Pre-irradiation tumour volumes defined by MRI and dual time-point FET-PET for the prediction of glioblastoma multiforme recurrence: A prospective study. Issue 2 (August 2016)

• Record Type: Journal Article
• Authors: Harat, Maciej; Małkowski, Bogdan; Makarewicz, Roman
• Is Part Of: Radiotherapy and oncology. Volume 120:Issue 2(2016:Aug.)
• Page Start: 241
• Page End: 247
• Publication Date: 2016-08
• Subjects: Glioblastoma multiforme -- FET-PET -- MRI -- Tumour volume -- Radiotherapy; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2016.06.004
• Languages: English
• ISSNs: 0167-8140

Abstract

Abstract: Background and purpose: The diagnostic accuracy of magnetic resonance imaging (MRI) for glioblastoma multiforme (GBM) is suboptimal. We analysed pre-treatment MRI- and dual time-point 18F-fluoroethylthyrosine-PET (FET-PET)-based target volumes and GBM recurrence patterns following radiotherapy with temozolomide. Materials and methods: Thirty-four patients with primary GBM were treated according to MRI-based treatment volumes (GTVRM ). Patients underwent dual time-point FET-PET scans prior to treatment, and biological tumour volumes (GTVPET ) were contoured but not used for target definition. Progressions were classified based on location of primary GTVs. Volume and uniformity of MRI- vs. FET-PET/CT-derived GTVs and progression patterns assessed by MRI were analysed. Results: FET-based GTVs measured 10 min after radionuclide injection (a.r.i.; median 37.3 cm 3 ) were larger than GTVs measured 60 min a.r.i. (median 27.7 cm 3 ). GTVPET volumes were significantly larger than corresponding MRI-based GTVs. MRI and PET concordance for the identification of glioblastoma GTVs was poor (mean uniformity index 0.4). 74% of failures were inside primary GTVPET volumes, with no solitary progressions inside the MRI-defined margin +20 mm but outside the GTVPET detected. Conclusions: The size and geometry of GTVs differed in the majority of patients. The GTVPET volume depends on time after radionuclide injection. FET-PET better defined failure site than MRI alone.