Focus of the Report: The focus of this Health Technology Assessment (HTA) is to evaluate the effectiveness and safety of proton beam therapy (PBT) compared with conventional (photon-based) external beam radiation therapies to treat esophageal squamous cell carcinoma (ESCC) in adults.

Technology Description: PBT is a type of external radiation treatment in which positively charged subatomic particles (protons) are precisely targeted to a specific tissue mass using a sophisticated planning and delivery system. Compared with conventional approaches, PBT may deliver a similar or higher therapeutic dose of radiation to the target tissue while minimizing damage to nearby healthy tissue.

Controversy: The equivalence of the relative biological effects of protons and those of photons remains unknown, and there is uncertainty regarding the dose range for tumors that are deep seated (i.e., not close to the skin). Additionally, PBT is sensitive to heterogeneity within tissues and target motion; this is of particular relevance to EC because motion can occur during breathing, cardiac action, and gastric filling. The passive-scattering PBT technique generates neutrons, which are a secondary source of radiation exposure during treatment, and there is debate as to the location and significance of neutron production during passive-scattering PBT. The cost of PBT is substantially higher than other therapies, and there is a lack of cost-effectiveness studies of PBT for EC. Finally, there are fewer than 40 locations in the United States that provide PBT, making access to treatment a concern.

Key Questions:

  1. Is PBT effective for the treatment of ESCC in adults, in terms of tumor response and survival?

  2. How does PBT compare with other external beam therapies (including conventional photon-based therapies) for the treatment of ESCC?

  3. Is PBT in patients with ESCC safe?

  4. Have definitive patient selection criteria been identified for PBT for the treatment of ESCC in adults?

If you have a Hayes login, click here to view the full report on the Knowledge Center.