Efficacy Assessment of a Novel 3D Cartography-based Targeted Focal Microwave Therapy in Men With Localized Intermediate-risk Prostate Cancer (VIOLETTE)

Prospective Multicenter Trial Assessing the Efficacy of a Novel 3D Cartography-based Targeted Focal Microwave Therapy in Men With Localized Intermediate-risk Prostate Cancer

Multicenter, prospective, European, single-arm, open-label, 12-month follow-up clinical trial. The purpose of this study is to evaluate the efficacy of a 3D cartography-based targeted microwave ablation for the treatment of the index lesion in patients with intermediate risk prostate cancer.

Study Overview

• Status: Completed
• Conditions: Prostate Cancer
• Intervention / Treatment: Device: Targeted microwave ablation

Detailed Description

European and American guidelines recommend several therapeutic alternatives: radical surgical treatment, external beam radiotherapy or brachytherapy. However, whole-gland treatment induces significant morbidity and burden on quality of life. Targeted treatments of the index tumor are currently under investigation to decrease morbidity while proposing active treatment.

The purpose of this study is to assess the efficacy of a novel ablation treatment using microwaves, delivered transrectally or transperineally under real-time guidance with MRI-transrectal ultrasound image registration. The index tumor will be detected with prostate MRI and characterized with targeted biopsies using Organ Based Tracking (OBT) fusion with the TRINITY system (KOELIS, Meylan, France). The same system will be used to identify the index lesion and guide the targeted microwave ablation performed with the TATO3 device (Biomedical Srl, Florence, Italy).

All patients will undergo biopsy at 12 months of follow-up. A biopsy session will also be performed at 6 months, but only for patients with imaging results suspicious for cancer within the ablated area on the mpMRI.

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Brussels, Belgium, 1000
    • Institut Jules Bordet
• France
  • Bordeaux, France, 33000
    • Centre Hospitalier Universitaire de Bordeaux
  • Neuilly-sur-Seine, France, 92200
    • American Hospital of Paris
  • Paris, France, 75014
    • Hôpital Cochin (Assistance Publique - Hôpitaux de Paris)
  • Saint-Herblain, France, 44800
    • Urologie Nantes Clinique & Institut d'Urologie - Site Atlantis

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 41 years to 72 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient aged from 45 to 80 years old
• Life expectancy >10 years at the inclusion time

• Patient diagnosed with an intermediate-risk prostate cancer, defined by:

  • A T1c or T2a clinical stage
  • A unique cancer focus of Gleason (3+4) (Grade Group 2). In addition to the index lesion intended for treatment, the presence of additional microfoci < 10mm on mpMRI, for which biopsies present no evidence of cancer or a Gleason score of 3+3, is accepted
  • A PSA level <20 ng/mL
• Cancer focus identified on a multiparametric MRI of the prostate no more than 3 months before inclusion
• Confirmation of the suspicion of cancer identified on the MRI with transrectal or transperineal targeted and systematic biopsies performed with the KOELIS TRINITY system (no more than 3 months before inclusion)
• Patient suitable for IV sedation or general anesthesia and focal microwave ablation
• No debilitating medical or psychiatric illness that would preclude giving informed consent or receiving optimal treatment and follow-up
• Known coagulopathy or bleeding disorders are controlled
• Free, informed and written consent, dated and signed before the enrollment and before any exam required by the trial
• Patient affiliated to social security regimen or beneficiary of such regimen for local regions

Exclusion Criteria:

• Past medical history of prostate surgery
• Past medical history of radiotherapy or pelvic trauma
• Past medical history of acute prostatitis
• Presently taking hormonal manipulation or androgen supplements.
• Past medical history of cancer in the 5 previous years, excluding a non-metastatic basal cell carcinoma of the skin
• Severe BPH-related urinary tract symptoms, defined by an IPSS score >18
• Serious medical illness, including any of the following: uncontrolled congestive heart failure, uncontrolled angina, myocardial infarction, cerebrovascular event within 6 months prior to the screening visit
• Contraindications for MRI exam
• Extracapsular cancer extension or seminal vesicles or pelvic lymph node invasion suspected on prostate MRI
• Presence of two or more clinically significant cancer foci in the inclusion biopsy exam
• Presence of a clinically significant cancer with a Gleason score ≥8 (Grade Group ≥4)
• Tumor largest axis >15 mm on the prostate MRI
• Distance between the cancer focus and the apex <5 mm on the prostate MRI
• Distance between the cancer focus and the rectum <5 mm on the prostate MRI
• Patient already participating in an interventional clinical trial
• Patient protected by law

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Targeted microwave ablation; Targeted microwave transrectal or transperineal ablation of the prostatic index tumor using MRI-transrectal image registration and OBT fusion	Device: Targeted microwave ablation; Targeted ablation of the index tumor with microwaves, by using either a transperineal or a transrectal approach

