title: Association of clinical response and long-term outcome among patients with biopsied orbital pseudotumor receiving modern radiation therapy.
abstract: OBJECTIVE
  To retrospectively evaluate institutional outcomes for patients treated with modern radiation therapy (RT) for biopsied orbital pseudotumor (OP).
  
  
  METHODS
  Twenty patients (26 affected orbits) with OP were treated with RT between January 2002 and December 2011. All patients underwent biopsy with histopathologic exclusion of other disease processes. Sixteen patients (80%) were treated with intensity modulated RT, 3 (15%) with opposed lateral beams, and 1 (5%) with electrons. Median RT dose was 27 Gy (range 25.2-30.6 Gy). Response to RT was evaluated at 4 months post-RT. Partial response (PR) was defined as improvement in orbital symptoms without an increase in steroid dose. Complete response (CR) 1 and CR 2 were defined as complete resolution of orbital symptoms with reduction in steroid dose (CR 1) or complete tapering of steroids (CR 2). The median follow-up period was 18.6 months (range 4-81.6 months).
  
  
  RESULTS
  Seventeen patients (85%) demonstrated response to RT, with 7 (35%), 1 (5%), and 9 (45%) achieving a PR, CR 1, and CR 2, respectively. Of the 17 patients who had ≥ PR at 4 months post-RT, 6 (35%) experienced recurrence of symptoms. Age (>46 years vs ≤ 46 years, P=.04) and clinical response to RT (CR 2 vs CR 1/PR, P=.05) were significantly associated with pseudotumor recurrence. Long-term complications were seen in 7 patients (35%), including 4 with cataract formation, 1 with chronic dry eye, 1 with enophthalmos, and 1 with keratopathy.
  
  
  CONCLUSIONS
  RT is an effective treatment for improving symptoms and tapering steroids in patients with a biopsy supported diagnosis of OP. Older age and complete response to RT were associated with a significantly reduced probability of symptom recurrence. The observed late complications may be related to RT, chronic use of steroids/immunosuppressants, medical comorbidities, or combination of factors.
authors: Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA. rprabhu@emory.edu
authors: Roshan S
authors: RS
authors: Prabhu
authors: Shravan
authors: S
authors: Kandula
authors: Lang
authors: L
authors: Liebman
authors: Ted H
authors: TH
authors: Wojno
authors: Brent
authors: B
authors: Hayek
authors: William A
authors: WA
authors: Hall
authors: Hui-Kuo
authors: HK
authors: Shu
authors: Ian
authors: I
authors: Crocker
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001706:Biopsy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000473:pathology; D016727:Orbital Pseudotumor / Q000473:pathology / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects / Q000379:methods*; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D016896:Treatment Outcome