Updated strategies in the treatment of benign diseases-a patterns of care study of the german cooperative group on benign diseases

Radiotherapy for benign diseases in Turkey: a patterns of care survey of the Turkish Society for Radiation Oncology (TROD 05-002)

PURPOSE

We aimed to investigate the patterns of radiotherapy (RT) care in cases of benign diseases in Turkey.

METHODS

A questionnaire survey was sent to all radiation oncology (RO) departments in Turkey. The number of patients treated for benign disease between 2015 and 2020 was requested. A list of benign conditions was given, and information on the number of patients per disease, single and total doses prescribed, weekly fractions, radiation type, energy, and device was requested.

RESULTS

Of the 138 RO departments, 29 (21%) responded. The data received concerned 15 (52%) university, 10 (34%) public, and four (14%) private hospitals. A total of 130,846 patients were treated with RT in these departments. Of these patients, 6346 (4.85%) were treated for benign conditions. The most common benign diseases treated with RT were meningioma (35%), plantar fasciitis (19%), schwannoma (16%), arteriovenous malformation (11%), and pituitary adenoma (7%). Most centers performed RT for paraganglioma, heterotopic ossification, vertebral hemangioma, and Graves' ophthalmopathy, but none treated arthrosis. Wide variations were observed across the departments. Radiosurgery for intracranial pathologies was performed intensively in four centers. By contrast, RT for plantar fasciitis was predominantly treated in five centers, one of which had more than 1000 patients.

CONCLUSION

The ratio of patients who underwent RT for benign diseases in Turkey among all patients who underwent RT was 4.85%. The common pattern of RT in 72% of patients was radiosurgery for intracranial benign diseases, followed by low-dose RT for plantar fasciitis in 19%.

ArthroRad trial: randomized multicenter single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis-final results after 12-month follow-up

OBJECTIVE

Updated report about the randomized comparison of the effect of radiotherapy on painful osteoarthritis (OA) applying a standard dose vs. a very low dose regime after a follow-up of 1 year.

PATIENTS AND METHODS

Patients presenting with OA of the hand/finger and knee joints were included. After randomization (every joint region was randomized separately) the following protocols were applied: (a) standard arm: total dose 3.0 Gy, single fractions of 0.5 Gy twice a week; (b) experimental arm: total dose 0.3 Gy, single fractions of 0.05 Gy twice a week. The dosage was blinded for the patients. For evaluation the scores after 1‑year visual analog scale (VAS), Knee Injury and Osteoarthritis Outcome Score-Short Form (KOOS-PS), Short Form Score for the Assessment and Quantification of Chronic Rheumatic Affections of the Hands (SF-SACRAH) and 12-item Short-Form Health Survey (SF-12) were used (for further details: see [1]).

RESULTS

The standard dose was applied to 77 hands and 33 knees, the experimental dose was given to 81 hands and 30 knees. After 12 months, the data of 128 hands and 45 knees were available for evaluation. Even after this long time, we observed a favorable response of pain to radiotherapy in both trial arms; however, there were no reasonable statistically significant differences between both arms concerning pain, functional, and quality of life scores. Side effects did not occur. The only prognostic factor was the pain level before radiotherapy.

CONCLUSIONS

We found a favorable pain relief and a limited response in the functional and quality of life scores in both treatment arms. The possible effect of low doses such as 0.3 Gy on pain is widely unknown.

Low-Dose Radiation Therapy Impacts Microglial Inflammatory Response without Modulating Amyloid Load in Female TgF344-AD Rats

Background

Low-dose radiation therapy (LD-RT) has demonstrated in preclinical and clinical studies interesting properties in the perspective of targeting Alzheimer's disease (AD), including anti-amyloid and anti-inflammatory effects. Nevertheless, studies were highly heterogenous with respect to total doses, fractionation protocols, sex, age at the time of treatment and delay post treatment. Recently, we demonstrated that LD-RT reduced amyloid peptides and inflammatory markers in 9-month-old TgF344-AD (TgAD) males.

Objective

As multiple studies demonstrated a sex effect in AD, we wanted to validate that LD-RT benefits are also observed in TgAD females analyzed at the same age.

Methods

Females were bilaterally treated with 2 Gy×5 daily fractions, 2 Gy×5 weekly fractions, or 10 fractions of 1 Gy delivered twice a week. The effect of each treatment on amyloid load and inflammation was evaluated using immunohistology and biochemistry.

