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The Ablatherm® Integrated Imaging device is indicated for transrectal high intensity focused ultrasound (HIFU) ablation of prostate tissue.
The Ablatherm Integrated Imaging is a computer controlled medical device intended to provide High Intensity Focused Ultrasound (also referred as HIFU) to ablate prostate tissue. The system consists of the following main sub-assemblies: Treatment Module, Control Module, Endorectal Probe, and Ablapak. HIFU is a unique process of delivering a large amount of heat energy to a confined space in a highly controlled manner. This energy heats the tissue to ablation levels while minimizing the effect on surrounding structures.
The ultrasound energy is delivered via an endorectal probe, which includes an imaging system. The ultrasound waves propagate through the rectal wall and are focused on a portion of the prostate, generating intense heat and causing the ablation of tissue within the targeted area. The process is then repeated in a stepwise fashion to destroy the targeted tissues within the prostate. The apex, sphincter and rectum are preserved while prostate tissues are ablated.
Acceptance Criteria and Device Performance Study for Ablatherm Integrated Imaging
The provided document describes the Ablatherm Integrated Imaging device, indicated for transrectal high-intensity focused ultrasound (HIFU) ablation of prostate tissue. The study presented is a clinical study designed to demonstrate the device's effectiveness through measures of prostate tissue ablation and patient outcomes.
1. Table of Acceptance Criteria and Reported Device Performance
Since this is a submission for a 510(k) premarket notification, formal "acceptance criteria" for performance are not explicitly stated in the same way they might be for a PMA. Instead, the document focuses on demonstrating substantial equivalence to a predicate device (Sonablate 450) and providing clinical evidence of the device's ability to achieve its intended purpose (prostate tissue ablation) and its safety profile.
Therefore, the table below consolidates the performance metrics presented as evidence of the device meeting its intended use for prostate tissue ablation and the associated clinical outcomes.
| Performance Metric (Indicative of Acceptance) | Reported Device Performance (Ablatherm Integrated Imaging) | Notes/Context |
|---|---|---|
| Prostate Tissue Ablation | ||
| Mean Prostate Volume Reduction (post-HIFU vs. baseline) | 13.6 cc (95% CI: 10.9, 16.3) | Measured at first post-HIFU ablation biopsy. Mean post-HIFU volume: 9.0 cc; Baseline mean volume: 22.7 cc. |
| Mean PSA Nadir (first 6 months post-HIFU) | 0.53 ng/mL (95% CI: 0.37, 0.69) | |
| Mean % PSA Reduction from Baseline to Nadir | 87.97% (95% CI: 84.80, 91.15) | |
| PSA Reduction from Baseline (1-month post-HIFU) | 78.14% (95% CI: 72.95, 83.34%) | Mean PSA: 0.89 ng/mL |
| PSA Reduction from Baseline (1-year post-HIFU) | 80.34% (95% CI: 75.77, 84.91) | Mean PSA: 0.91 ng/mL |
| PSA Reduction from Baseline (2-year post-HIFU) | 82.25% (95% CI: 77.61, 86.89%) | Mean PSA: 0.72 ng/mL |
| Phoenix Biochemical Survival Rate | 90.5% (95% CI: 85.2, 95.8%) (116 evaluable subjects) | Defined as: No PSA between 6 and 24 months post-HIFU procedure ≥ PSA Nadir + 2 ng/ml. |
| Negative Post-Ablation Biopsy Rate | 59% (95% CI: 50, 68) (Total cohort of 135 patients) | For ITT analysis, 17 patients without biopsy were considered "positive". |
| Safety Profile (Adverse Events) | (All adverse events collected regardless of relationship to device/procedure, n=135) | |
| Any Adverse Event | 97.0% | |
| Erectile Dysfunction | 67.4% (61/135 unresolved at 2 years) | 12/61 subjects had pre-HIFU ED; 9/61 unresolved ED were mild. Expected due to targeting lateral margins. |
| Urinary Incontinence | 38.5% (21/135 unresolved at 2 years) | 16/21 unresolved UI were mild. |
| Urinary Obstruction (unresolved at 2 years) | 0.7% (1 subject) | |
| Stricture (unresolved at 2 years) | 2.2% (3 subjects) | |
| Bladder Neck Contracture (unresolved at 2 years) | 1.5% (2 subjects) | |
| Sepsis (unresolved at 2 years) | 0.7% (1 subject) | Two cases of sepsis reported, both not considered related to device/procedure. |
| Urinary Tract Infections (resolved within 2 years) | 34.1% (46 subjects) | All resolved within 2 years. |
| Bowel Injury (resolved within 2 years) | 3.0% (4 subjects) | All resolved within 2 years. Includes "anal tears". |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 136 subjects were enrolled, of which 135 subjects underwent the HIFU procedure. One subject was excluded due to calcifications.
