Focal One High-Intensity Focused Ultrasound (HIFU) offers a targeted approach for men diagnosed with localized prostate cancer. This treatment represents a significant shift from traditional whole-gland therapies, which often remove or irradiate the entire prostate gland. The Focal One system is designed to precisely destroy only the cancerous tissue, sparing the surrounding healthy tissue and delicate structures. This tissue-sparing method aims to effectively manage the cancer while minimizing the side effects commonly associated with more invasive procedures.
The Technology Behind Focal Ablation
The core mechanism of Focal One is High-Intensity Focused Ultrasound, which uses focused sound waves to generate intense heat within the targeted prostate tissue. The device delivers acoustic energy through a transrectal probe, concentrating the ultrasound beams at a specific focal point inside the prostate gland. This rapid energy concentration causes a localized temperature increase to between 80°C and 100°C, leading to thermal ablation and the immediate destruction of cancer cells.
The procedure’s precision relies heavily on sophisticated imaging and fusion technology integrated into the Focal One platform. Prior diagnostic images, typically from a multi-parametric Magnetic Resonance Imaging (mpMRI) scan and targeted biopsies, are merged with real-time ultrasound imaging. This process, known as fusion imaging, creates a detailed, three-dimensional map of the prostate, clearly outlining the tumor’s exact boundaries.
Using this fused map, the urologist can digitally “paint” the area of cancerous tissue to be treated, while simultaneously contouring and protecting critical structures like the neurovascular bundles and the urethral sphincter. The Focal One robotic system then automatically directs the high-intensity ultrasound energy to follow this pre-planned treatment boundary with sub-millimetric accuracy. During the ablation, the system provides real-time monitoring of the treatment zone and the surrounding rectal wall temperature to ensure safety and confirm the destruction of the targeted tissue.
Determining Patient Eligibility
The selection process for Focal One HIFU is rigorous because the therapy is designed specifically for localized, or focal, prostate cancer. Urologists use a set of criteria to confirm the cancer is suitable for a partial-gland treatment, which often includes a clinical stage of T1c or T2, meaning the tumor is confined within the prostate capsule. Patients are typically considered if their Prostate-Specific Antigen (PSA) level is \(\le 15\) to \(20\) ng/mL before treatment.
Tumor aggressiveness, as measured by the Gleason Score, is also a determining factor for focal therapy candidacy. Generally, the procedure is recommended for tumors with a Gleason Score of \(7\) or less, corresponding to Grade Group \(3\) or lower.
Furthermore, the physical characteristics of the prostate and the tumor itself play a role in eligibility. The index lesion, which is the largest and most aggressive tumor focus, must be clearly visible on mpMRI and often limited in size, sometimes defined as less than \(20\) millimeters in diameter. Patients with a very large prostate, often exceeding \(40\) grams, may not be ideal candidates as the size can limit the effective delivery of the ultrasound energy.
The Treatment Experience and Immediate Recovery
The Focal One HIFU procedure is typically performed in a single session and is often an outpatient procedure, allowing patients to return home the same day or after a short overnight stay. The treatment is conducted under general or regional anesthesia to ensure patient comfort and prevent movement during the precise energy delivery.
A temporary catheter is placed into the bladder to manage urinary flow and is a standard part of the immediate post-procedure care. This catheter is necessary because the prostate tissue, though ablated by heat, swells temporarily as it heals, which can obstruct the urethra. The catheter is usually removed a few days later, often between day one and day six, after the initial swelling has subsided.
The primary advantage of focal therapy is the preservation of healthy tissue, which translates into significantly lower rates of functional side effects compared to radical prostatectomy or whole-gland radiation. For instance, urinary continence is preserved in a high percentage of patients, with some studies reporting rates of 96% at one year.
Preservation of erectile function is also a main goal of the focal approach, since the neurovascular bundles responsible for potency are often avoided. While some patients may experience temporary or permanent changes, reported potency preservation rates are strong, often ranging from 74% to over 80% in preoperatively potent men.
Long-Term Monitoring and Surveillance
After undergoing Focal One HIFU, patients transition to a long-term monitoring protocol designed to ensure the cancer remains controlled. Since only the cancerous portion of the prostate is ablated, the remaining healthy tissue is still at risk for developing new cancer cells in the future.
The post-treatment regimen typically involves regular Prostate-Specific Antigen (PSA) testing, often scheduled every three months during the first year. A successful focal ablation usually results in a significant drop in PSA levels, and this trend is closely monitored for any subsequent rise, which could indicate a recurrence.
In addition to PSA checks, multi-parametric MRI (mpMRI) scans are routinely performed, typically at the one-year mark, to visually assess the treated area and the rest of the prostate gland. The mpMRI helps identify any suspicious areas that may have been missed or where new disease may have developed. If the imaging or PSA trend raises concern, a protocol-mandated, targeted biopsy is often performed, usually at one year post-treatment, and potentially again at three years.
The goal of this ongoing surveillance is to detect any potential recurrence early, which is most often found in the untreated areas of the prostate. If a localized recurrence is found, the patient has several options, including a second focal treatment, or moving to a whole-gland treatment like radical prostatectomy or radiation therapy.