Stereotactic body radiotherapy (SBRT) versus conventional fractionated intensity-modulated radiotherapy (CF-IMRT) for Asian patients with early-sta...

Date 24 November 2018
Event ESMO Asia 2018 Congress
Session Poster display - Cocktail
Topics Prostate Cancer
Complications/Toxicities of Treatment
Radiation Oncology
Presenter Darren Poon
Citation Annals of Oncology (2018) 29 (suppl_9): ix67-ix73. 10.1093/annonc/mdy434
Authors D.M. Poon1, D. Lam1, K. Wong1, F. Mok1, F. Mo1, C.M. Chu2, A.C.F. Ng3, J. Suen1, A.T.C. Chan1
  • 1Department Of Clinical Oncology, The Chinese University of Hong Kong, 000 - Hong Kong/HK
  • 2Department Of Imaging And Interventional Radiology, The Chinese University of Hong Kong, 000 - Hong Kong/HK
  • 3Sh Ho Urology Centre, The Chinese University of Hong Kong, Shatin/HK

Abstract

Background

It remains uncertain whether stereotactic body radiotherapy (SBRT) is superior to conventional fractionated intensity-modulated radiotherapy (CF-IMRT) in the treatment of early-stage prostate cancer. Here we report the acute toxicity results from this randomized phase II study comparing SBRT and CF-IMRT.

Methods

The primary endpoint of this single centre randomized phase II study is the health-related quality of life (HRQOL), as measured by the bowel and urinary domains of the Expanded Prostate Cancer Index Composite (EPIC) instrument. The secondary endpoints include acute and late toxicities, biochemical control and overall survival. We enrolled low and intermediate risk localized prostate cancer patients (T1-T2, Gleason score ≤7 and PSA <20). Patients were randomly assigned in a 1:1 ratio to receive either CF-IMRT with 38 fractions of 2 Gy in 7.5 weeks (five fractions per week) or SBRT with 5 fractions of 7.25 Gy in 2 weeks (three fractions per week). Image-guidance with intra-prostatic fiducial markers matching was used during treatments in both arms. Neoadjuvant androgen-deprivation treatment is optional for the intermediate risk patients. An acute adverse event is defined as the first occurrence of worst severity of the adverse event ≤30 days after the completion of RT, and it was evaluated with the Common Terminology Criteria for Adverse Events (version 4.0). Patient recruitment was completed in May, 2017. The study is registered at ClinicalTrials.gov (NCT02339701).

Results

Between Jan 2015 and May 2017, 68 patients were recruited and 4 patients were not eligible. 64 patients were randomized to treatments with SBRT (n = 31) or CF-IMRT (n = 33). No grade 3 or above acute toxicities were reported in either arms. SBRT patients experienced significantly less ≥ grade 1 acute gastrointestinal (GI) toxicities (SBRT vs IMRT: 35% vs 87%, p < 0.0001) and less ≥grade 2 acute genitourinary (GU)toxicities (SBRT vs IMRT: 3% vs 24%, p = 0.0426).

Conclusions

SBRT results in significantly less acute GI and GU toxicities than CF-IMRT in Asian patients with low and intermediate risk localized prostate cancer.

Editorial acknowledgement

Clinical trial identification

NCT02339701.

Legal entity responsible for the study

The Chinese University of Hong Kong.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.