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The purpose of this study was to assess mammographic and sonographic findings in a long-term follow-up (>or=3 years) after breast-conserving surgery (BCS) and IORT, either applied as boost or exclusively. Follow-up-findings of 54 patients were retrospectively evaluated and compared to a control group of 48 patients, treated with BCS and whole-breast radiotherapy. After IORT patients had a higher incidence of fat necroses manifesting as oil cysts in the late follow-up mammograms (n = 31 vs n = 8); furthermore, oil cysts were larger in the IORT group (median 4.5 vs 1.4 cm(2)). In 25 IORT patients the oil cysts arose from partially organized hematomas/seromas, which in this group were generally more frequent (n = 38 vs n = 9) and larger (median 3.6 vs 1.8 cm(2)). After IORT a decreasing incidence of hematomas/seromas was reciprocal to an increasing incidence of oil cysts, and the size of both entities correlated with each other. Liquid lesions with polypoid inner wall thickening on ultrasound, attributed to organized hematomas/seromas or fat necroses, appear more frequently after IORT (n = 15 vs n = 1). In conclusion, IORT is associated with a high incidence of large oil cysts, which arise from likewise large partially organized wound cavities. On ultrasound pronounced partial organization with polypoid inner wall thickening is a frequent finding in those cavities.

Aggressive cancer cells show histological similarities to embryonic stem cells. As differentiated cells can re-acquire pluripotency and self-renewal by transfection with the transcription factors OCT4, SOX2, KLF4 and MYC, with Nanog as readout for success, we comprehensively investigated their occurrence and frequency in human astrocytomas of different malignancy grades, primary and matched recurrent glioblastomas, short- and long-term glioblastoma cultures and glioma cell lines. Among astrocytomas, mRNA expression of OCT4, MYC and (less robust) KLF4 increased with malignancy, while in recurrent glioblastomas MYC expression slightly decreased. Correlation analysis revealed distinct positive correlation between distinct stem cell markers, and this effect was most prominent in the recurrent glioblastoma cohort. In situ, embryonic stem cell factors were found also in more differentiated tumor regions. Respective cells were rarely actively proliferating and showed single or combined expression signatures, which, at least in parts, corresponded to observed positive correlations of mRNA expression. However, a 'master-marker' defining the complete glioma stem cell subset could not be confirmed. In glioma cell lines, long- and short-term cultures, embryonic markers were detected at comparable levels. Upon exposure to temozolomide, increased expression of KLF4 (and lesser Nanog and OCT4) was observed. Experimental intrinsic overexpression of SOX2, KLF4 or OCT4 did not affect the other stem cell factors. The embryonic stem cell factors comprehensively investigated in this project can control self-renewal and pluripotency, and therefore tumorigenicity. They should be considered for the development of future diagnostic and therapeutic strategies.

Intraoperative radiotherapy (IORT) with low-energy x-rays is increasingly used in breast-conserving therapy (BCT). Previous non-randomized studies have observed mammographic changes in the tumor bed to be more pronounced after IORT. The purpose of this study was to reassess the postoperative changes in a randomized single-center subgroup of patients from a multicenter trial (TARGIT-A). In this subgroup (n = 48) 27 patients received BCT with IORT, 21 patients had BCT with standard whole-breast radiotherapy serving as controls. Overall 258 postoperative mammograms (median follow-up 4.3 years, range 3-8) were retrospectively evaluated by two radiologists in consensus focusing on changes in the tumor bed. Fat necroses showed to be significantly more frequent (56% versus 24%) and larger (8.7 versus 1.6 sq cm, median) after IORT than those in controls. Scar calcifications were also significantly more frequent after IORT (63% versus 19%). The high incidence of large fat necroses in our study confirms previous study findings. However, the overall higher incidence of calcifications in the tumor bed after IORT represents a new finding, requiring further attention.

Radial trajectories facilitate high-resolution balanced steady state free precession (bSSFP) because the efficient gradients provide more time to extend the trajectory in k-space. A number of radial bSSFP methods that support fat-water separation have been developed; however, most of these methods require an environment with limited B0 inhomogeneity. In this work, high-resolution bSSFP with fat-water separation is achieved in more challenging B0 environments by combining a 3D radial trajectory with the IDEAL chemical species separation method. A method to maintain very high resolution within the timing constraints of bSSFP and IDEAL is described using a dual-pass pulse sequence. The sampling of a unique set of radial lines at each echo time is investigated as a means to circumvent the longer scan time that IDEAL incurs as a multi-echo acquisition. The manifestation of undersampling artifacts in this trajectory and their effect on chemical species separation are investigated in comparison to the case in which each echo samples the same set of radial lines. This new bSSFP method achieves 0.63 mm isotropic resolution in a 5-minute scan and is demonstrated in difficult in vivo imaging environments, including the breast and a knee with ACL reconstruction hardware at 1.5 T.

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