Results

A daily treatment did not affect amyloid and reduced only microglial-mediated inflammation markers, the opposite of the results obtained in our previous male study. Moreover, altered fractionations (2 Gy×5 weekly fractions or 10 fractions of 1 Gy delivered twice a week) did not influence the amyloid load or neuroinflammatory response in females.

Conclusions

A daily treatment consequently appears to be the most efficient for AD. This study also shows that the anti-amyloid and anti-inflammatory response to LD-RT are, at least partly, two distinct mechanisms. It also emphasizes the necessity to assess the sex impact when evaluating responses in ongoing pilot clinical trials testing LD-RT against AD.

The immunomodulatory properties of low-level ionizing radiation as a potential treatment for COVID-19's life-threatening symptoms

Public health experts are looking into the current coronavirus outbreak to see if there are any ways to prevent potentially fatal symptoms. Low-Dose Radiotherapy (LD-RT) induces anti-inflammatory cytokine responses that act as a counterweight to pro-inflammatory cytokines, potentially providing therapeutic benefits for COVID-19-related diseases associated with significant morbidity and mortality. This study will look into positive immuno-radiological reactions to see if they are feasible, practicable, and effective in lowering the critical inflammatory condition of the crucial stage COVID-19. This study aims to investigate the use of low-dose lung radiation in bacterial and viral pneumonia, as well as to provide a treatment plan for COVID-19-associated pneumonia. This article discusses the evidence for and against LD-RT theories in COVID-19 patients. The use of LD-RT at various stages of COVID-19 appears to be beneficial, with fewer side effects than other currently being studied treatments.

The 5Rs dilemma of radiotherapy for non-malignant diseases: 5Rs to darken OR 5Rs to shine

Many benign diseases, so called because they are not a direct cause of death, nevertheless cause significant damage to the health of patients due to the associated pain, reduced functionality, increased disability and the negative impact they have on quality of life, which, together with the limited efficacy of many of the available treatments, make their management a challenge for every specialist. Radiotherapy, which has demonstrated its efficacy not only against cancer but also in many non-tumorous diseases, appears as a therapeutic option that deserves to be taken into account. However, there is still much resistance to considering the use of radiotherapy as a valid and acceptable alternative. The 5Rs to darken summarize the doubts and contradictions many specialists face to accept radiotherapy in non-neoplastic diseases. However, other 5Rs (to shine) can be argued to claim for the safety, reliability, and usefulness of radiation treatment for benign disease and as radiotherapy specialists we have to help the evidence shine and the darkness disappear.

Radiation as a Tool against Neurodegeneration-A Potential Treatment for Amyloidosis in the Central Nervous System

Radiotherapy (RT) is a relatively safe and established treatment for cancer, where the goal is to kill tumoral cells with the lowest toxicity to healthy tissues. Using it for disorders involving cell loss is counterintuitive. However, ionizing radiation has a hormetic nature: it can have deleterious or beneficial effects depending on how it is applied. Current evidence indicates that radiation could be a promising treatment for neurodegenerative disorders involving protein misfolding and amyloidogenesis, such as Alzheimer's or Parkinson's diseases. Low-dose RT can trigger antioxidant, anti-inflammatory and tissue regeneration responses. RT has been used to treat peripheral amyloidosis, which is very similar to other neurodegenerative disorders from a molecular perspective. Ionizing radiation prevents amyloid formation and other hallmarks in cell cultures, animal models and pilot clinical trials. Although some hypotheses have been formulated, the mechanism of action of RT on systemic amyloid deposits is still unclear, and uncertainty remains regarding its impact in the central nervous system. However, new RT modalities such as low-dose RT, FLASH, proton therapy or nanoparticle-enhanced RT could increase biological effects while reducing toxicity. Current evidence indicates that the potential of RT to treat neurodegeneration should be further explored.

