Low level lasers in dentistry

Low level laser therapy (LLLT) uses light energy, in the form of adenosine triphosphate (ATP), to elicit biological responses in the body. The increased cellular energy and changes in the cell membrane permeability result in pain relief, wound healing, muscle relaxation, immune system modulation, and nerve regeneration. This article investigates the clinical effects of LLLT and explains how it can be applied in the dental field.

Suppressing effect of low-dose gamma-ray irradiation on collagen-induced arthritis

We previously reported attenuation of autoimmune disease by low-dose gamma-ray irradiation in MRL-lpr/lpr mice. Here, we studied the effect of low-dose gamma-ray irradiation on collagen-induced arthritis (CIA) in DBA/1J mice. Mice were immunized with type II collagen, and exposed to low-dose gamma-rays (0.5 Gy per week for 5 weeks). Paw swelling, redness, and bone degradation were suppressed by irradiation, which also delayed the onset of pathological change and reduced the severity of the arthritis. Production of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6, which play important roles in the onset of CIA, was suppressed by the irradiation. The level of anti-type II collagen antibody, which is essential for the onset of CIA, was also lower in irradiated CIA mice. The population of plasma cells was increased in CIA mice, but irradiation blocked this increase. Since regulatory T cells are known to be involved in suppression of autoimmune disease, the population of CD4(+)CD25(+)Foxp3(+) regulatory T cells was measured. Intriguingly, a significant increase of these regulatory T cells was found in irradiated CIA mice. Overall, our data suggest that low-dose gamma-ray irradiation could attenuate CIA through suppression of pro-inflammatory cytokines and autoantibody production, and induction of regulatory T cells.

Development of samarium [32P] phosphate colloid for radiosynoviorthesis applications: Preparation, biological and preliminary clinical studies experience

A new therapeutic radio colloid for radiosynoviorthesis (RS) applications is reported. The method of preparation involves the reaction of SmCl3 carrier with carrier added [32P]H3PO4 in the presence of gelatin. The pure colloid was recovered by dialysis purification leading to radiochemical yield of around 90%. The radiochemical purity of the pure colloid formulated in isotonic saline was over 98%, for the usage period of 14 days, as assessed by paper chromatography. Ninety percent of colloid particles were in the size of 1-10 microm as evident from the laser diffraction particle size analysis, ideally suitable for the intended end use. Animal studies revealed complete retention of the radio colloid in the rabbit knee joint. The results of clinical trials in humans are satisfactory and encouraging, satisfactory retention of the colloid in the knee joint and negligible leakage into the systemic circulation.

Die Radiosynoviorthese im orthopädischen und rheumatologischen Alltag

Radionuclide synoviorthesis (RSO) is a local radiotherapy that can be used in cases of synovialitis. RSO is performed by intraarticular injection of beta emitters (Er-169, Re-186, Y-90). Before RSO is planned, a precise indication is necessary, which must be verified by the acting nuclear physician, preferably using soft-tissue scintigraphy. If RSO is handled in an interdisciplinary fashion, it will be a valuable tool in the treatment of synovialitis.

The intra-articular distribution of 90yttrium does not influence the clinical outcome of radiation synovectomy of the knee

OBJECTIVES

To assess the impact of the intra-articular distribution of (90)yttrium-citrate ((90)Y) on the clinical effect of radiosynoviorthesis (RSO) of the knee and on (90)Y leakage from this joint.

METHODS

Patients with arthritis of the knee received 185 MBq (90)Y combined with a glucocorticoid, followed by clinical bed rest. Intra-articular (90)Y distribution, measured with a dual-head gamma camera immediately or after 24 hours, was scored as mainly diffuse or mainly focal. Leakage to regional lymph nodes, the liver and spleen was assessed with a dual-head gamma camera after 24 hours. Clinical effect was scored after 6 months by a composite change index (CCI), range 0-12; responders were defined as having a CCI > or =6.

RESULTS

Seventy-eight knees of 69 patients, mostly suffering from undifferentiated arthritis (42%) or RA (28%), were treated. (90)Y distribution was mainly diffuse in 54% and mainly focal in 46% with clinical response rates of 40% versus 56%, respectively, p = 0.3. CCI was not correlated with distribution. (90)Y leakage was found only to the liver and the spleen (mean leakage 0.4% and 1.1%, respectively). Leakage was significantly less in case of diffuse intra-articular (90)Y distribution, whereas leakage to the liver was correlated with distribution (r = 0.68, p<0.001). (90)Y leakage was not correlated with CCI.

