title: Systemic lupus erythematosus, radiotherapy, and the risk of acute and chronic toxicity: the Mayo Clinic Experience.
abstract: OBJECTIVE
  To determine the acute and chronic toxic effects of radiotherapy in patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  Medical records of 21 consecutive patients with SLE, who had received 34 courses of external beam radiotherapy and one low-dose-rate prostate implant, were retrospectively reviewed. Patients with discoid lupus erythematosus were excluded.
  
  
  RESULTS
  Median survival was 2.3 years and median follow-up 5.6 years. Eight (42%) of 19 patients evaluable for acute toxicity during radiotherapy experienced acute toxicity of Grade 1 or greater, and 4 (21%) had acute toxicity of Grade 3 or greater. The 5- and 10-year incidence of chronic toxicity of Grade 1 or greater was 45% (95% confidence interval [CI], 22-72%) and 56% (95% CI, 28-81%), respectively. The 5- and 10-year incidence of chronic toxicity of Grade 3 or greater was 28% (95% CI, 18-60%) and 40% (95% CI, 16-72%), respectively. Univariate analysis showed that chronic toxicity of Grade 1 or greater correlated with SLE renal involvement (p < 0.006) and possibly with the presence of five or more American Rheumatism Association criteria (p < 0.053). Chronic toxicity of Grade 3 or greater correlated with an absence of photosensitivity (p < 0.02), absence of arthritis (p < 0.03), and presence of a malar rash (p < 0.04).
  
  
  CONCLUSIONS
  The risk of acute and chronic toxicity in patients with SLE who received radiotherapy was moderate but was not prohibitive of the use of radiotherapy. Patients with more advanced SLE may be at increased risk for chronic toxicity.
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Melva E
authors.initials: ME
authors.lastname: Pinn
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Gold
authors.forename: Ivy A
authors.initials: IA
authors.lastname: Petersen
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Osborn
authors.forename: Paul D
authors.initials: PD
authors.lastname: Brown
authors.forename: Robert C
authors.initials: RC
authors.lastname: Miller
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002648:Child; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007668:Kidney / Q000528:radiation effects; D008180:Lupus Erythematosus, Systemic / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011832:Radiation Injuries / Q000401:mortality / Q000473:pathology*; D011878:Radiotherapy / Q000009:adverse effects; D012189:Retrospective Studies; D016019:Survival Analysis