Low-Dose Radiotherapy Leads to a Systemic Anti-Inflammatory Shift in the Pre-Clinical K/BxN Serum Transfer Model and Reduces Osteoarthritic Pain in Patients

Osteoarthritis (OA) is the leading degenerative joint disease in the western world and leads, if left untreated, to a progressive deterioration of joint functionality, ultimately reducing quality of life. Recent data has shown, that especially OA of the ankle and foot are among the most frequently affected regions. Current research in OA points towards a complex involvement of various cell and tissue types, often accompanied by inflammation. Low-dose radiotherapy (LDRT) is widely used for the treatment of degenerative and inflammatory diseases. While the reported analgesic effects are well known, the underlying molecular mechanisms are only poorly understood. We therefore correlated a clinical approach, looking at pain reduction in 196 patients treated with LDRT with a pre-clinical approach, utilizing the K/BxN serum transfer mouse model using flow cytometry and multiplex ELISA for analysis. While an improvement of symptoms in the majority of patients was found, patients suffering from symptoms within the tarsi transversa show a significantly lower level of improvement. Further, a significant impact of therapy success was detected depending on whether only one or both feet were affected. Further, patients of younger age showed a significantly better outcome than older ones while needing fewer treatment series. When looking on a cellular level within the mouse model, a systemic alteration of immune cells namely a shift from CD8+ to CD4+ T cells and reduced numbers of DCs was observed. A general reduction of inflammatory cytokines was detected, with significant alterations in IL-4 and IL-17 levels, all of which could potentially be responsible for the highly effective clinical improvement in patients. Taken together our data indicate that LDRT can be regarded as a highly effective treatment option for patients suffering from OA of the foot and ankle, in terms of analgesic effects, especially in younger patients. Furthermore, the observed effects are mediated by an interplay of cellular and soluble immune factors, as observed in the K/BxN serum transfer model. With this interdisciplinary approach we aim to encourage the usage of LDRT as an additive treatment strategy not only as a last resort, but also earlier in the course of 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.

Low-dose radiation therapy for osteoarthritis and enthesopathies: a review of current data

BACKGROUND

Osteoarthritis (OA), the most common degenerative joint disease, is associated with severe functional limitation and impairment of quality of life. Numerous reports have documented the clinical efficacy of low-dose radiotherapy (LD-RT) in the management of various inflammatory disorders, including OA. In this paper, we assessed the clinical literature involving the use of LD-RT in the treatment of OA, its dose-response features, possible underlying mechanistic features, and optimal therapeutic dose range.

METHODS

We carried out a systematic review based on the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements and evaluated articles meeting the inclusion criteria for this review.

RESULTS

A total of 361 articles were identified from databases, such as Scopus, PubMed, Embase, and Science Direct out of which 224 articles were duplicates and were discarded. Of the remaining 137 articles, 74 articles were un-related, 27 articles were review articles, eight were conference abstracts, three were letters, two were editorials, two were notes, and one was a book chapter. Finally, 20 articles met all the inclusion criteria and were included in this systematic review.

DISCUSSION

Several single-arm retrospective/prospective studies showed advantages for LD-RT in the management of OA in terms of pain relief, improvement of mobility and function, and showed minimal side effects. Mechanistic considerations involve positive subcellular effects mediated by the activation of a nuclear factor erythroid 2-related transcription factor (Nrf2) mediated antioxidant response. Further research on both the short- and long-term effects of LD-RT on OA and other inflammatory disorders is recommended.

Treatment by low-dose brain radiation therapy improves memory performances without changes of the amyloid load in the TgF344-AD rat model

Alzheimer's disease (AD) is a neurodegenerative condition affecting memory performance. This pathology is characterized by intracerebral amyloid plaques and tau tangles coupled with neuroinflammation. During the last century, numerous therapeutic trials unfortunately failed highlighting the need to find new therapeutic approaches. Low-dose brain radiotherapy (LD-RT) showed efficacy to reduce amyloid load and inflammation in patients with peripheral diseases. In this study, the therapeutic potential of 2 LD-RT schedules was tested on the TgF344-AD rat model of AD. Fifteen-month-old rats were irradiated with 5 fractions of 2 Gy delivered either daily or weekly. The daily treatment induced an improvement of memory performance in the Y-maze. In contrast, the weekly treatment increased the microglial reactivity in the hippocampus. A lack of effect of both regimens on amyloid pathology was unexpectedly observed. The positive effect on cognition encourages to further evaluate the LD-RT therapeutic potential and highlights the impact of the design choice of the LD-RT regimen.

Low-Dose Radiation Therapy: A New Treatment Strategy for Alzheimer's Disease?

