rate was statistically significant in patients whom PFPT is greater than 3.5 cm. The Böhler’s angle range is about 20–40 deg. Complete response rates were higher in patients with degree of Böhler’s Angle 30 and below.

Conclusions

Simplicity of treatment, lack of acute adverse effects and low cost, seem to make radiotherapy one of the safest, cheapest and also an effective treatment modality for PPHS.

X-Ray treatment of carbuncles and furuncles (boils)

The goal of this article was to assess the historical role of radiotherapy in the treatment of selected inflammatory diseases. The specific research involved a literature-based assessment of the use of x-rays during the first half of the 20th century for the treatment of furuncles and carbuncles, the potentially serious staphylococcus infections. X-Rays were reported to be effective as a treatment at relatively low dose, about 10–20% of the skin erythema dose, which often quickly and profoundly reduce pain and accelerate the resolution/healing of the furuncles and carbuncles. These findings were based on considerable clinical experience that was generally reported in the form of case studies. The mechanism of x-ray–induced reduction of inflammation and acceleration of healing was suggested to result from a combination of immune alterations that enhanced phagocytosis as well as via an anti-localization effect on the pathogenic organism that facilitates their destruction.

The role of x-rays in the treatment of gas gangrene: a historical assessment

While the use of x-rays to treat patients with gas gangrene ended in the early 1940's with the advent of antibiotics, x-ray had been widely accepted as a useful and highly effective treatment for this condition. The present paper re-assesses the historical foundations of this belief, the quality of the data, use of confirmatory animal models, and underlying mechanisms that might account for the therapeutic role of x-rays in the treatment of gas gangrene.

Search for clastogenic factors in the plasma of locally irradiated individuals

In studies reported in the 1960s and in several investigations since, plasma from irradiated individuals was shown to induce chromosomal aberrations when transferred into normal blood cultures. In the present study, the aim was to investigate the occurrence of these clastogenic factors (CF) using markers representing DNA damage produced in reporter lymphocytes that are treated with plasma from locally exposed individuals. Blood plasma was obtained from clinical patients with benign conditions before and after they had received radiation to small treatment volumes. Three patient groups were studied: (I) marginal resected basal cell carcinoma, (II) painful osteoarthritis of the knee, and (III) painful tendinitis of the elbow or the heel. Patients in each treatment group obtained the same fractionated treatment regimen, ranging from a total dose of 40 Gy (8 × 5 Gy, 2 factions/week) to a very small volume (1-3.5 cm³) in group I to a total dose of 6 Gy (6 × 1 Gy, 2 fractions/week) for groups II and III (treatment volumes 800-1150 cm³ and 80-160 cm³, respectively). The presence of CF in the plasma was investigated through cytogenetic (chromosomal aberrations, micronuclei) assays and kinetics of early DNA damage (γ-H2AX foci) in reporter cells. With the experimental settings applied, local radiation exposure had no apparent effect on the induction of CF in patient plasma; no deviations in chromosomal aberrations or micronucleus or focus induction were observed in reporter cells treated with postexposure plasma with respect to pre-exposure samples when the mean values of the groups were compared. However, there was a large interindividual variation in the plasma-induced DNA-damaging effects. Steroid treatment of patients was demonstrated to be the most influential factor affecting the occurrence of plasma factors; plasma from patients treated with steroids led to significant reductions of γ-H2AX foci and reduced numbers of chromatid aberrations in reporter cells. In addition to the locally exposed patients, newly obtained plasma samples from three radiological accident victims exposed in 1994 were examined. In contrast to the patient data, a significant increase in chromosomal aberrations was induced with plasma from two accident victims.