What can I do to prepare for the cancer treatment (radiation or chemotherapy or both)

[icon name=”user” class=”” unprefixed_class=””] Meenakshi Noll, MD, Ph.D.

Cancer-PrepFirst of all ask questions, questions and questions from your doctor and be well informed about what to expect. Or send us a message if you need more information on the disease and treatment or anything that is not clear.

Although the side effects vary with treatment (and in various people) but the common side effect is nausea and vomiting. For these side effects appropriate antiemetic medication 1 will be prescribed by the doctor, make sure to use those proactively. A preventative approach is the best as these symptoms become uncontrollable once they begin. In addition, nausea and especially vomiting is very distressful for the body and make you miserable.How to manage the nausea/vomiting associated with radiation or chemotherapy or both 2

  • Take the anti nausea medication as prescribed before the symptoms get out of control
  • Try not to eat anything 1-2hours before the treatment, or eat something light a few hours before the treatment
  • Eat small meals throughout the day, eat before you get hungry as empty stomach causes nausea as well
  • You can eat what appeals to you, however, avoid hot, spicy, greasy foods and foods with strong odors. In addition, prevent eating your favourite foods at this time as you might associate them with nausea and vomiting. Then they will no longer be your favourite foods.
  • Rest (sitting up) after eating, as this slows down the digestion and should help preventing nausea
  • Some of the friendly foods during this time: crackers, yogurt, toast, rice or noodles, boiled potatoes, bland vegetables, flat soda 3

If you are already vomiting

  • Try to stay hydrated by taking sips of cold fluids like flat ginger ale, lemonade, very dilute fruit juice, icy pops or hard candy with minimum flavour.
  • In addition follow the above steps to try eating small meals or crackers, toast etc.
  • Wear loose fitting clothes to feel as comfortable as possible
  • Avoid the smells that bother you or any strong odors
  • Some distraction techniques that might work are: meditation or relaxation music or watch something you like e.g. movies etc.

Why does the cancer treatmentcause vomiting/nausea?

Cancer cells are our own cells that are growing uncontrollably. We still don’t have many successful treatments that would distinguish between cancer cells and normal cells. Thus, the radiation and chemotherapy used at this time kills ALL body cells including cancer cells. There are a few reasons or pathways for nausea and vomiting during the course of chemotherapy or radiation treatment.

Central nervous system controls the nausea and vomiting in the body via two centers namely 4:

  • The vomiting center
  • Chemoreceptor trigger zone (CTZ): This center is located in the medulla of the brain. It has a defensive mechanism for the body. It detects the circulating toxins and other chemicals, infections and even radiation. CTZ does not cause vomiting by itself rather sends message to the vomiting center that leads to vomiting and nausea.

Thus the pathways by which the vomiting or nausea occurs by chemotherapy/radiation are:

  • The gastric lining cells have one of the highest turnover rates in the body, thus stomach is one of the most affected organs. It sends impulses to the vomiting center in the brain, causing nausea and vomiting.
  • Cytotoxic drugs (chemotherapy) or radiation, activate the CTZ center by stimulating the serotonin receptors. This causes the release of serotonin and dopamine (called neurotransmitters), which transmits the message to the vomiting center in the brain releasing acetylcholine (Ach). This, in turn causes vomiting and nausea.
  • Brain cortex and limbic system: this system reacts to taste, smell, emotions etc. Thus people who already have experienced bad bouts of vomiting and nausea during prior cycles of treatments.

There are three types of vomiting (emesis) with chemotherapy treatment 5

  • Acute emesis: in this case, the symptoms begin within 24hours of the treatment
  • Delayed: symptoms occur after 24-48hour of the first dose of chemotherapy
  • Anticipatory emesis: this occurs when the patients think they are going to get nausea and vomiting from the treatment. This usually happens in patients who have already experienced bad bouts of nausea/vomiting from previous round of treatment.


  1. Adelaide, S., Antiemetics. Australian Medicines Handbook 2007.
  2. CJ, D.; GV, L.-B.; DG, G.-S., Nausea and Vomiting: Mechanisms and treatment. Berlin: Springer-Verlag: 1986.
  3. Clinical Medicine. 5th ed.; WB Saunders Company: Edinburgh, 2002.
  4. M, L.; I, W.; SR, R., Oxford Handbook of Clinical Medicine. 6th ed.; Oxford University Press: Oxford, 2004.
  5. P, G.; A, G.; C, L., Nausea and vomiting in the cancer patient. In Oncology, Springer New York: 2006; pp 1482-1496.
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