To determine the diagnostic performance of diffusion-weighted (DW) imaging for the prediction of treatment failure in primary head and neck squamous cell carcinoma (HNSCC).
The study was approved by ...the local institutional ethics committee and conducted with informed written consent in patients with primary HNSCC treated with radiation therapy and chemotherapy. DW imaging of the primary tumor was performed before treatment in 37 patients and was repeated within 2 weeks of treatment in 30 patients. Histograms of apparent diffusion coefficients (ADCs) were analyzed, and mean ADC, kurtosis, skewness, and their respective percentage change were correlated for local failure and local control at 2 years by using the Student t test. Univariate and multivariate analyses of the ADC parameters, T stage, and tumor volume were performed by using logistic regression for prediction of local failure.
Local failure occurred in 16 of 37 (43%) patients and local control occurred in 21 of 37 (57%) patients. Pretreatment ADC parameters showed no correlation with local failure. There was significant intratreatment increase in mean ADC and a decrease in skewness and kurtosis (P < .001, P < .001, P = .024, respectively) for the whole group of patients when compared with those before treatment. During treatment, primary tumors showed a significantly lower increase in percentage change of mean ADC, higher skewness, and higher kurtosis for local failure than for local control (P = .016, .015, and .040, respectively). These ADC parameters also were significant for predicting local failure with use of univariate but not multivariate analysis.
Early intratreatment DW imaging has the potential to allow prediction of treatment response at the primary site in patients with HNSCC.
This study was aimed to determine whether pure molecular-based diffusion coefficient (D) and perfusion-related diffusion parameters (perfusion fraction f, perfusion-related diffusion coefficient D*) ...differ in healthy livers and fibrotic livers through intra-voxel incoherent motion (IVIM) MR imaging.
17 healthy volunteers and 34 patients with histopathologically confirmed liver fibrosis patients (stage 1 = 14, stage 2 = 8, stage 3 & 4 = 12, METAVIR grading) were included. Liver MR imaging was performed at 1.5-T. IVIM diffusion weighted imaging sequence was based on standard single-shot DW spin echo-planar imaging, with ten b values of 10, 20, 40, 60, 80, 100, 150, 200, 400, 800 sec/mm2 respectively. Pixel-wise realization and regions-of-interest based quantification of IVIM parameters were performed.
D, f, and D* in healthy volunteer livers and patient livers were 1.096±0.155 vs 0.917±0.152 (10(-3) mm2/s, p = 0.0015), 0.164±0.021 vs 0.123±0.029 (p<0.0001), and 13.085±2.943 vs 9.423±1.737 (10(-3) mm2/s, p<0.0001) respectively, all significantly lower in fibrotic livers. As the fibrosis severity progressed, D, f, and D* values decreased, with a trend significant for f and D*.
Fibrotic liver is associated with lower pure molecular diffusion, lower perfusion volume fraction, and lower perfusion-related diffusion. The decrease of f and D* in the liver is significantly associated liver fibrosis severity.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To compare the toxicities, tumor control, survival, and quality of life of nasopharyngeal cancer (NPC) patients treated with sequential neoadjuvant chemotherapy followed by concurrent ...cisplatin-radiotherapy (CRT) or CRT alone.
Previously untreated stage III to IVB NPC were randomly assigned to (1) neoadjuvant docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) every 3 weeks for two cycles, followed by cisplatin 40 mg/m(2)/wk concurrent with radiotherapy, or (2) CRT alone. Planned accrual was 30 patients per arm to detect 20% difference of toxicities based on 95% CIs.
From November 2002 to November 2004, 65 eligible patients were randomly assigned to neoadjuvant chemotherapy followed by CRT (n = 34) or CRT alone (n = 31). There was a high rate of grade 3/4 neutropenia (97%) but not neutropenic fever (12%) during neoadjuvant chemotherapy. No significant differences in rates of acute toxicities were observed between the two arms during CRT. Dose intensities of concurrent cisplatin, late RT toxicities and quality of life scores were comparable in both arms. The 3-year progression-free survival for neoadjuvant versus control arm was 88.2% and 59.5% (hazard ratio = 0.49; 95% CI, 0.20 to 1.19; P = .12). The 3-year overall survival for neoadjuvant versus control arm was 94.1% and 67.7% (hazard ratio = 0.24; 95% CI, 0.078 to 0.73; P = .012).
