Radiotherapy for osteoarthritis—an analysis of 295 joints treated with a linear accelerator

Comparative effectiveness of kilo- and megavoltage energies in low-dose radiotherapy for painful degenerative musculoskeletal diseases: a systematic review and meta-analysis

PURPOSE

This study aimed to assess the impact of different energy levels on the effectiveness of low-dose radiotherapy (LDRT) for treating painful degenerative musculoskeletal diseases, as comparative efficacy data are currently lacking.

METHODS

A systematic review was conducted in PubMed, Embase, and the Cochrane Library databases to identify studies with response information on the energy used (kilovoltage [kV] vs. megavoltage [MV]). The primary endpoint was the overall response rate (ORR), and the secondary endpoint was the complete response rate (CRR). Exploratory subgroup analyses included treatment site, study period, study design, country, and dose per fraction.

RESULTS

A total of 33 studies involving 12,143 patients were analyzed. Short-term follow-up (up to 6 months) showed a pooled ORR of 64% (95% CI 46-78%) for kV and of 62% (95% CI 54-70%) for MV. Long-term follow-up (at least 12 months) revealed a pooled ORR of 85% (95% CI 65-95%) for kV and of 69% (95% CI 62-75%) for MV. Subgroup analysis indicated no significant differences in ORR for energy level stratified by treatment site and other factors. Regarding dose per fraction (0.5 Gy vs. 1.0 Gy), comparable ORRs were demonstrated between the two energies. No clinical side effects were noted.

CONCLUSION

This meta-analysis suggests that the known effectiveness of LDRT in painful degenerative musculoskeletal disease may not depend on the energy used. Additional studies using standardized evaluation methods are warranted to establish consistency and enhance the comprehensiveness of research. Further research is also needed to explore treatment modality selection considering disease-specific biology.

Implementing a low-dose radiation therapy program for musculoskeletal pain disorders: tips, tricks, and essentials for clinical researchers

INTRODUCTION

Painful musculoskeletal disorders (PMDs) represent an increasing public health concern, particularly among aging populations. When conservative therapies prove insufficient, low-dose radiotherapy (LDRT) has emerged as a non-invasive and effective treatment alternative. Despite growing clinical evidence supporting its efficacy, LDRT remains underutilized due to persistent skepticism and the absence of standardized clinical guidelines.

MATERIALS AND METHODS

This review synthesizes current evidence on the use of LDRT for PMDs, focusing on its biological mechanisms, optimal dosing regimens, clinical efficacy, and safety profile. Attention is given to dose fractionation strategies, timing of re-irradiation, and technological advancements that enhance treatment precision.

RESULTS

LDRT provides pain relief in 60-90% of treated cases, with the most favorable results achieved using fraction doses between 0.3 and 0.7 Gy. Its anti-inflammatory effects are mediated through immune modulation, reduced proinflammatory cytokine expression, and promotion of tissue repair. Re-irradiation performed 10-12 weeks after the initial cycle may be beneficial in patients experiencing symptom persistence or recurrence. Long-term follow-up data confirm sustained efficacy and indicate a minimal risk of radiation-induced malignancies in older adults.

CONCLUSION

LDRT is a safe and effective treatment option for PMDs, especially in patients unresponsive to conventional therapies. To facilitate its broader adoption, this review underscores key clinical evidence and proposes practical considerations for integrating LDRT into multidisciplinary pain management protocols.

Effects of low dose rate radiotherapy on pain relief, performance score, and quality of life in patients with knee osteoarthritis; a double-blind sham-controlled randomized clinical trial

INTRODUCTION

Knee osteoarthritis (OA) is a prevalent chronic condition characterized by progressive damage to the articular cartilage, resulting in chronic pain, swelling, and reduced range of motion with a range of prevalence of 10-40%. This study aims to investigate the efficacy of low-dose radiation as a local treatment option for knee OA symptoms.

METHODS

In this prospective study, patients with confirmed OA and older than 65 years were randomly assigned to treatment and control groups. The protocol plan IRCT20160706028815N6 was registered in Iranian registry of clinical trials system. The treatment group received 3 Gy radiation over six fractions, while the control group continued routine treatment without radiation. The pain intensity and functional levels were assessed at pretreatment and each month following completion of therapy for six consecutive months by Visual Analog Scale (VAS) and the Lysholm 100-point Scale, respectively. Analgesic medication usage and performance status (PS) were also assessed.

RESULTS

The mean age of the patients was 77 years (range 72-89). All variables including VAS pain score, Lysholm scale, PS and analgesic consumption were improved following radiation from first month to the end of assessments (p value <0.01).