Alzheimer's disease (AD) is a neurodegenerative disease characterized by extracellular amyloid-β (Aβ) peptide aggregates, forming amyloid plaques, and intracellular deposits of phosphorylated tau. Neuroinflammation is now considered as the third hallmark of AD. The majority of clinical trials tested pharmacological strategies targeting amyloid, tau, and neuroinflammation, with disappointing results overall. In parallel, innovative strategies exploring other pathways and approaches are being tested. In this article, we focus on the rationale and preliminary preclinical evidence for a novel application to AD of a widely used therapeutic strategy for oncological and benign conditions: low-dose radiation therapy (LD-RT). LD-RT has shown to be effective against systemic amyloid deposits, as well as against chronic inflammatory diseases, and could thus be able to modulate amyloid load and neuroinflammation in AD. The anti-amyloid effect could be possibly mediated by the LD-RT action on the β-sheet structure of amyloid fibrils, by breaking H-bonds, and depolymerize glucoaminoglycans which are highly radiation-sensitive molecules associated with amyloid fibrils. The anti-inflammatory effect could be linked to the decrease of leukocytes-endothelial cells interactions and to the stimulation of the release of anti-inflammatory molecules. One preclinical study has observed a dramatic reduction of amyloid plaques 4 weeks post-RT, more important with fractionated protocols at low doses than hypofractionated single dose treatments, associated with modulation of inflammatory and anti-inflammatory cytokines and cognitive improvement. Ongoing Phase I clinical trials will test the ability of LD-RT to hold these promises.

Low-dose radiotherapy (LD-RT) for COVID-19-induced pneumopathy: a worth considering approach

PURPOSE

It seems that 2020 would be always remembered by the name of novel coronavirus (designated as SARS-CoV-2), which exerted its deteriorating effects on the health care, economy, education, and political relationships. In August 2020 more than eight hundred thousand patients lost their lives due to acute respiratory syndrome. In the limited list of therapeutic approaches, the effectiveness of low-dose radiation therapy (LD-RT) for curing inflammatory-related diseases have sparkled a light that probably this approach would bring promising advantages for COVID-19 patients. LD-RT owns its reputation from its ability to modulate the host inflammatory responses by blocking the production of pro-inflammatory cytokines and hampering the activity of leukocytes. Moreover, the cost-effective and availability of this method allow it to be applied to a large number of patients, especially those who could not receive anti-IL-6 treatments in low-income countries. But enthusiasm for applying LD-RT for the treatment of COVID-19 patients has been muted yet.

CONCLUSION

In this review, we take a look at LD-RT mechanisms of action in the treatment of nonmalignant diseases, and then through studying both the dark and bright sides of this approach, we provide a thorough discussion if LD-RT might be a promising therapeutic approach in COVID-19 patients.

Delivery of high-dose radiation for recurrence of breast cancer in a patient with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterised by inflammatory nodules, abscesses, sinus tract formation and scarring. There is a lack of evidence for the use of radical radiotherapy for patients with a diagnosis of HS. A 56-year-old woman with a long-standing diagnosis of HS presented with a cutaneous local recurrence of breast cancer. Radical radiotherapy was offered despite issues with previous prolonged postoperative wound healing associated with the underlying HS. A multidisciplinary evaluation was conducted with breast surgeons, dermatologists and radiation oncologists to assess the safety of delivery of radical radiotherapy. Five weeks post radiotherapy, the patient had no significant residual symptoms from her breast cancer treatment for her HS and no escalation of treatment was required for her HS. Factors contributing to safe delivery of radical radiotherapy include medical optimisation prior to and during treatment, radiation dose, radiation technique and vigilant post-treatment surveillance.

