**3.2 Radiotherapy**

168 12 Chapters on Nuclear Medicine

DOT techniques (Berghammer et al., 2001). The differences in tumor biology such as blood flow, metabolism, concentration of specific receptors or differences in antigen expression are exploited in order to target radionuclides to the tumor tissue (Glasspool & Evans, 2000). The major advantage of nuclear medicine is that just picomolar concentrations of radiotracers are

Future developments in nuclear medicine are in the area of development of specialized imaging systems. One example of specialized gamma camera is scintimammography in imaging of breast and axillary nodes. Scintimammography term is given to radionuclide imaging of breast cancer (Schillaci et al., 2007). Scintimammography is performed after injection of the radiopharmaceutical into an arm vein contralateral to the suspected tumor or into a pedal vein and the subsequent imaging with right and left lateral, prone and supine views, covering both breasts and both axillae and later computer acquisition of data (Nguyen et al., 2009; Brem et al., 2005). Most studies evaluating the role of scintimammography, have compared it with mammography, ultrasound and MRI. Its sensitivity has ranged from 62% to 93% with specificity from 79% to 94% (Schillaci & Buscombe, 2004). Its sensitivity is greater for palpable lesions. Current recommendations for

1. As a general adjunct to mammography to differentiate between benign and malignant breast lesions in patients with palpable masses or suspicious mammograms. 2. In patients referred for biopsy when lesions are considered to have a low probability of

3. In patients with probably benign findings on mammography, but are recommended for

4. In patients who have dense breast tissues and are considered difficult to evaluate on

5. For detection of axillary lymph node metastases in patients with confirmed breast cancer. The main limitations of scintimamography are low sensitivity and high dose of radionuclide that is used for imaging. Currently, for overcoming the cited limitations, the researchers are

To understand the diagnostic needs for breast cancer, it is important to understand the range of approaches for breast cancer treatment. With the exception of early and late stage disease, almost all breast cancer therapy methods, involve a combination of locoregional and systemic treatments. Locoregional therapy includes surgery and radiotherapy and systemic therapy includes chemotherapy, hormone therapy and targeted therapy. Because the breast cancer, that is metastatic beyond the regional node, is rarely cured, systemic therapy is the primary treatment for metastatic disease with locoregional treatment reserved for symptom control and is used possibly in some patients with limited metastatic disease

Surgery is the oldest and still the most widely used treatment modality that is available for breast cancer patients and can be accomplished by mastectomy, removal of the entire

close follow-up (e.g. repeated mammography in 3–6 months).

required to provide a measurable signal (Cook et al., 2003).

the use of scintimammography are (Fass, 2008):

studying on targeted molecular imaging methods.

**2.7.1 Scintimammography** 

malignancy.

mammography.

**3. Treatment of breast cancer** 

who may achieve prolonged remissions.

**3.1 Surgery** 

In radiotherapy, also known as radiation therapy, high-energy ionizing radiation such as x or γ-rays is irradiated to the tumor tissues for killing the cancer cells. Radiation can be delivered via external radiation from a source outside the body directing to the tumor or by an internal radiation source (brachytherapy) which is positioned inside the body adjacent to or inside the tumor. Radiation must affect only cancer cells in the treated area and not normal cells. To treat secondary tumors and stopping growth of any remaining tumor cells, radiation therapy is often used in conjunction with other treatment modalities like chemotherapy and surgery (Luini et al., 2007).
