high-intensity focused *ultrasound: a minimally invasive technique used for the treatment of primary localized prostate cancer and prostate cancer that has recurred after radiotherapy. An ultrasound probe is inserted into the rectum and precisely focuses a beam of high-intensity ultrasound on the cancerous tissue resulting in coagulative necrosis by raising the temperature of the target tissue to approximately 90°C. The procedure may have fewer side-effects than other treatments for localized prostate cancer.
a malignant tumour (*carcinoma) of the prostate gland, a common form of cancer in elderly men. In most men it progresses slowly over many years and gives symptoms similar to those of benign enlargement of the prostate (see prostate gland). Before it was possible to test for *prostate specific antigen (PSA), the tumour had often invaded locally, spread to regional lymph nodes, and metastasized to bone before clinical presentation. By checking elevated levels of PSA or *PCA3, prostate cancer can be detected 5–10 years before the tumour would present symptomatically. If the disease is confined to the prostate, the patient may be offered active surveillance or radical *prostatectomy, radical radiotherapy, or *brachytherapy; *cryotherapy or *HIFU are available in specialized centres. In elderly patients, it may be enough to monitor the tumour growth. If the disease is outside the prostate, androgen deprivation therapy may be used; this may be achieved by *gonadorelin analogues, *anti-androgens, surgical castration, or oestrogen therapy.... prostate cancer
(ultrasonic waves) n. sound waves of high frequency (above 20 kHz), inaudible to the human ear. Ultrasound in the range 2–20 MHz can be used to produce images of the interior of the human body as the waves reflect off structures back to the probe (see ultrasonography). Ultrasound waves have the advantage over X-rays of not being ionizing and are therefore much less harmful, particularly at energy levels used for diagnosis. The vibratory effect of ultrasound can also be used to break up stones in the body (see lithotripsy) and in the treatment of rheumatic conditions and cataract (see phacoemulsification). Ultrasonic instruments are used in dentistry to remove *calculus from the surfaces of teeth and to remove debris from the root canals of teeth in *root canal treatment. High-intensity focused ultrasound (see HIFU) can be used to destroy tissue, such as tumours. Keepsake ultrasound is the provision of ultrasound images of a fetus to the parents for nonmedical purposes; it is said by its proponents to help with bonding and to strengthen relationships in the family. See also endoscopic ultrasound.... ultrasound
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