Multimodal assessment of early tumor response to chemotherapy: comparison between diffusion-weighted MRI, 1H-MR spectroscopy of choline and USPIO particles targeted at cell death.
NMR Biomed
; 25(4): 514-22, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-21874657
ABSTRACT
The aim of this study was to determine the value of different magnetic resonance (MR) protocols to assess early tumor response to chemotherapy. We used a murine tumor model (TLT) presenting different degrees of response to three different cytotoxic agents. As shown in survival curves, cyclophosphamide (CP) was the most efficient drug followed by 5-fluorouracil (5-FU), whereas the etoposide treatment had little impact on TLT tumors. Three different MR protocols were used at 9.4 Tesla 24 h post-treatment diffusion-weighted (DW)-MRI, choline measurement by (1) H MRS, and contrast-enhanced MRI using ultrasmall iron oxide nanoparticles (USPIO) targeted at phosphatidylserine. Accumulation of contrast agent in apoptotic tumors was monitored by T(2) -weighted images and quantified by EPR spectroscopy. Necrosis and apoptosis were assessed by histology. Large variations were observed in the measurement of choline peak areas and could not be directly correlated to tumor response. Although the targeted USPIO particles were able to significantly differentiate between the efficiency of each cytotoxic agent and best correlated with survival endpoint, they present the main disadvantage of non-specific tumor accumulation, which could be problematic when transferring the method to the clinic. DW-MRI presents a better compromise by combining longitudinal studies with a high dynamic range; however, DW-MRI was unable to show any significant effect for 5-FU. This study illustrates the need for multimodal imaging in assessing tumor response to treatment to compensate for individual limitations.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
/
Colina
/
Dextranos
/
Imagem de Difusão por Ressonância Magnética
/
Nanopartículas de Magnetita
/
Neoplasias Hepáticas
/
Antineoplásicos
Tipo de estudo:
Diagnostic_studies
/
Guideline
/
Observational_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
NMR Biomed
Assunto da revista:
DIAGNOSTICO POR IMAGEM
/
MEDICINA NUCLEAR
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Bélgica