Dr. Mihai Florin Radulescu, Saarbrücken
Dr.Ovidiu Ursu, Saarbrücken
Material and Method
HIFU(high intensity focused ultrasound ) is a highly precise medical procedure using high-intensity focused ultrasound to heat and destroy pathogenic tissue rapidly. It is a minimal invasive or not invasive method to deposit acustic energy into tissue .
Beetween september 2005 and ianuary 2007 we proceed 11 HIFU therapies . The indication was local failure after External Beam Radiation (9 Patients ), local reccurency after Radical Prostatectomy (2) . The general outcome was well tolerated from all this patients .One patient has a acute urinary obstruction and was temporary thrugh a cystostomy treated .The average PSA follow up shows normality (< 0,2 ng/ml).
Conclusion :HIFU is a promisive method for the tratement of reccurencies after external beam radiation or radical prostatectomy .
The first investigations of HIFU for non invasive ablation were reported by Lynn et al in the early 1940s.Extesive important early work was perfomed in the 1950s and 1960s by William Fry and Francis Fry at the University of Illinois and Carl Towsend , Howard White and George Gardner at the Interscience Research Institute of Champagne Ill. , culminated in clinical treatments of neurogical disorders . In particular High Intensity ultrasound and ultrasound visualisation was accomplished stereotaxically with a Cincinatti precision milling maschine to perform ablation of the brain tumors . Until recently clnical trials of HIFU were few , perhaps due to the complexity of the treatments and the difficulty of targeting the beam non invasively .With recent advances in medical imaging and ultrasound technology the interes in HIFU ablation of tumors has increased.
The first HIFU maschine was launched in Europe in 2001 after receving CE approuval , bringing a a first medical validation of the technology for localised prostate cancer . Comprehensive studies by practicioners at more centers using the device have demonstrated clinical efficacity at more than 8 years with limited occurrence of side effects . Studies by Murat and collegues at Edurd Herrio Hospital in Lyon showed that fter treatment the progression –free survival rates are very high for low and intermediate risk patoents with reccurent prostate cncer .
HIFU tretement of prostate cancer is currently an approved therapy in Europe ; South Korea,Australia ,Japan . This year HIFU may be aproved by FDA for prostate cancer ..
Currently over 9000 patients were treated worldwide.
General principle of HIFU
As an acoustic wave propagates through the tissue ,part of it is absorbed and converted to heat .With focused beams , a very small focus can be achieved deep in tissues . When no enough , the tissue is thermaly coagulated .At high enough acoustic intensities , cavitation (microbubbles forming and interacting with the ultrasound field ) can occur .During inertial cavitation ,very high temperatures inside the bubbles occur , and the collaps is associated with a shock wave that can maechanichaly dammage tissue .
The intensity at 30 Watts over 2000W/cm2 .This may produce heat of 80-100 grad C which destroy the tissue and kill the cancer .
This technology can achieve precise “ ablation “ of diseased tissue therefore called HIFU surgery.Because it detroys the dieseased tissue non-invsively , it is also known as “Non –invasive HIFU surgery”,:
Developpement of this therapy significantly broadened the range of treatement options from uterine fibrosis.HIFU treatement for uterine fibrosii was approuved by the Food and Drug Administration (FDA) in october 2004.
HIFU has been succesfully applied in treatement of cancer to destroy solid tumors of the bone brain ,breast, liver ,pancreas,rectum,kidney,prostate .
The earlest widespread use of HIFU ablation was as a treatement for prostate cancer .Developed and rafined ,this treatment is administrated trought a trans-rectal probe and relies on heat developed by focusing ultrasound wawes into the prostate to kill the tumor .Promissing results have been reported in in large series of prostate cancer patients .These treatements are performed unter ultrasound imaging guidance , which allows for tratement plannng and some minimal indication of the energy deposition .
In international HIFU Centers HIFU is used to ablate the entire prostate gland using a transrectalprobe ..It is an out patient procedure that usualy last1-3 hours. Results show it greatly reduces side effects common with other tretments for prostate cancer .
Patient indication and selection
The patients who benefit a HIFU therapy are the patients with T1-T2 prostate cancer (primary and recurrent after radical prostatectomy and radiation). The best results is confined to the group of patients with a PSA < 10 and Gleason 7 .
The general exclusion criteria of the patients for HIFU are :
- prostate larger than 40 gr and a distance to the anterior rectal-wall > 4 cm(unless two treatments to be scheduled –hormones)
- patients with large intra-prostatic stones or calcifications (if they cause signficat shadowing)
- patients with previous rectal wall surgery or hemorrhoids
- patients with latex allergy reactions (probe sheat material is latex)
Features of the Sonablate 500 PC include
-small probe (at tip = 33 mm, at neck =17 m )
-TRUS ( Transrectal Ultrasound Scanning and Therapy)= dual function piezo-electric transducer
-real time imaging during treatement .
-3 D planning software with
- reference images
- numerous safety checks as rectal wall monitoring = automatic temperature and distance control
-simultaneus transversal and longitudinal imaging
This sytem called the “ Visualy Directed HIFU Concept is a surgeon directed interactive situation-driven conrol and performance of the procedure by adjusting teatment parameters in real time through a direct flexible control of energy and 2 D and 3D Modus for ad-hoc redefined treatment plan .
The patient is in lithotomy position in general or spinal anestesia .
The key steps of treatment are :
The rectal ultasounnd probe shows and definethe anatomy of the prostate in tranversal and longitudinal views .
In this phase we Display the treatment zones from base to apex of the prostate .
We are treating the whole gland agressively but carefully to avoid injury to the adjycent structures as the rectal wall , rhabdo-sphikter, ureters,neurovascularbundels, urethra.
Prof . Marberger from University of Vienna treated 38 patients .
The japanese Study data showed 97 % freedom from biochemical progression .
(Prof .Uschida _ Tokio – folow up of 409 patients .
British study from the University College London
(Prof. Marc Emberton )
Our experience as a center of the European Multicenter – Study – upublished .
N : patients , follow up min 3 Month 11
PSA mean 8
Continence 100 %
1 cystoskopie to remove debris .
Advantages over other techniques
High Intensity Focused Ultrasound is considered a promising technology within the non invasive or minimally invasive therapy segments of medical technology .HIFU `s capacity to generate in-depth precise tissue necrosis using an external aplicator , with no effect on the surrounding structure is unique .
Technology has continualy improved and additional clinical applications , both diagnostic and therapeutic , have become an integral part of the new medecine today .
M.Emberton. The Institute of Urology , University College London- Abstract at the Britisch Association of Urological Surgeons 2006
Uchida T , Clinical outcomes and quality of life after HIFU for localisated prostate cancer
Uchida T etal Jap Endourol 7 Year Folow –up . Oxford 2006
FT. Murat . L Poissonier , Recurent Prostate Cancer after Radiotherapy –Salvage Treatment