This necessitated reevaluation of the position of the chosen seed points and

repositioning check details into aerated parts of the lungs. This way tumour burden and growth was assessed quantitatively using the decrease in aerated lung volume as a surrogate. The initial increase in lung volume in the first 4 months was attributed to normal growth. In the comparatively small group examined here, tumour growth seemed to occur at a later point of time in male animals as compared to Paclitaxel Female animals. Female animals showed clinical signs of tumour necessitating sacrifice earlier compared to male animals. Statistical analysis Repeated measurement analysis of the time points 2, 4, 6, 7-13 months showed significant changes of the segmented lung volumes over time (p = 0.009). Interaction of the measurements was rejected (p = 0.035). Testing for group differences did not show significant results, due to the small number of animals and the spread of lung volume at early time points in normal animals. Analysis of time points 8 to 13 months, when tumour progression occurs, showed significant group differences (p = 0.043). Linear regression analysis yielded equation 1 to calculate lung volume. The correlation coefficient was determined as R = 0.538. BVD-523 supplier (1) Discussion In this study we examined the tumour growth kinetics of SPC-raf transgenic mice by serial micro-CT examinations.

Small animal imaging allows assessment using each animal as its own control in follow-up examinations. Given the relevant inter-individual spread it has the potential to optimize studies. To prevent intra-individual spread sophisticated imaging and post-processing techniques have to be established as elaborated below. An advantage of imaging especially in diffuse or multifocal pathologies is that the entire volume can be assessed additional to circumscribed areas of sectional histopathology obtained. Very few studies on follow-up micro-CT examination have been performed in transgenic murine models of lung cancer (mainly K-ras transgenic) [12–14]. Other groups performed follow-up examination in single lesions caused by intrapulmonary injection of tumour cells

or several/multiple lesions initiated by intraperitoneal injection of urethane [15–17]. To the best of our knowledge, no report on micro-CT assessment of tumour Docetaxel growth kinetics in the SPC-raf transgenic lung tumour mouse model has been published so far. Furthermore, the follow-up exams reported did usually include only a limited number of imaging time points as compared to up to 15 time points in this study, allowing a more detailed assessment of growth kinetics. Further studies have shown the use of micro-CT for the detection of primary lung tumours or pulmonary metastases without a follow-up being performed [7, 18]. All the various imaging approaches of murine animal models of human lung tumour have different advantages and disadvantages.