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Stereotactic Re-irradiation of Local Recurrences of Prostate Cancer After Radiotherapy

Phase 2
Recruiting
Conditions
Radiotherapy
Local Recurrence of Malignant Tumor of Prostate
Interventions
Radiation: Stereotactic Body Radiotherapy
Registration Number
NCT06201078
Lead Sponsor
Maria Sklodowska-Curie National Research Institute of Oncology
Brief Summary

The goal of this clinical study is to evaluate the toxicity and efficacy of re-irradiation using focal stereotactic body radiotherapy (SBRT) in patients with local recurrence of prostate cancer after definitive or post-operative radiotherapy.

The main question is the tolerance of such treatment, concerning the incidence of Grade ≥ 2 and Grade ≥ 3 GU and GI toxicity. Also the efficacy of SBRT will be measured in terms of Biochemical Control with other secondary endpoints which include: Biochemical Response, Biochemical Failure-Free Survival, Metastases-Free Survival, Relapse-Free Survial, Local Control, Overall Survival and patients' reported tolerance measured with Quality of Life questionnaires (QoL C-30 and PR-25).

The evaluation of the tolerance and effectiveness of stereotactic radiotherapy (SBRT) will be performed in 3 subgroups: in patients with local recurrence after conventionally fractionated/moderately hypofractionated definitive radiotherapy (Group A) or ultrahypofractionated definitive SBRT (Group C) or after prostatectomy and post-operative radiotherapy (Group B).

The study group is planned to include 55 patients.

Detailed Description

The diagnosis of local recurrence after radiotherapy in patients with prostate cancer is a serious clinical problem. Interventional salvage treatment in the previously irradiated area is difficult with safety issues of special concern. According to the MASTER meta-analysis the effectiveness of various local salvage methods turned out to be comparable in patients with local recurrence after definitive radiotherapy. Stereotactic radiotherapy (SBRT) had the best toxicity profile, so this non-invasive treatment may be a suitable alternative to other methods. A particular problem is local recurrences after post-prostatectomy radiotherapy. The data on SBRT in such setting are even more scarce than in the case of relapses after definitive radiotherapy. Still, they show a low percentage of serious adverse events of grade ≥3 and good treatment tolerance.

Considering the own experience with re-irradiation of patients with prostate cancer, it was decided that re-irradiation should be carried out in the form of focal SBRT. With the objective of enhancing the safety and quality of salvage re-irradiation, and a comprehensive evaluation of the efficacy of this treatment it was determined that it should be implemented as a prospective phase II study- PROSTARE (PROstate cancer STereotActic Reirradiation).

The evaluation of the tolerance and effectiveness of stereotactic radiotherapy (SBRT) will be performed in patients with local recurrence after conventionally fractionated/moderately hypofractionated definitive radiotherapy (Group A), ultrahypofractionated definitive SBRT (Group C), or after prostatectomy and postoperative radiotherapy (Group B).

The study will be conducted as a single-centre study. The evaluation of the safety and effectiveness of such treatment could help develop qualification criteria for repeated irradiation. As a consequence, this should allow for the implementation of this form of treatment into radiotherapy protocols and then, in a controlled and safe way, into clinical practice.

The total sample size will comprise 55 patients. The expected recruitment period is 6 years (10 patients per year).

Requirements for reirradiation with SBRT:

1. Both PET-PSMA and MR of the prostate or prostate bed are required in patients with recurrence after definitive radiotherapy or surgery followed by radiotherapy

2. Fiducial implantation is not routinely required

3. Empty rectum and partially empty/partially filled bladder (improved reproducibility)\* during treatment planning and during each fraction of stereotactic radiotherapy

4. Treatment with a linear accelerator is preferred

5. CBCT must be performed before each fraction of SBRT with verification for tumour location (GTV)\*\*

6. Focal radiotherapy, i.e., irradiation of only the visible tumour with an appropriate margin

7. Hormonal treatment is not routinely recommended (according to the ESTRO ACROP consensus) - up to the decision of the attending physician

* Principles of preparation with laxatives - Bisacodyl is advocated 4-5 hours before SBRT. If the diameter of the rectum on the CT for treatment planning exceeds 4 cm in diameter, the procedure should be repeated after appropriate preparation of the patient.

