Value of diffusion weighted MR imaging as an early surrogate parameter for evaluation of tumor response to high-dose-rate brachytherapy of colorectal liver metastases

<p>Abstract</p> <p>Background</p> <p>To assess the value of diffusion weighted imaging (DWI) as an early surrogate parameter for treatment response of colorectal liver metastases to image-guided single-fraction ¹⁹²Ir-high-dose-rate brachytherapy (HDR-BT).</p> <p>Methods</p> <p>Thirty patients with a total of 43 metastases underwent CT- or MRI-guided HDR-BT. In 13 of these patients a total of 15 additional lesions were identified, which were not treated at the initial session and served for comparison. Magnetic resonance imaging (MRI) including breathhold echoplanar DWI sequences was performed prior to therapy (baseline MRI), 2 days after HDR-BT (early MRI) as well as after 3 months (follow-up MRI). Tumor volume (TV) and intratumoral apparent diffusion coefficient (ADC) were measured independently by two radiologists. Statistical analysis was performed using univariate comparison, ANOVA and paired t test as well as Pearson's correlation.</p> <p>Results</p> <p>At early MRI no changes of TV and ADC were found for non-treated colorectal liver metastases. In contrast, mean TV of liver lesions treated with HDR-BT increased by 8.8% (<it>p </it>= 0.054) while mean tumor ADC decreased significantly by 11.4% (<it>p </it>< 0.001). At follow-up MRI mean TV of non-treated metastases increased by 50.8% (<it>p </it>= 0.027) without significant change of mean ADC values. In contrast, mean TV of treated lesions decreased by 47.0% (<it>p </it>= 0.026) while the mean ADC increased inversely by 28.6% compared to baseline values (<it>p </it>< 0.001; Pearson's correlation coefficient of r = -0.257; p < 0.001).</p> <p>Conclusions</p> <p>DWI is a promising imaging biomarker for early prediction of tumor response in patients with colorectal liver metastases treated with HDR-BT, yet the optimal interval between therapy and early follow-up needs to be elucidated.</p

Le musée d’histoire en France entre traditions nationales et soucis identitaires

The museums of history have known some spectacular changes in contemporary\ud France for two decades. New buildings have been constructed, and a lot of old ones have\ud been renovated. The study of some specific cases, for example the museums devoted to the\ud history of World War II, or to the history of migrations, demonstrates how museology is\ud nowadays far from the pure illustration of erudite knowledge. The ideal museum of french\ud history is today a museum very concerned by the present state of affairs, the political agenda\ud or the social agency. Its aims are linked to the consciousness of « heritage » in the contemporary\ud society. One difficulty is not to becoming a commercial product, a kind of entertainment, or of\ud « edutainment » for kids. The challenge is to play the role of a place of memory, or even to\ud figure a tool for collective thinking about the new stakes of national identity