HIFU and cryoablation – non or minimal touch techniques for the treatment of prostate cancer. Is there a role for contrast enhanced ultrasound?

Abstract

The incidence of prostate cancer is increasing, and therefore also the need for optimal treatment. Because of the appearance of many different disease stages different treatment modalities are desirable for the treatment of localized prostate cancer. The established therapies, radical prostatectomy and radiation therapy, are associated with a lot of risks, complications and co-morbidity, and not all patients are eligible for these treatments. That is why the need for reliable minimally invasive alternatives has developed. For this paper a literature search was conducted on published studies and review articles to determine the role of HIFU (high intensity focused ultrasound) and cryoablation as minimally invasive treatment modalities for localized prostate cancer. Both therapies are being used as a primary or secondary (salvage) treatment, but can they replace surgery or radiation? And is there a role for contrast enhanced ultrasound (CEUS) of the prostate to improve diagnostics, treatment outcomes and follow-up? To date the outcomes of both therapies are promising but no prospective and comparative randomized studies with a long term follow-up were available for analysis. From this review we can conclude that until those studies are available, HIFU and cryoablation are good alternatives for patients not eligible for prostatectomy or radiation. They should not be used as a first treatment option as long as diagnostics and follow-up have not improved.

High‐intensity focused ultrasound in prostate cancer; a systematic literature review of the French Association of Urology

“…HIFU was used on patients who were ≈ 70 years old, with stage T1-T2, N0M0 disease, mainly Gleason score < 7 (median ≈ 6), a PSA level of 7-28 ng/mL and a prostate volume 23-37 mL. Other reviews recommend HIFU in patients with T1b-T1c or T2 N0M0 disease, a PSA level of < 15-20 ng/mL, fewer than four positive biopsies in a sextant biopsy, and a Gleason score of < 7 [4,42,43], in particular, if these patients are unsuitable [18,19]. for (or refuse) radical therapy because of, e.g.…”

Contrast-enhanced ultrasonography for real-time monitoring of interstitial laser thermal therapy in the focal treatment of prostate cancer

“…Contrastenhanced ultrasonography (CEUS) using intravascular microbubble agents has been developed to aid in diagnosing disease by defining regions of abnormal blood perfusion or vascular filling patterns, and as a method for local delivery of drugs. 5 CEUS has also been used to assess treatment response for ablative therapies such as radiofrequency ablation [6][7][8][9] and high-intensity focused ultrasonography, 10 typically several days after the therapy. Tissue changes following radiofrequency ablation of canine prostates 6 have been monitored 10-15 minutes after completion of therapy.…”

Novel contrast-enhanced ultrasound imaging in prostate cancer

“…Molecular ultrasound imaging with targeted microbubbles could play a role in selecting patients for the most appropriate treatment. For follow-up, CEUS can also enable visualization of the effects of therapy or medical treatments that influence the perfusion of the prostate (Brachy, radiotherapy, HIFU, cryoablation, or hormonal therapy) and identify early PCa relapses that might not be detected by PSA rise [33]. …”