Transcript High Intensity Focused Ultrasound (HIFU)

Alternative Treatments for
Localized Prostate Cancer
Dr. Ronald Sorensen
Overview
• Currently, the options for localized prostate cancer often
straddle two ends of a spectrum with active surveillance at
one end and radical therapy, such as prostatectomy or
radiotherapy at the other
• Tissue preserving strategies aim to target the cancer and not
the whole organ when it is morphometrically possible to do so
and thus limit damage to collateral tissue
Overview
• Men can expect the following rates of toxicity from
radical therapy on average:
– Erectile dysfunction: 30-90%
– Incontinence: 5-20%
– Rectal toxicity: 5-20%
Patient Selection
• Appropriate selection is key when considering
alternative treatment modalities:
– Pts who cannot tolerate radical treatments
– Pts who have a short life expectancy
– Pts with low risk disease who do not wish to undergo
conservative management
Ablative Technology
• Cryotherapy: ablation of tissue by extremely
cold temperatures
Ablative Technology
• High Intensity Focused Ultrasound (HIFU): mechanical
vibrations above the threshold of human hearing (16 kHz)
which have the ability to interact with tissue to produce
biological changes
Ablative Technology
• Photodynamic therapy: uses a
photosensitizing drug that is
active, after a given drug-light
interval, by light of a specific
wavelength. It requires tissue
oxygen for the treatment
effect with the active drug
forming reactive oxygen
species, which are directly
responsible for damage to the
treated volume
Ablative Technology
• Focal Irreversible Electroporation: causes
tissue damage by permanently altering the
cell homeostasis using low-energy current
leading to cell death.
Radiofrequency Ablation (RFA)
• RFA: converts radiofrequency waves to
heat, resulting in thermal damage. Highfrequency current flows from the needle
electrode to target tissue with resultant
ionic agitation and heat producing
molecular friction, denaturation of proteins,
and cell membrane disintegration.
Outcomes
• Most of these treatments are experimental and thus
high-quality long term outcome data is lacking
• Outcomes must be considered in light of patient
goals-of-care