- Data Provenance: Not explicitly stated (e.g., country of origin). The study seems to be a prospective clinical study (IDE study) where subjects were enrolled and followed over time. The first subject was enrolled on May 4, 2006, and the last on June 30, 2010.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts used to establish the ground truth or their qualifications. The clinical outcomes (prostate volume reduction, PSA levels, biopsy results, adverse events) were likely assessed by the treating physicians and clinical staff involved in the study, consistent with standard medical practice.
4. Adjudication Method for the Test Set
The document does not describe any formal adjudication method (e.g., 2+1, 3+1). Clinical data such as PSA levels, prostate volume, and biopsy results are generally based on objective measurements and established clinical diagnostic criteria, rather than subjective expert interpretation requiring adjudication in this context. Adverse events were collected and summarized.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, If So, What Was the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
No MRMC comparative effectiveness study was done. This device is a treatment device (HIFU for prostate ablation), not an AI-assisted diagnostic or imaging interpretation device. Therefore, the concept of "human readers improve with AI" is not applicable here.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
No standalone algorithm performance study was reported. This device is a medical instrument used by trained physicians, not an autonomous AI system.
7. The Type of Ground Truth Used
The ground truth used in the clinical study is a combination of:
- Objective Medical Measurements:
- Prostate Volume Reduction: Measured clinically.
- PSA Levels: Standard laboratory test results.
- Biopsy Results: Histopathological analysis (determines presence/absence of cancer cells post-ablation or tissue characteristics).
- Clinical Outcomes/Patient Reported Outcomes:
- Adverse Events: Clinically observed and reported events during follow-up.
These are considered relevant clinical endpoints for evaluating the effectiveness and safety of a prostate ablation device.
8. The Sample Size for the Training Set
The document does not mention a "training set" in the context of an AI/machine learning model. The clinical study described involved 135 subjects who underwent the HIFU procedure, which served as the primary clinical evidence for the device's performance in this 510(k) submission. Therefore, it's not applicable to the concept of a training set for an algorithm.
9. How the Ground Truth for the Training Set Was Established
Since there is no mention of a training set for an AI/machine learning algorithm, this question is not applicable. The clinical data used to support the device's effectiveness and safety were gathered prospectively from the 135 subjects undergoing the procedure and evaluated against established clinical benchmarks and adverse event reporting.
§ 876.4340 High intensity ultrasound system for prostate tissue ablation.
(a)
Identification. A high intensity ultrasound system for prostate tissue ablation is a prescription device that transmits high intensity therapeutic ultrasound energy into the prostate to thermally ablate a defined, targeted volume of tissue, performed under imaging guidance. This classification does not include devices that are intended for the treatment of any specific prostate disease and does not include devices that are intended to ablate non-prostatic tissues/organs.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Non-clinical performance data must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Characterization of acoustic pressure and power output at clinically relevant levels;
(ii) Measurement of targeting accuracy and reproducibility of high intensity ultrasound output;
(iii) Ultrasound-induced heating verification testing at target and non-target tissues;
(iv) Electrical safety testing; and
(v) Electromagnetic compatibility testing.
(2) Software verification, validation, and hazard analysis must be performed.
(3) The elements of the device that may contact the patient's mucosal tissue must be demonstrated to be biocompatible.
(4) Performance data must demonstrate the sterility of the device components that contact the patient's mucosal tissue.
(5) Performance data must support shelf life by demonstrating continued sterility of the device or the sterile components, package integrity, and device functionality over the identified shelf life.
(6) Performance data must support the instructions for reprocessing all reusable components.
(7)
In vivo testing must demonstrate that the device thermally ablates targeted tissue in a controlled manner without thermal injury to adjacent, non-target tissues.(8) Clinical testing must document the adverse event profile, provide evidence of prostatic ablation, and demonstrate that the device performs as intended under anticipated conditions of use.
(9) Training must be provided so that upon completion of the training program, the physician can:
(i) Use all safety features of the device;
(ii) Accurately target the high intensity ultrasound energy within the desired region of the prostate; and
(iii) Perform the ablation procedure in a manner that minimizes damage to non-target tissues.
(10) Labeling must include:
(i) A section that summarizes the clinical testing results, including the adverse event profile and evidence of prostate ablation achieved; and
(ii) An expiration date or shelf life for single use components.