What Is Chemotherapy
This treatment uses chemicals to kill fast-growing malignant cells in a patient’s body. Cytotoxic medicines are administered systemically. Drugs can also be administered orally or by injection or IV or on the skin.
One or more cytotoxic drugs can be used.
These powerful drugs eliminate or inhibit the growth of fast-multiplying malignant cells
It is considered a systemic treatment because the drugs travel throughout the body and destroy cancer cells that have spread (metastasized) all over from the original (primary) tumor site. This treatment is therefore different from radiation and surgery.
Surgery and radiation can be called local treatments because they are focused on one part of the body. Surgery extracts a tumor from a certain part of the body. Radiation is aimed at a certain area of the body. In chemotherapy the drugs travel throughout the body.
Chemotherapy sets out to achieve either of three main goals: to achieve a cure (although oncologists are guarded in using this specific term) or control (shrink the tumor and control the cancer and give the patient a chance to live longer) or palliation (reduce pain and ease other symptoms in cases where the cancer is very far advanced).
A cancer doctor or oncologist can recommend a single drug or a combination of drugs.
Several types of alkalating agents impact on DNA to prevent the cell from reproducing. They are used in chemo treatments: mustard gas derivatives (eg Cyclophosphamide, Melphalan, Ifosfamide).
Chemotherapy is administered via IV over a period of time, called sessions. This is followed by a period of rest. This treatment uses chemicals that destroy malignant cells. However, chemotherapy also kills healthy fast growing cells e.g. in the bone marrow where red blood cells, white blood cells and platelets are produced. Also hair follicles and the digestive tract are affected. When the gut lining is destroyed it leads to nausea, vomiting, diarrhea and hair loss because of damaged hair follicles (news-medical.net).
Cytotoxic agents also affect healthy cells that divide normally (in the bone marrow or digestive tract along with hair follicles.
Chemotherapy can be combined with radio therapy and surgery and anti cancer drugs. Sometimes chemotherapy is first given to shrink a tumor, after which it is operated on (neoadjuvant chemotherapy). Adjuvant chemotherapy occurs when the tumor is first removed followed by the treatment.
Palliative chemotherapy provides relief for terminally ill patients.
Cancer management often involves surgery to reduce (“debulk”) nd chemotherapy and radiotherapy to follow through. Laparoscopy (a procedure where a fibre-optic instrument is inserted to view organs in the abdomen) and imaging and modern robotic surgery has made surgery less painful.
What Is Radiation
Radiation is energy. Radiation therapy or radiotherapy involves the use high doses of radiation to kill cancer cells or reduce the size of malignant tumors. Radiation uses ionizing energy (in the form of an invisible light beam) to target a specific region. X-rays, gamma rays and charged particles are some types of radiation used. These are high-powered beams of energy which target cancer cells and destroy them. The beams damage or alter the DNA of cancer cells, thereby slowing them down
There are four types of radiation therapies IMRT, VMAT, IGRT, SRS.
Intensity-modulated radiation therapy (IMRT), Volumetric modulated radiation therapy (VMAT), Image-guided radiation therapy (IGRT), Stereotactic radiosurgery (SRS).
Radiation therapy from beams can be generated by a linear accelerator (a machine that accelerates electrons to produce X rays or gamma rays). Proton therapy is another form of external beam radiation therapy that uses cyclotrons or synchrotrons to produce ‘charged’ atoms that destroy tumors (www.radiologyinfo.org). If placed inside the patient it is called brachytherapy – where radioactive sources are sealed in needles, wires or catheters and implanted into or near the tumor. This is a common treatment for cancers of the prostate, uterus, cervix or breast.
If radiation therapy is given before surgery, it is called neoadjuvant treatment. If radiation is given after surgery, it is called adjuvant treatment.
Radiation oncology involves the use of X rays and Gamma rays over a period of time (a single treatment session being called a fraction). Unfortunately radiotherapy too, causes side-effects. This can vary according to the size of the site, dosage or amount of radiation. Side-effects may be early or late (chronic). In the latter case tissue damage may not be replaced by new cells e.g. scarring of the lungs, spinal cord damage, and liver damage.
Stereostatic Radiosurgery is used to target smaller tumors over a few treatment sessions.
What Is Surgery
In cancer surgery, the tumor is removed during an operation. Such an operation is performed by a surgical oncologist. www.cancer.gov. Surrounding tissue may also be removed. The tissue around the tumor is called the margin. Tumor removal is also called curative or primary surgery.