PURPOSE: To evaluate the ability of 11C-methionine positron emission tomography (MET-PET) to delineate target volumes for brain metastases and to investigate to what extent tumor growth is presented by magnetic resonance imaging (MRI) and MET-PET. MATERIALS AND METHODS: Three observers undertook target definition in 19 patients with 95 brain metastases by MRI and MET-PET images. MRI gross target volume (GTV) (GTV-MRI) was defined as the contrast-enhanced area on gadolinium-enhanced T1-weighted MRI. MET-PET GTV (GTV-PET) was defined as the area of an accumulation of MET-PET apparently higher than that of normal tissue on MET-PET images. The size of occupation ratio was determined using the following equation: SOR (%) of MET are within x mm margin outside GTV-MRI = the volume of the GTV-PET within x mm outside the GTV-MRI/the volume of the GTV-PET. RESULTS: For GTV-MRI volumes of <or=0.5 mL, the sensitivity of tumor detection by MET-PET was 43%. For GTV-MRI volume of >0.5 mL, GTV-PET volumes were larger than GTV-MRI volumes and a significant correlation was found between these variables by linear regression. For all tumor sizes and tumor characteristics, a 2-mm margin outside the GTV-MRI significantly improved the coverage of the GTV-PET. CONCLUSIONS: Although there were some limitations in our study associated with spatial resolution, blurring effect, and image registrations with PET images, MET-PET was supposed to have a potential as a promising tool for the precise delineation of target volumes in radiotherapy planning for brain metastases.
PURPOSE: To evaluate the ability of 11C-methionine positron emission tomography (MET-PET) to delineate target volumes for brain metastases and to investigate to what extent tumor growth is presented by magnetic resonance imaging (MRI) and MET-PET. MATERIALS AND METHODS: Three observers undertook target definition in 19 patients with 95 brain metastases by MRI and MET-PET images. MRI gross target volume (GTV) (GTV-MRI) was defined as the contrast-enhanced area on gadolinium-enhanced T1-weighted MRI. MET-PET GTV (GTV-PET) was defined as the area of an accumulation of MET-PET apparently higher than that of normal tissue on MET-PET images. The size of occupation ratio was determined using the following equation: SOR (%) of MET are within x mm margin outside GTV-MRI = the volume of the GTV-PET within x mm outside the GTV-MRI/the volume of the GTV-PET. RESULTS: For GTV-MRI volumes of <or=0.5 mL, the sensitivity of tumor detection by MET-PET was 43%. For GTV-MRI volume of >0.5 mL, GTV-PET volumes were larger than GTV-MRI volumes and a significant correlation was found between these variables by linear regression. For all tumor sizes and tumor characteristics, a 2-mm margin outside the GTV-MRI significantly improved the coverage of the GTV-PET. CONCLUSIONS: Although there were some limitations in our study associated with spatial resolution, blurring effect, and image registrations with PET images, MET-PET was supposed to have a potential as a promising tool for the precise delineation of target volumes in radiotherapy planning for brain metastases.
Authors: Andor W J M Glaudemans; Roelien H Enting; Mart A A M Heesters; Rudi A J O Dierckx; Ronald W J van Rheenen; Annemiek M E Walenkamp; Riemer H J A Slart Journal: Eur J Nucl Med Mol Imaging Date: 2012-12-12 Impact factor: 9.236
Authors: David O Kamson; Sandeep Mittal; Amy Buth; Otto Muzik; William J Kupsky; Natasha L Robinette; Geoffrey R Barger; Csaba Juhász Journal: Mol Imaging Date: 2013 Jul-Aug Impact factor: 4.488