title: Evolution in regression patterns following chemoreduction for retinoblastoma.
abstract: OBJECTIVE
  To evaluate the change in regression pattern following chemoreduction and tumor consolidation therapy (thermotherapy or cryotherapy) for retinoblastoma
  
  
  METHODS
  Retrospective medical record analysis was completed for 557 retinoblastomas (239 eyes of 157 patients) that were treated with chemoreduction and showed regression to 1 of 5 patterns (type 0, no visible remnant; type 1, completely calcified remnant; type 2, completely noncalcified remnant; type 3, partially calcified remnant; and type 4, atrophic chorioretinal flat scar). Evolution of these regression patterns was observed over time.
  
  
  RESULTS
  Immediately following 6 cycles of chemoreduction, types 0 (2%), 1 (30%), 2 (3%), 3 (33%), and 4 (32%) regression patterns were found. During a mean follow-up period of 56 months (median, 48 months; range, 18-145 months), there was no change in regression patterns classified as type 0, 1, or 4. However, there was evolution of regression pattern types 2 and 3. Over time, type 2 tumor scars either remained stable (41%) or evolved to type 4 (41%), 3 (9%), or 1 (9%) scars. Type 3 tumor scars remained stable (74%) or evolved to type 1 (26%) scars.
  
  
  CONCLUSIONS
  Following chemoreduction and tumor consolidation therapy, retinoblastoma regression patterns types 2 and 3 can slowly evolve over time into a slightly different appearance, even without additional treatment. Ophthalmologists should be familiar with these regression patterns and their evolution.
authors.affiliation: Ocular Oncology Service, Wills Eye Institute, Philadelphia, PA 19107, USA.
authors.forename: Melis
authors.initials: M
authors.lastname: Palamar
authors.forename: Archana
authors.initials: A
authors.lastname: Thangappan
authors.forename: Carol L
authors.initials: CL
authors.lastname: Shields
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D012160:Retina / Q000473:pathology*; D019572:Retinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D012175:Retinoblastoma / Q000188:drug therapy* / Q000473:pathology; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents