Frequently Asked Questions

1.The Theory of Radiotherapy

Radiotherapy, also known as radiation therapy, utilizes high dose of radiation to treat tumors. High energy photons (a subtype of radiation) produced by radiotherapy machines can damage cancer cell DNA effectively, leading to reduced proliferation of cancer cells. Therefore, we can use radiation to kill cancer cells and shrink tumors. The response of cells to radiation depends on their cell types, hence the treatment course will be designed according to various clinical goals with respective treatment duration and radiation dose.

2.Why radiation therapy can target cancer cell?

Radiation therapy uses high energy to destroy the DNA in the cell nucleus during cell division phase, thus prohibit cell growth. Cancer cells divide more frequently than normal tissue cells, thus they are more affected by radiation therapy. Most normal tissue cells are not in cell division phase, therefore they are less affected. Some normal tissue cells, such as skin cells and mucous membrane cells are also highly affected by radiation therapy due to their rapid growth characteristic, which lead to side effect of radiation therapy.

Reference

  1. Therapy, R., & Cdks, B. (2014). The science behind radiation therapy. Am Cancer Soc, 15.
3.Will I get the same radiation therapy treatment as other patients?

No, you will not. With the advancement in technology, modern radiotherapy advocates "personalized" design as the treatment orientation. In order to meet the individual needs of each patient, our entire team will tailor-make a treatment plan for each individual to ensure the accuracy of the treatment. Under the instructions of the oncologist, radiation therapists will perform a "treatment simulation". In addition to performing computer scans for dose calculation, radiation therapists will also make different immobilization devices depending on the patient's treatment site, so that patient’s position can be fixed for future treatments. The radiation position and dosage are customized according to the location and characteristics of each patient's tumor. In the process of radiation dose design, the tumor and normal tissues that may be irradiated will be drawn on each computerized tomographic image of the patient, and then undergo a dose optimization procedure by considering the required therapeutic dose of targets and the tolerable dose of the adjacent normal tissues.

Reference

  1. 何謂放射治療?化學治療? 作者:臺大醫院腫瘤醫學部放射腫瘤科郭頌鑫主任 專題報導 2016年11月臺大醫院健康電子報. (n.d.).
  2. Savoca, G., Calvaruso, M., Minafra, L., Bravatà, V., Cammarata, F. P., Iacoviello, G., Abbate, B., Evangelista, G., Spada, M., Forte, G. I., & Russo, G. (2020). Local disease-free survival rate (lsr) application to personalize radiation therapy treatments in breast cancer models. Journal of Personalized Medicine, 10(4), 177. https://doi.org/10.3390/jpm10040177
4.Is radiotherapy only used to treat late stage of cancer?

No, radiation therapy is not only used to treat late-stage cancers, instead, it is a treatment option for various types and stages of cancers.

Radiation therapy could be given alone or in combination with other treatments to cure the cancer. Those treatments include surgery, chemotherapy and immunotherapy. Sometimes, radiation is given before surgery to reduce the size of tumour so it could be removed by surgery more easily. Other times, radiation therapy is used to prevent cancer from returning or spreading.

When it is not possible to completely cure the cancer, doctor might recommend palliative radiation therapy. The role of such therapy acts as a symptomatic treatment, such as to alleviate pain, trouble breathing, bowel blockages or other problems caused by tumours. As such, patient’s quality of life could be improved.

Reference

  1. Baskar, R., Lee, K. A., Yeo, R., & Yeoh, K. W. (2012). Cancer and radiation therapy: current advances and future directions. International journal of medical sciences, 9(3), 193.
5.Is radiation therapy only used to extend patient’s life instead of curing the cancer?

In treating cancer, radiotherapy can be categorized into 3 main types: radical, adjuvant and palliative treatments. Different treatment techniques, prescription dose, fractionation, day are applied according to different treatment types.

Radical Radiotherapy can be used to cure cancer and manage cancer cell metastasis. Studies show radical radiotherapy yields improved survival in treating nasopharyngeal caner, prostatic cancer, and also cervical cancer. As well, when combined with chemotherapy, the synergetic effect is shown to improve cancer cell elimination and stop metastasis.

