The patient is generally hospitalized the evening
before the treatment. The patient is given an enema for colorectal
preparation approximately two hours before treatment.
Procedure
The treatment is generally performed under spinal anesthesia.
The treatment is executed with the patient lying in
a right lateral position. St rict immobility is necessary
during the treatment, which explains the administration
of a sedative.
The treatment is performed transrectally. A probe is placed in the
rectum. This probe emits a beam of high intensity convergent
ultrasound. In the point where the ultrasounds are focused
(focal point) the sudden and intense absorption of the ultrasound
beam creates a sudden elevation of the temperature (from 85
to 100°C) which destroys the cells located in the targeted
zone.
The
targeted prostatic volume is localized with the
ultrasound imaging transducer.
High-energy
ultrasound waves are focused through the rectal wall to
the targeted prostate area.
The targeted zone destroyed by each shot is oval-shaped
and measures up to 24 mm in height by less than 2 mm
in diameter. By repeating the shots, and moving the
focal point between each shot, it is possible to destroy
a volume that includes the whole tumor (400 to 600 shots
are generally done to treat the volume previously defined).
The treatment duration varies according to
prostate volume (1 to 2 hours). Swelling of the prostate appears
immediately after the treatment and compresses the urethra.
A temporary urine catheter is inserted. This allows the elimination
of urine until the edema recedes (which takes generally from
3 to 8 days depending on the case).
To reduce the need for post treatment catheterization, a “mini”
transurethral resection (TURP) can be done before or immediately
after the treatment with HIFU (during the same anesthesia):
this is mainly performed on patients presenting signs of prostatic
obstruction (weak urinary stream, frequent nocturnal urination,
residual urine volume in the bladder).
Preparation