CONCLUSIONS

Intra-articular (90)Y distribution does not influence the clinical effect of RSO of the knee. Although (90)Y leakage from the joint is less if (90)Y distributes diffusely in the joint cavity, leakage does not seem to hamper the clinical effect.

In vivo study of the inflammatory modulating effects of low-level laser therapy on iNOS expression using bioluminescence imaging

This study was designed to demonstrate that bioluminescence imaging (BLI) can be used as a new tool to evaluate the effects of low-level laser therapy (LLLT) during in vivo inflammatory process. Here, the efficacy of LLLT in modulating inducible nitric oxide synthase (iNOS) expression using different therapeutic wavelengths was determined using transgenic animals with the luciferase gene under control of the iNOS gene expression. Thirty transgenic mice, FVB/N-Tg(iNOS-luc)Xen, were allocated randomly to one of four experimental groups treated with different wavelengths (lambda = 635, 785, 808 and 905 nm) or a control group (nontreated). Inflammation was induced by intra-articular injection of zymosan A in both knee joints. Laser treatment (25 mW cm(-2), 200 s, 5 J cm(-2)) was applied to the knees 15 min after inflammation induction. Measurements of iNOS expression were performed at various times (0, 3, 5, 7, 9 and 24 h) by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera. The results showed a significant increase in BLI signal after irradiation with 635 nm laser when compared to the nonirradiated animals and the other LLLT-treated groups, indicating wavelength dependence of LLLT effects on iNOS expression during the inflammatory process, and thus demonstrating an action spectrum of iNOS gene expression following LLLT in vivo that can be detected by BLI. Histological analysis was also performed and demonstrated the presence of fewer inflammatory cells in the synovial joints of mice irradiated with 635 nm compared with nonirradiated knee joints.

Perspektiven der Strahlentherapie gutartiger Erkrankungen

PURPOSE

The numbers of patients with nonmalignant diseases referred for radiation therapy had to be evaluated for the last 4 years.

PATIENTS AND METHODS

In the years 2002, 2004, and 2005 radiation therapy was performed in 61, 40, and 26 patients, respectively. Regularly, more women than men were treated, median age annually was 57, 54, and 55 years, respectively (Table 1). The radiotherapy scheme was not modified within the evaluated period.

RESULTS

The proportion of nonmalignant diseases among all patients treated decreased from 4.7% in 2002 to 3.3% in 2004 and 2.2% in 2005, respectively. A shift was noticed toward the treatment of four main diseases (endocrine orbitopathy, prevention of heterotopic ossification, meningeoma, tendinitis, Table 2). The number of referring physicians decreased from 19 to six.

CONCLUSION

Due to administrative restrictions for treatment in hospitals, budget restrictions in private practices and lasting, insufficient revenues for radiotherapy in nonmalignant diseases, radiation therapy for the entire group of benign diseases is endangered.

Radiosynoviorthese

Intraarticular therapy is an established form of therapy in chronic inflammatory joint diseases. Besides the injection of glucocorticoids, radiosynoviorthesis is a frequently used procedure. Intraarticular injected beta-emitting radionuclides are indicated in chronic synovitis with recurrent joint effusions in rheumatoid arthritis, seronegative spondyloarthritis, villonodular synovitis after surgery and for bleeding prophylaxis in haemophilic arthropathy. The value of radiosynoviorthesis in activated osteoarthritis is not yet clarified.

Ungewöhnliche Fingergelenkdestruktionen nach Radiosynoviorthese (RSO) und Cortisoninjektionstherapie bei Bouchard-Arthrose

Starting in 1998, a female patient suffering from activated Bouchard arthrosis was treated with intra-articular steroid injections into digits of both hands. In September 2001, an additional therapy with erbium-169 injections into the same joints was begun. The injections were continued until March 2003. No benefit was observed. Instead, severe destruction of the involved joints with articular necroses and marked periarticular calcifications had occurred. The course of events are documented by plain film examinations.

CONCLUSIONS

The indication for alternating steroid injections and radio-synovectomies in patients with activated Bouchard arthrosis has to be reconsidered. In vivo and in vitro experiments are necessary to evaluate the potential harms of this combination of therapies. A close clinical and radiological control of treatment outcome with reevaluation of the indication is necessary.

Laser Therapy on Arthritis Induced by Urate Crystals

OBJECTIVE

We aimed to evaluate low-power laser therapy efficacy on fibrinogen (PF) in the plasma of rats with arthritis induced by urate crystals. In addition, anatomopathological (AP) studies were carried out.