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The proportion of patients with no evidence of cancer on targeted biopsy	The proportion of patients with no evidence of cancer on targeted biopsy at 12 months, defined by a minimum of 2 targeted core biopsies taken from the index tumor site treated with microwave ablation for focal treatment of intermediate risk prostate cancer	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of radical salvage treatment	Proportion of patients undergoing radical salvage treatment of the index lesion	12 months
Time to radical salvage treatment	Time to radical salvage treatment of the index lesion	12 months
Proportion of patients with any cancer in the untreated area	Proportion of patients with any cancer in the untreated area, determined by a minimum 12 cores systematic biopsy	12 months
Proportion of patients undergoing treatment for cancer in the untreated area	Proportion of patients undergoing treatment for cancer in the untreated area and time to treatment	12 months
IPSS questionnaire	Changes in patients' reported outcome measures (PROMs) for urinary symptoms using IPSS score compared to baseline, score ranging from 0 to 35 (the higher the worse)	7 days and 1, 6 and 12 months
IIEF-5 questionnaire	Changes in patients' reported outcome measures (PROMs) for erectile function using IIEF-5 score compared to baseline, score ranging from 5 to 25 (the lower the worse)	7 days and 1, 6 and 12 months
MSHQ-EjD-SF questionnaire	Changes in patients' reported outcome measures (PROMs) for ejaculatory function and bother using MSHQ-EjD-SF score compared to baseline, score ranging from 1 to 15 (the lower the worse) for ejaculatory function and from 0 to 5 for bother/satisfaction (the higher the worse)	7 days and 1, 6 and 12 months
Urine flow	Change in urine flow, using a uroflowmeter compared to baseline	7 days and 1, 6 and 12 months
Adverse events	Number and severity of device and procedure related adverse events	12 months
Patient post-operative pain level	Average patient post-operative pain level reported on a pain numeric rating scale, with a range from 0 (no pain) to 10 (worst pain ever)	Treatment day-evaluated between 2 and 4 hours after the procedure
Patient satisfaction	Patient satisfaction with the microwave ablation procedure as determined by questionnaire (no score assigned)	1, 6 and 12 months
Ease of the procedure	Ease of the procedure measured with a score chosen by the operator (1: easy, 2: moderate, 3: difficult)	Day 1
Duration of the procedure and associated variables	Duration of the procedure and associated variables	Day 1
PSA	Change in PSA measurement compared to baseline	1, 3, 6, 9 and 12 months
PSA Nadir	Time to PSA Nadir after treatment of the index lesion	12 months
Prostate volume	Change in volume of the prostate on the mpMRI compared to baseline	7 days and 6 and 12 months
Patient motivation	Characterization of patient motivation to undergo targeted microwave ablation for treatment of the index lesion, as assessed by patient questionnaire (no score assigned)	Baseline
Surgeon opinion regarding adequate guidance of the microwave ablation needle	To evaluate the adequate guidance of the microwave ablation needle by the surgeon opinion	Day 1
Adequate guidance of the microwave ablation needle on the treated index lesion	To evaluate the adequate guidance of the microwave ablation needle by percentage of covering of the treated index lesion	Day 1
Adequate guidance of the microwave ablation needle on the treated index lesion and margins	To evaluate the adequate guidance of the microwave ablation needle by percentage of covering of the treated index lesion and margins	Day 1
Learning curve of the TMA procedure	To evaluate the learning curve of the TMA procedure by the duration of the intervention (delay between probe in and the end of anesthesia (minutes).	Day 1

Collaborators and Investigators

• Sponsor: Koelis
• Investigators: Study Chair: Roland VAN VELTHOVEN, MD, Uro Science & Consulting

Publications and helpful links

General Publications

• Delongchamps NB, Peltier A, Potiron E, Bladou F, Diamand R, Messas A, Roche JB, Robert G, Hoepffner JL, Piechaud T, Anract J, Velthoven RV. Targeted microwave ablation of localised prostate cancer (VIOLETTE trial): a prospective multicentre study. BJU Int. 2026 Mar 11. doi: 10.1111/bju.70220. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Actual): February 11, 2021
• Primary Completion (Actual): July 29, 2025
• Study Completion (Actual): August 21, 2025

Study Registration Dates

• First Submitted: September 29, 2020
• First Submitted That Met QC Criteria: October 5, 2020
• First Posted (Actual): October 9, 2020

Study Record Updates

• Last Update Posted (Actual): April 6, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Cancer; Prostate; Microwave; Targeted treatment
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Neoplasms; Prostatic Neoplasms
• Other Study ID Numbers: VIOLETTE; 2019-A00803-54 (Other Identifier: ANSM)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No