Prostate Cancer (Adenocarcinoma)
Conditions
Keywords
SBRT, Cyberknife, radiotherapy
Brief summary
This study evaluates whether adaptive stereotactic body radiotherapy (SBRT) provides dosimetric advantages compared to non-adaptive SBRT in localized prostate cancer. Five low-dose CT scans are performed before each SBRT session to assess anatomical variations (bladder filling, rectal volume) and determine if a dosimetric recalculation would have been required. The study also evaluates cumulative dose to organs at risk, patient-reported quality of life over 24 months, and overall and recurrence-free survival.
Interventions
OTHERLow-dose CT imaging before each SBRT session
Five low-dose, non-contrast CT scans performed immediately before each SBRT session (≈10 min before treatment) to assess anatomical variations impacting target volume and organ-at-risk dosimetry.
Sponsors
Clinique Sainte Clotilde
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
60 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Male aged ≥60 years * Localized prostate cancer of low or intermediate risk (T1-T2) * Gleason score 6-7 * PSA \<15 ng/mL * No evidence of metastatic disease * Radiotherapy indicated for prostate cancer * Affiliated with or benefiting from a French social security system * French-speaking patient * Patient appropriately informed and having signed a written informed consent form
Exclusion criteria
* Unable to read, write, or understand French * Vulnerable patient as defined by Article L1121-6 of the French Public Health Code * Adult under guardianship, curatorship, or legal protection (sauvegarde de justice) * Patient unable to personally provide informed consent according to Article L1121-8 of the French Public Health Code * Patient already included in another interventional study that could interfere with study outcomes * History of urological (prostate) or digestive surgery that could influence study outcomes * Refusal to sign the written informed consent form
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of patients requiring dosimetric recalculation due to anatomical variations | At each of the 5 SBRT sessions (10 days max) Based on scanners low-dose comparison. | Percentage of patients for whom at least one stereotactic body radiotherapy (SBRT) fraction would have required a dosimetric recalculation due to anatomical variations (bladder filling and/or rectal emptying), based on comparison between the initial treatment plan and pre-treatment low-dose CT scans acquired before each SBRT fraction (5). This outcome reflects the potential benefit of an adaptive radiotherapy approach compared to a non-adaptive strategy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline in global quality of life (EORTC QLQ-C30) | Time Frame: Baseline (pre-radiotherapy) 1 month 3 months 6 months 12 months 18 months 24 months post-radiotherapy | Change from baseline in global quality of life assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). Score range: 0-100 Higher scores indicate better quality of life. |
| Survival outcomes | 1, 3, 6, 12, 18, 24 months post-radiotherapy | Overall Survival (OS): Death from any cause. |
| Cumulative delivered dose to Organs at Risk (OARs) | From baseline CT + all 5 fraction low-dose CT scans. (up to 10 days) | Definition: Quantitative assessment of the dose actually delivered to each OAR across all fractions, based on dose-volume parameters derived from the low-dose CTs and DVH (Dose-Volume Histogram) analyses. OARs and parameters include: Rectum Maximum dose (0.03 cc) Dose to 3 cc Dose to 10%, 20%, and 50% of the volume Bladder Maximum dose (0.03 cc) Dose to 10% and 50% of the volume Penile bulb Maximum dose Dose to 3 cc Femoral heads Dose to 10 cc (combined left and right) Maximum dose Bowel (GETUG-14 constraints) D5cc D1cc Urethra Maximum dose |
| Change from baseline in prostate cancer-specific quality of life (EORTC QLQ-PR25) | Baseline, 1, 3, 6, 12, 18, and 24 months post-radiotherapy | Change from baseline in prostate cancer-specific quality of life domains assessed using the EORTC QLQ-PR25 questionnaire. Score range: 0-100 Higher scores indicate worse symptoms. |
| Change from baseline in urinary symptoms (IPSS) | Baseline, 1, 3, 6, 12, 18, and 24 months post-radiotherapy | Change from baseline in urinary symptoms assessed using the International Prostate Symptom Score (IPSS). Score range: 0-35 Higher scores indicate worse urinary symptoms. |
| Recurrence-Free Survival (RFS) | 1, 3, 6, 12, 18, 24 months post-radiotherapy | Clinical, biochemical, or radiological recurrence. |
Countries
Reunion
Contacts
Primary ContactMANON Leprince, Clinical Research Associate
Backup ContactMickael Begue, Principal Investigator
Outcome results
None listed