Toxicity assessment of pelvic intensity-modulated radiotherapy with hypofractionated simultaneous integrated boost to prostate for intermediate- and high-risk prostate cancer

Int J Radiat Oncol Biol Phys. 2009 Oct 1;75(2):413-20. doi: 10.1016/j.ijrobp.2008.10.050. Epub 2009 Apr 11.


Purpose: To evaluate the toxicity of pelvic intensity-modulated radiotherapy (IMRT) with hypofractionated simultaneous integrated boost (SIB) to the prostate for patients with intermediate- to high-risk prostate cancer.

Methods and materials: A retrospective toxicity analysis was performed in 30 consecutive patients treated definitively with pelvic SIB-IMRT, all of whom also received androgen suppression. The IMRT plans were designed to deliver 70 Gy in 28 fractions (2.5 Gy/fraction) to the prostate while simultaneously delivering 50.4 Gy in 28 fractions (1.8 Gy/fraction) to the pelvic lymph nodes. The National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to score toxicity.

Results: The most common acute Grade 2 events were cystitis (36.7%) and urinary frequency/urgency (26.7%). At a median follow-up of 24 months, late toxicity exceeding Grade 2 in severity was uncommon, with two Grade 3 events and one Grade 4 event. Grade 2 or greater acute bowel toxicity was associated with signficantly greater bowel volume receiving > or =25 Gy (p = .04); Grade 2 or greater late bowel toxicity was associated with a higher bowel maximal dose (p = .04) and volume receiving > or =50 Gy (p = .02). Acute or late bladder and rectal toxicity did not correlate with any of the dosimetric parameters examined.

Conclusion: Pelvic IMRT with SIB to the prostate was well tolerated in this series, with low rates of Grade 3 or greater acute and late toxicity. SIB-IMRT combines pelvic radiotherapy and hypofractionation to the primary site and offers an accelerated approach to treating intermediate- to high-risk disease. Additional follow-up is necessary to fully define the long-term toxicity after hypofractionated, whole pelvic treatment combined with androgen suppression.

MeSH terms

  • Aged
  • Androgen Antagonists / therapeutic use
  • Cystitis / etiology
  • Dose Fractionation, Radiation
  • Humans
  • Intestines / radiation effects*
  • Lymphatic Irradiation / adverse effects
  • Lymphatic Irradiation / methods
  • Male
  • Middle Aged
  • Pelvis
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / diagnostic imaging
  • Prostatic Neoplasms / drug therapy
  • Prostatic Neoplasms / radiotherapy*
  • Radiation Injuries / complications*
  • Radiography
  • Radiotherapy, Intensity-Modulated / adverse effects*
  • Radiotherapy, Intensity-Modulated / methods
  • Retrospective Studies
  • Urinary Bladder / radiation effects*
  • Urination Disorders / etiology


  • Androgen Antagonists
  • Prostate-Specific Antigen