Ultrasound allows physicians to do much more than just diagnoses. Sound waves have long been used for therapy, for instance for patients with malignant tumours and too much hip fat. What is possible using ultrasound will again be one of the main topics at MEDICA 2010, World Forum for Medicine - International Trade Fair and Congress, to be held from November 17 – 20, 2010 in Düsseldorf, Germany. With more than 4,000 exhibitors from over 60 countries, it is the world’s largest international medical trade fair and congress. While the latest developments in ultrasound technology will be shown within the framework of the trade fair, many of the speakers at the accompanying congress will present the various application options, for instance in oncology. There will again be practice-oriented sonography courses as well.
Ultrasound has been firmly established in diagnostics for more than 20 years. But physicians are increasingly using sonography for therapy. So-called high-intensity focused ultrasound (HIFU), also known as high energy ultrasound, works with concentrated energy: A hollow mirror concentrates the waves emitted by the probe head. With the heat that is created – up to 90 degrees centigrade – doctors can target and destroy tumors in the prostate or liver, for example. Surrounding tissue is not destroyed, as the high temperatures develop only in the focal point. Hence there are fewer cases of incontinence and impotence in prostate cancer patients after treatment with HIFU than after conventional surgery.
For instance, there was quite a stir last year after the first successful brain surgery using transcranial (through the skull) high-energy ultrasound performed by a research team under the leadership of Professor Daniel Jeanmonod from the Department of Functional Neurosurgery of the University Hospital of Zurich and Professor Ernst Martin, Director of the Magnetic Resonance Centre of the University Children’s Hospital. The completely non-invasive procedure opens up new horizons for neurosurgery and the therapy of neurological patients. Overall, the Zurich scientists treated ten patients with therapy-resistant unbearable pain – for instance caused by neurinoma or trigeminal neuralgia. The surgery in Zurich was performed in a 3-tesla magnetic resonance system. This MRT system was retrofitted with the ExAblate 4000 high-energy ultrasound system from the Israeli cooperation partner InSightec to form a platform for image-guided, non-invasive surgery. Last year at Brigham and Women’s Hospital in Boston, a small study with high-energy ultrasound was started with patients suffering from glioblastomas and brain metastases.
Therapeutic ultrasound is on the advance
Whereas high-energy ultrasound in neurosurgery is still at a very experimental stage, in other areas it has already advanced significantly. For instance, therapeutic ultrasound has long been used in urology on prostate carcinomas, but above all in gynaecology for instance, as an alternative to hysterectomy in infertile women with uterine myomas. At the Marienhospital in Bottrop (Germany), for example, magnetic-resonance-guided focused ultrasound (MRgFUS) has been used since last summer, mainly in therapy for women with uterine myomas. This ultrasound therapy (MR guided Focused Ultrasound Surgery, MRgFUS) was developed by the American company GE Healthcare in cooperation with InSightec. Integrated into a special MRT treatment table is a probe head whose sound waves can melt tissue with precision at specific points. Similar to a magnifying glass that concentrates sunlight, the ultrasound wave is focused on a point inside the myoma. A local temperature of 60 to 80 degrees Celsius is created, thereby melting the myoma but sparing the surrounding tissue. The body then casts off the dead tissue. The temperature within the body is continuously measured under MRT monitoring so that the attending physician can follow the progress of therapy and verify its success.
The surgery is an outpatient procedure, patients can go home just hours later and generally go about their daily chores the following day. Another decisive advantage for patients of child-bearing age is that with MRgFUS treatment of myomas their fertility is maintained. “Because hysterectomy is still the most common treatment method for symptomatic uterine myomas. However, many patients would like a treatment option that spares the womb,” explains Dr. Hans-Christian Kolberg, Chief Physician of Gynaecology and Obstetrics at the Marienhospital. In addition, the more gentle procedure is also offered as palliative care in cases of bone metastases. Research is also being carried out in cooperation with InSightec on the use of MRgFUS to treat mastocarcinoma. The MEDICA 2010 exhibitor Philips Healthcare’s Sonalleve MR-HIFU is another MRT-guided ultrasound system for myoma therapy.
“Bloodless scalpel” for an increasing number of applications
For a long time, oncologist have also been testing the “bloodless scalpel” on patients with completely different, even malignant, tumors such as malignomas of the kidneys, liver, pancreas and bladder. Even primary malignant bone tumors such as osteosarcomas and chondrosarcomas are now being successfully “attacked” with high-energy ultrasound, sometimes in combination with chemotherapy, as recently reported by Chinese scientists (source: „Radiology“ June 2010; 255(3):967-78). Successful means primarily that patients are spared an amputation (standard therapy in cases of primary bone malignomas) and that the survival rate and length of survival are improved.
Perhaps the newest trend in therapeutic ultrasound is the removal of excess subcutaneous fatty tissue (“love handles”) using high-energy sound waves. A bloodless and anaesthetic-free procedure such as the LipoSonix System from Medicis Technologies Corporation in the U.S. offers an easier option. With this treatment, undesirable fat cells are heated and destroyed by means of focused high-frequency ultrasound waves that penetrate the skin to a depth of about 1.5 centimetres. This does not damage the skin, assures Dr. Ute Gleichmann, who uses this procedure in her private practice in Bad Oeynhausen. After treatment the wound healing process begins and the destroyed fat cells are carried off. According to Dr. Gleichmann, waist size can be reduced by three to four centimetres, i.e. one clothing size. Results are visible after 8 to 12 weeks. That is the length of time required by the body to naturally break down the destroyed fat cells. Some patients experience minor discomfort during the treatment. They may feel cold, slight pricking, tickling, heat, mild discomfort or pain. After treatment, a temporary redness, small bruises, mild discomfort and swelling may occur. Most treatments take approximately 45 minutes, depending on the area to be treated. No special diet is required.
Dermatologist Dr. Afschin Fatemi from the S-Thetic Clinic in Düsseldorf (Germany) reports quite positive results with the procedure. However, this gentle technique cannot always replace conventional liposuction. According to the manufacturer, it should not be used on patients with a BMI of more than 30 kg/m2. And: Patients must carry the cost themselves.
For additional information on the products and technologies discussed in this article, see MEDICA 2010.