Radiotherapy serves an auxiliary role in adjuvant radiotherapy. With surgery serves as a main treatment approach, radiotherapy helps shrink the tumor prior to surgery to ensure operability. A post-op adjuvant radiotherapy can also be used to eradicate residue tumor cells to minimize the odds of recurrence. Common examples for adjuvant radiotherapy are breast cancer and rectal cancer.

Palliative radiotherapy serves an important role in symptomatic treatment. It is commonly used in pain control, bleeding control, and relieving critical organ compression.

In short, radiation therapy has different nature. As long as sufficient radiation dose is given in the right place, the tumor can also be completely eradicated.

Reference

  1. Effects of Radiotherapy and Surgery in Early Breast Cancer — An Overview of the Randomized Trials. (1996). New England Journal Of Medicine, 334(15), 1003-1003. doi: 10.1056/nejm199604113341522
  2. Hajdenberg, J. (2009). Adding radiotherapy to endocrine therapy improved survival in locally advanced prostate cancer. Annals Of Internal Medicine, 150(12), JC6. doi: 10.7326/0003-4819-150-12-200906160-02006
  3. Sun, X., Su, S., Chen, C., Han, F., Zhao, C., & Xiao, W. et al. (2014). Long-term outcomes of intensity-modulated radiotherapy for 868 patients with nasopharyngeal carcinoma: An analysis of survival and treatment toxicities. Radiotherapy And Oncology, 110(3), 398-403. doi: 10.1016/j.radonc.2013.10.020
  4. Thomas, G. (1999). Improved Treatment for Cervical Cancer — Concurrent Chemotherapy and Radiotherapy. New England Journal Of Medicine, 340(15), 1198-1200. doi: 10.1056/nejm199904153401509
6.Is it painful during the delivery of radiotherapy?

No, there is no pain induced by radiotherapy per se as it is similar to taking an X-ray film. Patients just have to stay still in the treatment position according to the instructions given by the therapists.

The only discomfort patients might encounter usually come from the side effects induced by the radiation following a few treatments. The most commonly found radiation-induced skin reaction would be redness much like a sunburn, burning, dryness, soreness and itching sensations.

7.Having Radiotherapy with a Cardiac Implantable Electronic Device

Radiation may interfere or damage cardiac implantable electronic device (CIED) such as pacemaker or implantable cardioverter defibrillator (ICD). Therefore, if you are going to have radiotherapy with a CIED, be sure to tell your doctor that you have a CIED implanted. A multidisciplinary team including cardiologist, clinical oncologist, medical physicist, radiation therapist, nurse and CIED specialist will work together so that the risks can be assessed and special considerations can be taken during the course of radiotherapy.

Reference

  1. Lester, J., Evans, L., Mayles, P., Buckley, H., Home, P., & Yousef, Z. (2015). (rep.). Management of cancer patients receiving radiotherapy with a cardiac implanted electronic device: A clinical guideline. The Royal College of Radiologists. Retrieved from https://www.rcr.ac.uk/sites/default/files/mgmt_cancer_patients_receiving_radiotherapy_cardiac_implanted_electronic_device_sep2015.pdf
8.Is it necessary to have radiation therapy even after surgery?

Surgery is a localized treatment were physicians attempt to remove the entire tumor. However, there could still be some microscopic spread around the primary site, leading to cancer recurrence in the future. For this reason, radiation therapy often plays an important role in eradicating the remnant microscopic cancer cells following the surgery.

Radiation therapy typically has different purposes and advantages for different cancers. Different studies have also shown that patients have improved survival when treated with surgical resection followed by adjuvant radiation therapy.

At times, radiation therapy is not the only adjuvant therapy option, other therapies such as chemotherapy, hormonal therapy, targeted therapy could also be in place to cure the cancer. Though, optimal treatment modalities differ depending on the type and stage of cancer. Patients should talk with their doctor to discuss about the advantages of various treatment options.

Reference

  1. Washington, C. M., & Leaver, D. T. (2016). Principles and practice of radiation therapy.
9.What do I need to do during radiotherapy?

There is no pain or any other sensation during radiotherapy treatment, the patient only needs to keep still and relax throughout the process. For some treatments that utilize the breath-holding technique, the patient is required to follow instructions given by the therapists and control the breathing accordingly.

