Treatment outcome of high-dose image-guided intensity-modulated radiotherapy using intraprostate fiducial markers for localized prostate cancer at a single institute in Japan - Abstract

BACKGROUND:Several studies have confirmed the advantages of delivering high doses of external beam radiotherapy to achieve optimal tumor-control outcomes in patients with localized prostate cancer.

We evaluated the medium-term treatment outcome after high-dose, image-guided intensity-modulated radiotherapy (IMRT) using intra-prostate fiducial markers for clinically localized prostate cancer.

METHODS:In total, 141 patients with localized prostate cancer treated with image-guided IMRT (76Gy in 13 patients and 80Gy in 128 patients) between 2003 and 2008 were enrolled in this study. The patients were classified according to the National Comprehensive Cancer Networkdefined risk groups. Thirty-six intermediate-risk patients and 105 high-risk patients were included. Androgen-deprivation therapy was performed in 124 patients (88%) for a median of 11months (range: 2-88 months). Prostate-specific antigen (PSA) relapse was defined according to the Phoenix-definition (i.e., an absolute nadir plus 2 ng/ml dated at the call). The 5-year actuarial PSA relapse-free survival, the 5-year distant metastasis-free survival, the 5- year cause-specific survival (CSS), the 5-year overall survival (OS) outcomes and the acute and late toxicities were analyzed. The toxicity data were scored according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up was 60 months.

RESULTS:The 5-year PSA relapse-free survival rates were 100% for the intermediate-risk patients and 82.2% for the high-risk patients; the 5-year actuarial distant metastasis-free survival rates were 100% and 95% for the intermediate- and high-risk patients, respectively; the 5-year CSS rates were 100% for both patient subsets; and the 5-year OS rates were 100% and 91.7% for the intermediate- and high-risk patients, respectively. The Gleason score (< 8 vs. [greater than or equal to]8) was significant for the 5-year PSA relapse-free survival on multivariate analysis (p=0.044). There was no grade 3 or 4 acute toxicity. The incidence of grade 2 acute gastrointestinal (GI) and genitourinary (GU) toxicities were 1.4% and 8.5%, respectively. The 5-year actuarial likelihood of late grade 2-3 GI and GU toxicities were 6% and 6.3%, respectively. No grade 4 GI or GU late toxicity was observed.

CONCLUSIONS: These medium-term results demonstrate a good tolerance of high-dose image-guided IMRT. However, further follow-up is needed to confirm the long-term treatment outcomes.

Written by:
Takeda K, Takai Y, Narazaki K, Mitsuya M, Umezawa R, Kadoya N, Fujita Y, Sugawara T, Kubozono M, Shimizu E, Abe K, Shirata Y, Ishikawa Y, Yamamoto T, Kozumi M, Dobashi S, Matsushita H, Chida K, Ishidoya S, Arai Y, Jingu K, Yamada S.   Are you the author?

Reference: Radiat Oncol. 2012 Jul 6;7(1):105. Epub ahead of print.
doi: 10.1186/1748-717X-7-105

PubMed Abstract
PMID: 22770471 Prostate Cancer Section