title: Whole-pelvis, "mini-pelvis," or prostate-only external beam radiotherapy after neoadjuvant and concurrent hormonal therapy in patients treated in the Radiation Therapy Oncology Group 9413 trial.
abstract: OBJECTIVE
  The Radiation Therapy Oncology Group (RTOG) 9413 trial demonstrated a better progression-free survival (PFS) with whole-pelvis (WP) radiotherapy (RT) compared with prostate-only (PO) RT. This secondary analysis was undertaken to determine whether "mini-pelvis" (MP; defined as > or = 10 x 11 cm but < 11 x 11 cm) RT resulted in progression-free survival (PFS) comparable to that of WP RT. To avoid a timing bias, this analysis was limited to patients receiving neoadjuvant and concurrent hormonal therapy (N&CHT) in Arms 1 and 2 of the study.
  
  
  METHODS
  Eligible patients had a risk of lymph node (LN) involvement > 15%. Neoadjuvant and concurrent hormonal therapy (N&CHT) was administered 2 months before and during RT for 4 months. From April 1, 1995, to June 1, 1999, a group of 325 patients were randomized to WP RT + N&CHT and another group of 324 patients were randomized to receive PO RT + N&CHT. Patients randomized to PO RT were dichotomized by median field size (10 x 11 cm), with the larger field considered an "MP" field and the smaller a PO field.
  
  
  RESULTS
  The median PFS was 5.2, 3.7, and 2.9 years for WP, MP, and PO fields, respectively (p = 0.02). The 7-year PFS was 40%, 35%, and 27% for patients treated to WP, MP, and PO fields, respectively. There was no association between field size and late Grade 3+ genitourinary toxicity but late Grade 3+ gastrointestinal RT complications correlated with increasing field size.
  
  
  CONCLUSIONS
  This subset analysis demonstrates that RT field size has a major impact on PFS, and the findings support comprehensive nodal treatment in patients with a risk of LN involvement of > 15%.
authors.affiliation: University of California San Francisco, San Francisco, CA 94143-1708, USA. roach@radonc17.ucsf.edu
authors.forename: Mack
authors.initials: M
authors.lastname: Roach
authors.forename: Michelle
authors.initials: M
authors.lastname: DeSilvio
authors.forename: Richard
authors.initials: R
authors.lastname: Valicenti
authors.forename: David
authors.initials: D
authors.lastname: Grignon
authors.forename: Sucha O
authors.initials: SO
authors.lastname: Asbell
authors.forename: Colleen
authors.initials: C
authors.lastname: Lawton
authors.forename: Charles R
authors.initials: CR
authors.lastname: Thomas
authors.forename: William U
authors.initials: WU
authors.lastname: Shipley
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D017619:Hemibody Irradiation / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D010388:Pelvis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000532:radiotherapy*; D018709:Statistics, Nonparametric
chemical_list: D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen