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

Fleischmann, Daniel F.; Unterrainer, Marcus; Schoen, Rudolph; Corradini, Stefanie; Maihoefer, Cornelius; Bartenstein, Peter; Belka, Claus; Albert, Nathalie L. und Niyazi, Maximilian (2020): Margin reduction in radiotherapy for glioblastoma through F-18-fluoroethyltyrosine PET? - A recurrence pattern analysis. In: Radiotherapy and Oncology, Bd. 145: S. 49-55

Abstract

Background and purpose: F-18-fluoroethyltyrosine (F-18-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 F-18-FET PET imaging, a recurrence pattern analysis was performed. Patients and methods: GBM patients undergoing F-18-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 cm(3);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 F-18-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 F-18-FET PET imaging prior to primary RT of GBM.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0167-8140
• Sprache: Englisch