title: Long-term Outcome After Fractionated Radiotherapy for Pituitary Adenoma: The Curse of the Secretory Tumor.
abstract: OBJECTIVE
  To determine the influence of secretory status on long-term outcome after fractionated radiotherapy (RT) for gross residual pituitary adenoma.
  
  
  METHODS
  This is a retrospective study of 116 consecutively treated patients who met the following inclusion criteria: tissue diagnosis of pituitary adenoma, visible tumor at the time of RT, treatment with fractionated RT, and imaging follow-up of ≥2 years. Hypersecretion of growth hormone, adrenocorticotrophic hormone, prolactin, or thyroid-stimulating hormone was documented in 30 patients (26%). The RT dose in most (78%) patients was 45 Gy at 1.8 Gy per fraction. The major outcome endpoint is clinical and biochemical control, meaning no growth on follow-up scans and normalization of hypersecretion, if present before RT.
  
  
  RESULTS
  Long-term tumor control was outstanding for nonsecretory tumors: 96% at 10 years. There was a major drop in the control rate of secretory tumors: 10-year clinical and biochemical control was 62% (P<0.0001 vs. 96%). Multivariate analysis confirmed secretory status as the only independent prognostic factor (variables analyzed were sex, age, tumor size, RT dose, and secretory status).
  
  
  CONCLUSIONS
  Secretory pituitary adenomas have a worse prognosis than nonsecretory tumors after 45 to 50 Gy of conventionally fractionated RT. As a result of this finding, our plan is to increase the intensity of RT in secretory tumors, but our data did not evaluate this approach. The treatment guidelines that we currently use in pituitary adenoma are as follows. Radiosurgery (20 to 30 Gy) is our first-choice treatment of a secretory tumor that cannot be completely resected. When treating gross residual pituitary adenoma with fractionated RT, we use the following dose schedules: Nonsecretory: 45 Gy at 1.8 Gy/fraction, once-daily fractionation. Secretory: 54 Gy at 1.8 Gy/fraction once daily or 55.2 Gy at 1.2 Gy/fraction with twice-daily treatment.
authors.affiliation: Departments of *Radiation Oncology †Neurosurgery, College of Medicine, University of Florida, Gainesville, FL.
authors.forename: Stacey
authors.initials: S
authors.lastname: Scheick
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Amdur
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Kirwan
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Morris
authors.forename: William M
authors.initials: WM
authors.lastname: Mendenhall
authors.forename: Steven
authors.initials: S
authors.lastname: Roper
authors.forename: William
authors.initials: W
authors.lastname: Friedman
mesh_terms: D049913:ACTH-Secreting Pituitary Adenoma / Q000473:pathology / Q000532:radiotherapy; D000236:Adenoma / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D019583:Dose Fractionation, Radiation; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D005500:Follow-Up Studies; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000473:pathology / Q000532:radiotherapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018365:Neoplasm, Residual; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D011379:Prognosis; D015175:Prolactinoma / Q000473:pathology / Q000532:radiotherapy; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D013972:Thyrotropin / Q000378:metabolism; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D005640:Follicle Stimulating Hormone; D013972:Thyrotropin