H. Bolte

Correlation between p53, c-erbB-2, and topoisomerase II alpha expression, DNA ploidy, hormonal receptor status and proliferation in 356 node-negative breast carcinomas: prognostic implications

Various new prognostic indicators have been identified for mammary carcinomas, but the issue of their significance remains unsettled. The prognostic impact of p53, c‐erbB‐2, and topoisomerase IIα expression was investigated in relation to standard prognostic factors for carcinomas of the breast and to the tumour cell growth fraction. Paraffin‐embedded specimens of 356 node‐negative infiltrating ductal carcinomas were stained immunohistochemically using a polyclonal antiserum to c‐erb B‐2, and the monoclonal antibodies DO‐1 (p53), Ki‐S4 (topoisomerase IIα), and Ki‐S5 (Ki‐67). The patients were followed for a median duration of 99 months. Both p53 and c‐erb B‐2 were significantly associated with high tumour grade, large tumour size, DNA aneuploidy, lack of steroid hormone receptors, young age, and increased topoisomerase IIα and Ki‐67 expression levels. The correlation of p53 and c‐erb B‐2 was not significant. Topoisomerase IIα and Ki‐67 scores closely paralleled each other, indicating that both reflect the proliferative activity of tumour cells. A univariate analysis of overall (OS), specific (SS), and disease‐free survival (DFS) revealed all the above‐mentioned parameters to be statistically significant except patient age, which was relevant only to overall survival. Multivariate analysis with inclusion of all covariates selected tumour size and proliferation (topoisomerase IIα and Ki‐67) indices as independent predictors of survival in all three models. No additional information was gained by p53 or c‐erb B‐2. It is concluded that the proliferative activity, as assessed by topoisomerase IIα or Ki‐67 immunostaining, is the most useful indicator of breast cancer prognosis, except for tumour size. Copyright

Endocultivation: 3D printed customized porous scaffolds for heterotopic bone induction

The aim of this study was to evaluate the ability of computer assisted designed (CAD) synthetic hydroxyapatite and tricalciumphosphate blocks to serve as precise scaffolds for intramuscular bone induction in a rat model. A central channel to allow for vessel pedicle or nerve integration was added. Natural bovine hydroxyapatite blocks served as controls to evaluate and compare biocompatibility of the new matrices. Individually designed 3D-printed rounded and porous hydroxyapatite (HA) and tricalcium phosphate (TCP) blocks were placed in pouches in the Musculus latissimus dorsi in 12 Lewis rats bilaterally. Bovine hydroxyapatite blocks with and without a central channel served as controls. Simultaneously, 200 microg rhBMP-2 in 1 ml sodium chloride was injected on both sides. For 8 weeks, bone generation was monitored by computer tomography and fluorescence labeling. The increase rates of bone density in CT examinations were higher in the HA groups (184-220 HU 8 weeks after implantation) compared to the TCP group (18 HU; p<0.0001). Microradiography and fluorescence microscopy 8 weeks after implantation showed new bone formation for all materials tested. For all scaffolds, toluidine staining revealed vital bone directly on the scaffold materials but also in the gaps between. It can be concluded from our data that the specially shaped hydroxyapatite and tricalcium phosphate blocks tested against the bovine hydroxyapatite blocks showed good biocompatibility and osteoinductivity in vivo. Further studies should explore if the stability of the individually designed blocks is sufficient to cultivate larger replacements without an external matrix for support.

Reproducibility of computer-aided volumetry of artificial small pulmonary nodules in ex vivo porcine lungs

Objective:The main purpose of this study was to investigate the reproducibility of computed tomography (CT)-based volumetric measurements of small pulmonary nodules. Methods:We implanted 70 artificial pulmonary nodules in 5 ex vivo porcine lungs in a dedicated chest phantom. The lungs were scanned 5 times consecutively with multislice-CT (collimation 16 × 0.75 mm, slice thickness 1 mm, reconstruction increment 0.7 mm). A commercial software package was used for lesion volumetry. The authors differentiated between intrascan reproducibility, interscan reproducibility, and results from semiautomatic and postprocessed volumetry. Results:Analysis of intrascan reproducibility revealed a mean variation coefficient of 6.2% for semiautomatic volumetry and of 0.7% for human adapted volumetry. For interscan reproducibility a mean variation coefficient of 9.2% and for human adapted volumetry a mean of 3.7% was detected. Conclusion:The presented volumetry software showed a high reproducibility that can be expected to detect nodule growth with a high degree of certainty.

