Supportive Coaching for Patients with Glioblastoma and Their Families—and How It Influences Adherence to Treatment with Tumor Therapy Fields (TTFields) (COCOON Study)

Brain tumors are classified into four grades according to a system established by the World Health Organization (WHO); the higher the grade, the more aggressive the tumor. Glioblastoma is the most common primary malignant brain tumor in adults and has a very poor prognosis. It is classified as WHO Grade 4. The current standard of care consists of surgery, chemoradiotherapy, and chemotherapy with temozolomide. The treatment cannot cure the tumor but can prolong survival. Glioblastoma is difficult to treat because it grows rapidly and diffusely into surrounding brain tissue, making it hard to delineate and remove. The cancer cells are also genetically very diverse, which means that not all cells respond equally to treatment. Treatment often kills only a portion of the cells, while others survive and continue to grow. As a result, even after intensive treatment, a new tumor usually forms within just a few months. WHO Grade 4 astrocytomas with an IDH mutation biologically belong to the same highest aggressiveness category as glioblastoma, but they typically progress somewhat more slowly and sometimes respond better to treatment.

To further slow tumor growth after chemoradiotherapy, additional treatment with tumor therapy fields (TTFields) may be used following chemoradiotherapy. TTFields therapy is administered concurrently with subsequent chemotherapy using temozolomide, which is given in several cycles over about half a year.

During this process, electrodes—worn directly on the shaved scalp like a special cap—generate weak alternating electric fields that specifically disrupt the division of tumor cells. The therapy is well tolerated but requires that the device be worn daily for many hours. TTFields are an integral part of standard therapy for glioblastomas and are also increasingly being studied for WHO Grade 4 astrocytomas (IDH-mutated). Because using the device in daily life can be challenging, patients’ family members play an important role in supporting and assisting with the therapy.

The goal of the COCOON study is to investigate whether structured coaching for patients and their family members helps them use TTFields therapy more regularly and over a longer period of time. To this end, patients and their families will be randomly assigned to two groups: a study group (intervention arm) and a control group. All participants will receive the standard medical treatment and psychosocial support provided at certified neuro-oncology centers. Participants in the study group will also receive a specialized coaching program via video consultation. Over a period of about ten weeks, a total of six structured video sessions with experienced psycho-oncologists will take place, accompanied by brief follow-up phone calls. Patients and family members participate in the sessions together. The first sessions begin shortly after the start of radiation and chemotherapy and are designed to help participants feel more confident in dealing with their diagnosis and treatment. Once the radiation phase is complete, the focus shifts to daily life with TTFields therapy, coping with stress, practical questions, and strengthening self-care and motivation. Observation as part of the study lasts for approximately nine months. The primary endpoint of the study is the effectiveness of the intervention, measured by how consistently and over what period of time TTFields therapy is actually used. The study does not alter the medical treatment itself.

Women and men aged 18 and older who have been newly diagnosed with glioblastoma or an IDH-mutated WHO Grade 4 astrocytoma are eligible to participate in the study. A prerequisite is that a combination of radiation therapy and chemotherapy with temozolomide, followed by TTFields therapy, is planned. Participation is possible if radiation therapy has not yet begun or was started within the last two weeks. Close relatives of the patients may also participate in the study.