Radiation Therapy and Nutrition in cancer patients

Cure sometimes, treat often, comfort always.

Radiation therapy, like chemotherapy, kills rapidly dividine cancer cells. But additionally, it also affects rapidly dividing normal tissue in the vicinity of the tumour. The cells most affected are in the S and M phase of the cell cycle (see p. 32 in 'Cancer Treatments').

The damage to normal cells causes unwanted side-effects. This treatment, therefore, involves maintaining a balance between destroying the cancer cells and minimizing the effects on normal tissue. Unlike chemotherapy, the cell destruction by radiation does not necessarily occur right away. At times, it may take days or weeks after the exposure to radiation for the cells to self-destruct. Normal tissues, made up of rapidly growing cells like skin and bone marrow, are often affected earlier than the tumour. Others tissues like nerves, brain and breast generally show late effects. It is for this reason that this form of treatment may still cause sideeffects long after the therapy is over.

Side Effects of Radiation

Therapy Advances in radiation therapy, like Image-Guided Radiation, accurately focus the radiation on to the diseased tissue. While this minimizes the side-effects, some fibrosis of normal tissue may still occur. Since the treatment is localized, the side-effects depend on the area of the body receiving the treatment.

Common side-effects are: fatigue, skin changes, lymphoedema, low blood counts, loss of appetite, nausea, vomiting, diarrhoea and secondary tumours.

 Fatigue

The extreme tiredness redness that follows radiation not relieved is often labelled as fatigue. There is no single cause que, nor any single treatment for it (see p 107-09 in Chemotherapy and Nutrition').

Skin Changes

Faint redness of the skin surface may develop and progress renderness, blistering, and dryness. Peeling of skin mostly coeurs three to four weeks after the start of treatment. It esembles a case of severe sunburn. Hair loss over the treated area is common. Moisturizing the skin or taking Vitamin E supplements may help once treatment is over.

During the period of treatment avoid the following: exposure to the sun (the skin is sensitive to sunlight), moisturizers, soap, deodorant or perfume. Avoid scrubbing the area or applying hot or cold packs. Wear loose, soft garments to allow for proper blood circulation.

Lymphoedema

The blockage of the lymphatic vessels causing swelling of the limb that results from the accumulation of body fluid in the tissue is called lymphoedema. The lymph nodes in the axilla are removed during surgery for breast cancer. These lymph nodes not only drain the breast tissue but also the entire arm. Their removal is necessary to prevent the spread of the disease via the lymphatic vessels and also for staging the cancer. Radiation therapy given for breast cancer not only targets the breast, but also the axilla. This may result in the blockage of the lymphatic vessels, in an already compromised lymphatic system (since the lymph nodes have been surgically removed). The block mphatic vessels interferes with the drainage of the lymph " (interstitial or body fluids) from the arm, resulting in its collection in the soft tissue and the development of lymphoedema of the affected arm. After radiation ends the side-effect lasts for three to four weeks, but at timesmay persist for longer.

 Secondary

Tumours The risk of secondary tumours developing in th location, or in nearby organs, has been reported radiation therapy. Though the incidence is small in nu these are a cause for concern.

I recall reporting on the biopsy of eighty-seven-year. Mrs G. She developed cancer of the left cheek, but w non-smoker and did not chew tobacco or eat betel nu After careful questioning, she revealed having had treatme for breast cancer on the left side twenty-five years ago this had included radiation therapy. Those were the days of less precise radiation. Her tumour in the cheek was likely a secondary cancer occurring post-radiation therapy. Fortunately, the focused radiation technique has significantly reduced this side-effect.

Miscellaneous Effects

Head and neck radiation may cause dryness of mouth, loss of taste, and thick, rope-like saliva. These side-effects are short-lived and disappear over time. If problems persist consult the oncologist.

Nausea, vomiting and headaches may be delayed side-effects of radiation to the head and neck region. Nutrition should not be the casualty during treatment (for the management of the symptoms, refer to p. 104-05 'Chemotherapy and Nutrition').

 DIET DURING RADIATION THERAPY

• The body needs adequate calories, proteins and vitamins for its energy demands, repair and healing las given for surgeryl-during and after radiation therapy.
• It is important not to lose weight during treatment as the radiation therapy plan is specific to the patients size and shape.
• When appetite is a problem, extra energy and proteins can be added to the diet without having to actually consume extra food (see p. xx in Managing Palliative Care').
• High energy drinks like milkshakes or soup (see p. 122-23) work well.
• Hydration, by consuming plenty of fluids including water and tea, is important for healing.
• Have many small meals rather than large meals; six to eight small meals instead of three full meals will take care of the calorie requirements.
• Have a soft or a liquid diet it swallowing is a problem.
• Avoid alcohol or spicy food in case of mouth ulcers. Energy foods and proteins form the backbone of the diet during radiotherapy.
• Food safety (see p. 110) should be carefully adhered to ensuring that the food is cooked at proper temperature and avoiding raw foods.
• If diarrhoea develops after lower abdominal radiation, probiotics like yogurt can be eaten.