Radiation therapy employs high-energy beams to damage or destroy cancer cells. Targeting the affected area precisely impedes the cells' ability to grow and divide, ultimately eliminating or shrinking tumours. While focused on cancer, this treatment may also affect nearby healthy cells, leading to side effects. Radiation therapy is given internally or externally, providing a localised approach to cancer treatment. The goal is to maximise the impact on cancer cells. At the same time, the aim is to minimise harm to surrounding healthy tissues, making it a crucial component in cancer care alongside other treatments like surgery and chemotherapy

Radiation therapy, also known as radiotherapy, is a medical treatment that utilises high doses of radiation to target and kill cancer cells. The primary objective is to shrink tumours, destroy cancer cells, or prevent their growth and division. Here is a detailed overview of radiation therapy for cancer.

Types Of Radiation Therapy

In the type of radiation therapy selected, certain cancer-specific factors are considered. These factors are -

Proximity to Normal Tissues
Tumour Characteristics
Medical Conditions
Age of the Patient
Overall Health Assessment

1. External Beam Radiation: A large, non-invasive machine directs radiation toward the cancerous site. The machine moves around the patient, delivering radiation from various angles. External beam radiation therapy precisely targets a specific part of the body.

External Beam Radiation

2. Internal Radiation (Brachytherapy): Radioactive sources are placed inside or close to the tumour. Brachytherapy is a solid approach where seeds, ribbons, or capsules are placed in or near the tumour for localised treatment.

Side Effects

Common side effects include fatigue, skin changes, and localised discomfort.
Side effects are typically temporary, and the benefits often outweigh the risks.

Combination Therapies

Radiation therapy may be used alone or combined with surgery, chemotherapy, or immunotherapy.

Palliative Radiation

To relieve symptoms and improve the quality of life in advanced cases.

Follow-Up Care

Regular monitoring and follow-up assessments are crucial to evaluate treatment effectiveness.
Multidisciplinary Approach
Collaboration with oncologists, radiation oncologists, and other specialists for comprehensive cancer care.

How Does Radiation Therapy for Cancer Work?

Radiation therapy for cancer works by using high doses of ionising radiation to target and damage the DNA within cancer cells, preventing them from dividing and growing. The goal is to destroy or shrink tumours while minimising damage to surrounding healthy tissues. Here's how the process typically works:

Simulation and Planning. Before treatment begins, precise imaging techniques are used for simulation.

Treatment planning involves determining the radiation dose and designing a tailored plan.

Targeting the Tumour.

1. External Beam Radiation: High-energy beams are directed from outside the body toward the tumour.

2. Brachytherapy (Internal Radiation): Radioactive sources are placed inside or very close to the tumour.

Brachytherapy (Internal Radiation)

3. Fractionation: Radiation is often delivered in smaller doses (fractions) over multiple sessions. This approach helps spare healthy tissues and enhances the body's ability to repair radiation damage.

4. Ionisation of DNA: Ionising radiation produces charged particles that interact with atoms in the DNA of cancer cells. These interactions create free radicals and other reactive molecules, causing breaks in the DNA strands.

5. DNA Damage Response: Cells attempt to repair the damaged DNA, but cancer cells are often less efficient in this process.

The accumulated damage can lead to cell death or impaired ability to divide.

6. Enhanced Precision: Advanced technologies, such as Intensity-Modulated Radiation Therapy (IMRT) and Image-Guided Radiation Therapy (IGRT), improve targeting accuracy.

These technologies allow for better conformity to the tumour shape and minimise exposure to healthy tissues.

7. Combination Therapies: Radiation therapy may be used as a standalone treatment or in combination with surgery, chemotherapy, or immunotherapy.

8. Palliative Care. In cases where a cure is not possible, radiation therapy can be used for palliative care to relieve symptoms and enhance the quality of life.

9. Monitoring and Follow-Up: Regular monitoring and follow-up assessments are crucial to evaluate treatment effectiveness and manage potential side effects.

Radiation therapy is a highly controlled and precise treatment modality that plays a crucial role in cancer care. The multidisciplinary approach involving oncologists, radiation oncologists, and other specialists ensures a comprehensive strategy for each patient's unique circumstances.

Conclusion

Radiation therapy is a critical component of cancer treatment, offering curative or palliative benefits based on the disease stage and goals of care. It requires careful planning, technological advancements, and a personalised approach to optimise its effectiveness while minimising potential side effects. Patients undergoing radiation therapy should receive comprehensive support and follow-up care to ensure the best possible outcomes.

Reference:

https://www.mayoclinic.org/tests-procedures/radiation-therapy/about/pac-20385162
https://www.cancer.net/navigating-cancer-care/how-cancer-treated/radiation-therapy/what-radiation-therapy