Endocultivation: the influence of delayed vs. simultaneous application of BMP-2 onto individually formed hydroxyapatite matrices for heterotopic bone induction

When bone morphogenetic protein (BMP) is delivered to matrices in vivo may affect tissue engineered bone constructs for jaw reconstruction after cancer surgery. This study compared the effects of BMP application at different times after matrix implantation for heterotopic bone induction in a rat model. Hydroxyapatite blocks were implanted unilaterally onto the surface of the latissimus dorsi muscle. A second block was implanted onto the contralateral muscle after 1, 2 or 4 weeks and 200 μg rhBMP-2 was injected into the blocks on both sides. Bone formation and density inside the blocks was analysed by CT and histology. 8 weeks after BMP application increases in bone density within the scaffolds were most pronounced in the simultaneous application group (179 HU). Less pronounced increases were observed for the 1 (65 HU), 2 (58 HU) and 4 (31 HU; p<0.0001) week delay group. Homogeneous bone induction started from the central channel of the blocks. Capillaries and larger vessels were seen in all constructs, samples receiving delayed BMP treatment demonstrated significantly greater neovascularization. Delayed application of BMP was less effective for heterotopic bone formation than simultaneous application. A central channel allows homogeneous bone induction directly from the centre of the blocks.

Prospective, Randomized Single-center Trial to Compare Cryoplasty versus Conventional Angioplasty in the Popliteal Artery: Midterm Results of the COLD Study

PURPOSE To evaluate safety and efficacy of cryoplasty versus conventional angioplasty for focal popliteal arterial occlusive disease. MATERIALS AND METHODS Patients with focal atherosclerotic stenoses and occlusions of the popliteal artery were randomized to cryoplasty or conventional angioplasty as the initial treatment strategy. The primary objective was target lesion patency. The secondary endpoint was treatment success without the need for stents. Duplex ultrasonography was performed at 3, 6, 9, and 15 months. RESULTS Eighty-six patients (mean age, 72 years; age range, 50-94 years) were enrolled in this study. Forty patients were randomized to cryoplasty and 46 to conventional angioplasty. Demographics, risk factors, clinical stage of disease, and lesion details were comparable. On intention-to-treat basis, initial success was 35% for cryoplasty versus 54% for conventional angioplasty (P = .02). The rate of grade C dissection was 35% after cryoplasty and 26% after conventional angioplasty (P = .4). Optional long-term percutaneous transluminal angioplasty (PTA) was performed in 58% of cryoplasty patients. The rate of stent placement for dissection and/or residual stenosis was 30% after cryoplasty (including long-term dilation) and 39% after conventional angioplasty (P = .34). The mean (+/-standard deviation) target lesion patency at 9 months was 79.3% +/- 7.5 for cryoplasty and 66.7% +/-8.1 for conventional angioplasty; however, the results are not significant (P = .14). CONCLUSIONS Cryoplasty of the popliteal artery alone showed a lower anatomic success when compared with conventional angioplasty. Combined with optional long-term PTA, however, stent placement was not needed more often. There was a trend toward higher patency after cryoplasty, but differences were not statistically significant and results of long-term follow-up have to be awaited.

4D-Imaging of the Lung: Reproducibility of Lesion Size and Displacement on Helical CT, MRI, and Cone Beam CT in a Ventilated Ex Vivo System

PURPOSE Four-dimensional (4D) imaging is a key to motion-adapted radiotherapy of lung tumors. We evaluated in a ventilated ex vivo system how size and displacement of artificial pulmonary nodules are reproduced with helical 4D-CT, 4D-MRI, and linac-integrated cone beam CT (CBCT). METHODS AND MATERIALS Four porcine lungs with 18 agarose nodules (mean diameters 1.3-1.9 cm), were ventilated inside a chest phantom at 8/min and subject to 4D-CT (collimation 24 x 1.2 mm, pitch 0.1, slice/increment 24 x 10(2)/1.5/0.8 mm, pitch 0.1, temporal resolution 0.5 s), 4D-MRI (echo-shared dynamic three-dimensional-flash; repetition/echo time 2.13/0.72 ms, voxel size 2.7 x 2.7 x 4.0 mm, temporal resolution 1.4 s) and linac-integrated 4D-CBCT (720 projections, 3-min rotation, temporal resolution approximately 1 s). Static CT without respiration served as control. Three observers recorded lesion size (RECIST-diameters x/y/z) and axial displacement. Interobserver- and interphase-variation coefficients (IO/IP VC) of measurements indicated reproducibility. RESULTS Mean x/y/z lesion diameters in cm were equal on static and dynamic CT (1.88/1.87; 1.30/1.39; 1.71/1.73; p > 0.05), but appeared larger on MRI and CBCT (2.06/1.95 [p < 0.05 vs. CT]; 1.47/1.28 [MRI vs. CT/CBCT p < 0.05]; 1.86/1.83 [CT vs. CBCT p < 0.05]). Interobserver-VC for lesion sizes were 2.54-4.47% (CT), 2.29-4.48% (4D-CT); 5.44-6.22% (MRI) and 4.86-6.97% (CBCT). Interphase-VC for lesion sizes ranged from 2.28% (4D-CT) to 10.0% (CBCT). Mean displacement in cm decreased from static CT (1.65) to 4D-CT (1.40), CBCT (1.23) and MRI (1.16). CONCLUSIONS Lesion sizes are exactly reproduced with 4D-CT but overestimated on 4D-MRI and CBCT with a larger variability due to limited temporal and spatial resolution. All 4D-modalities underestimate lesion displacement.

Total Percutaneous Endovascular Aneurysm Repair with the Dual 6-F Perclose-AT Preclosing Technique: A Case-control Study

PURPOSE To determine the safety and efficacy of total percutaneous access closure for endovascular aortic aneurysm repair with a suture-mediated preclosing technique. MATERIALS AND METHODS One hundred thirty-two femoral access sites in 70 patients who underwent endovascular aortic aneurysm repair were closed percutaneously with off-label use of two F-6 Perclose AT devices preapplied at a 90 degrees angle. Femoral access sizes ranged from 12 to 24 F. Technical success, complications, and procedure and access closure times were evaluated. Follow-up with computed tomography and/or magnetic resonance imaging was scheduled at 1-4 days and 3, 6, and 12 months and used to obtain groin hematoma and scar severity scores (grades 1-3). Data were compared with those from a cohort of 67 patients who underwent endovascular aortic aneurysm repair with surgical femoral cutdown. RESULTS Technical success was achieved with the preclosing technique in 127 of the 132 arteries (96.2%). Two to four closure devices were used per groin. Five technical failures were managed intraoperatively with surgical suture. There was no access-related mortality and no late groin complications. The mean procedure duration was 91 minutes +/- 32, and the mean access closure time was 12 minutes +/- 9. For surgical management, the mean procedure time was 153 minutes +/- 112 (P < .05), and the mean closure time was 12 minutes +/- 13 (not statistically significant). Hematoma severity score at 1-4 days was 1.8 for total percutaneous endovascular aneurysm repair and 2.1 for surgical closure. Scar severity scores at 3, 6, and 12 months were 1.1, 1.0, and 1.0 for total percutaneous endovascular aneurysm repair and 2.4, 2.4, and 2.3 for surgical management, respectively. CONCLUSIONS Total percutaneous endovascular aneurysm repair with a dual 6-F-Perclose preclosing technique is safe and effective. Compared with femoral cutdown, there are fewer late groin complications and scar tissue formation is less severe.

Endocultivation: Does delayed application of BMP improve intramuscular heterotopic bone formation?

