Health Technology Brief

supporting sound, evidence-based decision making

Proton Beam Therapy for Treatment of Pituitary Adenomas

February 5, 2019

Health Problem: Tumors originating in the pituitary are the fourth most common type of intracranial tumor. The majority are slow-growing benign adenomas that do not metastasize. Symptoms from pituitary adenomas (PAs) result from endocrine dysfunction or compression of brain structures as the tumor enlarges, which may result in significant morbidity.

Technology Description: Proton beam therapy (PBT) is a type of radiation composed of positively charged subatomic particles. PBT has the theoretical potential to achieve more selective treatment of the tumor mass, minimizing radiation to nontarget tissues, and to deliver higher doses of radioactivity.

Controversy: A challenge associated with radiation therapy to the pituitary is the proximity of surrounding organs at risk, including the brain, brain stem, and spinal cord, with risk of toxicity and the potential development of secondary tumors (radiation oncogenesis) later in life. Whether PBT is as effective as conventional photon therapy remains unknown. Although purported, it is unknown if PBT actually results in reduced risk of radiation oncogenesis, radiation toxicity to the developing nervous system, or improved quality of life. In addition, new-onset hypopituitarism with PBT is of concern. Related cost-effectiveness of PBT for the treatment of PAs, specifically, is unknown.

Key Questions:

  • Is PBT effective in treating PAs?
  • How does PBT compare with clinical alternatives for the treatment of PAs?
  • Is PBT safe for the treatment of PAs?
  • Have definitive patient selection criteria been identified for the use of PBT for the treatment of PAs?