What are the side effects of proton therapy?

Although it limits irradiation of healthy organs and thus side effects as much as possible, proton therapy nonetheless produces a certain number of unwelcome side effects.

Like all treatments, proton therapy may produce unwanted side effects. These effects vary considerably from one patient to another. They depend on the dose (photons and protons) administered, the location of the treatment and the reactions of each patient. A special treatment is offered if such reactions occur.

For tumors of the eye

Early unwanted side effects are rare, and often occur in addition to those of surgery.
They may, however, include swelling of the eyelid due to placement of the props, or irritation of the cornea, which will be monitored during treatment by an ophthalmologist.

In the immediate aftermath of a treatment or simulation session, the patient may experience blurred vision in the eye treated, which disappears after a couple of hours and is linked to the anesthetic collyrium.

For intra-cranial tumors

  • Fatigue: It is often not significant, but gentle exercise, such as walking, and rest may ease symptoms.
  • Headaches, nausea and vomiting: These are the result of swelling in or around the tumor, which reacts to the irradiation. This swelling may lead to irritation of the area of the brain that controls nausea and/or vomiting.
  • Alopecia or hair loss: A result of the rays, this is temporary and appears only where the rays pass; hair grows back within three to six months. When combined with chemotherapy, hair loss may be total.
  • Erythema or skin redness: It is temporary and disappears within 2 to 3 weeks after irradiation. Direct exposure to sun after radiation should be avoided. Headgear should be worn when exposed to the sun for one year after treatment.
  • Loss of taste and appetite: These can be connected or may appear independently. They often improve slowly after treatment, in a few weeks to a few months.
  • Anxiety and depression: These are legitimate and must be dealt with. Psychological support may be offered and special treatment may be prescribed, if necessary. Anxiety and depression may lead to sleep and/or eating problems.
  • Inflammation of the mucous membranes: For low tumors close to the upper spine, irradiation may irritate the pharyngeal mucous membranes.