Focal therapy in prostate cancer: a real alternative in highly selected patients
Prostate cancer is the most common form of cancer in men in the world. For more than 50 years, a wide variety of therapeutic approaches have been researched and developed to address this disease.
The treatments with curative intent most commonly used today consist of the removal or radical radiation of the entire prostate tissue (surgery or external radiotherapy). However, in recent years focal therapy has been gaining exponential interest and recognition.
Focal therapy is distinguished from other treatments by its ability to treat specific areas of cancer in the prostate, while sparing surrounding healthy tissue. This highly focused approach seeks to minimize the potential side effects of radical treatments (preserving erectile function and urinary continence), which are aspects of absolute importance for the quality of life of patients.
Indications for focal therapy
Focal therapy is generally considered appropriate for patients with localized, low-risk or intermediate-risk prostate tumors. Those patients who wish to minimize the impact on sexual and urinary function may also be ideal candidates.
There are different energies to treat prostate tumors locally. At Dr Puche Sanz’s clinic, the two main possibilities are offered: cryotherapy and high-intensity ultrasound (HIFU). Each energy has its particularities and therefore, the selection of patients for this therapeutic approach must be based on a thorough evaluation of the individual clinical situation, considering factors such as age, stage of cancer, location of the tumor within the prostate and the patient preferences.
Advantages of focal therapy:
- Minimally invasive treatment
- Preservation of quality of life
- No irradiation, no incision
- Treatment can be performed under spinal anesthesia
- Trauma to the pelvic and perineal area.
- The treatment can be done in a single session
- Short stay in hospital (24 hours)
- Treatment can be repeated
- Allows consideration of other subsequent therapeutic alternatives if the results are unsatisfactory
- The treatment can be used to treat cancer recurrence after radiation therapy
Disadvantages and considerations of focal therapy:
Possible risk of recurrence:
There is a chance that cancer may come back in the prostate after focal therapy, which may require additional treatments or long-term follow-up.
Requires continuous evaluation:
Patients undergoing focal therapy need regular and careful follow-up to monitor the effectiveness of the treatment and detect any signs of recurrence. It is likely that a repeat biopsy will be necessary after months of treatment.
Limitations in certain cases:
Not all prostate cancer patients are ideal candidates for focal therapy. In some cases, especially when the cancer is more advanced or has affected large areas of the prostate, other treatments may be more appropriate.
There are different energies to treat prostate tumors in a focused way. At Dr Puche Sanz‘s clinic, the two main possibilities are offered: cryotherapy and high-intensity ultrasound (HIFU). Each energy has its particularities and therefore, the selection of patients for this therapeutic approach must be based on a thorough evaluation of the individual clinical situation, considering factors such as age, stage of cancer, location of the tumor within the prostate and the patient preferences.
It is essential that patients consider these aspects and discuss in depth with their urologist the treatment options available, as well as the specific benefits and risks for their individual case. The decision on the most appropriate therapeutic approach should be based on a complete evaluation of the medical situation and a clear understanding of the possible outcomes and side effects.
What is HIFU treatment?
The use of high-intensity ultrasound or High-Intensity Focused Ultrasound (HIFU) is a real option for selected patients with low and intermediate risk prostate cancer.
The 3 physical principles of HIFU are:
Thermal effect
Heat induction at the focal point
Rapid increase in temperature (>80 °C)
Mechanical effect
Generation of gas bubbles
Cavitation effect
Breakdown of cell walls.
Tissue effect
Immediate: coagulation necrosis
After 7 days: inflammatory response
After 14 days: induction of fibrosis
This thermal ultrasound energy is applied through a robotic system (FocalOne®) that allows its application in an extremely precise way. Its fundamental technological pillars are:
1.- Planning:
The robot allows the acquisition of high-precision real-time ultrasound images and the fusion of previous nuclear magnetic resonance (MRI) images. This allows the area to be treated in a focused manner to be defined with enormous precision. Photo: selection of the area to treat.
2.- Treatment:
The robotic system allows electronic displacement of the focal point without any mechanical movement and conformational treatment (removal of a precise area around the tumor without affecting the surrounding healthy tissue). The time in which this treatment can be carried out is especially interesting. A standard treatment usually does not exceed 45-60 minutes in duration.