BACKGROUND DATA

Raised blood uric acid may form microscopic crystals in the joint. These crystals set up the inflammation called "acute gouty arthritis."

METHODS

Two mg of uric acid were injected in both joints of the lower limbs of rats over 2 days. A group was treated with He-Ne laser (6 mW) on the injected joints during 3 consecutive days. After 96 h of the first injection, animals were sacrificed to determine fibrinogen by spectrophotometry. Sections from the lower limbs were used for AP studies.

RESULTS

A statistically significant increase (p < 0.001) in plasma fibrinogen levels was observed in the group injected with urates, when compared to both control group and the laser-treated group. The AP observed in the untreated group showed an intense fibroblastic proliferation and chronic inflammation. In the group treated with laser no inflammatory reaction was observed.

CONCLUSIONS

Laser therapy has an anti-inflammatory effect in arthropathy induced in rats injected with urates, determined by fibrinogen levels and by histological involution.

Yttrium90 synovectomy in the management of chronic knee arthritis: a single institution experience

Radiation synovectomy (RS) has been used to treat chronically inflamed joints refractory to treatment using conventional agents. In RS, the radioactive isotope is concentrated in the synovial membrane from the injected colloid suspension, where it exerts its activity. However, despite numerous reports confirming its safety and efficacy, this procedure is not widely practised. In the Singleton Hospital NHS Trust, yttrium(90) (Y(90)) RS has been practised since 1990 for refractory synovitis. In this study, we analyse the results of therapy and complications in 38 joints so treated. Doses of 10 mCi were used in the majority of patients. Most responses were apparent by 6 months following the procedure. Altogether, 68% of the treated joints showed satisfactory response at 3 years, with 29% having all symptoms under control beyond 3 years. In three patients, there was evidence of minor pigmentation at the injection site. Two patients had extravasation of the isotope and needle track ulcers, which were recorded as major toxicity. We find Y(90) radiosynovectomy to be safe, quick, and effective in the management of patients with refractory synovitis. The efficacy of RS should be tested in randomised clinical trials involving large numbers of patients.

Analysis of lapine cartilage matrix after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate

OBJECTIVE

To study the short and long term effects of radiosynovectomy on articular cartilage in growing and mature rabbits.

METHODS

The articular cartilage of the distal femurs of rabbits was examined four days, two months, and one year after radiosynovectomy with holmium-166 ferric hydroxide macroaggregate ([(166)Ho]FHMA). Arthritic changes were evaluated from histological sections by conventional and polarised light microscopy, and glycosaminoglycan measurements using safranin O staining, digital densitometry, and uronic acid determination. Proteoglycan synthesis was studied by metabolic [(35)]sulphate labelling followed by autoradiography, and electrophoretic analysis of extracted proteoglycans. Northern analyses were performed to determine the mRNA levels of type II collagen, aggrecan, and Sox9 in cartilage samples.

RESULTS

Radiosynovectomy had no major effect on the histological appearance of articular cartilage in mature rabbits, whereas more fibrillation was seen in [(166)Ho]FHMA radiosynovectomised knee joints of growing rabbits two months after treatment, but not after one year. Radiosynovectomy did not cause changes in the glycosaminoglycan content of cartilage or in the synthesis or chemical structure of proteoglycans. No radiosynovectomy related changes were seen in the mRNA levels of type II collagen, whereas a transient down regulation of aggrecan and Sox9 mRNA levels was seen in young rabbits two months after [(166)Ho]FHMA radiosynovectomy.

CONCLUSIONS

[(166)Ho]FHMA radiosynovectomy caused no obvious chondrocyte damage or osteoarthritic changes in mature rabbits, but in growing rabbits some transient radiation induced effects were seen--for example, mild cartilage fibrillation and down regulation of cartilage-specific genes.

Monarthritis of the ankle as manifestation of a calcaneal metastasis of bronchogenic carcinoma

We report a case of bronchiogenic carcinoma metastasizing to the calcaneus and clinically manifesting itself as a therapy-refractory monarthritis in the right ankle. There is a wide spectrum of possible diagnoses of acute ankle monarthritis including different forms of inflammatory rheumatic diseases, sarcoidosis, osteoarthritis, or septic arthritis. Primary or metastatic malignancies of the hand or foot bones are considered to be rare. Persistent monarthritis as a sole symptom of a calcaneal metastasis has never been reported. This case demonstrates possible difficulties in the early differential diagnosis of acute monarthritis, and will be discussed with respect to the few reports on foot acrometastases.

