MicroPET/CT imaging of an orthotopic model of XXXX @entity463 multiforme and evaluation of pulsed low-dose irradiation.

@entity1 @entity1313 @entity5 @entity19 @entity204 @entity463
PURPOSE: @entity463 ( @entity463 ) is an aggressive @entity5 that typically causes @entity204 due to local progression. To assess a novel low-dose radiotherapy regimen for treating @entity463 , we developed an orthotopic @entity19 model of @entity1 @entity463 and evaluated in vivo treatment efficacy using micro-positron-emission tomography/computed tomography (microPET/CT) @entity5 imaging. METHODS: Orthotopic @entity463 xenografts were established in @entity19 and treated with standard 2-Gy fractionation or 10 0.2-Gy pulses with 3-min interpulse intervals, for 7 consecutive days, for a total dose of 14 Gy. @entity5 growth was quantified weekly using the Flex Triumph (GE Healthcare/Gamma Medica-Ideas, Waukesha, WI) combined PET-single-photon emission CT (SPECT)-CT imaging system and necropsy histopathology. Normal tissue damage was assessed by counting dead neural cells in tissue sections from irradiated fields. RESULTS: @entity5 engraftment efficiency for U87MG cells was 86%. Implanting 0.5 * 10(6) cells produced a 50- to 70-mm(3) @entity5 in 10 to 14 days. A significant correlation was seen between CT-derived @entity5 volume and histopathology-measured volume (p = 0.018). The low-dose 0.2-Gy pulsed regimen produced a significantly longer @entity5 growth delay than standard 2-Gy fractionation (p = 0.045). Less normal neuronal cell @entity204 was observed after the pulsed delivery method (p = 0.004). CONCLUSION: This study successfully demonstrated the feasibility of in vivo @entity1313 imaging and longitudinal assessment of @entity5 growth and treatment response with microPET/CT. Pulsed radiation treatment was more efficacious than the standard fractionated treatment and was associated with less normal tissue damage.
