Care for Cancer Patients undergoing radiation therapy

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Oncology guide

- The Concept of Radiation Therapy

Radiation therapy is a type of cancer treatment that uses ionized radiation, such as X-rays, gamma rays, high-energy electrons, or heavy particles, to destroy cancer cells in the body. Modern radiation therapy techniques are highly precise, directing radiation beams at the cancer site while minimizing damage to healthy tissues.

The therapy works by damaging the genetic material of cancer cells, preventing them from growing and dividing. Although healthy cells may also be affected, they can recover more effectively than cancer cells. The main goal of radiation therapy is to treat cancer while causing minimal harm to healthy tissues.

Radiation therapy can be administered externally or internally, and in some cases, both methods are used. The most common method is external beam radiation therapy, where a device called a linear accelerator directs high-energy beams at specific areas of the body. Internal radiation therapy (brachytherapy) involves placing small solid implants near or within the cancer site.

- Uses of Radiation Therapy

Radiation therapy can be used:

• As a standalone treatment when surgical removal of the tumor is not feasible (primary treatment).
• Before surgery to shrink the tumor (neoadjuvant therapy).
• After surgery to eliminate residual cancer cells (adjuvant therapy).
• In combination with other treatments like chemotherapy to enhance effectiveness.
• For advanced stages to relieve symptoms (palliative therapy), especially for cancers that have spread to the brain, bones, or soft tissues.

Radiation therapy is also used to treat specific cancers such as thyroid cancer, localized head and neck cancers, and cervical cancer.

- Methods of Radiation Delivery

1. External Radiation Therapy:
This method uses a large machine to direct energy waves directly at the tumor. Special shields may be used to protect surrounding healthy tissues. Treatments are painless and typically last a few minutes.

2. Internal Radiation Therapy:
This method delivers high doses of radiation inside the body, close to the cancer, over a shorter period compared to external therapy. The radiation source may be swallowed, injected, or implanted as radioactive "seeds" or capsules. Some implants remain temporarily, while others are permanent.

- Planning for Radiation Therapy

Radiation therapy requires meticulous planning by a healthcare team to ensure the right dose is delivered to the precise target area. The plan includes:

1. Radiation Simulation:
During this stage, the radiation team determines the most comfortable position for the patient, who must remain still during treatment. Using cushions and supports, the patient is stabilized on a specialized treatment table. Sometimes, a body mold or a mesh face mask is made to keep the patient in position. Marks may be made on the skin with a marker or small permanent tattoos to indicate the treatment area.

2. Imaging for Treatment Planning:
Imaging techniques like CT scans or MRIs are used to create a treatment plan. During these scans, the patient must remain in the treatment position, wearing the custom mask or mold. The radiation team determines the type of radiation and dosage based on the cancer type, the patient's overall health, and the treatment objectives.

Accurate planning minimizes damage to healthy tissues while targeting cancer cells effectively.

- Radiation Therapy Sessions

The Linear Accelerator (Linac):
During external radiation therapy, a linear accelerator delivers high-energy beams to the body. It moves around the patient, targeting the tumor from various angles. The treatment is outpatient-based, meaning patients do not need to stay in the hospital.

Patients typically undergo five sessions per week over several weeks, allowing healthy cells to recover between treatments. Occasionally, a single session is used for pain relief or symptom management in advanced cases.

Each session lasts 10-30 minutes, most of which is spent positioning the patient correctly. The actual radiation delivery is painless and feels similar to getting an X-ray.

- Side Effects of Radiation Therapy

The side effects of radiation therapy depend on the area treated and the radiation dose. These effects can occur during treatment and are usually manageable. While most side effects resolve after therapy, some may appear weeks, months, or even years later. In rare cases, radiation therapy may cause a secondary cancer decade after treatment, known as a second primary cancer.

A. General Side Effects:

• Radiation Sickness: Causes nausea, vomiting, and depression.
• Radiation Wasting: Leads to loss of appetite, weight loss, and anemia.
• Hematologic Effects: Includes anemia, leukopenia (low white blood cells), and thrombocytopenia (low platelets).

B. Local Side Effects:

• Skin: Redness, edema, chronic ulcers, fibrosis, and hair loss in the treated area.
• Bones and Cartilage: Bone inflammation, necrosis, or pathological fractures.
• Digestive System: Increased mucus production, ulcers, bleeding, and perforation.
• Kidneys: Radiation nephritis or chronic kidney failure.
• Reproductive Organs: Germ cell atrophy, causing infertility.
• Bone Marrow and Blood: Anemia, leukopenia, thrombocytopenia, or leukemia.

- Radiation Safety Precautions

Skin changes in the treatment area are common and expected. The type of skin reaction depends on:

• The treated body part.
• The type of radiation therapy.
• The radiation dose received.

Patients must inform their radiation oncologist if they:

• Smoke cigarettes or use vaping devices.
• Have high blood pressure or diabetes.
• Have vascular diseases or connective tissue disorders (e.g., rheumatoid arthritis).
• Have a history of skin cancer in the treatment area.
• Have previously undergone radiation therapy in the same area.

These factors may affect skin reactions and healing.

- Types of Skin Reactions During Radiation Therapy

Patients may experience one or more of the following:

• Skin discoloration (pink, red, or bronze), which may darken with continued treatment.
• Swelling or puffiness.
• Dry, tight, itchy, or flaky skin.
• Blistering, which may lead to open sores.
• Rash or signs of infection in sun-exposed areas.
• Hair loss in the treated area, often regrowing after 3-6 months post-treatment.

Skin reactions typically peak two weeks after the final treatment session and may take several weeks to heal.

- How to Care for the Patients Skin During Radiation Therapy

These guidelines apply only to the treatment area:

1. Keep Skin Clean:
• Bathe daily using warm water and mild, unscented soap.
• Avoid scrubbing; gently pat the skin dry with a soft towel.
• Do not use alcohol-based products on the treated area.
2. Moisturize Regularly:
• Apply fragrance-free, lanolin-free moisturizers twice daily but avoid applying them immediately before a session.
• Do not apply moisturizers on cracked or open skin.
3. Avoid Skin Irritation:
• Wear loose, soft cotton clothing over the treatment area.
• Do not use cosmetics, perfumes, or deodorants on the treated skin.
• Avoid shaving the area or using adhesive tapes.
4. Temperature Management:
• Protect skin from extreme temperatures. Avoid hot baths, heating pads, or ice packs.
5. Protect from Sun Exposure:
• Wear sun-protective clothing and use sunscreen (SPF 30 or higher).
• Avoid tanning or intentional sunburn on treated areas during and after therapy.

 Managing Skin Itching

• Consult the radiation team before using over-the-counter products for itching.
• Avoid scratching the skin.
• Use soothing gels, saline solutions, or special dressings to reduce discomfort.

 When to Contact the Radiation Team

Patients should report the following to their oncologist:

• Fever over 100.4°F (38°C).
• Chills or worsening pain.
• Skin redness, swelling, or hardening.
• Rash, blisters, or discharge from the treated area.
• Open wounds or any significant changes in the skin.

- References

1. Radiation Therapy and You: Support for People with Cancer – National Cancer Institute.
2. Radiation Therapy Overview – RadiologyInfo.org.
3. External Beam Therapy (EBT) – RadiologyInfo.org.
4. Gunderson & Tepper’s Clinical Radiation Oncology, 5th Edition.