Therapists position the patient every time before the treatment begins. Depends on the treatment region, different immobilization devices are used to assist patients in holding a stable posture.  Coordinate markings that therapists use to position the patient are marked either on the patient’s skin or on the immobilization cast. Patients are required to preserve the markings throughout the whole treatment course. During positioning, the patient should stay still and relaxed unless he/ she is instructed to move.

Therapists then carry out treatment verification and delivery in the Control Room while monitoring the patient relaxes on the treatment couch through the CCTV. If the patient has any question or discomfort, he/she can press the call bell and talk to the therapists instantly through the intercom system. Therapists will provide immediate assistance.

Reference

  1. Verhey, L. J. (1995). Immobilizing and positioning patients for radiotherapy. Seminars in Radiation Oncology, 5(2), 100–114. https://doi.org/10.1016/s1053-4296(95)80004-2
10.Can I meet my family members after receiving radiation therapy?

External beam radiation therapy makes use of high energy photon beams, which enter the human body and kill the cancel cells directly. The output of the treatment machine is extremely stable. The radiation will stop emitting and not remain in the patient body after the machine is switched off. After receiving external beam radiation therapy, the radiation will not remain in the treated tissue, there is no secondary radiation produced from the patient body. Therefore, patient can go home after completing the treatment without keeping a safe distance from their families, and need not worry about transmitting radiation to them.

Reference

  1. Team, C. C. (2020, October 6). Can Your Cancer Treatment Be Hazardous to Others? Health Essentials from Cleveland Clinic. https://health.clevelandclinic.org/can-your-cancer-treatment-be-hazardous-to-others/#:~:text=Some%20cancer%20patients%20who%20receive,is%20fine%2C%E2%80%9D%20Snyder%20says.
  2. 以璿 作者:林. (2020, August 17). 放療有輻射?關於癌症放射線治療的6個迷思 別被誤導了!. Heho健康. https://heho.com.tw/archives/19586.
  3. 放射治療」專刊引言. (n.d.). http://www.kmuh.org.tw/www/kmcj/data/10611/20.htm.
11.The tumour size has not changed after a few fractions of radiation therapy. Is radiation therapy working for me?

The effect to the tumour cell caused by radiation is related to the cell cycle of the tumour cell and also the cell type. Radiation therapy does not eliminate tumour right away after treatment. Instead, radiation induces genetic damage to cancer cells. As a result, they enter cell division prematurely with mispaired DNA. Eventually, they will lose the ability to replicate, leading to mitotic cell death. Several attempted divisions might occur before sufficient genetic damage is accumulated to trigger cell death. Underlying the reason why tumour has delayed response to radiotherapy.

Furthermore, mitotic cell death implies that the cell dies when it attempts to divide. If a tumour cell does not divide, it will not die. However, at the same time, it cannot grow and spread. Different cell types undergo cell division at different speed, which means the time for tumour to shrink varies with patient’s condition and disease. After radiotherapy, the patient's condition will be reviewed regularly every few months.

Reference

  1. Sia, J., Szmyd, R., Hau, E., & Gee, H. E. (2020). Molecular Mechanisms of Radiation-Induced Cancer Cell Death: A Primer. Frontiers in Cell and Developmental Biology, 8. https://doi.org/10.3389/fcell.2020.00041
12.Will I have the same side effects as other patients with the same disease?

Side effects could vary from person to person, even when they receive the same type of radiation therapy. The radiation treatment plan you received is tailored by the radiation oncology team. Your treatment plan is different from others depending on the location of cancer, the dose of radiation, schedule of treatment and any other treatments you might be having at the same time.

Depending on how your general health is, and how your body reacts to therapy, you might experience different types and severity of side effects or even no issues. Some side effects come about during the treatment, while some could continue after the treatment ends. It is affected by which tissue or organ being irradiated and how your body cells recover from radiation. Your oncologist will discuss with you what to expect before treatment. It is always important to talk with your health care team about any side effects that you experience so they could help you cope with them.

Reference

  1. Bentzen, S. M. (2006). Preventing or reducing late side effects of radiation therapy: radiobiology meets molecular pathology. Nature Reviews Cancer, 6(9), 702-713.
13.Will I lose hair from radiation therapy?

