Phase III Clinical Trial on Conventionally Fractionated Conformal Radiotherapy (CF-CRT) Versus CF-CRT Combined With High-dose-rate Brachytherapy or Stereotactic Body Radiotherapy for Intermediate and High-risk Prostate Cancer.
Prostate cancer is considered as a disease with relatively slow natural course and good
clinical prognosis. Such description, however, does not well refer to intermediate and
high-risk cases where long-term rate of biochemical progression remains not satisfactory,
and the available treatment modalities entail a considerable morbidity. Over the last decade
several competitive therapeutic approaches have evolved in curative treatment for
intermediate and high-risk prostate cancer. The use of intensity-modulated radiation therapy
(IMRT) made possible to escalate the total dose to the prostate without excessive toxicity.
Based on assumption of low value of low α/β value for adenocarcinoma of prostate, there is a
potential of escalating the biological dose to the tumor with higher dose per fraction.
High-dose-rate brachytherapy (HDR-BT) is one of the options, with the ability to conform
radiation dose to the prostate with sharp dose gradient adjacent to critical organs. An
increasing number of studies suggest its usefulness as a boost in intermediate and high risk
disease. The randomized trial conducted in UK compared external beam radiotherapy (EBRT)
alone with EBRT and HDR brachytherapy as a boost. Combining EBRT with HDR BT - boost
resulted in significantly higher relapse-free-survival (RFS) with comparable incidence of
severe late toxicity. However, the total dose used in EBRT alone - arm and radiotherapy
technique may be considered suboptimal according to current standards.
Stereotactic body radiotherapy (SBRT) may be an interesting alternative to HDR
brachytherapy, not requiring implantation of multiple catheters and anesthesia. SBRT boost
for advanced localized prostate cancer has the potential to reduce toxicity while escalating
the dose. First results of trials combining conventional irradiation with hypofractionated
stereotactic boost and institutional pilot results gave promising outcome.
The comparison of these modalities of radiation therapy for prostate cancer will be
performed in the current phase III trial study.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment
Freedom from biochemical failure (FFBF)
according to Phoenix definition (rise of PSA level of 2 ng/ml over the absolute nadir)
Rafał Suwiński, MD, PhD
Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland
Poland: Ethics Committee