The aim of this phase II international multicenter study is to evaluate the safety, feasibility, and efficacy of CT or MRI-adaptive SBRT, delivered in five weekly fractions, in patients with newly diagnosed localized prostate cancer who have lower urinary tract symptoms and/or prostatic hyperplasia.
Background: Stereotactic body radiotherapy (SBRT) for localized prostate cancer has demonstrated non-inferior oncological outcomes and toxicity profiles to conventionally or moderately hypofractioned radiotherapy regimens, while offering the advantage of shorter treatment durations. However, SBRT may not be suitable for all patients, particularly those with lower urogenital tract symptoms and/or prostatic hyperplasia. Methods: This study aims to evaluate the safety and efficacy of weekly computed tomography (CT) or magnetic resonance image-guided (MRI) online adaptive SBRT in patients with intermediate to (very) high-risk localized prostate cancer who present with lower urinary tract symptoms (International Prostate Symptom Score \[IPSS\] \> 12) and/or have prostate hyperplasia (prostate volume \>60 mL). The primary outcome measure is urogenital toxicity grade ≥3 within 3 months after completion of SBRT (according to CTCAE V5.0 and RTOG) or discontinuation of therapy. Our aim is to show that the event rate is at 3% below a clinically acceptable threshold, which is set at 20%. Under the null hypothesis, this design with an alpha of 0.05 and power of 80% results in an expected number of cases of 30. In our validation cohort we assume that around 3% of patients will have grade 3 long-term urogenital toxicity (i.e. 2 patients). The rate of treatment discontinuation within 3 months is considered negligible. Our aim is to show with high probability, that the event rate is below a clinically acceptable threshold, which is set at 12%. Under the null hypothesis, this design with an alpha of 0.05 and power of 80% results in an expected number of cases of 75.
Study Type
OBSERVATIONAL
Enrollment
75
Patients with prostate cancer in the medium or high risk range who are planned to receive definitive CT or MRI-adaptive SBRT.
Klinik für Radioonkologie und Strahlentherapie, Universitätsklinikum Heidelberg
Heidelberg, Baden-Wurttemberg, Germany
NOT_YET_RECRUITINGKlinik und Poliklinik für Strahlentherapie und Radioonkologie, Universitätsklinikum LMU
Munich, Bavaria, Germany
NOT_YET_RECRUITINGUniversity Hospital Zurich, Department of Radio-Oncology
Zurich, Canton of Zurich, Switzerland
RECRUITINGacute grade ≥ III urogenital toxicity
The primary endpoint is acute grade ≥ III urogenital toxicity ≤3 months after completion of radiotherapy (according to the NCI CTCAE V5 or RTOG) or treatment discontinuation related to treatment.
Time frame: ≤ 3 months after completion of radiotherapy
Gastrointestinal toxicity of grade ≥3
Gastrointestinal toxicity of grade ≥3 within 3 months after completion of radiotherapy (according to CTCAE V5.0 and RTOG)
Time frame: ≤ 3 months after completion of radiotherapy
Mortality
Mortality (related to treatment and/or disease).
Time frame: ≤1 year after initiation of radiotherapy
Urogenital and gastrointestinal toxicities
Number of urogenital and gastrointestinal toxicities within 5 years after completion of radiotherapy and their severity.
Time frame: ≤ 5 years after completion of radiotherapy
Biochemical progression-free survival
Biochemical progression-free survival (determined from the start of therapy until the occurrence of PSA recurrence according to the Phoenix criteria i.e. post- therapeutic PSA nadir + 2 ng/ml),
Time frame: ≤ 5 years after completion of radiotherapy
Hormonal therapy-free survival
Hormonal therapy-free survival (determined from the start of therapy until the start of hormonal therapy,
Time frame: ≤ 5 years after completion of radiotherapy
Overall survival
overall survival (defined from the start of therapy until death or censoring)
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Time frame: 5 years after completion of radiotherapy
Quality-of-life questionnaire C-30 from the European Organisation for Research and Treatment of Cancer
Quality-of-life measured using the EORTC QLQ-C30 questionnaire during and after treatment All of the scales and single-item measures range in score from 0 to 100. A high scale score represents a higher response level. Thus a high score for a functional scale represents a high/healthy level of functioning, a high score for the global health status/QoL represents a high QoL, but a high score for a symptom scale/item represents a high level of symptomatology/problems.
Time frame: ≤ 5 years after completion of radiotherapy
Uroflowmetry (optional)
Uroflowmetry prior to the start of radiotherapy (optional study procedure)
Time frame: Uroflowmetry ≤ 6 weeks prior to the start of radiotherapy
Quality-of-life questionnaire PR25 of the European Organisation for Research and Treatment of Cancer
Quality-of-life measured using the QLQ-PR25 questionnaire during and after treatment All of the scales and single-item measures range in score from 0 to 100. A high score for the Sexual Activity and Sexual Functioning scales represents a high level of functioning, whereas a high score for the Urinary, Bowel, and Hormonal Treatment-Related symptoms scales and Incontinence Aid item represents a high level of symptomatology or problems.
Time frame: ≤ 5 years after completion of radiotherapy