INTRODUCTION The time point of Bone morphogenetic protein (BMP) delivery on matrices in vivo may play an important role. Delayed application could be advantageous as this would allow soft tissue (ST) ingrowth and vascularisation of scaffolds prior to BMP-loading. The aim of this study was to compare the application of BMP injected simultaneously during matrix implantation with delayed application four weeks after matrix implantation for endocultivation in a rat model. MATERIAL AND METHODS Bovine hydroxyapatite blocks were placed in pouches in the Musculus latissimus dorsi in 6 Lewis rats unilaterally to allow for soft tissue ingrowth. Four weeks later, a second block was inserted on the contralateral side of each rat. At that time point, 100microg rhBMP-2 in 2ml sodium chloride was injected on both sides to induce bone formation. For eight weeks, bone regeneration was monitored by computed tomography (CT) and fluorescent labelling. RESULTS The simultaneous and delayed BMP application groups were significantly different (p=0.01). Slightly lower bone densities were seen for the delayed BMP application with a mean of 588 Hounsfield Units (HU) (standard deviation (SD) 30HU). Simultaneous BMP application revealed slightly higher densities with a mean of 633HU (SD 30HU). The largest differences were observed when comparing bone density directly after implantation or at the end of the observation period (p<0.0001). CONCLUSION Bone density was slightly lower in the case of delayed application of BMP-2. The increase of bone density after application of BMP-2 was similar for both groups. Thus, delayed application of BMP had no advantageous effect in this particular study design. Further studies are needed to explore if varying delays, different material designs or special BMP application devices may alter these results.

Low-profile Stent Placement with the Monorail Technique for Treatment of Renal Artery Stenosis: Midterm Results of a Prospective Trial

PURPOSE To determine feasibility, safety, and midterm patency of a monorail balloon stent device for the treatment of renal artery stenosis (RAS). MATERIALS AND METHODS During a period of 30 months, 47 patients (with severe hypertension, n=45; renal insufficiency, n=20) with 50 cases of RAS and indications for stent implantation (calcified ostial lesion, n=41; insufficient percutaneous transluminal angioplasty, n=6; dissection, n=3) were enrolled into the prospective evaluation. After predilation, 59 stents (Rx-Herculink 4 mm, n=2; 5 mm, n=19; 6 mm, n=35; 7 mm, n=3) were implanted under manometer control with use of the long-sheath technique (5 F; 6 F for 7-mm stents) via a femoral (n=44) or transbrachial approach (n=6). Parameters of hypertension and renal insufficiency were determined before and after the procedure and for a maximum of 18 months. Restenosis rate was determined with color duplex ultrasonography. RESULTS Renal artery stent placement (mean diameter, 5.7 mm; mean length, 16 mm) was technically successful in all cases (100%). Mean blood pressure and serum creatinine level decreased from 177/93 mm Hg to 145/78 mm Hg and from 1.8 mg/dL to 1.5 mg/dL, respectively. Within 48 hours after the implantation, acute occlusions occurred in two patients, supposedly triggered by cholesterol embolization. Primary and primary assisted patency rates were 87% and 92% at 6 months and 75% and 84% at 18 months. CONCLUSIONS Renal artery stent placement with the rapid-exchange monorail system is a safe procedure with promising patency rates. In combination with the long-sheath technique, adequate control of stent deployment is guaranteed during the entire intervention. The low profile of the device facilitates the use of small sheaths (5 F) to minimize access-site complications.

Evaluation of Ultra-Low Dose CT in the Diagnosis of Pediatric-Like Fractures Using an Experimental Animal Study

Objective The aim of this prospective study was to evaluate the performance of ultra-low dose CT for the diagnosis of pediatric-like fractures and ascertain the lowest dose level sufficient for diagnostics. Materials and Methods Fifty-one bones of young pig cadavers were artificially fractured and subsequently examined by using a 64 multi-detector CT with 36 various dose levels down to a dose comparable with that of X-rays. Two pediatric radiologists analysed the CT scans according to the presence or absence of a fracture, determination of the fracture type and the displacement as well as the diagnostic certainty. For each dose protocol, a success rate for the correct determination of the above-mentioned CT analyses was calculated. A success rate of at least 95% was considered sufficient for diagnostics. Results All but the lowest dose levels were sufficient to identify the fracture. Only the two lowest dose levels were insufficient to detect the fracture type. All dose levels were adequate for the identification of the displacement. The lowest dose level sufficient for diagnostics was 120 kVp, 11 mAs, and pitch 1.5, with a CTDIvol of 10% of a standard dose and an effective dose three times as large as that of X-rays. Conclusion Ultra-low dose CT provides the feasibility of a significant dose reduction, still allowing sufficient diagnostics of pediatric-like fractures.