The effect of radiation synovectomy in patients with persistent arthritis: a prospective study

OBJECTIVE

To investigate and compare the effects of radiation synovectomy of various joints in a rheumatological practice.

METHODS

Consecutive patients referredfor radiation synovectomy to Medical Center Alkmaarfrom 1993 till 1996 were analyzed (n = 138). Patients had to have persistent arthritis despite at least two intra-articular glucocorticoid injections with 20 mg triamcinolone hexacetonide. The knees were treated with 185 MBq Yttrium-90; shoulders, elbows, wrists, hips and talocrural joints received 185 MBq Rhenium-186 and meta-carpophalangeal joints and proximal interphalangeal joints 37 MBq Erbium-169. The radionuclide injection was followed by injection of 20 mg triamcinolone in order to prevent flare-up of synovitis (due to chemical irritation) and needle-track burn. The clinical effect was assessed by evaluating VAS pain (0-10 point scale), functional disability, tenderness and swelling of the treated joint and patient's and physician's global assessments of the effect of therapy (each on a 4-point scale).

RESULTS

The overall success rate for radiation synovectomy one year after treatment was 70% with a significant improvement in the variables VAS pain, functional disability and joint tenderness and swelling, when compared to baseline values (p < 0.000001). Moderate to considerable satisfaction of patients and physicians one year after treatment was found for > 50% of cases. Wrists and shoulders were the joints with highest success rate of treatment, followed by the elbows. Lowest success rates were found for hips and ankles. In RA treatment was effective in 76% of cases whereas patients with OA exhibited a success rate of 50%. In RA all treated joints, except the ankles, exhibited a success rate of > or = 75%. No short-term clinical adverse side effects were noted.

CONCLUSION

Radiation synovectomy seems to be a successful treatment for persistent arthritis when other therapeutic modalities have failed.

Acute arthritis as an unusual complication of malignancy

A 59-year-old man presented with an inability to weight-bear due to an acute, red, hot, swollen knee joint which was subsequently found to be due to a malignant joint effusion consequent to colonic carcinoma. Treatment with radiation therapy relieved his symptoms. A review of the literature reveals that malignant joint effusion is rare and this is only the third reported case secondary to colonic carcinoma.

Systemic radiation therapy with unsealed radionuclides

Systemic unsealed radiation therapy is achieved when a radioactive substance is administered orally or parenterally and that material is concentrated in an organ or site for sufficient time to deliver a therapeutic dose of radiation. The radioactive material usually emits beta particles. In general, there is intense local radiation of the abnormal tissues, and normal organs, which do not trap the radioactive material, are exposed to a small radiation dose. The most frequent treatments involve radioiodine (131)I for hyperthyroidism and differentiated thyroid cancer. Other applications include treatment of painful skeletal metastases, polycythemia vera, malignant cysts, and neuroendocrine tumors. The treatments are usually well tolerated and not associated with long-term effects, such as cancer or infertility.

Radiation synovectomy using 165Dy ferric-hydroxide and oxidative DNA damage in patients with different types of arthritis

Radiation synovectomy is an effective treatment for chronic synovitis refractory to pharmacological treatment in patients with rheumatoid or seronegative arthritis. Concerns persist about possible radiation-induced cytogenetic damage after radiation synovectomy leading to recommendations to use this technique only in the elderly. Micronucleus (MN) frequency in lymphocytes and urinary excretion of 8-hydroxy-2'-deoxyguanosine (8OHdG) as an indicator of cellular oxidative DNA base damage are biomarkers of radiation-induced cytogenetic damage. The course of both biomarkers was studied in patients with different types of chronic synovitis undergoing radiation synovectomy with very short-lived 165Dy-ferric-hydroxide (DFH).

METHODS

Radiation synovectomy of the knee was performed in 13 men and 12 women (mean age, 44+/-15 y) using a mean activity of 9.48+/-1.65 GBq 165Dy-DFH in 27 consecutive treatments. MN frequency in lymphocytes and urinary excretion of 8OHdG, measured by high-performance liquid chromatography, were assessed before and 4 (MN only) and 20 h after radiation synovectomy.

