Radiotherapy: Treat Cancer, Procedure, Side Effects

Choose the content to read

• What is radiotherapy?
• What conditions can radiotherapy treat?
• What is the radiotherapy procedure?
• What are the side effects of radiotherapy?
• What is self-care after radiotherapy?
• Radiotherapy, MedPark Hospital
  
• Does radiotherapy hurt?
• What is the difference between radiotherapy and chemotherapy?
• How Long Does Radiotherapy Take?

Radiotherapy

Radiotherapy, or radiation therapy, is a core cancer treatment modality using high-energy radiation such as X-rays, gamma rays, or charged particles on the tumor to destroy the genetic material (DNA) of the cancer cells, preventing them from dividing, gradually dying, and eventually being eliminated from the body. Radiotherapy shrinks tumors, relieves cancer-related pain, reduces risks of local recurrence, and enhances the efficacy of other combined treatments such as surgery, chemotherapy, or targeted therapy. Radiotherapy varies from person to person; the radiation oncologist will consider treatment based on the type of cancer, stage, and size of the tumor, and the patient's overall health. Currently, radiation machines are designed to be more highly efficient. Modern radiation machines can destroy cancer with great precision while leaving little effect on nearby healthy tissues.

Goals of radiotherapy

Doctors prescribe radiotherapy for one of the four primary goals:

1. Cure (Definitive Treatment): Radiotherapy aims for a complete cure. Some cancers are curable with radiotherapy alone or in conjunction with other treatments.
2. Control (Neoadjuvant/Adjuvant): Radiotherapy can control certain types of cancer to stop growing and shrinking, reducing pressure on nearby organs and preventing the cancers from encroaching on adjacent tissue.
3. Increase treatment efficiency: To improve the overall outcome, the radiation oncologist may recommend radiotherapy before (neoadjuvant) or after (adjuvant) other cancer treatments. Adjuvant therapy helps reduce the risk of local or regional lymph node cancer recurrences following the surgery.
4. Palliative care: When cancer has progressed to the advanced stage, radiotherapy can help relieve pain, minimize the need for painkillers, reduce bleeding from cancer tumors, and help the patient maintain the best possible quality of life.

What conditions can radiotherapy treat?

1. Head and neck cancers: Brain cancer, paranasal sinus and nasal cavity cancer, nasopharyngeal cancer, oral cancer, thyroid cancer, tonsil cancer, laryngeal cancer, and tongue cancer.
2. Chest Cancers: Lung cancer and breast cancer.
3. Gastrointestinal cancers: Esophageal cancer, colon cancer, liver cancer, and pancreatic cancer.
4. Genitourinary cancers and reproductive system cancers: Bladder cancer, uterine cancer, cervical cancer, endometrial cancer, and prostate cancer.
5. Tumors and non-cancerous diseases: Brain tumors, spinal cord tumors, trigeminal neuralgia, meningioma, acoustic neuroma, and arteriovenous malformation (AVM).
6. Keloid scars or hypertrophic scars to prevent recurrence.

How many types of radiotherapy?

There are 2 common types of radiotherapy, or radiation therapy, that the radiation oncologists currently use to treat cancers, including the following:

1. External Beam Radiotherapy (EBRT): EBRT involves directing the high-energy radiation beam emitted from a linear accelerator machine outside the body to the tumor or cancers within the body. 
   • Techniques include 2D, 3D Conformal Radiotherapy (CRT), Intensity-Modulated Radiation Therapy (IMRT), or Volumetric Modulated Arc Therapy (VMAT).
   • The radiation oncologist uses a CT simulator to delineate the tumor's location and extent precisely.
   • This highly accurate mapping determines the size, shape, direction, and dose (intensity) of the radiation beam to ensure the tumor receives the correct dose of radiation with minimal impact on nearby healthy organs.
2. Internal Radiotherapy (Brachytherapy): This method involves placing high doses of a radioactive source directly into the body, either inside the tumor or near the location of the tumor.
   • Brachytherapy gradually radiates out high-dose radiation directly to the cancerous cells for a short period to destroy cancer cells.
   • The radiation oncologist then removes the radioactive sources from the body, with no residual radiation left, and poses no risk to the people nearby
   • The radiation oncologist performs an ultrasound or CT scan to guide the treatment plan and the precise placement of the radiation sources.

What is the diagnosis before radiotherapy?

The radiation oncologist reviews patient data, conducts a thorough physical examination, and scrutinizes diagnostic imaging such as X-rays, CT scans, and MRIs, as well as PET-CT scans and pathology results (biopsy), to confirm the type of cancer and stage of the cancer to determine treatment options as follows:

1. Early-Stage or Localized Cancer: The oncologist may recommend a single cancer treatment modality, such as surgery or radiotherapy alone, or radiotherapy after surgery, such as adjuvant treatment, to reduce the risk of local recurrence.
2. Advanced or Metastatic Cancer: The oncologist may recommend a combination of treatments, such as radiotherapy combined with chemotherapy (chemoradiation). In cases of small lesions, the radiation oncologist may treat the cancer with stereotactic radiotherapy (SRS), which involves delivering high-dose radiation precisely to the tumor 3-5 times over 1–2 weeks.

What is the radiotherapy procedure?

Once the radiation oncologist has determined that radiotherapy is the best treatment option for cancer. They will assess the patient's condition to determine which radiation technique and the number of radiotherapy sessions (fractions) are required to achieve the maximum anti-cancer effect while remaining safe for the adjacent healthy tissues.

