Tumor treating fields (Optune®)

Tumor treating fields (TTF) was first reviewed by the HTA program in 2016.

  • In 2017, an update literature search was conducted on TTF to determine if newly available evidence published since the 2016 assessment could change the original coverage determination.
  • In 2018, the HCA director selected tumor treating fields for rereview based on newly available published evidence.
  • A rereview of tumor treating fields was conducted later in 2018.

Status: Decision completed

Policy context

Optune® (formerly the NovoTTF-100A System or Novocure), a delivery system for tumor treating fields, (TTFs), was approved by the U.S. Food and Drug Administration (FDA) in 2011 for the treatment of recurrent glioblastoma multiforme (GBM) and in 2015 for the treatment of newly diagnosed GBM in combination with temozolomide, an oral chemotherapy drug.

The Health Technology Clinical Committee (HTCC) voted in January 2016 to not cover Optune®. The 2018 health technology assessment (HTA) reviews the efficacy, safety, and cost-effectiveness of TTFs for treating GBM and other cancers to assist the HTCC in reviewing its existing policy and determining coverage for this medical device.

Primary criteria ranking

  • Safety = Low
  • Efficacy = High
  • Cost = High
Documents (all assessments)

Assessment (2018)

Update literature (2018)

Assessment (2016)

Assessment timeline (2018)

  • Draft key questions published: May 31, 2018
  • Public comment period: June 1 to June 14, 2018
  • Final key questions published: June 22, 2018
  • Draft report published: August 31, 2018
  • Public comment period: August 31, to October 1, 2018
  • Final report published: October 17, 2018
  • HTCC public meeting: November 16, 2018


In 2018, an estimated 1,735,350 new cancer cases and 609,640 cancer deaths will occur in the United States.1 Cancer is typically treated by surgery, radiation therapy, or systemic therapy (e.g., chemotherapy). Targeted cancer therapies such as hormone therapy (e.g., tamoxifen for breast cancer) or immunotherapy (e.g., rituximab for non-Hodgkin lymphoma) are systemic therapies that are used to interfere with specific molecules involved in cancer cell growth. Targeted drugs can (a) block or turn off molecular signals that control cell division and proliferation, (b) change proteins within the cancer cells so they are no longer viable, (c) stop making new blood vessels that feed cancer cells, (d) trigger the immune system to kill the cancer cells, or (e) carry toxins to cancer cells to kill them. Radiation therapy is a physical method that uses high-energy beams to kill cancer cells; although it is typically administered from a source outside of the body, it can also be delivered internally (e.g., brachytherapy).

Another physical treatment is a form of electromagnetic field therapy that uses alternating electrical fields to disrupt mitosis (i.e., cell division); cellular proteins are prevented from moving to their correct locations, resulting in cancer cell death. This therapy, also known as tumor treating fields (TTFs), externally delivers alternating electric fields that are very-low intensity and of intermediate frequency (i.e., 100-300 kHz) to an area of proliferating cancer cells. The specific frequency used in treatment is inversely related to the size of the specific cancer cells. Normal cells, which are affected at -50 kHz, remain unaffected by the frequencies used to treat cancer cells. TTFs have been shown to arrest cell proliferation and destroy cancer cells during division in animal models and human cancer cell lines.2-6