CONCLUSION

Results showed significant pain score improvements and enhanced joint function with no adverse effects. Findings were compared with previous studies, revealing mixed conclusions on low dose radiation therapy (LDRT) efficacy. Mechanistic hypotheses suggest LDRT may modulate inflammatory pathways. The study suggests LDRT at 3 Gy could benefit knee osteoarthritis patients and calls for further research on mechanisms of action in early-stage osteoarthritis.

Low-dose Radiation Therapy (LDRT) in Managing Osteoarthritis: A Comprehensive Review

Osteoarthritis (OA) is the most common degenerative arthropathy, impacting the quality of life for millions worldwide. It typically presents with chronic pain, stiffness, and reduced mobility in the affected joints. Nonsurgical treatments like physiotherapy or pharmacotherapy may provide limited relief and may have adverse effects and complications. Recently, low-dose radiation therapy (LDRT) has emerged as a potential alternative for managing OA, utilizing its anti-inflammatory effects. LDRT's anti-inflammatory effects involve modulating immune responses, reducing pro-inflammatory cytokines, and inducing apoptosis in inflammatory cells. Clinical studies show varying degrees of symptom relief, with some patients experiencing pain reduction and improved joint mobility while others show minimal response. The variability in LDRT treatment designs, radiation dosages, and patient populations complicates standardized treatment protocols and raises concerns about potential carcinogenic risks. Despite these issues, LDRT shows promise as an alternative to other OA treatments, especially for patients who don't respond to other treatments. This review aims to provide updated information on the effectiveness, mechanisms, and safety of LDRT in treating OA. We reviewed the literature of studies on the safety and efficacy of LDRT on affected joints by OA, its biological effects, potential therapeutic and adverse effects, application and contraindications, clinical outcomes, and clinical evidence in subjects with OA.

How Effective is Low-dose Radiotherapy (LD-RT) for Heberden's Osteoarthritis? An Analysis of the Current Literature

Low-dose radiotherapy is an established treatment option for non-malignant skeletal disorders. It is used in the treatment of Heberden's osteoarthritis (HA), but the evidence of efficacy does not seem to be certain. This paper reviews current literature for scientific evidence of efficacy in the treatment of HA.The PubMed and Cochrane Library databases were searched for relevant publications.9 publications were identified that published data from 7 studies. Only one study was randomised, placebo-controlled and double-blinded. None of the studies exclusively investigated HA. The studies were all inhomogenous with regard to inclusion criteria, follow-up criteria, radiation mode and interpretation or treatment success. In the RCT, no difference was found between the verum and control groups.The study situation is currently weak. The researched publications are not sufficiently focused on the collective of Heberden's osteoarthritis and are generally too inhomogenous with regard to the criteria applied. Future targeted studies are therefore required to prove efficacy.

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 radiotherapy of osteoarthritis: from biological findings to clinical effects-challenges for future studies

Osteoarthritis (OA) is one of the most common and socioeconomically relevant diseases, with rising incidence and prevalence especially with regard to an ageing population in the Western world. Over the decades, the scientific perception of OA has shifted from a simple degeneration of cartilage and bone to a multifactorial disease involving various cell types and immunomodulatory factors. Despite a wide range of conventional treatment modalities available, a significant proportion of patients remain treatment refractory. Low-dose radiotherapy (LDRT) has been used for decades in the treatment of patients with inflammatory and/or degenerative diseases and has proven a viable option even in cohorts of patients with a rather poor prognosis. While its justification mainly derives from a vast body of empirical evidence, prospective randomized trials have until now failed to prove the effectiveness of LDRT. Nevertheless, over the decades, adaptions of LDRT treatment modalities have evolved using lower dosages with establishment of different treatment schedules for which definitive clinical proof is still pending. Preclinical research has revealed that the immune system is modulated by LDRT and very recently osteoimmunological mechanisms have been described. Future studies and investigations further elucidating the underlying mechanisms are an essential key to clarify the optimal patient stratification and treatment procedure, considering the patients' inflammatory status, age, and sex. The present review aims not only to present clinical and preclinical knowledge about the mechanistic and beneficial effects of LDRT, but also to emphasize topics that will need to be addressed in future studies. Further, a concise overview of the current status of the underlying radiobiological knowledge of LDRT for clinicians is given, while seeking to stimulate further translational research.

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.

The Role of Ionizing Radiation for Diagnosis and Treatment against COVID-19: Evidence and Considerations

The Coronavirus disease 2019 (COVID-19) pandemic continues to spread worldwide with over 260 million people infected and more than 5 million deaths, numbers that are escalating on a daily basis. Frontline health workers and scientists diligently fight to alleviate life-threatening symptoms and control the spread of the disease. There is an urgent need for better triage of patients, especially in third world countries, in order to decrease the pressure induced on healthcare facilities. In the struggle to treat life-threatening COVID-19 pneumonia, scientists have debated the clinical use of ionizing radiation (IR). The historical literature dating back to the 1940s contains many reports of successful treatment of pneumonia with IR. In this work, we critically review the literature for the use of IR for both diagnostic and treatment purposes. We identify details including the computed tomography (CT) scanning considerations, the radiobiological basis of IR anti-inflammatory effects, the supportive evidence for low dose radiation therapy (LDRT), and the risks of radiation-induced cancer and cardiac disease associated with LDRT. In this paper, we address concerns regarding the effective management of COVID-19 patients and potential avenues that could provide empirical evidence for the fight against the disease.

