Rare-16. Case Report: Delayed Development of Pseudoprogression in 2 Glioblastoma Patients Treated With Ttfields
Year: 2017
Type: conference-abstract
Abstract: Pseudoprogression in response to chemoradiation is a recognized problem in treating glioblastoma (GBM) patients. Imaging can show increased T1+C enhancement or FLAIR hyperintensity not associated with histopathological progression. Two indicators for pseudoprogression are positive MGMT methylation status and length of time after initial chemoradiation treatment. Pseudoprogression most commonly occurs 3 months after radiation therapy and can occur up to 6 months later. Tumor treatment fields (TTFields) have been shown to improve progression free and overall survival but has not yet been investigated for its effects on pseudoprogression. We present here the first 2 cases of TTField delayed pseudoprogression. CASE REPORT: Two GBM patients being treated with TTFields showed signs of radiographic progression 5+ months after completing radiation. Patient 1 is a 66-year-old female with a history of breast cancer who presented with new onset seizure. Imaging revealed a right frontal ring-enhancing lesion with diffusely infiltrating FLAIR. Patient 2 is a 47-year-old male with a history of neurofibromatosis and HIV related anal lymphoma. He presented with left sided parasthesia. Imaging found a heterogeneously enhancing right parietal mass. Both patients were diagnosed pathologically with MGMT un-methylated GBM. Chemoradiation treatment was completed followed by temodar (TMZ) plus TTFields. Five and 7 months after radiation treatment, respectively, radiographic progression was noted. A second surgical resection was pathologically evaluated and both cases were discovered to be treatment effect. These are the first 2 known cases of delayed pseudoprogression in patients on adjuvant TMZ with TTFields. Both patients developed new enhancement outside the typical pseudoprogression window and were unlikely candidates given their methylation status. Both patients resumed adjuvant TMZ with TTFields. New contrast enhancement in patients on adjuvant TMZ with TTFields should be interpreted cautiously as it may represent pseudoprogression. Pathologic confirmation of tumor progression should be considered prior to changing treatment.
Source: Neuro-Oncology
Institutions: Medical College of Wisconsin, Froedtert Hospital
Language: English
Subfield: Genetics
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2767221354