High-dose irradiation for prostate cancer via a high-dose-rate brachytherapy boost: Results of a phase I to II study

Journal Article · Sun Oct 01 04:00:00 EDT 2006 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2006.04.045· OSTI ID:20850116

Vargas, Carlos E ^[1]; Martinez, Alvaro A ^[1]; Boike, Thomas P ^[1]; Spencer, William ^[2]; Goldstein, Neal ^[3]; Gustafson, Gary S ^[1]; Krauss, Daniel J ^[1]; Gonzalez, Jose ^[2]

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1. Radiation Oncology Department, William Beaumont Hospital, Royal Oak, MI (United States)
2. Urology Department, William Beaumont Hospital, Royal Oak, MI (United States)
3. Pathology Department, William Beaumont Hospital, Royal Oak, MI (United States)

Objective: To evaluate outcomes of intermediate- and high-risk prostate cancer patients on a prospective dose-escalation study of pelvic external-beam radiation therapy (EBRT) combined with high-dose-rate (HDR) brachytherapy boost. Methods: From November 1991 to April 2003, 197 patients were treated for intermediate- and high-risk disease features. All patients had prostate-specific antigen >10 ng/ml, Gleason score {>=}7, or clinical stage {>=}T2b, and all received pelvic EBRT (46 Gy) while receiving either two or three HDR boost treatments. HDR dose fractionation increased progressively and was divided into two dose levels. The mean prostate biologic equivalency dose was 88.2 Gy for the low-dose group and 116.8 Gy for the high-dose group ({alpha}/{beta} = 1.2). Clinical failure was either local failure or distant metastasis; clinical event-free survival (cEFS) was defined as patients who lived free of clinical failure. Results: Median follow-up was 4.9 years. The 5-year rates were as follows: biologic failure (BF), 18.6%, clinical failure (CF), 9.8%, cEFS 84.8%, cause-specific survival (CSS), 98.3%, and overall survival (OS), 92.9%. Five-year biochemical failure (68.7% vs. 86%, p < 0.001), CF (6.1% vs. 15.6%, p = 0.04), cEFS (75.5% vs. 91.7%, p = 0.003), CSS (95.4% vs. 100%, p = 0.02), and OS (86.2% vs. 97.8%, p = 0.002) were significantly better for the high-dose group. Multivariate analysis showed that high-dose group (p = 0.01, HR 0.35) and Gleason score (p = 0.01, HR 1.84) were significant variables for cEFS. Multivariate analysis showed that high-dose group (p = 0.01, HR 0.14) and age (p = 0.03, HR 1.09 per year) were significant variables for overall survival. Conclusion: There is a strong dose-response relationship for intermediate- to high-risk prostate cancer patients. Improved locoregional control with higher radiation doses alone can significantly decrease biochemical and clinical failures.

• OSTI ID: 20850116
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 2 Vol. 66; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ANTIGENS
BEAMS
BRACHYTHERAPY
CARCINOMAS
DOSE RATES
DOSE-RESPONSE RELATIONSHIPS
FAILURES
FRACTIONATED IRRADIATION
HEALTH HAZARDS
METASTASES
MULTIVARIATE ANALYSIS
PATIENTS
PROSTATE
RADIATION DOSES