Study of Tumor-treating Fields to Treat Leptomeningeal Metastases from Breast Carcinoma Involving the Spine


About this study

The purpose of this study is to evaluate the safety and feasibility of the spinal array in treatment of patients with leptomeningeal metastases within the spine

The median survival of patients with LM with treatment is generally less than 5 months. There are four FDA-approved drugs for intra-CSF use in LM, but all have shown limited activity with no clear increase in survival outcome with treatment. Intra-CSF treatment is also invasive, involving either surgical placement of an intraventricular reservoir, or treatment (intrathecal) via repetitive lumbar punctures, and there is risk of adverse events including vomiting, headache, arachnoiditis and leukoencephalopathy with treatment. Systemic chemotherapy, targeted agents and immunotherapy have largely been ineffective in treatment of LM, in part due to limited CNS/CSF penetration. New effective treatments are needed.

TTF represents a new modality that is well tolerated with minimal adverse events. TTF has not produced significant additive toxicity when combined with systemic treatments. In addition, no invasive procedures are required, and treatment has been administered for long term without apparent cumulative toxicities.  TTF is currently approved for treatment of glioblastoma and mesothelioma. TTF is currently under study for treatment of CNS parenchymal metastases, lung and pancreatic cancer. There is potential application for symptomatic treatment of LM and intradural, extradural and vertebral metastases. Given the lack of effective therapies for LM, TTF is a promising alternative modality that should be explored. In addition, the lack of overlapping toxicities would potentially allow the use of TTFields in conjunction with other ongoing treatments for the leptomeningeal or systemic cancer. For these reasons, we are proposing an exploratory, phase I feasibility study of TTFields in treatment of the spinal component of leptomeningeal metastases, If feasible, consideration will be given to expansion to a Phase 1/2 study in a selected cohort of patient with LM.  

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Key Inclusion Criteria:

  • Age ≥ 18 years old.
  • Prior tissue diagnosis of breast cancer.
  • Confirmed diagnosis of LM with positive CSF cytology for malignancy and meningeal enhancement (type 1A, 1B, and 1C); or, if CSF negative, presence of clinical symptoms or signs compatible with LM, and recent (< 1 year) or active systemic cancer  
  • Radiographic evidence on MRI of leptomeningeal enhancement within the cervical, thoracic or lumbar spine on spinal MRI.
  • Life expectancy of at least 6 weeks.
  • ECOG performance status of 0, 1, 2, or 3
  • Recovery from any neurotoxic effects of prior therapy. 
  • Platelet count greater than 25,000/mm^3, and ANC greater than 0.5 mm^3.
  • Patients must have adequate liver function, total bilirubin < 2.5 mg%, unless elevated indirect bilirubin due to Gilbert’s disease, AST < 3.5 times upper limits of normal; adequate renal function (calculated eGFR > 30%.
  • Patients or legal medical representative must provide written informed consent.
  • Patients must have suitable body habitus for placement of transducer arrays.
  • Patients must be willing to wear the device for at least 18 hours a day (averaged over monthly).
  • Patients must be willing to return for the scheduled evaluations and perform the required assessments.
  • Patients are without other disease or situation which would significantly compromise adequate assessment of safety and feasibility of the TTF.
  • Patient willing to start a study Treatment with TTF ≤ 14 days from registration

Key Exclusion Criteria:

  • Concomitant therapy:
    1. Must not be receiving concurrent high-dose methotrexate (> 3 g/m2), high dose thiotepa, or high-dose cytarabine (>3 g/m2). Any other systemic chemotherapy, targeted treatment, hormonal or immunotherapy directed at the primary systemic malignancy is permitted
    2. Must not have received RT to the brain or spinal cord within 2 weeks of initiation of TTF
    3. Must be at least 1 week from cessation of any prior intrathecal chemotherapy
  • Women of childbearing age who are pregnant or lactating.  (Male and female patients who are fertile must be willing to use an effective means of birth control to avoid pregnancy.)
  • Patients with uncontrolled or untreated infection including active hepatitis, and HIV.
  • Patients receiving any other investigational agents and must not have received any other investigational agent within 14 days prior to registration. The 14-day period should be extended if the investigational agent is known to have delayed toxicity.
  • Patients known to be allergic to the hydrophilic gel utilized for transducer attachment.
  • Patients with surgical hardware within the planned area of treatment in the spine (e.g., titanium rods, screws, fixation devices)


Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Jacksonville, Fla.

Mayo Clinic principal investigator

Kurt Jaeckle, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office


More information


Publications are currently not available

Mayo Clinic Footer