RESULTS

Urinary excretion of 8OHdG in patients (in micromol/mol creatinine; pretreatment mean, 3.1+/-3.4; median, 2.27) was not significantly different from that in healthy volunteers (mean, 2.0+/-1.2; median, 1.87) and not altered by radiation synovectomy (post-treatment mean, 2.5+/-1.5; median, 2.04, NS). An increase in 8OHdG levels after radiation synovectomy of more than 1 SD was found in only 1 patient, who experienced leakage to the lymph nodes but who already had elevated urinary 8OHdG levels before treatment. The frequency of MN/500 binucleated cells (BNCs) was slightly lower in patients (pretreatment mean, 4.3+/-2.6; median, 4.25) than in healthy volunteers (mean, 5.4+/-2.3; median, 5.3) and did not significantly change after therapy, either (4-h post-treatment mean, 3.9+/-2.1, median, 3.8; 20-h post-treatment mean, 4.1+/-2, median 3.8 MN/500 BNC). In 22 of 27 treatments, no leakage to nontarget organs could be monitored, whereas leakage to the local lymph nodes and the liver was detected after 5 treatments.

CONCLUSION

Radiation synovectomy using 165Dy-DFH causes no significant radiation burden to most patients as indicated by the absence of adverse changes in levels of biomarkers of cytogenetic damage and a low incidence of leakage. These data suggest that the risk of malignancy may not be elevated.

[Value of radiosynovectomy in rheumatology and orthopedics]

For many years radiosynovectomy has proved its worth in the treatment of inflammatory joint disease. More recently there has also been growing interest in the use of this method for outpatient treatment. In this overview we discuss the established and new indications. With increasing use of the method, interest should be focused on adequate quality control. Accordingly, basic requirements for correct performance of radiosynovectomy in clinical practice are addressed. Our results, based on five years' experience of radiosynovectomy in outpatients, have shown improvement of clinical symptoms in 60-70% of cases. However, success rates of this kind require high quality standards and close cooperation with the referring rheumatologists.

Radionuclide therapy

Nuclear medicine therapy uses unsealed radioactive sources for the selective delivery of radiation to tumours or target organs. For benign disorders such as thyrotoxicosis and arthritis radionuclide therapy provides an alternative to surgery or medical treatment. In cancer treatment, it often combines the advantage of target selectivity (like brachytherapy or external beam radiotherapy) with that of being systemic, as with chemotherapy, and it may be used as part of a therapeutic strategy with curative intent or for disease control and palliation. Toxicity is generally limited to the haematopoietic tissue and few side-effects are observed. When cure is feasible, the long-term consequences of radionuclide therapy (eg, fertility disorders and leukaemia or other secondary cancers) do compare favourably with the risks associated with and accepted for chemotherapy and radiotherapy.

Radiobiological mechanisms of anti-inflammatory radiotherapy

Radiotherapy with total doses of < or =6 Gy has been given as very effective and low risk treatment of painful degenerative joint diseases and other inflammatory processes. Recent radiobiological experiments in vitro and in vivo identified mechanisms which may be related to these anti-inflammatory radiation effects, in particular functional modulation of the adhesion of white blood cells to activated endothelial cells and modulation of the induction of nitric oxide synthase in activated macrophages.

[The effects of low-dose Co-60 irradiation on the course of aseptic arthritis in a rabbit knee joint]

PURPOSE

Numerous clinical observations demonstrate the efficacy of low radiation doses in the treatment of painful osteoarthritis. Experimental investigations remain scarce. We investigated the effects of locally daily 5 times 1.0 Gy 60-Co irradiation on an artificially induced aseptic gonarthritis in rabbits.

MATERIAL AND METHODS

Three separate experiments (EV) were performed (10 rabbits per experiment, 5 treated/5 controls; duration: EV1: 18 days; EV2: 6 days; EV3: 29 days). An aseptic arthritis in the right knee joint of rabbits was induced by intraarticular injection of 0.5 ml papain solution (3%, 30,000 USP/mg) on day 0. The arthritic knee joint of the anesthesized animals was irradiated daily from day 1 to 5 with 5 times 1.0 Gy. The controls were sham-irradiated under the same conditions. The time course of arthritis in treated animals and sham-treated controls was evaluated by clinical, laboratory-chemical and histological criteria. The clinical investigation was performed daily, the puncture of the knee-joints was carried out several times in EV1, and at the end of experiments in EV2 and EV3. At the end of the observation period, animals were killed and the knee joints excised for histological analysis.