Radiation therapy could damage hair cells, particularly those that grow at a rapid rate, resulting in thinning of hair or hair loss on the treated area of the body. If radiation is given to the head region, hair might fall out from the scalp. For the thorax region, it might affect that armpit or chest area involved in the treatment area.

Hair usually begins to fall out 2-3 weeks after the first treatment. It might be temporary or permanent, depending on the total dose of radiation and number of fractions. If the case is temporary, hair often grows back in 6-12 months after the completion of treatment. However, the hair that grows back may be thinner or in a different colour.

If you find your scalp more sensitive, wash your hair with mild shampoo; avoid brushing, blow-drying or apply products such as gels and clips. Some people might choose to wear a wig, hat, scarf after losing their hair.

Reference

  1. Ahmad, I., Sardana, K., Chufal, K., & Bhatt, C. P. (2018). Radiation induced alopecia: an under-appreciated side effect of whole brain radiotherapy and strategies to ameliorate it. J Nucl Med Radiat Ther, 9, 002.
  2. Olver, I. (Ed.). (2018). The MASCC textbook of cancer supportive care and survivorship. Springer.
14.Possible skin reaction during radiotherapy and the care

Radiation therapy can make the skin tender, red like sun burnt, darker and itchy. This tends to start one to two weeks after treatment begins. To minimize the skin reaction during radiation therapy, please keep the skin of the treatment area dry and clean. Only wash the area with warm water and mild non-perfumed body wash or shampoo. Afterwards, you can gently pat dry the skin using a soft towel and keep the skin marks. If the marks have faded, let your radiation therapist know and do not retouch them on your own. Refrain from using hot water, heating pads or ice pad on the treatment area.

It is not recommended to bath, swim, or take a sauna so that skin irritations could be reduced to the minimal. Do not use non-prescribed cream, lotions, perfume, powder, or deodorants over the treatment area. Avoid rubbing, scrubbing, scratching or shaving the treatment area. Patients can consider keeping fingernails short to protect skin from accidental scratching. Wear loose collar clothing to avoid friction to the treatment area. As well, avoid exposing the treatment area to direct sunlight by wearing a hat or using an umbrella.

Reference

  1. American Society of Clinical Oncology (ASCO). Side effects of radiation therapy. Accessed at https://www.cancer.net/navigating-cancer-care/how-cancer-treated/radiation-therapy/side-effects-radiation-therapy on December 26, 2019.
  2. Gosselin T, Ginex PK, Backler C, et al. ONS Guidelines for Cancer Treatment–Related Radiodermatitis. Oncology Nursing Forum. 2020; 47(6).
15.Possible side effect and care for head radiotherapy
  1. Fatigue
  2. Skin reaction
  3. Hair loss
  4. Headaches and Brain swelling
  5. Nausea and Vomiting

To manage the side effect, please get plenty of rest to restore energy. Try to maintain a balanced, nutritious diet. To improve your appetite, please try small frequent meals. Prevent any alcohol or irritating food such as spicy and salty food. If you experience headaches or brain swelling during treatment, please report to your oncologist.

Reference

  1. American Society of Clinical Oncology (ASCO). Side effects of radiation therapy. Accessed at https://www.cancer.net/navigating-cancer-care/how-cancer-treated/radiation-therapy/side-effects-radiation-therapy on December 26, 2019.
16.Possible side effects of head and neck radiation therapy and their care
  1. Fatigue
  2. Skin reaction
  3. Hair loss
  4. Change of taste, dry mouth, loss of appetite
  5. Stiffness in the jaw
  6. Sore throat, mouth, and gum sores; Difficulty in swallowing
  7. Hoarseness
  8. Hearing impair

Avoid spicy and rough foods, such as raw vegetables, dry crackers, and nuts. Do not eat or drink very hot or very cold foods or beverages. Prevent smoking, chewing tobacco, or drinking alcohol – these can make mouth sores worse. Rinse your mouth with warm salt every 1 to 2 hours as needed. (Use 1 teaspoon of salt and 500ml of water.) Moisten food with gravies and sauces to make it easier to eat. Ask your oncologist about medicines to help treat mouth sores and control pain while eating.