Low Dose Radiation Therapy, Particularly with 0.5 Gy, Improves Pain in Degenerative Joint Disease of the Fingers: Results of a Retrospective Analysis

Low-dose radiation therapy (LDRT) has been successfully established for decades as an alternative analgesic treatment option for patients suffering from chronic degenerative and inflammatory diseases. In this study, 483 patients were undergoing LDRT for degenerative joint disease of the fingers and thumb at the University Hospital Erlangen between 2004 and 2019. Radiotherapy was applied according to the German guidelines for LDRT. Several impact factors on therapeutic success, such as the age and gender, the number of affected fingers, the single and cumulative dose, as well as the number of series, were investigated. In summary, 70% of the patients showed an improvement of their pain following LDRT. No significant impact was found for the factors age, gender, the number of series or the cumulative dosage. Patients with an involvement of the thumb showed a significantly worse outcome compared to patients with an isolated affection of the fingers. In this cohort, patients receiving a single dose of 0.5 Gy reported a significantly better outcome than patients receiving 1.0 Gy, strongly suggesting a reduction in the total dose. In summary, LDRT is a good alternative treatment option for patients suffering from degenerative and inflammatory joint disease of the fingers.

Radiation-induced DNA double-strand breaks in peripheral leukocytes and therapeutic response of heel spur patients treated by orthovoltage X-rays or a linear accelerator

Purpose

Biodosimetric assessment and comparison of radiation-induced deoxyribonucleic acid (DNA) double-strand breaks (DSBs) by γH2AX immunostaining in peripheral leukocytes of patients with painful heel spur after radiation therapy (RT) with orthovoltage X‑rays or a 6-MV linear accelerator (linac). The treatment response for each RT technique was monitored as a secondary endpoint.

Patients and methods

22 patients were treated either with 140-kV orthovoltage X‑rays (n = 11) or a 6-MV linac (n = 11) with two weekly fractions of 0.5 Gy for 3 weeks. In both scenarios, the dose was prescribed to the International Commission on Radiation Units and Measurements (ICRU) dose reference point. Blood samples were obtained before and 30 min after the first RT session. γH2AX foci were quantified by immunofluorescence microscopy to assess the yield of DSBs at the basal level and after radiation exposure ex vivo or in vivo. The treatment response was assessed before and 3 months after RT using a five-level functional calcaneodynia score.

Results

RT for painful heel spurs induced a very mild but significant increase of γH2AX foci in patients’ leukocytes. No difference between the RT techniques was observed. High and comparable therapeutic responses were documented for both treatment modalities. This trial was terminated preliminarily after an interim analysis (22 patients randomized).

Conclusion

Low-dose RT for painful heel spurs with orthovoltage X‑rays or a 6-MV linac is an effective treatment option associated with a very low and comparable radiation burden to the patient, as confirmed by biodosimetric measurements.

Prospective Evaluation of Changes in Pain Levels, Quality of Life and Functionality After Low Dose Radiotherapy for Epicondylitis, Plantar Fasciitis, and Finger Osteoarthritis

Background: The objective benefits of low dose radiotherapy (LDRT) for non-malignant joint disorders are controversial. This study evaluated changes in pain, quality of life (QoL) and function after LDRT for epicondylitis, plantar fasciitis, and finger osteoarthritis. Materials and Methods: Patients over 40 years old with epicondylitis, plantar fasciitis, and finger osteoarthritis were had pain following at least 6 months of conservative therapy. Patients received 0.5 Gy LDRT twice weekly for 4 weeks repeated once after 8 weeks in patients who failed to achieve complete pain relief. Patients assessed their pain according to the visual analog scale. Handgrip strength was measured with an isometric dynamometer and the fast self-paced walking test was used in patients with plantar fasciitis. QoL was evaluated according to the EQ-5D and HAQ-DI questionnaires. Results: Outcomes for 157 patients (204 sites) were documented at 2, 6, and 12 months after last LDRT. Pain reduction at rest (p < 0.001), during activity (p < 0.001) and increase in handgrip strength (extension p < 0.001, flexion p = 0.002) were highly significant for patients with lateral epicondylitis. Patients with medial epicondylitis reported pain relief at rest (p = 0.041) and during activity (p = 0.041) and significant increase in handgrip strength (p = 0.022). Patients with plantar fasciitis reported pain reduction at rest (p < 0.001), during activity (p < 0.001) and faster walking times (p < 0.001). A trend toward improved QoL was observed. Patients with finger osteoarthritis reported significant pain relief during activity (p < 0.001) and a gain in handgrip strength (p = 0.004), with a trend to both pain relief at rest (p = 0.056) and stronger pinch grip (p = 0.099). Conclusions: LDRT achieved significant pain relief at rest and during activity and a corresponding objective improvement in handgrip strength in patients with epicondylitis. Pain relief at rest, during activity and improvement in walking time were demonstrated in patients with plantar fasciitis. LDRT achieved pain relief during activity, and handgrip strength was improved in patients with finger osteoarthritis. No significant effect was seen on quality of life measures for these conditions. The observed benefits were maintained 12 months after LDRT for all 3 indications and we recommend this low cost, safe intervention for patients over 40 who have failed prior conservative therapy.

