***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Scientific background  Percutaneous transluminal angioplasties ( PTA ) through balloon dilatation with or without stenting , i.e. vessel expansion through balloons with or without of implantation of small tubes , called stents , are used in the treatment of peripheral artery occlusive disease ( PAOD ) . The intravascular vessel irradiation , called intravascular brachytherapy , promises a reduction in the rate of repeated stenosis ( rate of restenosis ) after PTA . Research questions The evaluation addresses questions on medical efficacy , cost-effectiveness as well as ethic , social and legal implication s in the use of brachytherapy in PAOD patients . Methods A systematic literature search was conducted in August 2007 in the most important medical electronic data bases for publications beginning from 2002 . The medical evaluation included r and omized controlled trials ( RCT ) . The information synthesis was performed using meta- analysis . Health economic modeling was performed with clinical assumptions derived from the meta- analysis and economical assumptions derived from the German Diagnosis Related Groups ( G-DRG-2007 ) . Results Medical evaluation Twelve publications about seven RCT on brachytherapy vs. no brachytherapy  were included in the medical evaluation . Two RCT showed a significant reduction in the rate of restenosis at six and /or twelve months for brachytherapy vs. no brachytherapy after successful balloon dilatation , the relative risk in the meta- analysis was 0.62 ( 95 % CI : 0.46 to 0.84 ) . At five years , time to recurrence of restenosis was significantly delayed after brachytherapy . One RCT showed a significant reduction in the rate of restenosis at six months for brachytherapy vs. no brachytherapy after PTA with optional stenting , the relative risk in the meta- analysis was 0.76 ( 95 % CI : 0.61 to 0.95 ) . One RCT observed a significantly higher rate of late thrombotic occlusions after brachytherapy in the subgroup of stented patients . A single RCT for brachytherapy vs. no brachytherapy after stenting did not show significant results for the rate of restenosis at six months . Both , early and late thrombotic occlusions appeared more frequently in the brachytherapy group . Health economic evaluation Additional costs of brachytherapy were estimated to be 1,655 or 1,767 Euro according to the used G-DRG . The incremental cost-effectiveness ratio per avoided restenosis was calculated to be 8,484 Euro or 9,058 Euro for brachytherapy use after successful balloon dilatation , 19,027 Euro or 20,314 Euro for brachytherapy after PTA with optional stenting and -39,646 Euro or -48,330 Euro for brachytherapy after stenting . Discussion Partially poor performing and reporting quality of the RCT exacerbate the interpretation and the transferability of the study results . The used method ical approach enables the highest evidence level for the determined results and presents a good approximation of the current brachytherapy related costs for the German health care system . Conclusions Brachytherapy after successful balloon dilatation in PAOD can be recommended from a medical point of view for the reduction of the rate of restenosis at one year . However from a health economic view the answer is not yet clear . Based on the current data the use of brachytherapy after stenting in PAOD can not be recommended neither from a medical nor from a health economic point of view . The informed consent of the patients is an important ethical aspect in the use of brachytherapy BACKGROUND Early studies indicate brachytherapy is a potential clinical treamtent for restenosis after coronary angioplasty procedures . The objective of this study was to evaluate the safety and efficacy of gamma radiation plus stenting in patients ' previous restenosis . METHODS In patients with previous coronary restenosis , balloon dilatation and /or coronary stenting was undertaken and then patients were r and omly assigned to receive either Iridium-192 or placebo . Quantitative coronary angiographic , intravascular ultrasonographic , and clinical follow-up was obtained . RESULTS Of the 55 patients enrolled , 26 were treated with Iridium-192 and 29 were in the placebo group . Late luminal loss was significantly lower in the treated group compared to the placebo group ( 0.38 + /- 1.06 mm vs. 1.03 + /- 0.97 mm , p = 0.03 ) . Restenosis ( stenosis of > or = 50 % at follow-up ) was found in 17 % of treated patients compared to 54 % of placebo patients ( p = 0.01 ) . The need for target lesion revascularization was observed in 12 % of patients in the treated group compared to 45 % in the placebo