Pre-Treatment (Simulation and Planning)

• CT Simulation: The radiation oncologist will have the patient perform a CT simulation to simulate radiotherapy by positioning the patient on the treatment table and performing a CT scan to delineate the exact location and shape of the tumor. The radiologist will mark small marker tattoos on the patient’s skin to ensure correct positioning for future treatments.
• Treatment Planning: The radiation oncologist will prescribe the appropriate radiation dose based on the type and stage of cancer. The medical physicist will assist in calculating and planning the radiation distribution to ensure the most suitable coverage, maximizing tumor coverage while minimizing exposure to healthy tissue. The planning time may vary based on the complexity of the disease.

Treatment (Irradiation)

• Daily Setup and Verification: Before delivering the daily radiation dose, the radiation therapist meticulously adjusts the patient's posture and position to match the simulation plan, using the Image-Guided Radiation Therapy process, often with Cone-Beam Computed Tomography (CBCT), to precisely map the size and shape of the tumor, including compensating for daily tumor variations.
• Irradiation: Once the patient assumes the correct position, the radiologist will begin the irradiation process, using the linear accelerator machine to deliver the collimated radiation beam to the marker tattoo. The radiation oncologist and radiologists will monitor the patient throughout the treatment session.
• Treatment Duration: Typically, the actual radiotherapy duration will take a brief 2–5 minutes. If included in the positioning steps, the total duration will take approximately 15 minutes.

Post-Treatment

• Daily Routine: After treatment, the patient can return home and can live normally with family members and friends as usual, with no radiation emitted to nearby people or the environment.
• Follow-up: Initially, the radiation oncologist will schedule an appointment to monitor symptoms and evaluate treatment outcomes every 2-4 weeks. If the treatment results are good and there are no areas of concern, the follow-up appointments will be spaced out further, and a repeat X-ray examination may be considered, depending on each individual.

What are the side effects of radiotherapy?

Radiotherapy side effects vary from person to person, depending on which body organ is being irradiated. Side effects from radiotherapy are temporary and minor and usually can be treated with prescribed medication. Common side effects of radiotherapy include:

• Systemic: Exhaustion, fatigue, loss of appetite, and sometimes nausea or fever.
• Skin (at the treatment site): Dry skin, redness, skin darkening, or skin itching (radiation dermatitis).
• Site-Specific (Head & Neck): Dry throat, dry mouth, sore throat, or dental issues.
• Site-Specific (Chest): Cough, shortness of breath, or lymphedema.

Combining radiation and chemotherapy can lead to more side effects, such as esophagitis, pneumonia, and low blood counts during radiotherapy. Most of these symptoms are only temporary and will gradually improve after treatment is completed. Currently, treatment planning and radiation techniques play a significant role in helping control the amount of radiation given to the tumor, reducing skin burns, and better avoiding affecting nearby organs.  

What is self-care after radiotherapy?

• Medication: Take all prescribed medications as instructed by the doctor to reduce side effects.
• Hygiene: Shower as usual, but avoid rubbing on the irradiated skin region and the marked areas.
• Skin Protection: Protect the irradiated skin from sunlight and excessive heat.
• Nutrition: Stay hydrated by drinking plenty of water. Eat balanced protein-rich foods such as meat, eggs, nuts, and milk to aid tissue repair.
• Lifestyle: Exercise as tolerated, get enough sleep, stay stress-free, and relieve anxiety. Refrain from smoking, drinking alcohol, using unapproved herbs and drugs
• Oral Care (for head/neck radiation): Use a soft-bristled toothbrush and dental floss. Rinse the mouth frequently with plain water or a doctor-recommended solution. Avoid alcohol-containing mouthwash, as it can worsen inflammation.

Can radiotherapy cure cancer?

Radiotherapy results vary depending on the type and stage of the cancer. Early cancer treatment has a cure rate of more than 90%, while treatment for metastatic cancers is strictly for palliation. Therefore, annual cancer screenings will help detect cancer at earlier stages and allow you to receive timely treatment.

Radiotherapy, MedPark Hospital

Light of Day Radiation Oncology Center, MedPark Hospital, Bangkok, Thailand, provides comprehensive cancer treatment for all stages, from early to challenging complex, using gold-standard, best-practices by a team of experienced radiation oncologists integrates multimodality treatments, including chemotherapy, immunotherapy, targeted therapy, radiotherapy, bone marrow/stem cell transplants, and surgery, utilizing advanced medical equipment and state-of-the-art technology, along with a multidisciplinary team, to provide consistent follow-up care with the ultimate goal is the patient is cured of cancer, minimize complications, prevent a recurrence, and allow patients to have a healthy physical, and a good quality of life.

FAQ

• Does radiotherapy hurt?
  No. Radiotherapy does not hurt or cause any acute pain or burning. The radiation used in the treatment is similar to the radiation used in a chest X-ray or computerized tomography.
• Does radiotherapy cause hair loss?
  Radiotherapy is considered a local cancer therapy. Wherever radiation is applied, it will only kill cancer cells in that part of the organ. For example, radiotherapy for breast cancer will only be effective in the breast region and will not cause hair loss. Head hair loss is the only side effect of radiotherapy for head cancer.
• What is the difference between radiotherapy and chemotherapy?
  Chemotherapy is a systemic treatment involving administering drugs intravenously or orally to eliminate cancer cells throughout the body, whereas radiotherapy is a local treatment that uses high-energy radiation beams such as X-rays, gamma photons, or charged particles to precisely target and destroy cancer cells within a specific tumor or region.
• How Long Does Radiotherapy Take?
  The total duration of the radiotherapy course typically takes 2 to 7 weeks.
  
  • Patients usually receive treatment five successive days per week, followed by a two-day break to allow healthy tissues time to repair and recover.
  • The daily procedure, including patient setup and verification, takes approximately 15 minutes, with the actual radiation delivery lasting only 2-5 minutes.