Radiation Oncology - Exploring the Benefits

What Is Radiation Oncology?

Radiation oncology, also known as radiotherapy is one of the essential specialties in cancer therapy. Treatment of cancer has been evolving as a multidisciplinary approach which includes chemotherapy, radiotherapy, hormone therapy, target therapy, and surgery. These therapeutic interventions have improved the survival rates of cancer patients when used alone or in combination.

What Type of Radiation Is Used and How Does It Work?

The radiation is a focused high-energy beam that kills the cancer cells and shrinks the tumor size. The radiation beam can be in the form of X-rays (photons), gamma rays, electrons, or protons. Among them, the most commonly used radiations are X-rays. These radiations are extremely painless, invisible and are used to treat different types of cancers. The radiation beam destroys the cancer cells and kills them by damaging the DNA (deoxyribose nucleic acid) in the cancer cells leading to reduced growth. When the DNA in the cancer cells gets completely damaged and goes beyond repair, they stop dividing leading to cell death. These dead cells are degraded and removed from the body by various physiological processes. Radiation does not kill the cancer cells in a single exposure. It takes several days or weeks for the DNA to undergo damage and progressive cell death of cancer cells. Subsequently, these exposed cancer cells continue to disintegrate for weeks or months even after the completion of radiation therapy.

Can Radiation Therapy Be Combined With Other Treatments?

Radiation destroys the cancer cells and also prevents their reoccurrence. It can be used alone or in combination with other therapeutic interventions such as hormone therapy, chemotherapy, and surgery. Radiation can be given before or after, or even concomitantly with other treatments. The primary goal of radiation therapy is to prevent cancer progression and ease the clinical symptoms caused by cancer. If the patient is undergoing surgical removal of cancer or tumor, radiation can be used in two ways:

Neoadjuvant Therapy: Radiation is used to shrink the tumor size before surgery.

Adjuvant Therapy: Radiation is given after the surgical removal of cancer to stop the growth of remaining cancer cells. This prevents relapse of cancer.

Intraoperative Therapy: Radiation is given during the surgery so that the radiation beam directly reaches the target cancer cells without passing through the skin. With this technique surrounding normal tissues can be protected from radiation effects.

Palliative Therapy: In people with advanced stages of cancer or metastases, radiation is used to lessen the pain or suffering caused by cancer. For example, severe headaches due to metastases in the brain, extreme weakness caused by inability to eat or drink due to metastases in the intestine, and severe pain due to bone metastases could be effectively treated by radiation therapy. The main aim of this therapy is to reduce suffering and improve patients' quality of life.

What Are the Factors to Be Considered Before Radiation?

The radiation oncologist decides and opts for radiation therapy by taking into consideration of the following factors.

1. Tumor type (benign or malignant) and size of cancer (if overlying any major blood vessel or nerve).

2. Location of the tumor and involvement of associated lymph nodes.

3. Distance between cancerous growth and vital organs (heart, lungs, brain) that are sensitive to radiation.

4. Age and general health status of the individual.

5. Previous history of cancer treatments.

What Are the Types of Radiation Therapy?

Radiation oncologists are specialized in delivering radiation therapy to the patients and it is delivered in the following two methods:

1. External beam radiation therapy.

2. Internal beam radiation therapy.

External Beam Radiation Therapy: The external beam comes from the prescribed equipment and targets only the affected area. This machine generates loud noise, is sophisticated, does not touch the patient, and revolves around the targeted area so that radiation hits the target region from all directions. It is considered as a local therapeutic intervention as it targets a specific organ. For example in the case of breast cancer, radiation will be targeted only on the chest portion but not the entire body.

Types of external beam radiation therapy are:

1. Intraoperative Radiation Therapy: Radiation therapy that is carried out during surgery is called intraoperative radiation therapy. By this method, the effects of radiation on the surrounding tissues can be minimized.

2. Image-Guided Radiation Therapy ( IGRT): In IGRT, high-quality images of the cancer are captured before every treatment session. This helps in focusing powerful radiation on the precise cancerous area by assessing the treatment outcome.

3. Intensity-Modulated Radiation Therapy ( IMRT): This is an advanced form of radiation therapy where the radiation can be customized according to clinical needs.

4. Stereotactic Body Radiation Therapy: This type of radiation uses many high-energy beams to target the cancerous tissue.

Internal Beam Radiation Therapy: In internal radiation beam therapy, the source of radiation is not from the external unit like the external beam therapy. In internal radiation therapy, the radiation is delivered inside the body through various agents. It can be liquid or solid. It is classified into two types.

1. Internal radiation therapy with a solid source is also called brachytherapy.

2. Internal radiation therapy with a liquid source is also known as systemic therapy.

What Are the Side Effects of Radiation?

Radiation therapy which is targeted at localized areas in the body causes side effects like:

• Lack of appetite.

• Difficulty in chewing and swallowing (in head and neck cancers).

• Nausea and vomiting.

• Intestinal problems like diarrhea due to gas disturbances and bloating.

• Change in taste.

• Mouth sores or ulcers.

• Dehydration and weight loss.

What Are the Dietary Recommendations for Patients on Radiation?

Food is an important part of treatment, especially during cancer therapies, because:

• Food supports patients’ immune system by making them strong and reducing side effects.

• A strong immune system reduces the risk of infections and enhances recovery.

• Nutrients are needed to promote the growth of healthy tissue.

• Helps to maintain energy and tolerate side effects.

The dietary recommendations include:

• Pay Attention: Being attentive to the side effects of radiation and its effects on food intake. Discuss with the doctor regarding diet and make necessary changes. For example, some doctors advise a bland diet, making it more colorful by adding fruits and vegetables. The more colorful the food intake, the more variety of minerals and vitamins.

• Plan: Planning and being prepared. Stock up the kitchen and pantry with all the nutritious and healthy foods. Preplanning helps to eat well when you are not feeling well.

• Focus On Eating: Focusing on eating nutrient-dense meal including fruits and vegetables, lean protein, and whole grains.

• Change eating habits: Eating smaller portions at regular intervals helps in easy food digestion rather than taking three larger meals.

• Drinking Plenty of Liquids: Hydration is most important during radiation therapy as it prevents problems like constipation. In addition, hydration flushes out toxins and reduces the side effects like improper bowel movement, nausea, weakness, and bloating.

• Foods to Avoid: Sugar, salty foods, alcohol, smoking, and saturated fats.

Conclusion:

Treatment techniques and the technology used in radiation oncology to treat cancer conditions are progressively improving. Cancer patients have benefited from radiation therapy since it has many advantages like faster treatment, accurate delivery, fewer side effects, high cure rates, and reduced number of treatment appointments.