group ( p = 0.01 ) . CONCLUSIONS In this initial trial , at 12 months follow-up , patients with previous restenosis were benefited by catheter-based gamma radiation therapy Following a report of the efficacy of total lymphoid irradiation ( TLI ) in the treatment of chronic progressive multiple sclerosis a further r and omised double-blind placebo-controlled study was undertaken with the intention of entering 56 patients . In the event it was possible to recruit only 27 patients in a 2.5 year period . Three patients received active treatment openly and 24 were r and omised to either active ( 14 ) or sham ( 10 ) treatment . Treatment was 1980 cGy to the lymphoid system and spleen or sham treatment after full simulation . The primary outcome measure was a comparison of the mean rates of change between treatment groups on the exp and ed Kurtzke disability scale ( EDSS ) over the two year follow up period . Patients were also assessed on other clinical outcome measures , psychometry , and serial MRI of the brain . Active treatment result ed in a profound and prolonged fall in T lymphocytes especially those with the CD4 marker and a reversal in CD4:CD8 ratio . No significant benefit was demonstrated on the rate of clinical disease progression ( EDSS ) . A small but significant benefit was found on a score of bladder function . No significant benefit was demonstrated on other clinical or psychometric indices or on subjective visual analogue scales . There was a small but significant difference in the rate of accumulation of lesions on brain MRI favouring the treatment group . The treated group had a higher incidence of clinical ly relevant side effects , notably amenorrhoea and infections : three deaths ( one in the TLI group , two in the sham treated group ) occurred . A post hoc calculation indicates that the study had a possible 35 % risk of a false negative result using the principal outcome measure . The study fails to confirm the previously reported clinical benefit of TLI although there may be a minor benefit on disease progression as indicated by MRI lesion counts . It is concluded that TLI can not be recommended for the routine treatment of chronic progressive multiple sclerosis but the beneficial effect on MRI lesions , though modest , suggests that further research into immune modulation of this condition may be worthwhile In the r and omized , placebo-controlled , physician-blinded Canadian cooperative trial of cyclophosphamide and plasma exchange , neither active treatment regimens ( group I : IV cyclophosphamide and prednisone ; group II : weekly plasma exchange , oral cyclophosphamide , and prednisone ) were superior to placebo ( group III : sham plasma exchange and placebo medications ) using the blinded , evaluating neurologists ' assessment s of disease course ( primary analysis ) . All patients were examined by both a blinded and an unblinded neurologist at each assessment in this trial . We compared the blinded and unblinded neurologists ' judgment of treatment response and analyzed the clinical behavior of patients who correctly guessed their treatment . The unblinded ( but not the blinded ) neurologists ' scores demonstrated an apparent treatment benefit at 6 , 12 , and 24 months for the group II patients ( not group I or placebo ; p < 0.05 , two-tailed ) . There were no significant differences in the time to treatment failure or in the proportions of patients improved , stable , or worse between the group II and group III patients who correctly guessed their treatment assignments and those who did not . Physician blinding prevented an erroneous conclusion about treatment efficacy ( false positive , type 1 error ) OBJECTIVES To determine the effects of low-dose external beam irradiation compared with observation on the visual function of eyes with subfoveal choroidal neovascularization ( CNV ) complicating age-related macular degeneration ( ARMD ) . DESIGN Prospect i ve , double-masked , r and omized clinical trial . Patients r and omized to the radiation group received external beam irradiation at a dose of 14 Gy in 7 fractions of 2 Gy . Patients r and omized to the observation group received sham radiation . SETTING Tertiary care retinal referral practice . PATIENTS Individuals with classic , mixed , or occult subfoveal CNV secondary to ARMD . MAIN OUTCOME MEASURES Change in visual acuity from baseline to specified time periods . Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression . RESULTS Forty-two eyes were r and omized to observation ; 41 eyes , to radiation . Baseline characteristics and demographics did not differ between groups . The median distance visual acuity ( DVA ) in radiation-treated eyes decreased from 20/80 at baseline to 20/320 ( mean loss rate , 4.14 lines ) at 1-year follow-up . The median DVA in observation group eyes decreased from 20/125 at baseline to 20/250 ( mean loss rate , 3.39 lines ) at 1-year follow-up . There were no statistically significant differences in changes in DVA , contrast sensitivity , or fluorescein angiographic progression from baseline between groups at any follow-up period . CONCLUSIONS At 1-year follow-up , low-dose external beam irradiation at 14 Gy in 7 fractions of 2 Gy is neither beneficial nor harmful for subfoveal CNV complicating ARMD Background —Intracoronary brachytherapy is effective in preventing restenosis after coronary interventions . However , in vitro and animal studies have shown that irradiation produces immediate and sustained endothelial dysfunction . This study assesses the clinical relevance of impaired vasomotoric function induced by brachytherapy . Methods and Results —We analyzed the occurrence of postradiation coronary artery spasms in 1 animal study and 2 clinical trials investigating the effects of high-dose intracoronary & bgr;-radiation  after de novo coronary artery stenting . Irradiated segments ( IRSs ) proximal and distal to the stent were studied by quantitative coronary angiography after stenting , after radiation , and at the end of the procedure . There was an 67 % overall incidence of coronary artery spasm in the IRSs immediately after & bgr;-radiation compared with 9 % after sham treatment ( P < 0.001 ) . Whereas in most cases this phenomenon was only minor or moderate , in 12 cases , 4 ( 22 % ) animals and 8 ( 28 % )  patients , severe coronary spasm ( > 90 % diameter stenosis ) with significant ECG-changes or hemodynamic instability was observed . Relief of spasms was protracted ( mean time until complete relief of spasm 423±122 seconds ) and required repetitive intracoronary administration of nitroglycerin ( mean dose : 1.2±0.6 mg ) . Conclusions —Vasoconstriction is a frequent reaction of coronary arteries after high-dose intracoronary & bgr;-radiation , necessitating repetitive administration of vasodilators Although the cause of amyotrophic lateral sclerosis ( ALS ) remains unknown , recent studies have suggested an autoimmune mechanism of pathogenesis . Previous trials of immunosuppressive treatment have yielded inconclusive results . Our study was design ed to determine whether more powerful and prolonged immunosuppression , produced by total lymphoid irradiation ( TLI ) , would alter the course of ALS . In a double‐blind , r and omized , placebo‐controlled study , 30 patients with classic ALS were treated with TLI , and 31 were given sham radiation .  Quantitative measurements of muscle strength , functional motor activity , and humoral and cellular immune status were followed for 2 years , or until death or respirator dependence . Motor function in the TLI‐treated and control groups showed no significant differences throughout the study . Overall survival was not significantly different in the TLI‐treated and control groups . TLI effectively suppressed cellular and humoral immune function throughout the 2‐year study period . Analysis of the relationship between immunosuppression and motor functions showed no consistent effect of treatment . We conclude that powerful and prolonged immunosuppression produced by TLI did not benefit patients with ALS . This fails to support the concept of an autoimmune mechanism of pathogenesis of ALS PURPOSE To examine the effect of proton beam irradiation on subfoveal choroidal neovascular membranes ( CNVM ) associated with age-related macular degeneration (AMD).R and omized , prospect i ve , sham-controlled , double-masked treatment trial . METHODS Thirty-seven subjects with subfoveal CNVM due to AMD were r and omly assigned to 16-Gy proton irradiation delivered in two fractions 24 hours apart or to sham control treatment . Recruitment was halted at 37 subjects for ethical reasons regarding r and omization to sham treatment when Food and Drug Administration approval of Visudyne was anticipated . RESULTS Proton irradiation was associated with a trend toward stabilization of visual acuity , but this association did not reach statistical significance . No correlations were found within the fluorescein angiography data , including greatest linear dimension of CNVM total size , area of active leakage , area of associated subretinal hemorrhage , and intensity . CONCL 
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This review showed that it is possible to carry out sham radiotherapy with due regard for ethical concerns , with effective blinding and high levels of patient acceptance .