Reference

  1. Drapek L. Radiation therapy. In Newton S, Hickey, Brant, JM, eds. Mosby’s Oncology Nurse Advisor. 2nd ed. St Louis, MO: Elsevier; 2017:168-171.
17.Possible side effects of thoracic radiotherapy and their care
  1. Fatigue
  2. Skin reaction
  3. General weakness
  4. Difficulty in swallowing
  5. Loss of appetite
  6. Dry Cough or shortness of breath

Avoid exposing the treatment area to direct sunlight by wearing a hat or using an umbrella. Get plenty of rest to restore energy. Try small frequent meals and sour food to improve appetite. Prevent alcohol and irritating food such as spicy and salty food. To consume liquid or soft food or cut your food into small pieces. Eat small bites slowly.

18.Possible side effects of breast radiotherapy and their care
  1. Fatigue
  2. Skin reaction
  3. Breast discomfort or swelling
  4. Underarm hair loss
  5. Swelling and hardening of treated tissue, pigmentation

Keep the skin of the treatment area dry and clean. Wash the skin with warm water and mild non-perfumed body wash or shampoo. Gently pat dry the skin using a soft towel. Do not use hot water, heating pads or ice pads over the treatment area. Prevent bathing, swimming, or taking a sauna to reduce irritation to the skin. Do not use non-prescribed cream, lotions, perfume, powder, or deodorants over the treatment area. Avoid rubbing, scrubbing, or scratching the treatment area. Keep fingernails short to protect your skin from accidental scratching. Avoid shaving treated skin to minimize irritation. Wear loose-fitting clothing to avoid friction to the treatment area. Wear soft cotton bra without wire or lace. Avoid exposing the treatment area to direct sunlight.

Reference

  1. Early Breast Cancer: ESMO Clinical Practice Guidelines2019. F Cardoso and others Annals of Oncology, 2019. Volume 30, Issue 8, Pages 1194–1220
19.Possible side effects of abdominal radiotherapy and their care
  1. Fatigue
  2. Skin reaction
  3. Mild diarrhea, nausea, and vomiting
  4. Abdominal bloating and pain
  5. Loss of appetite

Keep the skin of the treatment area dry and clean. Wash the skin with warm water and mild non-perfumed body wash or shampoo. Gently pat dry the skin using a soft towel. Do not use hot water, heating pads or ice pads over the treatment area. Prevent bathing, swimming, or taking a sauna to reduce irritation to the skin. Do not use non-prescribed cream, lotions, perfume, powder, or deodorants over the treatment area. Avoid rubbing, scrubbing, or scratching the treatment area. Keep fingernails short to protect your skin from accidental scratching. Avoid shaving treated skin to minimize irritation. Wear loose-fitting clothing to avoid friction to the treatment area. Wear soft cotton bra without wire or lace. Avoid exposing the treatment area to direct sunlight. Get plenty of rest to restore energy. Try small frequent meals to improve appetite. Take meal supplements to maintain nutrition if needed. Avoid drinking alcohol and eating spicy food. Try foods with high protein and calories, but low dietary fiber.

Reference

  1. “Radiation Therapy Side Effects,” National Cancer Institute, 2018. [Online]. Available: https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/side-effects.
20.Possible side effects of pelvic radiotherapy and their care
  1. Fatigue
  2. Skin reaction
  3. Abdominal and/or Rectal discomfort
  4. Urinary changes (Increased Frequency of urination, a burning feeling while urinating
  5. Diarrhea and/or constipation
  6. Loss of appetite

Keep the skin of the treatment area dry and clean. Wash the skin with warm water and mild non-perfumed body wash or shampoo. Gently pat dry the skin using a soft towel. Do not use hot water, heating pads or ice pads over the treatment area. Prevent bathing, swimming, or taking a sauna to reduce irritation to the skin.  Drink more water to prevent dehydration if diarrhea occurs. Try small frequent meals to improve appetite and take meal supplements to maintain nutrition if needed. Avoid alcohol and irritating food such as spicy and salty food. Food that are rich in protein and calories, but low in dietary fiber is also beneficial in maintaining a healthy body weight.

Reference

  1. “Radiation Therapy Side Effects,” National Cancer Institute, 2018. [Online]. Available: https://www.cancer.gov/about-cancer/treatment/types/radiation-therapy/side-effects.