RESUMEN
The NovoTTF-100A device emits alternating tumor treating electric fields (TTFields) that interfere with cytokinesis and chromosome segregation during mitosis. Because it has a similar efficacy to cytotoxic chemotherapy, the device has been approved by the United States Food and Drug Administration for the treatment of recurrent glioblastoma. Although bevacizumab has been in use for recurrent glioblastoma, patients who experience incomplete or no response to bevacizumab may be predisposed to early bevacizumab treatment failure. However, the addition of TTFields therapy may augment the efficacy from bevacizumab. We report a patient with recurrent cystic glioblastoma who received add-on TTFields therapy due to an incomplete response to single-agent bevacizumab. After 6 cycles of therapy, a resolution of cystic enhancement was noted, together with reduction of the tumor cyst and resolution of most of the cerebral edema in the surrounding brain. However, the patient also suffered from relapsed disease at locations distant from the original glioblastoma and the corresponding radiation fields received at initial diagnosis. We conclude that combination TTFields and bevacizumab therapy is safe and may be efficacious for patients with recurrent glioblastoma. A further study would be needed to determine the relapse pattern and the distribution of the electric fields in the brain.
RESUMEN
The NovoTTF-100A System (NovoTTF™ Therapy, Novocure Inc.) is a device that delivers alternating electric fields (TTFields) to tumor cells and interferes with mitosis. It is approved for use as monotherapy for the treatment of recurrent glioblastoma (rGB). TTFields are delivered through insulated transducer arrays applied onto the shaved scalp and connected to a battery-operated field generator. The occurrence of dermatologic adverse events (dAEs) is primarily due to the continuous contact between the array-related components and the scalp for periods of 3-4 days (together with other risk factors). These dAEs may include allergic and irritant dermatitis, mechanical lesions, ulcers, and skin infection. The incidence of dAEs in the phase III trial (n = 116) was 16% (2% grade 2, 0% grade 3/4); the post-marketing surveillance program (n = 570) revealed 156 (21.8%) dAEs with some patients reporting more than one event. Prophylactic strategies for dAEs include proper shaving and cleansing of the scalp and array relocation. Treatment-based strategies are AE-specific and include topical or oral antibiotics, topical corticosteroids, and isolation of affected skin areas from adhesives and pressure. The addition of skin care strategies to the NovoTTF-100A System use will maximize adherence to therapy while maintaining quality of life, all of which contribute to the therapeutic benefit of NovoTTF Therapy in rGB.