Classification of Brachytherapy: Source Placement

A radiation source can be placed in two ways:

• Interstitially
• In contact

In interstitial placement, the radiation source is placed directly in the target tissue of the site for e.g the breast or prostate.

Whereas in case of ‘in contact’ brachytherapy, the radiation source is placed next to the affected tissue. It could be:

• An intracavity placement such as in uterus, cervix or vagina
• An intraluminal placement such as in oesophagus or tracea
• A Surface placement such as in the skin
• An intravascular placement for coronary in-stent restenosis

Classification of Brachytherapy: Dose Rate

Dose rate refers to the intensity of radiation delivered to the affected area and its surrounding. It is expressed in Grays per hour, denoted by Gy/h. Brachytherapy, on the basis of dose rate can be classified into three categories:

• Low rate brachytherapy
• Medium rate brachytherapy
• High rate brachytherapy

Low-dose brachytherapy uses radiation sources that emit a rate of up to 2 Gy/h. This type of brachytherapy is used for oral cavity, prostate, sarcomas and oropharynx cancer. These treatments are occasionally followed by pulsed dose rate brachytherapy, which simulates the effectiveness of the low dose.

Medium dose brachytherapy has radiation dose rate ranging between 2 Gy/h and 12 Gy/h. High dose rate exceeds 12 Gy/h and is used in tumors of cervix tumors, lungs, oesophagus, breasts, cervix and prostate.

Classification of Brachytherapy: Duration

Brachytherapy on the basis of duration of dose can be classified in two ways:

• Permanent brachytherapy
• Temporary brachytherapy

Permanent brachytherapy is administered by implanting radiation sources directly into affected areas. It is most commonly used for prostate cancer.

Temporary brachytherapy is administered for a set duration, usually for a few minutes or hours. The duration of brachytherapy depends on the dose and source placement. Usually in case of low doses, the duration ranges up to 24 hours whereas is as short as few minutes in case of high dose brachytherapy.

In case of permanent insertions, the ‘seed’ is left in the body to exhaust itself over the time and become inactive. The inactive seed can be taken out later if desired, or else it does nothing harmful or inconvenient.

Genetic screening is a breast cancer detection method where some genes are tested for mutations especially for women whose families have had a history of breast cancer in the past.  The most common method of detecting breast cancer is X-ray mammography.  This is a screening method that is recommended by experts for use on patients of any age.  However, this screening method may miss tumors when used on women with very dense breast tissue in which case MRI (Magnetic Resonance Imager) can be used.

MRI is particularly effective in detecting cancer for women carrying BRCA1 and BRCA2 breast cancer genes.  If common belief is anything to go by, biopsy is by far the most definitive and principal way of detecting breast cancer.  In this procedure, a small part or the lump in a breast is extracted and examined under the microscope to determine whether cancerous cells are present.  Although mammography can detect the smallest cancer that cannot be felt by the patient or the doctor at early stages, it cannot be used to determine between a malignant and benign tumor, it can therefore not be said to be 100 percent effective.

A clinical breast examination (CBE) is a breast cancer detection technique where the doctor checks for lumps or any other changes that could point at breast cancer tumors under the arms and the breasts.  It may involve palpation and bilateral inspection of the breasts as well as the supraclavicular and axillary areas.  Although its efficacy in detecting breast cancer is uncertain, CBE when used in combination with mammography is convincingly effective in women aged over 50 years.  It is recommended that women aged between 20 and 39 undergo CBE examination at least every three years while women aged 40 and above, they should undergo screening annually.

Early breast cancer detection is vital for successful treatment. Certain treatment methods (such as brachytherapy) can only be used for treating early stages of breast cancer – hence early detection gives women more chances for successful recovery.

To select the physicians, PHOENIX magazine randomly surveys 5,000 Valley physicians, including M.D.s (medical doctors), D.O.s (osteopathic doctors) and N.D.s/N.M.Ds (naturopathic doctors). The surveys ask the doctors to nominate other doctors who, in their judgment, are the best in their field and related fields.

Three of Arizona Breast cancer Specialists’ doctors were rated as “Top Docs” -Drs. Robert Kuske, Coral Quiet, and Farley Yang.

Special praise is offered to Dr. Coral Quiet, who received the most votes in the Valley as a cancer specialist. Drs. Tannehill and Maggass were also rated “Top Docs in Arizona” in the Arizona Business Magazine in 2009.

Unrelated to their cosmetic surgery, many of these women will later face breast cancer, says Robert Kuske, a radiation oncologist in Scottsdale, AZ. The augmentation surgery does not raise or lower a woman’s chances of developing breast cancer, but because breast cancer is so common, tens of thousands of women who undergo augmentation each year will develop breast cancer sometime in their lifetime.

The National Cancer Institute estimates about 1 in 8 of all U.S. women will be diagnosed with breast cancer in their lifetimes.

Having implants may affect the “cosmetic outcome” of breast cancer therapy. Traditional breast cancer therapy may include radiation therapy, which can expose the whole breast (including the implants) to radiation. One unwanted side effect that often occurs is that scar tissue can form around the implants, causing them to harden. In fact, says Kuske, about 55 percent of women with breast implants experience unwanted hardening of their implants after undergoing traditional whole-breast irradiation.

At the annual meeting of the Radiological Society of North America (RSNA) in Chicago, Kuske presented the results of a clinical study examining a technique known as brachytherapy for treating breast cancer while sparing implants.

Breast brachytherapy kills cancer cells by exposing them to radiation delivered within a tissue. Basically, thin plastic catheters are inserted into a breast in the area of the tissue surrounding a cancerous site, and then tiny “seeds” containing a small quantity of radioactive iridium-192 are inserted into the catheters. This technique has been studied for years in women without breast implants, says Kuske, but his study is the first to specifically look at its ability to treat women with breast implants and provide better cosmetic outcomes.

From June 2003 to June 2008, Kuske and his colleagues performed this treatment on 70 women, all of whom had breast augmentation and early-stage breast cancer. After these women had tumor masses removed via lumpectomy, they were administered brachytherapy for one week to kill the remaining cancer cells.

The study showed that brachytherapy is effective at treating the cancer while sparing the implants. Kuske found that implant hardening was reduced to zero.

Breast brachytherapy is a 5-day radiation therapy alternative for women with early stage breast cancer.  External beam radiation therapy is safe and very effective, but can take over six weeks of daily treatment. Breast brachytherapy, or partial breast irradiation (PBI), has been researched and tested by Dr. Robert Kuske since 1991 as a treatment method after lumpectomy. He has advanced the techniques and technology, and championed the research bringing breast brachytherapy to where it is today. He has remained totally commited to his patients, who let him know in no uncertain terms that they wanted a shorter more convenient alternative with less radiation exposure to surrounding healthy tissues.

Arizona Breast Cancer Specialists (ABCs) is the first clinic in the world dedicated to exclusively treating women with breast cancer with radiation. It is led by Dr. Robert Kuske and Dr. Coral Quiet, Radiation Oncologists who specialize in the treatment of breast cancer. Together, they have 43 years of experience treating this disease.