title: Orbital marginal zone B-cell lymphoma of MALT: radiotherapy results and clinical behavior.
abstract: OBJECTIVE
  To elucidate the clinical behavior and treatment outcome of low-grade primary orbital lymphoma arising from mucosa-associated lymphoid tissue (MALT).
  
  
  METHODS
  Forty-eight patients with pathologically confirmed marginal zone B-cell lymphoma of MALT were treated with radiotherapy (RT). Thirty-eight patients (79.1%) received thorough staging workup studies including bone marrow biopsy. Radiation doses ranged from 5.4 to 30.6 Gy (median, 30.6 Gy). Median follow-up period was 70 months.
  
  
  RESULTS
  Only 2 patients revealed extraorbital lymphoma involvement (bone marrow, skin). Forty-six of 52 eye lesions showed complete response to RT. Six lesions demonstrated a partial response and showed gradual regression during the follow-up period of 39-72 months. Three patients experienced local recurrences at 34, 48, and 52 months after RT, which seemed to be related to improper use of the lens shield. Salvage re-RT was successful. The 10-year actuarial relapse-free survival, cause-specific survival, and overall survival rates were 93.1%, 97.9%, and 86.9%, respectively.
  
  
  CONCLUSIONS
  Most of the MALT lymphoma of the orbit was localized at diagnosis and extraorbital relapse rarely occurred. Therefore, extensive staging workup at the time of diagnosis and follow-up studies to detect distant relapse may not be obligatory. Low-dose RT alone with proper lens shielding is the optimum treatment modality for orbital MALT lymphoma.
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Yonsei Cancer Center, Seoul, Republic of Korea. cosuh317@yumc.yonsei.ac.kr
authors.forename: Chang-Ok
authors.initials: CO
authors.lastname: Suh
authors.forename: Su Jung
authors.initials: SJ
authors.lastname: Shim
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Lee
authors.forename: Woo Ick
authors.initials: WI
authors.lastname: Yang
authors.forename: Sang Yeul
authors.initials: SY
authors.lastname: Lee
authors.forename: Jee Sook
authors.initials: JS
authors.lastname: Hahn
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D016393:Lymphoma, B-Cell / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009918:Orbital Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D011832:Radiation Injuries; D011879:Radiotherapy Dosage; D012074:Remission Induction; D016896:Treatment Outcome