ArthroRad trial: multicentric prospective and randomized single-blinded trial on the effect of low-dose radiotherapy for painful osteoarthritis depending on the dose-results after 3 months' follow-up

Purpose

Randomized comparison of the effect of radiotherapy on painful osteoarthritis (OA) applying a standard-dose vs. a very-low-dose regime

Patients and methods

Patients with OA of the hand and knee joints were included. Further inclusion criteria: symptoms for more than 3 months, favorable general health status, age above 40 years. Patients with prior local radiotherapy, trauma, rheumatoid arthritis, or vascular diseases were excluded. After randomization (every joint was randomized separately), the following protocols were applied: standard arm: total dose 3.0 Gy, single fractions of 0.5 Gy twice weekly; experimental arm: total dose 0.3 Gy, single fractions of 0.05 Gy twice weekly. The dosage was not known to the patients. The patients were examined 3 and 12 months after radiotherapy. Scores like VAS (visual analogue scale), KOOS-SF (the knee injugy and osteoarthritis outcome score), SF-SACRAH (short form score for the assessment and quantification of chronic rheumatic affections of the hands), and SF-12 (short form 12) were used.

Results

A total of 64 knees and 172 hands were randomized. 3.0 Gy was applied to 87 hands and 34 knees, 0.3 Gy was given to 85 hands and 30 knees. After 3 months, we observed good pain relief after 3 Gy and after 0.3 Gy, there was no statistically significant difference. Side effects were not recorded. The trial was closed prematurely due to slow recruitment.

Conclusion

We found favorable pain relief and a limited response in the functional and quality of life scores in both arms. The effect of low doses such as 0.3 Gy on pain is widely unknown. Further trials are necessary to compare a conventional dose to placebo and to further explore the effect of low doses on inflammatory disorders.

Prospective Evaluation of Low-Dose External Beam Radiotherapy (LD-EBRT) for Painful Trapeziometacarpal Osteoarthritis (Rhizarthrosis) on Pain, Function, and Quality of Life to Calculate the Required Number of Patients for a Prospective Randomized Study

Background: Retrospective studies have described the effectiveness of low-dose radiotherapy (LD-EBRT) in painful arthrosis of small finger joints, but two recent prospective studies have yielded ambiguous results. To generate accurate data for the planning of a trial, we conducted a prospective, monocentric, observational study to describe the effects of LD-EBRT as precisely as possible. Methods: Twenty-five consecutive patients with symptomatic trapeziometacarpal (TMC) arthrosis were irradiated with 6 × 0.5 Gy. Before, 3, and 12 months after LD-EBRT, we assessed subjective endpoints (modified “von-Pannewitz score”, 10-point visual analogue scale (VAS), “patient-rated wrist evaluation” (PRWE)), and objective measurements (“active range of motion” (AROM), Kapandji index, grip strength, pinch grip). Results: At 3/12 months, 80%/57% reported partial and 4%/18% complete remission according to the “von-Pannewitz” score. VAS “overall pain” significantly decreased from a median of seven (IQR 4) at baseline to three (IQR 6; p = 0.046) and to two (IQR 2; p = 0.013). Similar results were obtained for VAS “pain during exercise”, VAS “pain during daytime”, and VAS “function”. “PRWE overall score” was reduced from 0.5 at baseline (SD 0.19) to 0.36 (SD 0.24, p = 0.05) and to 0.27 (SD 0.18, p = 0.0009). We found no improvements of the objective endpoints (AROM, Kapandji, grip strength) except for flexion, which increased from 64° (SD 12°) at baseline to 73° (SD 9.7°, p = 0.046) at 12 months. Conclusions: We recommend the PRWE score as a useful endpoint for further studies for this indication. To prove a 15% superiority over sham irradiation, we calculated that 750 patients need to be prospectively randomized.

Low-dose radiotherapy for painful osteoarthritis of the elderly: A multicenter analysis of 970 patients with 1185 treated sites

PURPOSE

Painful osteoarthritis is common in elderly patients, and low-dose radiotherapy has been demonstrated to provide effective symptomatic treatment. We examined the analgesic effects of low-dose radiotherapy for osteoarthritis in the elderly aiming to reveal potential differences in the response rates relating to increasing age.