RESULTS

The intraarticular injection of papain caused a peracute inflammatory response in all animals. After 1 week the chronic stage was reached, and the experimental arthritis resolved slowly within several weeks. Local irradiation accelerated the decrease of inflammatory joint swelling, being significant by day 4. On day 6 the volume of synovial fluid in irradiated knee-joints was significantly smaller. The morphometric data indicated a reduction in thickness of synovial membrane, a decrease in number of synovial cell layers, and a decrease in distance between capillaries and the synovial membrane surface following irradiation of arthritic joints. Due to considerable individual variability, the morphometric data partially did not reach statistically significance.

CONCLUSION

The experiments provide evidence for an antiphlogistic effect of irradiation with 5 times 1.0 Gy in vivo. They support the clinical observations of the efficacy of anti-inflammatory radiotherapy.

[Low-level laser therapy in osteoarticular diseases in geriatric patients]

INTRODUCTION

Laser light absorption through the skin causes tissue changes, targeting the nervous, the lymphatic, the circulatory and the immune systems with an antalgic, anti-inflammatory, anti-edemic effect and stimulating tissue repair. Therefore low level laser therapy is now commonly used in numerous rehabilitation centers, including the "Istituto Gerontologico Pio Albergo Trivulzio", Milan, Italy. However, to activate the treatment program, the basic medical research results must always be considered to choose the best optical wavelength spectrum, technique and dose, for rehabilitative laser therapy. We analyzed the therapeutic effects of different wavelengths and powers in various treatment schedules. In particular, a protocol was designed to test such physical parameters as laser type, doses and individual schedule in different pathologic conditions. We report the results obtained with low level laser therapy in the rehabilitation of geriatric patients, considering the various physical and technical parameters used in our protocol.

MATERIAL AND METHODS

We used the following laser equipment: an HeNe laser with 632.8 nm wavelength (Mectronic), a GaAs Laser with 904 nm wavelength (Mectronic) and a CO2 Laser with 10,600 nm wavelength (Etoile). To evaluate the patient clinical status, we use a different form for each involved joint; the laser beam is targeted on the region of interest and irradiation is carried out with the sweeping method or the points technique. Irradiation technique, doses and physical parameters (laser type, wavelength, session dose and number) are indicated on the form. The complete treatment cycle consists of 5 sessions per week--20 sessions in all. At the end of the treatment cycle, the results were scored on a 5-grade semiquantitative scale--excellent, good, fair, poor and no results. We examined 3 groups of patients affected with gonarthrosis (149 patients), lumbar arthrosis (117 patients), and algodystrophy (140 patients) respectively.

RESULTS

In gonarthrosis patients, the statistical analysis of the results showed no significant differences between CO2 laser and GaAs laser treatments (p = .975), but significant differences between CO2 laser and HeNe laser treatments (p = .02) and between GaAs laser and HeNe laser treatments (p = .003). In lumbar arthrosis patients treated with GaAs or HeNe laser, significant differences were found between the two laser treatments and the combined sweeping-points techniques appeared to have a positive trend relative to the sweeping method alone, especially in sciatic suffering. In the algodystrophy syndrome, in hemiplegic patients, significant differences were found between CO2 and HeNe laser treatments (p = .026), between high and low CO2 laser doses (p = .024), and between low CO2 laser dose and high HeNe laser dose (p = .006).

CONCLUSIONS

Low level laser therapy can be used to treat osteoarticular pain in geriatric patients. To optimize the results, the diagnostic picture must be correct and a treatment program defining the physical parameters used (wavelength, dose and irradiation technique) must also be designed.

A survey of radiation synovectomy in Europe, 1991-1993

The prevalence of radiation synovectomy practice is unknown. As new particulate radiopharmaceuticals offering many potential advantages are being developed, it seems prudent to appraise the extent, frequency and variation in radiation synovectomy practice. We have evaluated radiation synovectomy practice in Europe over the period 1991-1993 by means of a postal questionnaire. More than 2300 European members of the European Association of Nuclear Medicine were questioned about the number of treated patients and joints, disease prevalence in their patients and the use of radiopharmaceuticals. Overall, 119/490 (24%) of centres replying to the survey practised radiation synovectomy during the 3 years. There were 13,450 different joint injections in 8578 patients. Rheumatoid arthritis was the most prevalent disease in patients treated (71%) and the most frequently treated joints were knee (46%) and finger joints (20%). Eight different radiopharmaceuticals were employed. Yttrium-90 colloids were most frequently and widely (100/119 centres) used, mainly employed for knee synovectomy but were also used to treat most appendicular joints. Erbium-169 colloid was almost exclusively used to treat finger joints (31/33 centres). Corticosteroid was routinely co-injected in 36/60 (60%) centres. Radiation synovectomy was widely practised throughout Europe during 1991-1993. There are variations in practice illustrated by the diversity of treated arthritides and injected joints and by the use and application of different radiopharmaceuticals.

