A Phase 2 interventional study of Prostate SBRT with Focal Boost and Triptorelin Injection in Prostatic Neoplasms, sponsored by Ottawa Hospital Research Institute. Recruiting at 1 site in Canada. Open to male participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2024-01-05.
Sponsored by Ottawa Hospital Research Institute · Phase 2, Interventional, and Treatment
External beam radiotherapy combined with androgen deprivation therapy is a standard treatment option for localized prostate cancer. The current standard involves delivering radiotherapy uniformly throughout the prostate gland in daily fractions, five days per week, for approximately four weeks. In this study, radiotherapy will be delivered using an ultra-hypofractionated approach in three larger fractions on alternating days over one week Multiparametric magnetic resonance imaging will be used to guide focal dose escalation to parts of the gland harboring tumor, which could potentially reduce the risk of cancer recurrence compared to standard dose of radiotherapy. The aim of this study is to confirm that this approach can be delivered safely, that is, with rates of urinary and bowel side effects at 1 year of follow-up that are not significantly greater than the current standard.
External beam radiotherapy (RT) in combination with androgen deprivation therapy (ADT) is a standard definitive treatment for localized prostate cancer. It confers long-term oncologic outcomes equivalent to those of radical prostatectomy. The current standard approach for prostate RT consists of uniform irradiation of the entire gland. This technique employs computed tomography (CT) images for planning, in which disease is not readily apparent. Multiparametric magnetic resonance imaging (mpMRI) of the prostate allows for accurate visualization of clinically significant tumour foci within the prostate gland. It thereby permits selective escalation of dose to tumours within the gland - a so-called focal boost or "microboost" - with the aim of improving treatment efficacy.
The current standard approach to prostate RT involves delivery of treatment in daily fractions, five days per week, over four weeks. Prostate cancer appears to exhibit an uncommon fractionation sensitivity among solid tumours. A consequence of this is that hypofractionation - that is, delivery of RT with larger fraction sizes - may further improve the therapeutic ratio. A number of large-scale studies have shown promise for an ultra-hypofractionated approach (that is, larger than 5-Gy fractions) in the treatment of localized prostate cancer.
There is an unmet need for innovations in radiotherapy that further reduce the risk of relapse without increasing toxicity or compromising health-related quality of life and that reduce the treatment burden. Both focal intraprostatic boosts - informed by mpMRI findings - and ultra-hypofractionation represent promising approaches to achieve this objective. To date, the optimal regimen that combines these two innovations remains to be explored. In this trial, we will investigate in a single-arm prospective cohort the safety of an mpMRI-defined focal boost technique with a convenient and radiobiologically compelling ultra-hypofractionated radiotherapy regimen (consisting of three fractionas delivered over one week) for localized unfavourable intermediate and high-risk localized prostate cancer.
This is a single-arm prospective trial conducted in patients with unfavourable intermediate-risk or high-risk localized prostate cancer. Treatment consists of ultra-hypofractionated intensity-modulated, image-guided prostate radiotherapy delivered to 27 Gy in 3 fractions (1 fraction per day every other day, over a 5 day period) to uninvolved regions, with up to 39 Gy in 3 fractions delivered to mpMRI-defined intraprostatic lesions, assuming normal tissue dosimetric criteria can be safely met. Radiotherapy will be combined with concurrent/adjuvant androgen deprivation therapy (6 months duration in patients with intermediate-risk disease and 24 months for patients with high-risk disease). There will be follow-up assessments for toxicity, quality of life, and biochemical control. The primary endpoint will be prevalence of grade ≥ 2 genitourinary or gastrointestinal toxicity at 12 months.
Primary Objective The primary objective is to determine whether, in a population of men with unfavourable intermediate-risk or high-risk localized prostate cancer receiving a combination of three-fraction ultra-hypofractionated RT and adjuvant androgen deprivation therapy, an mpMRI-defined focal boost can be delivered with acceptable GU and GI toxicity at 1 year of follow-up.
Secondary Objectives
The secondary objectives are to evaluate, in a population of men with unfavourable intermediate-risk or high-risk localized prostate cancer, the effects of an mpMRI-defined focal boost on:
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This study's planned enrollment of 54 is close to the median of 58 across 4,822 interventional studies indexed under Prostatic Neoplasms.
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Exclusion Criteria:
Stereotactic body radiotherapy to 27 Gy in 3 fractions to uninvolved regions of the prostate glad and up to 39 Gy in 3 fractions to mpMRI-defined intraprostatic lesions, with concurrent/adjuvant androgen deprivation therapy (6 months for intermediate risk, 24 months for high risk)
Radiation: Prostate SBRT with Focal Boost · Drug: Triptorelin Injection
Prostate stereotactic body radiotherapy delivered to 27 Gy in 3 fractions on alternating days to uninvolved regions with up to 39 Gy in 3 fractions delivered to mpMRI-defined intraprostatic lesions
Also known as: Ultrahypofractionated prostate radiotherapy with integrated microboost
Six months of androgen deprivation therapy for intermediate-risk localized prostate cancer and 24 months for high-risk localized prostate cancer
Also known as: Androgen Deprivation Therapy
Genitourinary and gastrointestinal toxicity
Number of patients with grade 2 or greater genitourinary or gastrointestinal toxicity as measured by Common Terminology Criteria for Adverse Events (CTCAE ) version 5.0 and Radiation Therapy Oncology Group radiation toxicity scale
Time frame: Up to 2 years
Bowel and urinary quality of life
Measured by Expanded Prostate Cancer Index Composite (EPIC)-26 bowel and urinary domains
Time frame: Up to 2 years
Disease-free survival
Number of patients free of biochemical recurrence (defined according to the Phoenix definition as an increase in serum PSA that is ≥ 2 ng/mL above the nadir value observed following radiotherapy) or death from any cause
Time frame: 2 years
Plan to share: No
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Ottawa Hospital Research Institute