Case report: Fractional brain tumor burden magnetic resonance mapping to assess response to pulsed low-dose-rate radiotherapy in newly-diagnosed glioblastoma. Front Oncol 2022;12:1066191
Date
12/24/2022Pubmed ID
36561526Pubmed Central ID
PMC9763264DOI
10.3389/fonc.2022.1066191Scopus ID
2-s2.0-85144231369 (requires institutional sign-in at Scopus site)Abstract
BACKGROUND: Pulsed low-dose-rate radiotherapy (pLDR) is a commonly used reirradiation technique for recurrent glioma, but its upfront use with temozolomide (TMZ) following primary resection of glioblastoma is currently under investigation. Because standard magnetic resonance imaging (MRI) has limitations in differentiating treatment effect from tumor progression in such applications, perfusion-weighted MRI (PWI) can be used to create fractional tumor burden (FTB) maps to spatially distinguish active tumor from treatment-related effect.
METHODS: We performed PWI prior to re-resection in four patients with glioblastoma who had undergone upfront pLDR concurrent with TMZ who had radiographic suspicion for tumor progression at a median of 3 months (0-5 months or 0-143 days) post-pLDR. The pathologic diagnosis was compared to retrospectively-generated FTB maps.
RESULTS: The median patient age was 55.5 years (50-60 years). All were male with IDH-wild type (n=4) and O6-methylguanine-DNA methyltransferase (MGMT) hypermethylated (n=1) molecular markers. Pathologic diagnosis revealed treatment effect (n=2), a mixture of viable tumor and treatment effect (n=1), or viable tumor (n=1). In 3 of 4 cases, FTB maps were indicative of lesion volumes being comprised predominantly of treatment effect with enhancing tumor volumes comprised of a median of 6.8% vascular tumor (6.4-16.4%).
CONCLUSION: This case series provides insight into the radiographic response to upfront pLDR and TMZ and the role for FTB mapping to distinguish tumor progression from treatment effect prior to redo-surgery and within 20 weeks post-radiation.
Author List
Amidon RF, Santos-Pinheiro F, Straza M, Prah MA, Mueller WM, Krucoff MO, Connelly JM, Kleefisch CJ, Coss DJ, Cochran EJ, Bovi JA, Schultz CJ, Schmainda KMAuthors
Joseph A. Bovi MD Professor in the Radiation Oncology department at Medical College of WisconsinJennifer M. Connelly MD Professor in the Neurology department at Medical College of Wisconsin
Max O. Krucoff MD Assistant Professor in the Neurosurgery department at Medical College of Wisconsin
Wade M. Mueller MD Professor in the Neurosurgery department at Medical College of Wisconsin
Fernando Santos-Pinheiro MD Assistant Professor in the Neurology department at Medical College of Wisconsin
Kathleen M. Schmainda PhD Professor in the Biophysics department at Medical College of Wisconsin
Christopher J. Schultz MD Chair, Professor in the Radiation Oncology department at Medical College of Wisconsin
Michael W. Straza MD, PhD Assistant Professor in the Radiation Oncology department at Medical College of Wisconsin
