Multidetector-row cardiac CT: diagnostic value of calcium scoring and CT coronary angiography in patients with symptomatic,but atypical,chest pain

The aim of this study was to investigate the accuracy of multidetector-row cardiac CT (MDCT), calcium scoring (Ca-Sc), and MDCT coronary angiography (MD CTA) in the assessment of coronary atherosclerosis. Thirty-eight patients underwent invasive coronary angiography (CA) and MDCT (collimation 4×1 mm, pitch 1.5 mm, TI 500 ms, 120 kV, 300 mAs, and retrospective ECG-gating). Calcium scoring was calculated for the total coronary artery territory and for RCA, LCA, and LCX separately. The MD CTA served to assess the degree and the localization of stenoses. All findings were compared to invasive coronary angiography. Approximately 68.4% (390 of 570) of all coronary segments could be visualized by MDCT. Correlation coefficient for MD CTA and CA amounted to r=0.58, showing distinct differences for the individual segments. Proximal segments generally showed better correlation (range 0.81–0.77) than medial segments (range 0.91–0.20), distal segments (range 0.55–0.04), or side branches (range 0.76–0.00). Patients with hemodynamically relevant (>75%) stenoses were detected by MD CTA with 72.2% sensitivity (13 of 18) and 100% specificity (20 of 20). For Ca-Sc sensitivity ranged between 94.7% (17 of 18) and 66.7% (12 of 18), specificity between 20% (4 of 20) and 80% (16 of 20) respectively, depending on the prevailing cutoff value. Combination of both methods led to 83.3% sensitivity (15 of 18) and 100% specificity (20 of 20), reaching no level of significance as compared with Ca-Sc (p=0.73) or MD CTA (p=0.23) alone. Calcium scoring as a single method showed highest sensitivity in the detection of coronary atherosclerosis but at the expense of low specificity. In patients with no or moderate calcifications, combination with MD CTA helped to distinctly increase specificity and NPVM. Britten and C. Herzog contributed equally to this study     

Quantitative real-time PCR for quick simultaneous determination of therapy-stratifying markers MYCN amplification, deletion 1p and 11q.

Amplification of the oncogene MYCN as well as deletions in 1p and 11q are important prognostic and in part therapy-stratifying factors in human neuroblastoma. Due to the increasing clinical relevance of these molecular markers, accurate and fast assessment of the status of MYCN, 1p, and 11q is essential. As 2 techniques are recommended to avoid artefacts and to circumvent technical limitations, we developed a real-time q-PCR assay using genomic DNA from frozen and paraffin-embedded tissue as template as an alternative to LOH analyses and Southern blot (SB) and in addition to fluorescence in situ hybridization (FISH). Determination of deletion or amplification was achieved by comparing the copy number of a target gene (TG from the region of interest) to an unaffected reference gene (RG) within the same chromosome. PCR raw data were normalized to a serial dilution standard curve and a ratio TG/RG was created. The ratio to define a deletion was set as 0.5 (= expected ratio 1 TG copy/2 RG copies), the amplification threshold was set as >10.0. Data were compared to results obtained by FISH and were consistent in 10 of 13 (77%) tumors with deletion 1p, 18 of 20 (90%) with deletion 11q, 12 of 12 (100%) with MYCN amplification, and 146 of 151 (97%) samples without any aberration. Three tumors with aberrations in 1p and 2 tumors with aberrations in 11q were detectable by FISH but not by PCR. Three cases indicated a deletion 11q, 1 tumor a deletion 1p by PCR only. Specificity was 98% for 1p and MYCN each and 92% for 11q. Sensitivity was 77% for 1p, 90% for 11q, and 100% for MYCN. The discrepant results were mostly caused by heterogeneous cell populations of the investigated tissue; the use of real-time q-PCR for the detection of chromosomal aberrances in NB enables a fast and reliable assessment of the 3 most relevant chromosomal aberrations simultaneously. As the assay does not require reference tissue, can be performed with small amounts of DNA, and allows the investigation of paraffin-embedded material for the MYCN-status, it can be regarded alternative to LOH or SB analyses and in addition to FISH.     

Pulmonary injury and tumor response after stereotactic body radiotherapy (SBRT): results of a serial follow-up CT study.

PURPOSE: To evaluate the CT morphological pattern of tumor response and pulmonary injury after stereotactic body radiotherapy (SBRT) for early stage non-small lung cancer (NSCLC) and pulmonary metastases. MATERIALS AND METHODS: Seventy patients (lesions n=86) with pulmonary metastases (n=48) or primary early stage NSCLC (n=38) were analyzed. Patients were treated with hypofractionated SBRT (three to eight fractions with a single dose between 6 and 12.5 Gy; n=56) or with radiosurgery (26 Gy; n=30). The pattern and sequence of pulmonary injury and of tumor response was evaluated in 346 follow-up CT studies, 4.9 on average. RESULTS: Symptomatic pneumonitis was observed in 10% after a median interval of 5 months. No pulmonary reaction was observed in most patients 6 weeks after treatment; spotted-streaky condensations were characteristic between 3 months and 6 months. Dense consolidation and retraction started after 9 months and the fibrotic remodelling process continued for years. Ten targets relapsed after a median of 7 months. At 12 months complete response was seen in 43% and the differentiation of residual tumor from pulmonary reaction was not possible in 33%. CONCLUSIONS: A typical sequence of pulmonary reactions was observed without differences between hypofractionated treatment and radiosurgery. Onset of pneumonitis was later compared to conventionally fractionated radiotherapy.