Adverse effects of androgen deprivation therapy on persistent genitourinary complications after carbon ion radiotherapy for prostate cancer.

Abstract

PURPOSE:

To determine the risk factors for persistent late genitourinary (GU) morbidity after carbon ion radiotherapy (C-ion RT) for prostate cancer.

METHODS AND MATERIALS:

Between April 2000 and November 2003, a Phase II study of 175 prostate cancer patients was performed to assess C-ion RT with a dose fractionation (66 Gray equivalent in 20 fractions) established from previous Phase I-II studies. The effects of the clinical and dosimetric parameters on the occurrence of persistent GU toxicity in 172 patients who survived for >18 months after C-ion RT were examined retrospectively. C-ion RT alone was performed for 33 low-risk patients, and 139 high-risk patients received C-ion RT combined with androgen deprivation therapy (ADT).

RESULTS:

Grade 1 and 2 persistent GU toxicities developed in 36 (21%) and 3 (2%) patients, respectively. The use of long-course ADT (>or=24 months) and acute GU toxicity were associated with the occurrence of persistent toxicity by multivariate analysis (p = 0.016 and p = 0.048, respectively), but short-course ADT (<24 months) had no effect on the development of toxicity (p = 0.35). The 5-year actuarial complication rate of 80 patients undergoing long-course ADT was 31.1%; the corresponding rate for the 92 patients who received no ADT or short-course ADT was 22.2%.

CONCLUSION:

Adverse effects with long-course ADT on persistent GU morbidity were observed in this study. Additional investigation is needed to identify suitable ADT administration according to risk groups, but long-course ADT should not be adopted for non-high-risk prostate cancer patients to reduce the GU toxicity rate with C-ion RT.

• Authors: Hitoshi Ishikawa, Hiroshi Tsuji, Tadashi Kamada, Naoki Hirasawa, Takeshi Yanagi, Jun-Estu Mizoe, Koichiro Akakura, Hiroyoshi Suzuki, Jun Shimazaki, Takashi Nakano, Hirohiko Tsujii
• Journal: International journal of radiation oncology, biology, physics (Int J Radiat Oncol Biol Phys) Vol. 72 Issue 1 Pg. 78-84 (Sep 01 2008) ISSN: 0360-3016 [Print] United States
• PMID: 18456419 (Publication Type: Clinical Trial, Phase II, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Androgen Antagonists
• Carbon Radioisotopes

Topics

• Aged
• Aged, 80 and over
• Analysis of Variance
• Androgen Antagonists (adverse effects, therapeutic use)
• Carbon Radioisotopes (adverse effects, therapeutic use)
• Combined Modality Therapy (methods)
• Dose Fractionation, Radiation
• Humans
• Incidence
• Male
• Middle Aged
• Orchiectomy
• Prostatic Neoplasms (drug therapy, radiotherapy, surgery)
• Radiation Injuries (epidemiology)
• Retrospective Studies
• Risk Factors
• Urethra (anatomy & histology, radiation effects)
• Urination Disorders (epidemiology, etiology)
• Urogenital System (radiation effects)