FOCAL HIFU THERAPY OF Prostate Cancer

 

Patients are routinely advised to consider surgery as a final option for a variety of conditions.  An invasive procedure is frequently accompanied by side effects which, in some cases, can be worse than the disease.  Prostate cancer presents the same concern for many patients. 

Within the urological community, there is a consensus that we are over treating prostate cancer.  We know that many of the cancers we are treating will not result in mortality for the patient, but unfortunately we don't have a means of identifying those cancers that will grow quickly and metastasize and those that will not.  Electing a path of watchful waiting poses its own issues.  Selecting the proper candidates for active surveillance can be difficult, and many patients are anxious about leaving a diagnosed cancer untreated. 

Currently, in 2012, the standard of care for organ confined prostate cancer is whole gland treatment.  This applies to surgical removal (radical prostatectomy), radiation therapy (IMRT or seed implants), and high intensity focused ultrasound (HIFU).  Recently, an article published in Lancet Oncology in the United Kingdom reported on short term follow up of a cohort of patients treated with focal therapy only.  In this protocol patients with limited burden disease (single site or confined to one lobe of the prostate) were treated by targeting only the known area of prostate cancer involvement, based either on multiple biopsies or biopsies combined with MRI imaging. 
The results of the published study have been interpreted as positive and optimistic and have led the National Institute for Clinical Excellence (NICE) in the United Kingdom to issue revised guidelines on focal therapy. 

These can be found on our website here.


Advantages of focal HIFU include reduced treatment time, fewer side effects, particularly incontinence and erectile dysfunction, and shortened time requirements for indwelling catheter drainage of the bladder.

Disadvantages of this approach mainly impact on cure rates.  Prostate cancer is generally regarded as a multi-focal disease, i.e. present in more areas than detected on biopsy and usually not confined to a single area of the prostate.  In recommending focal therapy one presupposes that disease not detected by biopsy is clinically insignificant and may never become clinically significant in the patient’s lifetime.  This fact is unproven by any long term follow up studies but does have intuitive appeal based on the slow growth rate of most prostate cancers.

Risks associated with focal therapy include early recurrence or persistence of prostate cancer in an incompletely treated prostate gland.  This may require re-treatment with HIFU or another form of prostate cancer treatment such as surgery or radiation therapy.   Further spread of the disease beyond the boundaries of the prostate is not impossible as well for disease originating in untreated areas.

Of all the treatment modalities currently available HIFU is the best suited for administering focal therapy.  The highly accurate targeting of areas of the prostate using Ablatherm HIFU makes it possible for patients to consider focal therapy as an option in relatively low grade and relatively non-aggressive prostate cancers.

At Maple Leaf HIFU the large majority of our patients are treated with whole gland ablation although in patients well informed of the risks associated with focal therapy this option is offered as well at Maple Leaf HIFU.