An interventional study of Radio-induced Lymphocyte Apoptosis (RILA) Assay and Stereotactic body radiotherapy (SBRT) in Prostate Cancer, sponsored by Clinique Sainte Clotilde. Not yet recruiting. Open to male participants aged 60 Years and older. Per ClinicalTrials.gov, last updated 2026-03-18.
Sponsored by Clinique Sainte Clotilde · Not applicable, Interventional, and Prevention
This monocentric interventional study investigates whether the Radio-induced Lymphocyte Apoptosis (RILA) assay can predict the occurrence of late radiation-induced toxicities in patients with localized prostate cancer treated with stereotactic body radiotherapy (SBRT). Eligible patients will undergo a peripheral blood sample collection for the RILA test prior to SBRT. Toxicities will be assessed using CTCAE v5.0 criteria, and quality of life will be evaluated with EORTC QLQ-PR25, QLQ-C30, and IPSS questionnaires over a 60-month follow-up. The results aim to optimize patient selection for SBRT and reduce the risk of severe late side effects.
PROSTERA is a prospective, single-arm, monocentric interventional study (RIPH-2) designed to evaluate the prognostic performance of the Radio-induced Lymphocyte Apoptosis (RILA) assay to predict late radiation-induced toxicities in patients with localized prostate cancer treated with stereotactic body radiotherapy (SBRT).
The primary objective is to determine whether pre-treatment RILA (percentage of apoptotic T-lymphocytes measured ex-vivo after controlled irradiation) is predictive of clinically meaningful late toxicities graded ≥2 according to CTCAE v5.0 within 24 months after SBRT. Secondary objectives include PSA kinetics, patient-reported outcomes (EORTC QLQ-PR25, QLQ-C30 and IPSS), dosimetric correlations, and estimation of diagnostic performance metrics (AUC, sensitivity, specificity) of the RILA assay.
A single peripheral blood sample (2 mL) is collected at the time of CT simulation (inclusion visit). Samples are transported to the designated laboratory (LIRS/RunResearch) and processed according to the RILA SOP: cells are placed in culture (RPMI 1640 + 20% FBS, dilution 1:10) within 4 hours of collection, incubated 16-24 hours, then irradiated ex-vivo (8 Gy; conformational irradiation using institutional accelerator) and incubated for an additional 48 hours. After post-irradiation incubation cells are stained for CD4/CD8 and propidium iodide and analysed by flow cytometry (FACS) on 10,000 events in triplicate to derive the percentage of apoptotic CD4+ and CD8+ T-cells. All assay timings and plate/aliquot identifiers are recorded in laboratory logs. The collected sample is entirely consumed for the assay (no sample retention).
Eligible participants are adult males with localized prostate adenocarcinoma meeting the protocol inclusion criteria (e.g. clinical stage T1-T2, Gleason score 6-7, PSA \<15 ng/mL as per protocol), able to provide written informed consent and compliant with follow-up procedures. Key exclusions include prior pelvic radiotherapy, metastatic disease, inability to consent, and other criteria listed in the protocol. Enrollment will be consecutive to limit selection bias.
All participants receive SBRT delivered according to institutional conformational technique (protocol-specified dose constraints and organ-at-risk delineation per RTOG recommendations; typical stereotactic schedule described in the protocol). Imaging data (centering CT and any low-dose CT), treatment plans and dose-volume histograms (DVH) will be collected and stored in the electronic CRF for dose-toxicity correlation analyses.
Safety and patient-reported outcomes will be recorded during routine follow-up visits at baseline (pre-SBRT) and at 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54 and 60 months post-radiotherapy; CTCAE v5.0 will be used for toxicity grading and the EORTC QLQ-PR25, QLQ-C30 and IPSS questionnaires for quality-of-life and urinary symptom assessment. PSA will be measured at the same scheduled timepoints. No additional study-specific clinic visits are required beyond standard care.
The planned sample size is 220 subjects (calculated to achieve the desired precision for the RILA AUC estimate; \~166 evaluable subjects minimally required), with an anticipated inclusion period of 24 months and maximum individual follow-up of 61 months (total study duration ≈ 88 months). Data will be recorded in a pseudonymized electronic CRF and source documents will remain available in patient medical records. The study will be conducted under the applicable ethical and regulatory framework (CPP approval, MR-001, GDPR).
6,367 studies on the registry are indexed under Prostatic Neoplasms; 1,397 are open to participants now.
This study's planned enrollment of 220 is above the median of 58 across 4,821 interventional studies indexed under Prostatic Neoplasms.
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Exclusion Criteria:
All participants assigned to this single experimental arm will receive stereotactic body radiotherapy (SBRT) to the prostate delivered according to the PROSTERA protocol with predefined dose prescription and organ-at-risk constraints. A single peripheral blood sample (2 mL, lithium-heparin) will be collected at the time of CT simulation for the Radio-induced Lymphocyte Apoptosis (RILA) assay. Samples are transported and processed at the designated laboratory (LIRS) and handled per the RILA SOP: processing within 4 hours of collection, incubation 16-24 hours, ex-vivo irradiation (8 Gy), further incubation 48 hours, staining for CD4/CD8 and propidium iodide, and flow cytometry analysis (10,000 events, measured in triplicate) to quantify apoptotic T-lymphocytes. RILA results will be used for correlative and prognostic analyses versus late genitourinary and gastrointestinal toxicities (CTCAE v5.0), PSA kinetics and patient-reported outcomes (EORTC QLQ-PR25, QLQ-C30, IPSS).
Diagnostic Test: Radio-induced Lymphocyte Apoptosis (RILA) Assay · Radiation: Stereotactic body radiotherapy (SBRT)
peripheral blood sample processed via the RILA assay to quantify apoptotic CD8+/CD4+ T cells following ex vivo irradiation.
SBRT delivered to the prostate with image guidance, respecting dose constraints for organs at risk;
Occurrence of one or more late radiation-induced complications
Number of participants presenting one or more late radiation-induced complications, assessed using the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0.
Time frame: 24 months post-stereotactic radiotherapy
Mortality rate of T-CD8+/-CD4+ lymphocytes
Percentage of T-CD8+/-CD4+ lymphocytes mortality measured by flow cytometry after in vitro culture of blood samples and irradiation at 8 Gy.
Time frame: After in vitro culture and irradiation at 8 Gy
Clinical and biological variables of patients
Evaluation of clinical and biological variables (e.g., blood counts, PSA, comorbidities) collected during follow-up. Unit of Measure: Values according to each variable (e.g., PSA ng/mL, blood counts G/L, yes/no for comorbidities)
Time frame: At baseline and during follow-up (up to 60 months post-radiotherapy)
Quality of life - EORTC QLQ-PR25
Scores reported according to the validated scale (0-100). Higher scores = worse symptoms/problems, better functioning for functional scales. Score (0-100)
Time frame: Baseline, 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months post-radiotherapy
Quality of life - EORTC QLQ-C30
Scores reported according to the validated scale (0-100). Higher scores = worse symptoms, better functioning for functional/global health. Unit of Measure: Score (0-100)
Time frame: Baseline, 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months post-radiotherapy
Urinary symptoms - International Prostate Symptom Score (IPSS)
Validated 0-35 scale, where higher scores = worse urinary symptoms. Unit of Measure: Score (0-35)
Time frame: Baseline, 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months post-radiotherapy
Treatment tolerance - Number of participants with adverse events
Graded according to CTCAE v5.0 (Grades 1-5).
Time frame: Baseline, 1, 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, and 60 months post-radiotherapy
No study locations are listed for this record.
Plan to share: Undecided
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This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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Clinique Sainte Clotilde