Neoadjuvant docetaxel-cisplatin followed by CRT was well tolerated with a manageable toxicity profile that allowed subsequent delivery of full-dose CRT. Preliminary results suggested a positive impact on survival. A phase III study to definitively test this neoadjuvant-concurrent strategy is warranted.
Purpose To evaluate the utility of amide proton transfer (APT) imaging in the characterization of head and neck tumors. Materials and Methods This retrospective study of APT imaging included 117 ...patients with 70 nasopharyngeal undifferentiated carcinomas (NUCs), 26 squamous cell carcinomas (SCCs), eight non-Hodgkin lymphomas (NHLs), and 13 benign salivary gland tumors (BSGTs). Normal tissues were examined in 25 patients. The APT means of malignant tumors, normal tissues, and benign tumors were calculated and compared with the Student t test and analysis of variance. The added value of the mean APT to the mean apparent diffusion coefficient (ADC) for differentiating malignant and benign tumors was evaluated by using receiver operating characteristic analysis and integrated discrimination index. Results The mean APT of malignant tumors (2.40% ± 0.97 standard deviation) was significantly higher than that of brain tissue (1.13% ± 0.43), muscle tissue (0.23% ± 0.73), and benign tumors (1.32% ± 1.20) (P < .001). There were no differences between malignant groups (NUC, 2.37% ± 0.90; SCC, 2.41% ± 1.16; NHL, 2.65% ± 0.89; P = .45 to P = .86). The mean ADC of malignant tumors (0.85 ± 0.17 × 10
mm
/sec) was significantly lower than that of benign tumors (1.46 ± 0.47 × 10
mm
/sec) (P = .001). Adding APT to ADC increased the area under the curve from 0.87 to 0.96, with an integrated discrimination index of 7.6% (P = .13). Conclusion These preliminary data demonstrate differences in amide proton transfer (APT) mean of malignant tumors, normal tissues, and benign tumors, although APT mean could not be used to differentiate between malignant tumor groups. APT imaging has the potential to be of added value to apparent diffusion coefficient in differentiating malignant from benign tumors.
Objective
To evaluate real-time shear wave ultrasound elastography (SWE) for characterizing focal thyroid lesions in routine clinical practice.
Methods
Seventy-four patients with 81 focal thyroid ...lesions undergoing conventional US with needle cytology also underwent SWE. Absolute and relative SWE stiffness measurements on colour-coded elastograms were correlated with cytology and their discriminatory performances assessed.
Results
Seventeen nodules were malignant (13 papillary, 4 other cancers), 45 benign (43 hyperplastic nodules, 2 focal thyroiditis), 5 indeterminate (“follicular lesions”), and 5 had inadequate cytology. SWE results were higher in malignant than benign nodules (
P
values 0.02–0.05) although their discriminatory performances were mediocre (AUCs 0.58–0.74). The most accurate SWE cut-off, 34.5 kPa for a 2-mm region of interest, achieved 76.9 % sensitivity and 71.1 % specificity for discriminating papillary cancer from benign nodules. No thresholds produced high sensitivity without lowering specificity appreciably, and vice versa. Nodule size correlated with SWE for benign nodules (
P
< 0.01). Intranodular cystic change or calcification did not influence SWE. Qualitatively, elastographic artefacts and foci lacking colour elasticity signal occurred in some solid nodules.
Conclusion
Although malignant nodules are generally stiffer than benign nodules, the precision results do not suggest a definitive role for SWE, at present, in identifying or excluding thyroid malignancy.
Key Points
•
Shear wave ultrasound elastography (SWE) offers new insight into thyroid disease
.
•
Papillary cancers have higher SWE indices (equating to higher stiffness) than benign nodules
.
•
SWE appears limited in terms of identifying or excluding thyroid malignancy accurately
.
•
Vertically aligned elastographic artefacts can occur in thyroid SWE
.
•
Areas lacking SWE colour signal can occur in some solid thyroid nodules
.
Sonography is a useful imaging tool in the evaluation of cervical lymph nodes. Gray-scale sonography and color and power Doppler sonography are commonly used in clinical practice. This article ...documents the common sonographic appearances of different causes of cervical lymphadenopathy.
The sonographic appearances of normal nodes differ from those of abnormal nodes. Sonographic features that help to identify abnormal nodes include shape (round), absent hilus, intranodal necrosis, reticulation, calcification, matting, soft-tissue edema, and peripheral vascularity.
