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Ultrasound Kills Cancer Cells

Posted February. 18, 2008 03:01,   


The survival rate of cancer patients is rising recently. This is largely thanks to the development of state-of-the-art treatments with fewer side effects. Doctors treat those suffering from gastric and liver cancers without using intrusive measures such as endoscope and high-frequency wave surgery. In a newly-developed radiotherapy that combines Computerized Tomography (CT), a machine selectively irradiates a certain body part with cancer cells, significantly reducing side effects. This treatment is considered more accurate since it even takes into consideration the body movements caused by the patient’s breathing.

A treatment that combines Magnetic Resonance Imaging (MRI) and ultra-sonogram is also expected to be used in hospitals soon and new anti-cancer medicines with high efficacy and low adverse effects are in the pipeline.

○ Only targets cancer cells

People usually think that anti-cancer medicines lead to terrible side effects such as hair loss and frequent vomiting. That is because anti-cancer medicines hurt normal cells as well as cancer cells.

In a bid to reduce these side effects, pharmaceuticals are developing drugs that only target cancer cells.

“Gleevec,” released in 2001, is the first anti-cancer drug that targets and turns off specific proteins in cancer cells that cause them to grow and multiply. It is used to treat chronic myeloid leukemia (CML) and certain tumors of the stomach and digestive system. “Iressa,” treating lung cancer, also interferes with the growth of certain cancer cells.

“Rituximab,” which is used to treat several types of non-Hodgkin lymphoma, only destroys certain proteins that are found in cancer cells.

In the case of “Avastin,” it starves cancer cells to death by cutting off blood vessels that supply nutrition.

Those anti-cancer medicines zooming in on only cancer cells, however, contribute little to raising the survival rate as they are mostly administered to terminally-ill cancer patients.

○ Use Target treatment in parallel with customized one

Doctors can maximize the efficacy of anti-cancer medicines targeting cancer cells when they have exact knowledge of each patient’s genes and proteins.

“When targeting cancer cells, we use medicines that sit well with individual patients after conducting drug response tests,” said Kim Won-seok, a professor of hemato-oncology at Samsung Cancer Center.

“Heceptin,” targeting breast cancer cells, shows its efficacy when used for breast cancer patients that have a relatively large number of HER-2 genes. Doctors carefully prescribe this medicine to patients who are HER-2 positive after conducting gene analysis.

A gene screening therapy that helps patients determine whether to go through additional chemotherapy after colon cancer surgery has also been developed. The method of replicating genes called Polymerase Chain Reaction (PCR) analyzes the instability of patents’ genes. Those with highly unstable genes do not need to receive chemotherapy because they are unlikely to suffer a relapse.

○ Non-intrusive Measures

Therapies employing radiation and ultrasound are being offered, relieving cancer patients from burdens of undergoing surgery.

TomoTherapy, which incorporates the functions of CT, subjects patients to thousands of beamlets of different intensities, after calculating minute body movements such as breathing.

Patients with localized and small-sized tumors, such as head and neck cancer, lung cancer, liver cancer, prostatic cancer and pancreatic cancer, are ideal ones to get TomoTherapy treatments. And the result of the treatment is almost the same as surgery. However, those with scattered tumors that affect larger body parts can undergo this therapy to relieve symptoms instead of expecting a complete cure.

High Intensity Focused Ultrasound (HIFU) burns tumors using ultrasound instead of radiation. HIFU removes cancer cells with high heat by converging ultrasound’s fine energy to one point. Since ultrasound spreads through body tissues, doctors are able to destroy tumors by applying the ultrasound device to the skin without incision. This therapy is as effective for prostatic cancer as surgery.

MRI-HIFU, incorporating MRI into HIFU, is a technology that goes one step further than HIFU. The new method, now in clinical trial, homes in on the exact point of treatment while increasing the accuracy and safety of the treatment by exploiting MRI technology that measures the rise of body temperatures.

MR-HIFU is found to be effective for treating pain and excessive menstruation that are associated with uterine myoma.

(Helped by Professor Kim Won-seok of hemato-oncology, Professor Ahn Yong-chan of radiation oncology, and Professor Lim Hyo-geun of radiology at the Samsung Medical Center)