Margin reduction in radiotherapy for glioblastoma through 18F-fluoroethyltyrosine PET? – A recurrence pattern analysis

Fleischmann DF, Unterrainer M, Schön R, Corradini S, Maihöfer C, Bartenstein P, Belka C, Albert NL, Niyazi M (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Radiotherapy and Oncology Elsevier

Book Volume: 145

Pages Range: 49-55

DOI: 10.1016/j.radonc.2019.12.005

Abstract

Background and purpose: 18F-fluoroethyltyrosine (18F-FET) PET is increasingly used in radiation treatment planning for the primary treatment of glioblastoma (GBM) patients additionally to contrast-enhanced MRI. To answer the question, whether a margin reduction in the primary treatment setting could be achieved through 18F-FET PET imaging, a recurrence pattern analysis was performed. Patients and methods: GBM patients undergoing 18F-FET PET examination before primary radiochemotherapy from 05/2009 to 11/2014 were included into the recurrence pattern analysis. Biological tumour volumes were semi-automatically created and fused with MR-based gross tumour volumes (MRGTVs). The pattern of recurrence was examined for MRGTVs and for PET-MRGTVs. The minimal margin including all recurrent tumour sites was assessed by gradual expansion of the PET-MRGTVs and MRGTVs until inclusion of all contrast-enhancing areas at recurrence. Results: 36 GBM patients were included to the analysis. The minimal margin including all contrast enhancing tumour at recurrence was significantly smaller for the PET-MRGTVs compared to the MRGTVs (median 12.5 mm vs. 16.5 mm; p < 0.001, Wilcoxon-Test). PET-MRGTVs with 15 mm CTV margins were significantly smaller than MRGTVs with 20 mm CTV margins (median volume 255.92 vs. 258.35 cm3; p = 0.020, Wilcoxon-Test; excluding 3 cases with large non-contrast enhancing tumours). The pattern of recurrence of PET-MRGTVs with 15 mm CTV margins was comparable to MRGTVs with 20 mm CTV margins (32 vs. 30 central, 2 vs. 4 in-field, 2 vs. 2 ex-field and no marginal recurrences). Conclusion: Target volume delineation of GBM patients can be improved through 18F-FET PET imaging prior to primary radiation treatment, since vital tumour can be detected more accurately. Furthermore, the results suggest that CTV margins could be reduced through 18F-FET PET imaging prior to primary RT of GBM.

Involved external institutions

Klinikum der Universität München (LMU Klinikum) DE Germany (DE) Deutsches Krebsforschungszentrum (DKFZ) DE Germany (DE)

How to cite

APA:

Fleischmann, D.F., Unterrainer, M., Schön, R., Corradini, S., Maihöfer, C., Bartenstein, P.,... Niyazi, M. (2020). Margin reduction in radiotherapy for glioblastoma through 18F-fluoroethyltyrosine PET? – A recurrence pattern analysis. Radiotherapy and Oncology, 145, 49-55. https://doi.org/10.1016/j.radonc.2019.12.005

MLA:

Fleischmann, Daniel F., et al. "Margin reduction in radiotherapy for glioblastoma through 18F-fluoroethyltyrosine PET? – A recurrence pattern analysis." Radiotherapy and Oncology 145 (2020): 49-55.

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