Second-line treatment in seronegative spondylarthropathies

The literature concerning second-line treatment of seronegative spondylarethropathies from 1940 to August 1993 was reviewed. Sulfasalazine appeared to be effective in the treatment of ankylosing spondylitis (AS) and promising in reactive arthritis (ReA) and Reiters' syndrome (RS). Methotrexate and azathioprine were associated with a remarkable improvement in some cases of AS and RS. Methylprednisolone and levamisole were both efficacious in AS, but levamisole was associated with occasional severe side effects. Radiation therapy led to short-term improvement in AS, but was abandoned because of severe long-term side effects. Only sulfasalazine has been studied in sufficient detail to allow definitive conclusions, but methotrexate and azathioprine may be promising drugs.

[Analgetic irradiation of degenerative-inflammatory skeletal diseases. Benefits and risks]

Between 1980 and 1991, ionizing radiation was applied for analgesic purposes to 181 patients (97 men, 84 women, mean age 54 [29-81] years) with degenerative-inflammatory skeletal disease. The long-term effects were evaluated by questionnaire. Radiation of 2.5 to 6.0 Gy achieved lasting pain relief in 21 of 30 patients (70%) with arthritis of the shoulder or humeroscapular periarthritis, 15 of 21 (71%) with arthritis of the hip, in 12 of 15 (80%) with heel spurs or Achilles tendon bursitis and 10 of 11 (91%) with epicondylitis. Pain relief lasted for longer than two years in 41 of the 77 patients (53%). There were no side effects at the stated dosage. According to dose measurements the theoretical risk of malignant tumour induction is 20-40/million radiated patients and thus four orders of magnitude below the spontaneous malignant tumour incidence rate. The genetic risk is even lower. Ionizing radiation of degenerative-inflammatory diseases is thus an effective form of treatment with few side effects.

Pulsed radio frequency therapy of experimentally induced arthritis in ponies

The effect of pulsed radio frequency therapy (PRFT) was evaluated on seven ponies with no arthritis and in 28 ponies in which arthritis was created using intra-articular amphotericin B to induce synovitis in the right middle carpal joint. The ponies were divided into five treatment and two control groups. Two levels of arthritis were created and two dosage levels of PRFT were evaluated. The effect of PRFT on arthritic and nonarthritic joints was measured by comparing synovial fluid parameters, the degree and duration of lameness, the range of carpal motion, and carpus circumference, for treated and untreated groups. Lesions seen radiographically, at gross pathology, and by histopathology were also compared between the treated and control groups. In the ponies with a mild form of induced arthritis, PRFT significantly (p less than 0.05) reduced the severity and duration of lameness, swelling of the carpus, and the severity of gross pathological and radiographic changes. In these ponies the synovial acid phosphatase levels were lower, the mucin clot quality was superior, and the synovial protein levels were lower for the ponies receiving PRFT as compared to the arthritic ponies receiving no treatment. A dose response effect was evident. In ponies with a slightly more severe form of arthritis, PRFT was evaluated at one dosage level. The treated ponies were significantly improved over the untreated ponies with respect to carpal range of motion, degree of lameness, carpus swelling, and radiographic lesions. No deleterious effects were noted when normal, PRFT treated, middle carpal joints were compared to contralateral untreated, normal joints. It was concluded that significant beneficial effects resulted when affected ponies were treated with PRFT.

[Problems and perspectives of radiotherapy of non-tumor diseases]

The experience of the world leading hospitals confirms the high efficacy and appropriateness of radiation therapy of nontumorous diseases. The authors consider the general principles of the organization of radiotherapeutic service, discuss reasons that have led to a decrease in the use of this method for therapy of nontumorous diseases in this country. They also emphasize the fact that radiation therapy must have its place among therapeutic modalities used for nontumorous diseases.

[Effect of local laser irradiation on the morphological and ultrastructural changes in the joint tissues in experimental arthritis]

The authors studied the results of the effect of local laser irradiation on the tissues of joints in experimental arthritis induced in rabbits. Laser irradiation suppressed the immunopathological process in the synovial membrane of joints and enhanced destruction of cartilage.

[Experiences with low-power laser therapy in internal medicine geriatrics]

The use of low power laser therapy in 30 in-patients aged from 72 to 86 years suffering from diseases of the movement apparatus resistant to treatment and from chronic peripheral and cerebral circulation disorders based on arteriosclerosis is proofed as efficient, riskless physicaltherapy method to improve the complaints and to economize with medicamentation.

