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

Mack Roach, Michelle DeSilvio, Richard Valicenti, David Grignon, Sucha O. Asbell, Colleen Lawton, Charles R. Thomas, William U. Shipley

Research output: Contribution to journalArticle

140 Scopus citations

Abstract

Purpose: 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 ≥10 × 11 cm but <11 × 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 and Materials: 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 × 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%.

Original languageEnglish (US)
Pages (from-to)647-653
Number of pages7
JournalInternational Journal of Radiation Oncology Biology Physics
Volume66
Issue number3
DOIs
StatePublished - Nov 1 2006

Keywords

  • Prostate cancer
  • Radiation field size
  • Randomized trials

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

Fingerprint Dive into the research topics of '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'. Together they form a unique fingerprint.

  • Cite this