Single- versus multifraction stereotactic body radiation therapy for pancreatic adenocarcinoma: outcomes and toxicity

Int J Radiat Oncol Biol Phys. 2014 Nov 15;90(4):918-25. doi: 10.1016/j.ijrobp.2014.06.066. Epub 2014 Oct 18.

Abstract

Purpose: We report updated outcomes of single- versus multifraction stereotactic body radiation therapy (SBRT) for unresectable pancreatic adenocarcinoma.

Methods and materials: We included 167 patients with unresectable pancreatic adenocarcinoma treated at our institution from 2002 to 2013, with 1-fraction (45.5% of patient) or 5-fraction (54.5% of patients) SBRT. The majority of patients (87.5%) received chemotherapy.

Results: Median follow-up was 7.9 months (range: 0.1-63.6). The 6- and 12-month cumulative incidence rates (CIR) of local recurrence for patients treated with single-fraction SBRT were 5.3% (95% confidence interval [CI], 0.2%-10.4%) and 9.5% (95% CI, 2.7%-16.2%), respectively. The 6- and 12-month CIR with multifraction SBRT were 3.4% (95% CI, 0.0-7.2%) and 11.7% (95% CI, 4.8%-18.6%), respectively. Median survival from diagnosis for all patients was 13.6 months (95% CI, 12.2-15.0 months). The 6- and 12- month survival rates from SBRT for the single-fraction group were 67.0% (95% CI, 57.2%-78.5%) and 30.8% (95% CI, 21.9%-43.6%), respectively. The 6- and 12- month survival rates for the multifraction group were 75.7% (95% CI, 67.2%-85.3%) and 34.9% (95% CI, 26.1%-46.8%), respectively. There were no differences in CIR or survival rates between the single- and multifraction groups. The 6- and 12-month cumulative incidence rates of gastrointestinal toxicity grade ≥3 were 8.1% (95% CI, 1.8%-14.4%) and 12.3% (95% CI, 4.7%-20.0%), respectively, in the single-fraction group, and both were 5.6% (95% CI, 0.8%-10.5%) in the multifraction group. There were significantly fewer instances of toxicity grade ≥2 with multifraction SBRT (P=.005). Local recurrence and toxicity grade ≥2 were independent predictors of worse survival.

Conclusions: Multifraction SBRT for pancreatic cancer significantly reduces gastrointestinal toxicity without compromising local control.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy
  • Adenocarcinoma / epidemiology
  • Adenocarcinoma / pathology
  • Adenocarcinoma / radiotherapy*
  • Adult
  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Confidence Intervals
  • Female
  • Follow-Up Studies
  • Gastrointestinal Tract / radiation effects
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / epidemiology
  • Pancreatic Neoplasms / drug therapy
  • Pancreatic Neoplasms / epidemiology
  • Pancreatic Neoplasms / pathology
  • Pancreatic Neoplasms / radiotherapy*
  • Radiosurgery / adverse effects
  • Radiosurgery / methods*
  • Radiotherapy Dosage
  • Survival Rate
  • Treatment Outcome