Microwave thermotherapy is a type of ultrasound treatment in which body tissue is exposed to high temperatures. Focused ultrasound waves with high intensity damage and kill cancer cells or to make cancer cells more sensitive to the effects of radiation and certain anticancer drugs.
Examples for such treatments are the transurethral microwave thermotherapy (TUMT) and transurethral needle ablation (TUNA) that are used for benign prostatic hyperplasia.

See also High Intensity Focused Ultrasound and Ultrasound Therapy.

Absorption is the transfer of energy from the ultrasound beam to the tissue. Absorption of acoustic energy increases the temperature of the tissue. This phenomenon, known as thermal radiation, has been used with some limited success to treat cancerous lesions in the breast and prostate gland. The absorption is proportional to the frequency.

See also Absorbed Dose, Thermal Effect, Thermotherapy.

Brachytherapy is a radiation therapy in which radioactive material (radioisotopes) sealed in needles, seeds or wires is placed directly into or near a tumor. Brachytherapy uses ultrasound imaging to visualize the needles for accurate placement of the small seeds or pellets (capsules) directly into e.g., the prostate. Ultrasound imaging allows accurate planning, placement and implantation of the radiation sources. Implantation of the seeds is a minimally invasive procedure.
Radioactive seeds are inserted through the perineum skin (the area between the scrotum and the anus) into the prostate gland. With correct planning, the surgeon can implant the radiation sources for maximum benefits to effective cancer treatment.

See also EchoSeed™, Prostate Ultrasound, Thermotherapy, High Intensity Focused Ultrasound, Urologic Ultrasound, Transurethral Sonography.

(HIFU / FUS) High intensity focused ultrasound is used in thermotherapy or thermoablation e.g., for the treatment of benign prostate hyperplasia or under study for the treatment of cancer.
An applied ultrasound probe (see transrectal sonography) focuses sound waves at one spot, elevating the tissue temperature to a point that the tissue destroys. Generally, lower frequencies (from 250 kHz to 2000 kHz) are used than for medical diagnostic ultrasound, but significantly higher time-averaged intensities.

See also Magnetic Resonance Guided Focused Ultrasound, Low Intensity Pulsed Ultrasound, and Lithotripsy.

Transurethral echography or sonography is used to detect small tumors of the urinary bladder or to visualize the urethra and surrounding muscles with special transducers. The bladder neck can be visualized using a transrectal probe.
In addition, high intensity focused ultrasound provides treatment of benign prostatic hyperplasia and adenocarcinoma of the prostate. Small catheter-based sectored tubular or planar transducers with highly directional energy deposition and rotational control are used for precise treatment. Regions of the prostate can be selective coagulatet while monitoring and controlling the treatment with MRI.

See also Urologic Ultrasound, Lithotripsy, Reflux Sonography, Ultrasound Therapy, Interventional Ultrasound and Thermotherapy.