Treatment strategies to prevent and reduce gynecomastia and/or breast pain caused by antiandrogen therapy for prostate cancer : Statement from the DEGRO working group prostate cancer

Aim

To provide an overview on the available treatments to prevent and reduce gynecomastia and/or breast pain caused by antiandrogen therapy for prostate cancer.

Methods

The German Society of Radiation Oncology (DEGRO) expert panel summarized available evidence published and assessed the validity of the information on efficacy and treatment-related toxicity.

Results

Eight randomized controlled trials and one meta-analysis were identified. Two randomized trials demonstrated that prophylactic radiation therapy (RT) using 1 × 10 Gy or 2 × 6 Gy significantly reduced the rate of gynecomastia but not breast pain, as compared to observation. A randomized dose-finding trial identified the daily dose of 20 mg tamoxifen (TMX) as the most effective prophylactic dose and another randomized trial described that daily TMX use was superior to weekly use. Another randomized trial showed that prophylactic daily TMX is more effective than TMX given at the onset of gynecomastia. Two other randomized trials described that TMX was clearly superior to anastrozole in reducing the risk for gynecomastia and/or breast pain. One comparative randomized trial between prophylactic RT using 1 × 12 Gy and TMX concluded that prophylactic TMX is more effective compared to prophylactic RT and furthermore that TMX appears to be more effective to treat gynecomastia and/or breast pain when symptoms are already present. A meta-analysis confirmed that both prophylactic RT and TMX can reduce the risk of gynecomastia and/or breast pain with TMX being more effective; however, the rate of side effects after TMX including dizziness and hot flushes might be higher than after RT and must be taken into account. Less is known regarding the comparative effectiveness of different radiation fractionation schedules and more modern RT techniques.

Conclusions

Prophylactic RT as well as daily TMX can significantly reduce the incidence of gynecomastia and/or breast pain. TMX appears to be an effective alternative to RT also as a therapeutic treatment in the presence of gynecomastia but its side effects and off-label use must be considered.

Long-term efficacy of low-dose radiation therapy on symptoms in patients with knee and hand osteoarthritis: follow-up results of two parallel randomised, sham-controlled trials

BACKGROUND

Low-dose radiation therapy is commonly used as treatment for benign diseases, including osteoarthritis, in some countries (eg, Germany). We have previously presented our 3-month follow-up results of two randomised sham-controlled trials, in which no substantial effects of low-dose radiation therapy on clinical outcomes were seen in patients with knee and hand osteoarthritis. Here we report the 6-month and 12-month results of these studies.

METHODS

In one randomised sham-controlled trial, patients with knee osteoarthrosis were recruited, and in the other trial patients with hand osteoarthritis were recruited. All patients were recruited from the department of rheumatology of Sint Maartenskliniek (Nijmegen, The Netherlands) and the trials were undertaken in parallel. Patients were eligible if they had knee or hand osteoarthritis according to American College of Rheumatology (ACR) criteria, had a pain score of 5 or more on a 0-10 scale for at least 15 of the past 30 days, and did not meet 2011 modified ACR criteria for fibromyalgia. In each study, patients were randomly assigned (1:1), stratified by pain score (<8 vs ≥8) using a computer-generated randomisation list and stratified block randomisation, to low-dose radiation therapy (six fractions of 1 Gy low-dose radiation therapy in 2 weeks) or sham (six sessions with 0 Gy of radiation therapy in 2 weeks) intervention. Patients and researchers involved in patient contact or assessments were masked to group allocation, whereas the radiotherapy technologist who did the treatment was unmasked. Patients completed questionnaires (numeric rating scale of patients' global assessment and validated measures for pain and functioning) at baseline and at 1, 2, 3, 6, and 12 months after starting treatment. The primary outcome was the proportion of participants who responded according to the Outcome Measures in Rheumatology Osteoarthritis Research Society International responder criteria at 3 months, which has been reported previously. Here we report the proportion of participants who responded at 6 months and 12 months, and other clinical outcomes of pain, functioning, and patients' global assessment of their symptoms. We used logistic and linear mixed-models analyses to assess differences in number of responders and continuous outcomes. Safety was assessed in all participants who received at least one fraction of low-dose radiation or sham treatment. This study is registered with the Netherlands Trial Registry, NTR4574, and is closed to accrual.