To technically investigate the non-Gaussian diffusion of head and neck diffusion weighted imaging (DWI) at 3 Tesla and compare advanced non-Gaussian diffusion models, including diffusion kurtosis ...imaging (DKI), stretched-exponential model (SEM), intravoxel incoherent motion (IVIM) and statistical model in the patients with nasopharyngeal carcinoma (NPC).
After ethics approval was granted, 16 patients with NPC were examined using DWI performed at 3T employing an extended b-value range from 0 to 1500 s/mm(2). DWI signals were fitted to the mono-exponential and non-Gaussian diffusion models on primary tumor, metastatic node, spinal cord and muscle. Non-Gaussian parameter maps were generated and compared to apparent diffusion coefficient (ADC) maps in NPC.
Diffusion in NPC exhibited non-Gaussian behavior at the extended b-value range. Non-Gaussian models achieved significantly better fitting of DWI signal than the mono-exponential model. Non-Gaussian diffusion coefficients were substantially different from mono-exponential ADC both in magnitude and histogram distribution.
Non-Gaussian diffusivity in head and neck tissues and NPC lesions could be assessed by using non-Gaussian diffusion models. Non-Gaussian DWI analysis may reveal additional tissue properties beyond ADC and holds potentials to be used as a complementary tool for NPC characterization.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To document utility of shear-wave (SW) elastography for assessing liver fibrosis in chronic hepatitis B and to compare its performance with that of transient elastography.
Ethics committee approved ...the study, and informed consent was obtained. Patients with liver biopsy correlation (n = 226) and healthy patients (n = 171) were analyzed. Results of SW elastography of liver, SW elastography of spleen, and transient elastography of liver were compared and correlated according to METAVIR scores. Areas under the receiver operating characteristic curve (AUCs), binary logistic regression, and Delong test were used.
AUC for SW elastography of liver, transient elastography of liver, and SW elastography of spleen was, respectively, 0.86, 0.80, and 0.81 for fibrosis (≥ F1 stage); 0.88, 0.78, and 0.82 for moderate fibrosis (≥ F2 stage); 0.93, 0.83, and 0.83 for severe fibrosis (≥ F3 stage); and 0.98, 0.92, and 0.84 for cirrhosis (F4 stage). SW elastography of liver showed significantly higher accuracy than transient elastography of liver and SW elastography of spleen in all fibrosis stages (P = .01-.04). SW elastography of spleen showed similar accuracy with transient elastography of liver (P = .21-.99). Combination SW elastography of liver and SW elastography of spleen to predict fibrosis staging showed diagnostic accuracy not further improved compared with SW elastography of liver alone (similar AUC; ≥ F1, P = .87; ≥ F2, P = .81; ≥ F3, P = .84; ≥ F4, P = .88). SW elastography of liver had higher successful rate than transient elastography of liver (98.9% vs 89.6%). Prevalence of discordance in at least two stages with liver histologic staging was 10.2% (23 of 226) for SW elastography of liver and 28.2% (58 of 206) for SW elastography of spleen.
SW elastography provides more accurate correlation of liver elasticity with liver fibrosis stage compared with transient elastography, especially in identification of stage F2 or greater.
We have previously demonstrated that terahertz pulsed imaging is able to distinguish between rat tissues from different healthy organs. In this paper we report our measurements of healthy and ...cirrhotic liver tissues using terahertz reflection spectroscopy. The water content of the fresh tissue samples was also measured in order to investigate the correlations between the terahertz properties, water content, structural changes and cirrhosis. Finally, the samples were fixed in formalin to determine whether water was the sole source of image contrast in this study. We found that the cirrhotic tissue had a higher water content and absorption coefficient than the normal tissue and that even after formalin fixing there were significant differences between the normal and cirrhotic tissues' terahertz properties. Our results show that terahertz pulsed imaging can distinguish between healthy and diseased tissue due to differences in absorption originating from both water content and tissue structure.
Terahertz (THz) light is non-ionizing and highly sensitive to subtle changes in water concentration which can be indicative of disease. The short THz penetration depth in bio-samples restricts
...measurements to be in a reflection geometry and the sample is often placed onto an imaging window. Upon contacting the imaging window, occlusion and compression of the skin affect the THz response. If not appropriately controlled, this could cause misleading results. In this work, we investigate and quantify how the applied pressure affects the THz response of skin and employ a stratified model to help understand the mechanisms at play. This work will enable future THz studies to have a more rigorous experimental protocol, which in turn will facilitate research in various potential biomedical applications under investigation.
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