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Frequently Asked Questions

Proton Therapy

For what types of cancer is proton therapy used?

Proton therapy is effective in treating many types of cancers, including liver, lung, central nervous system, base of skull, head & neck, esophagus, breast, pancreas, prostate, pediatric, and recurrent cancers.

How long do proton therapy treatments take?

Proton therapy treatments typically take between 5 to 45 minutes depending on the number of treatment fields and the complexity of daily patient setup

Are proton therapy treatments painful?

You will not experience any pain or discomfort during your treatment sessions, although a small number of people feel a slight warming or tingling sensation in the area being targeted. You will not be able to see, smell, taste, or hear the radiation.

What are the side effects of proton therapy?

Proton therapy is a completely non-invasive procedure that may offer fewer side effects than those associated with traditional radiotherapy, such as fatigue, pain, loss of appetite¹ and nausea.² There is also less risk of developing secondary cancers.³

Will proton therapy make me radioactive?

After proton treatment delivery, there may be an extremely small amount of residual radiation that lasts for only a few minutes.4,5 You will likely have no restrictions, but your treatment team will advise if you need to take certain precautions to reduce the exposure to other people.

Will proton therapy make my hair fall out?

Proton therapy only affects the area of the body where the tumor is located. You will not lose your hair unless your treatment targets a part of the body that grows hair, such as your scalp. If you do lose your hair, it would most likely grow back after your treatment is over.

Will proton therapy make me nauseous?

Proton therapy affects only those areas being treated, so if you are not receiving radiation to your abdomen, it is unlikely that you will experience nausea as a result of treatment. In some cases, a patient's nausea is caused by other aspects of his or her treatment, such as chemotherapy or pain medication.

Can proton therapy itself cause cancer?

Theoretically, yes, but it is highly unlikely. Given the precision of proton therapy with its stopping power, especially when compared to traditional photo radiotherapy, particles (or protons) deposit most of the dose within the tumor—minimizing damage to healthy tissue. As a result, there is less risk of developing secondary cancers.³

Will I be able to continue my daily activities during my proton treatments?

Almost all patients are able to continue all their normal daily activities during their course of treatment. You should, however, ask your doctor about your individual situation.

Can proton therapy be given at the same time as other treatments?

Proton therapy is sometimes the only type of treatment a patient needs, but some types of cancer respond best to a combination of approaches, which could involve radiation plus surgery, chemotherapy, and/or immunotherapy. When proton therapy is used to increase the effectiveness of another type of treatment, it is called adjuvant therapy.


  1. Wang XS, Shi Q, Williams LA, et al. Prospective Study of Patient-Reported Symptom Burden in Patients With Non-Small-Cell Lung Cancer Undergoing Proton or Photon Chemoradiation Therapy. J Pain Symptom Manage. 2016;51(5):832–838. doi:10.1016/j.jpainsymman.2015.12.316
  2. Romesser PB, Cahlon O, Scher E, et al. Proton beam radiation therapy (PBRT) results in significantly reduced toxicity compared with intensity-modulated radiation therapy (IMRT) for head and neck tumors that require ipsilateral radiation. Radiother Oncol. 2016;118(2):286–292
  3. Eaton BR, MacDonald SM, Yock TI, Tarbell NJ. Secondary Malignancy Risk Following Proton Radiation Therapy. Front Oncol. 2015;5:261.
  4. Thomadsen B, Nath R, Bateman FB, et al. Potential hazard due to induced radioactivity secondary to radiotherapy:/ The Report of Task Group 136 of the American Association of Physicists in Medicine. Health Phys. 2014;107(5) 442-60.
  5. Wu Q, Wang Q, Liang T, et al. Study on patient-induced radioactivity during proton treatment in hengjian proton medical facility. Appl Radiat Isot. 2016(115) 235-50.