3.- Validation:
Built-in contrast-enhanced ultrasound (CEUS) technology allows confirmation of devascularized areas. Thus, in the same operating room the treatment that the patient has received can be validated and, if necessary or if there are doubts as to whether the entire programmed area has been removed correctly, repeat it at the same time.
How the HIFU ablation technique is performed step by step.
You should know that, in accordance with the European Urological Clinical Practice Guidelines (EAU guidelines), if you are a candidate patient to be treated with this technology, your data and clinical evolution would be included in a European multicenter registry of patients treated with HIFU. . That is why your treatment and follow-up will be carefully scheduled and reviewed.
In the following link, you can access a video that shows how this procedure is performed:
What are the clinical results of HIFU?
In 2013, the publication of long-term results (10-year follow-up) has validated the effectiveness of this technology: depending on the cancer risk (low, intermediate or high risk cancer risk) the specific survival rates range between 92% and 99% at 10 years (3-5); 10-year metastasis-free survival ranges from 86% to 100%. For years, a new approach has been developed in the fight against prostate cancer, which consists of no longer treating the entire prostate, but only the area affected by cancer. Thus, in 2017, the results of the French multicenter study on the treatment of prostate cancer were published by the French Association of Urology (1). This study highlights the advantages of this approach, with an 85% absence of cancer in the treated area, while further reducing the side effects of the treatment.
What are the side effects?
The main side effects of whole gland HIFU treatments are presented in table 1. Narrowing of the intraprostatic urethra (stricture) can appear in the months after treatment and can sometimes lead to a short endoscopic intervention (urethrotomy) in order to relieve the urethra of fibrotic tissue that replaces the destroyed prostate tissue. Patients who experience incontinence may benefit from specific treatment. Preliminary results of focal treatment of prostate cancer, particularly those of a multicenter hemiablation study (1), have demonstrated excellent preservation of quality of life with minimal effect on urinary and sexual functions.
What follow-up is required after HIFU?
PSA levels are checked periodically every three months and a biopsy is performed 6 months after treatment. If cancer cells remain (10 to 15% of cases), a second HIFU treatment will likely be given. After the second session, if the cancer persists, adjuvant external radiation therapy will be proposed. If the biopsies are negative but the PSA is increasing, it may be a more advanced stage cancer that requires specific systemic treatment.
Patients with prostate cancer recurrence after initial radiotherapy or brachytherapy.
HIFU treatment can be offered to patients who develop a local recurrence after first-line treatment with radiotherapy. The absence of extraprostatic extension and/or metastasis must be proven (by bone exploration, thoracic-abdominal computed tomography and PET CT). Treatment is performed in the same way as for patients with HIFU as a first-line treatment. In some cases (5% of cases), treatment may not be feasible in certain patients who have a rectal stenosis or abnormal thickness of the rectal wall. In such cases, an alternative (usually androgen deprivation treatment) will have to be offered.
References:
- Rischmann P, Gelet A, Riche B, Villers A, Pasticier G, Bondil P, et al. Focal High In- tensity Focused Ultrasound of Unilateral Localized Prostate Cancer: A Prospective Multicentric Hemiablation Study of 111 Patients. Eur Urol. 2017;71(2):267-73.
- Crouzet S, Chapelon JY, Rouviere O, Mege-Lechevallier F, Colombel M, Tonoli-Ca- tez H, et al. Whole-gland ablation of localized prostate cancer with high intensity focused ultrasound: oncologic outcomes and morbidity in 1002 patients. Eur Urol. 2014;65(5):907-14.
- Baco, E., A. Gelet, S. Crouzet, E. Rud, O. Rouviere, H. Tonoli-Catez, V. Berge, J. Y. Chapelon, and H. B. Eggesbo. 2014. ‘Hemi salvage high-intensity focused ultra- sound (HIFU) in unilateral radiorecurrent prostate cancer: a prospective twocentre study’, BJU Int, 114: 532-40.
- Ganzer R, Fritsche HM, Brandtner A, Brundl J, Koch D, Wieland WF, et al. Four- teen-year oncological and functional outcomes of high-intensity focused ultra-sound in localized prostate cancer. BJU Int. 2013;112(3):322-9.