FINDINGS

Between Oct 14, 2015, and May 3, 2017, 213 patients were screened for inclusion for the knee osteoarthritis study, of whom 55 were eligible and randomly assigned to low-dose radiation therapy (n=27) or sham intervention (n=28). In parallel, for the hand osteoarthritis study, 368 patients were screened and 56 were randomly assigned low-dose radiation (n=28) or sham intervention (n=28). Some minor imbalances in baseline demographic characteristics in terms of sex and age were seen in both the knee and hand cohorts. In the knee osteoarthritis cohort, 48 patients were assessible at 6 months and 50 were assessible at 12 months, and in the hand osteoarthritis cohort 52 patients were assessible at 6 and 12 months. We found no significant differences at 6 or 12 months in the proportion of participants who had a response for both groups. In the knee osteoarthritis group, at 6 months, the number of responders was nine (41%) of 22 patients who received low-dose radiation therapy versus nine (35%) of 26 patients who received the sham intervention (difference in proportion 7% [95% CI -20 to 33]; odds ratio [OR] 1·34 [95% CI 0·41 to 4·42]); and at 12 months, 13 (52%) of 25 patients versus 11 (44%) of 25 patients responded (difference in proportion 8% [-19 to 35]; OR 1·41 [0·45 to 4·48]). In the hand osteoarthritis group, at 6 months, the number of responders was seven (28%) of 25 patients who received low-dose radiation therapy versus 11 (31%) of 27 patients who received the sham intervention (difference in proportion 12% [-38 to 13]; OR 0·57 [0·18 to 1·81]); and at 12 months, eight (31%) of 26 patients versus seven (27%) of 26 patients responded (difference in proportion 4% [-20 to 29]; OR 1·23 [0·37 to 4·12]). We did not find any difference between groups in other clinical outcomes at 6 or 12 months. Three participants with knee osteoarthritis in the sham intervention group and two participants with hand osteoarthritis in the low-dose radiation therapy group had serious adverse effects, none of which were considered to be related to the intervention.

INTERPRETATION

We did not find evidence of a delayed effect of low-dose radiation therapy for patients with knee and hand osteoarthritis. Our placebo-controlled results suggest that the large effects of low-dose radiation therapy reported in clinical practice and observational studies can probably be explained by a regression to the mean effect and response to placebo.

FUNDING

Dutch Arthritis Foundation and Stichting Landelijk Katholiek Reumacentrum, Netherlands.

First Insights into the Effect of Low-Dose X-Ray Irradiation in Adipose-Derived Stem Cells

(1) Background: Emerging interest of physicians to use adipose-derived stem cells (ADSCs) for regenerative therapies and the fact that low-dose irradiation (LD-IR ≤ 0.1 Gy) has been reported to enhance the proliferation of several human normal and bone-marrow stem cells, but not that of tumor cells, lead to the idea of improving stem cell therapies via low-dose radiation. Therefore, the aim of this study was to investigate unwanted side effects, as well as proliferation-stimulating mechanisms of LD-IR on ADSCs. (2) Methods: To avoid donor specific effects, ADSCs isolated from mamma reductions of 10 donors were pooled and used for the radiobiological analysis. The clonogenic survival assay was used to classify the long-term effects of low-dose radiation in ADSCs. Afterwards, cytotoxicity and genotoxicity, as well as the effect of irradiation on proliferation of ADSCs were investigated. (3) Results: LD (≤ 0.1 Gy) of ionizing radiation promoted the proliferation and survival of ADSCs. Within this dose range neither geno- nor cytotoxic effects were detectable. In contrast, greater doses within the dose range of >0.1–2.0 Gy induced residual double-strand breaks and reduced the long-term survival, as well as the proliferation rate of ADSCs. (4) Conclusions: Our data suggest that ADSCs are resistant to LD-IR. Furthermore, LD-IR could be a possible mediator to improve approaches of stem cells in the field of regenerative medicine.