METHODS

A retrospective analysis was performed at two university hospitals including elderly patients (≥ 65 years) undergoing radiotherapy for osteoarthritis between 2008 and 2020. Pain intensity and response were quantified using the numerical rating scale (NRS) and the Pannewitz score. Age groups were defined for young old (65-74 years), older old (75-84 years), and oldest old patients (≥ 85 years).

RESULTS

In all, 970 patients with 1185 treated sites and a median age of 76 years were analyzed. Mean NRS was 66 at baseline (t0), 53 after radiotherapy (t1), and 44 at first follow-up (t2) (p < 0.001 for t0-t1, t1-t2, and t0-t2). At t1, 1.5% exhibited a Pannewitz score of 0 (no pain), 58.5% of 1-2 (less pain), 36.1% of 3 (equal pain), and 3.9% of 4 (worse pain), while at t2, pain response shifted towards 6.9% (0), 58.6% (1-2), 28.1% (3), and 6.3% (4). Pain response did not differ between age groups at t1 (p = 0.172) or t2 (p = 0.684). In addition, pain response after re-irradiation (n = 384 sites) was 61.0% and was comparable between age groups (p = 0.535).

CONCLUSION

Low-dose radiotherapy results in pain reduction in about two-thirds of treated sites with no difference relating to increasing age, showing that radiotherapy is an effective analgesic treatment for osteoarthritis even at advanced ages.

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.

Radiotherapy of Lymphatic Fistulas after Vascular Surgery in the Groin

PURPOSE

Lymphatic fistulas are common complications after vascular surgery especially in the groin, which can lead to a prolongation of the inpatient stay, wound infections and follow-up operations. Radiotherapy is one of the non-surgical treatment options. However, there is limited evidence and discussion about the ideal dosage and timing.

METHODS AND MATERIALS

The analysis was performed on patients from a German university hospital and included 191 patients with 206 lymphatic fistulas from 2005 to 2016. Four different endpoints were analyzed. The patients were irradiated with a fraction dose of 3 Gy up to a cumulative dose of 9 Gy (94/206 cases) or 18 Gy (112/206 cases). The median age of the patients was 70.5 years with 74% male and 26% female patients. Vascular surgery included bypass grafts (52%), thrombendarterectomy/patch angioplasty (26%), and vascular access for aortic endografts (22%).

RESULTS

The response to radiotherapy for the four different endpoints was 88% (25% decrease in secretion volume), 80% (secretion below 50 ml/24 hours), 81% (removal of the drainage) and 75% (freedom from any intervention), respectively. The overall response for all four endpoints was 63% (129/206) after completion of radiotherapy, and 34% (70/206) after one course with a total dose up to 9 Gy. The median lymphatic secretion was 150 ml/24 hours before radiotherapy and 60 ml/24 hours one day after the end of therapy. The drainage could be removed a median of 3 days after radiotherapy completion. There was no significant difference between patients starting the radiation within 5-9 days or ≥10 days postoperatively (p = .971 OR = 0.99; 95%-CI: 0.56 to 1.74). No relevant factors influencing the response rate could be identified. Re-operation was required in 50/206 cases (25%), in 24/206 cases (12%) due to persistent lymphatic fistula and complications and in 26/206 cases (13%) due to wound and/or vascular complications.

CONCLUSION

Radiotherapy seems to be an effective, non-surgical treatment option for reducing lymphatic secretion after vascular surgery in the groin. Starting radiation early (≤9 days) or late (≥10 days) postoperatively does not affect the success rate.

The Influence of Radiation on Bone and Bone Cells-Differential Effects on Osteoclasts and Osteoblasts

The bone is a complex organ that is dependent on a tight regulation between bone formation by osteoblasts (OBs) and bone resorption by osteoclasts (OCs). These processes can be influenced by environmental factors such as ionizing radiation (IR). In cancer therapy, IR is applied in high doses, leading to detrimental effects on bone, whereas radiation therapy with low doses of IR is applied for chronic degenerative and inflammatory diseases, with a positive impact especially on bone homeostasis. Moreover, the effects of IR are of particular interest in space travel, as astronauts suffer from bone loss due to space radiation and microgravity. This review summarizes the current state of knowledge on the effects of IR on bone with a special focus on the influence on OCs and OBs, as these cells are essential in bone remodeling. In addition, the influence of IR on the bone microenvironment is discussed. In summary, the effects of IR on bone and bone remodeling cells strongly depend on the applied radiation dose, as differential results are provided from in vivo as well as in vitro studies with varying doses of IR. Furthermore, the isolated effects of IR on a single cell type are difficult to determine, as the bone cells and bone microenvironment are building a tightly regulated network, influencing on one another. Therefore, future research is necessary in order to elucidate the influence of different bone cells on the overall radiation-induced effects on bone.

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.