* If stereotactic radiotherapy is conducted on the CyberKnife - KV imaging and Tracking verification are required; additionally an assessment of bladder filling in ultrasonography should be performed

Recruitment & Eligibility

Status
RECRUITING
Sex
Male
Target Recruitment
55
Inclusion Criteria
  1. Local recurrence of prostate cancer after definitive radiotherapy

    1. biopsy proven or/and
    2. Consistent MRI and PET-PSMA results and PSA growth dynamics
  2. Time since primary radiotherapy - at least 2 years

  3. Good performance status (ZUBROD 0-1)

    • If the results of the MRI and PET PSMA are inconsistent, and if there is no technical possibility of performing an MRI biopsy, the treatment is acceptable, but repeated imaging (PET or MRI) should be performed to assess the dynamics of the recurrence.
Exclusion Criteria
  1. Polymetastatic dissemination in distant or regional lymph nodes (N1, M1) or oligometastatic dissemination, but not eligible for local forms of metastasis directed therapy (MDT)
  2. Tumour volume (GTV) > 14 cc
  3. Poor tolerability of primary radiotherapy (≥G3 toxicity) or persistent late toxicity ≥G2 interfering with re-irradiation
  4. Severe dysuria before repeated SBRT (e.g., IPSS ≥19)
  5. Diseases of the distal part of the rectum or anal canal that may affect SBRT tolerance (e.g., anal fissure)
  6. Previous prostate brachytherapy
  7. Substantial risk for further urologic interventions (e.g., TURB/TURP)

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Salvage SBRT for locally recurrent prostate cancer after radiotherapyStereotactic Body RadiotherapySBRT: 5 x 6.75 Gy (every other day) to the total dose of 33.75 Gy
Primary Outcome Measures
NameTimeMethod
Tolerance of salvage SBRT3 months post-SBRT, 2-years post-SBRT

Assessment of early and late radiation toxicity: Grade ≥ 3 radiation-induced bladder/urethral (GU) and bowel/rectal (GI) adverse events toxicity or other, according to CTCAE criteria

Secondary Outcome Measures
NameTimeMethod
Tolerance of salvage SBRT3 months post-SBRT, every 6 months post SBRT up to 3-years post-SBRT

Rate of moderate or worse early and late radiation toxicity: Grade ≥ 2 radiation-induced bladder/urethral (GU) and bowel/rectal (GI) adverse events toxicity or other, according to CTCAE criteria

Biochemical Control3 months post-SBRT, 6 months post SBRT, every 6 months thereafter up to 5-years post-SBRT

Biochemical Control will be defined as observations without biochemical recurrence defined as PSA concentration: a. \>2 ng/mL above the nadir (according to Phoenix) for groups A and C b. \>0.2 ng/ml (according to AUA) for group B

Biochemical Response3 months post-SBRT, 6 months post-SBRT, every 6 moths thereafter up to 5-years post-SBRT

Decrease in PSA level below baseline (pre-SBRT)

Biochemical Failure-Free Survival (BFS)3 months post-SBRT, 6 months post SBRT, every 6 months thereafter up to 5-years post-SBRT

Biochemical Failure Free Survival (BFS) is defined as the time interval between SBRT and biochemical, local, regional failure, distant metastasis or death irrespective of the cause

Metastases-Free Survival1-year post SBRT, then annually up to 5-years post-SBRT

Metastases-Free Survival is the time interval between SBRT and occurrence of distant metastases or death irrespective of the cause

Relapse-Free Survival1-year post SBRT, then annually up to 5-years post-SBRT

Relapse-Free Survival is the time interval between SBRT and occurrence of clinical relapse: local recurrence, regional or distant metastases, start of hormonal therapy, or death irrespective of the cause

Local Control1-year post SBRT, then annually up to 5-years post-SBRT

Local Control is defined as the observations without local failure (within prostate or prostate bed):

1. in-field

2. out-field

Overall Surival3 months post-SBRT, 6 months post-SBRT, every 6 moths thereafter up to 5-years post-SBRT

Overall Survival is the time interval between SBRT and patient death irrespective of the cause

Patients' reported Quality of Life2-years post SBRT, 3-years post SBRT

Evaluation of EORTC QLQ-C30 and PR-25 questionnaires

Trial Locations

Locations (1)

Maria Sklodowska Memorial Research Institute of Oncology

🇵🇱

Gliwice, Poland

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