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A Pilot Trial of Two-Fraction Stereotactic Body Radiation Therapy for Localized Prostate Cancer
Xinglei Shen1, Matthew Chen1, Ying Cao1
1Radiation Oncology, University of Kansas Medical Center, Kansas City, USA.
Cureus
|February 3, 2026
Summary
A pilot study shows that a two-treatment course of ultra-hypofractionated radiation therapy is safe and effective for low- to intermediate-risk prostate cancer, with no biochemical recurrence or severe toxicity observed.
Area of Science:
- Radiation Oncology
- Urologic Oncology
- Clinical Trials
Background:
- Ultra-hypofractionated radiation is a standard treatment for low- and intermediate-risk prostate cancer in the US, typically involving five fractions.
- There is a clinical interest in developing even shorter treatment courses, such as a two-fraction regimen.
Purpose of the Study:
- To assess the safety and preliminary efficacy of a two-fraction ultra-hypofractionated radiation therapy for prostate cancer.
- To determine the feasibility of a significantly reduced treatment schedule.
Main Methods:
- A prospective, single-arm pilot study enrolled 12 patients with low- to intermediate-risk prostate cancer.
- Patients received 25 Gy in two fractions (12.5 Gy each) separated by 2-3 days, with rectal spacer placement.
- Biochemical response was monitored via PSA levels, and toxicity was graded using CTCAE v5.0 criteria.
Main Results:
- Median follow-up was 4.8 years. All patients were NCCN intermediate-risk.
- No biochemical recurrence was observed. The median PSA nadir was 0.14.
- No grade 2 or worse gastrointestinal toxicity occurred. Acute and late grade 2 genitourinary toxicity occurred in 3/12 and 2/12 patients, respectively. No grade 3 toxicity was reported.
Conclusions:
- A two-fraction regimen of 25 Gy ultra-hypofractionated radiation is well-tolerated for prostate cancer.
- This approach demonstrates a low rate of long-term toxicity and promising biochemical control.
- Further investigation into two-fraction regimens for prostate radiation is warranted.
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