Treatment of antigen-induced arthritis in rabbits with dysprosium-165-ferric hydroxide macroaggregates

Dysprosium-165-ferric hydroxide macroaggregates (165Dy-FHMA) was used as an agent of radiation synovectomy in an antigen-induced arthritis model in New Zealand white rabbits. Animals were killed up to 6 months after treatment. 165Dy-FHMA was found to have a potent but temporary antiinflammatory effect on synovium for up to 3 months after treatment. Treated knees also showed significant preservation of articular cartilage architecture and proteoglycan content compared with untreated controls, but only during the first 3 months after treatment. In animals killed 3 and 6 months after treatment there were only minimal differences between the treated and untreated knees, indicating that the antiinflammatory effects on synovial tissue and articular cartilage preservation were not sustained.

[Radiation treatment of benign diseases--indications, results and technic]

Radiotherapy is an effective means to treat several benign diseases; in fact, the therapeutic effects set in quickly and are of a long-term nature. Relapses are rare. Side effects or other undesirable reactions are negligible. The gonads are under risk that should not be underestimated, but this is usually acceptable within reasonable limits. The age of the woman patient and localisation of the disease are decisive factors. Definite dosage reductions can be achieved by suitable radioprotective measures. Nevertheless, indications for any kind of radiotherapy with ionising radiation should be strict as a matter of principle.

Effect of the intra-articular injection of lutetium-177 in chelator liposomes on the progress of an experimental arthritis in rabbits

The treatment of rheumatoid arthritis by radiosynovectomy has been restricted by the difficulty of preventing leakage of the radioisotope from the joint cavity. We have previously shown that this leakage can be reduced to very low levels by delivering the radioisotope in liposomes containing the lipophilic chelator, 3-cholesteryl 6-[N'-iminobis-(ethylenenitrilo)tetraacetic acid]hexyl ether. The present study investigates the effectiveness of the beta-emitting isotope lutetium-177, delivered in chelator liposomes, in treating an experimental arthritis in rabbits. Chelator liposomes containing 0.35 mCi, 0.175 mCi Or 0.087 mCi of the isotope were injected into the synovial cavities of the knees of rabbits with an established experimental arthritis. The retention of the lutetium and the progress of the arthritis were followed for 47 days, and samples of the joint tissues were taken for histology at the end of the experiment. Results showed that losses of radioactivity averaged less than 1% per day over 47 days and that joints treated with 0.175 mCi showed significant reductions in both diameter and surface temperature compared with controls treated with a non-radioactive preparation. Post-mortem histology revealed that, whereas control joints showed a highly active synovitis, synovia of joints treated with 0.175 or 0.35 mCi lutetium-177 had very little inflammatory activity. Although some joints which had received 0.35 mCi showed signs of damage to the articular cartilage, this damage was not apparent wih either of the two lower doses. We conclude that, in this animal model, chelator liposomes complexed with a suitable radioisotope are capable of effecting an efficient synovectomy.

Synovectomy of the knee with 90Y

In 33 patients with chronic arthritis of the knee, 48 knees were treated with an intra-articular injection of 5 mCi yttrium silicate (90Y). There were 27 patients with rheumatoid arthritis (RA) and 6 with osteoarthrosis (OA); the mean follow-up period was 33 months. At clinical investigation after 1 year, no signs of pain or swelling were found in 15 knees. In most cases, pain and swelling improved subjectively, with a mean duration of 11 months; in 20 knees, the improvement lasted more than 22 months. When radiographs showed severe destruction, 90Y treatment was unsuccessful, but an important new finding was that most patients with mild or moderate radiological abnormalities appeared to have a long-lasting improvement. The result did not correlate with erythrocyte sedimentation rate (ESR), haemoglobin or Rose titre at the time of injection or at follow up, suggesting that the result of the treatment is more dependent on local factors than on the disease activity. The results of 90Y treatment in 6 OA knees with persistent swelling were promising regarding swelling, even in patients with moderate radiological abnormalities. The main side-effect was a sometimes painful swelling of the knee, which was always successfully treated with an intraarticular corticosteroid injection. In 90Y-treated knees, the incidence of unstable joints was not significantly higher than in non-treated knees. In conclusion, 90Y synovectomy may be a successful treatment for patients older than 50 years with chronic arthritis of the knee due to RA and probably also OA, even when moderate radiological abnormalities are present.