Can MR textural analysis improve the prediction of extracapsular nodal spread in patients with oral cavity cancer?

Objective

To explore the utility of MR texture analysis (MRTA) for detection of nodal extracapsular spread (ECS) in oral cavity squamous cell carcinoma (SCC).

Methods

115 patients with oral cavity SCC treated with surgery and adjuvant (chemo)radiotherapy were identified retrospectively. First-order texture parameters (entropy, skewness and kurtosis) were extracted from tumour and nodal regions of interest (ROIs) using proprietary software (TexRAD). Nodal MR features associated with ECS (flare sign, irregular capsular contour; local infiltration; nodal necrosis) were reviewed and agreed in consensus by two experienced radiologists. Diagnostic performance characteristics of MR features of ECS were compared with primary tumour and nodal MRTA prediction using histology as the gold standard. Receiver operating characteristic (ROC) and regression analyses were also performed.

Results

Nodal entropy derived from contrast-enhanced T1-weighted images was significant in predicting ECS (p?=?0.018). MR features had varying accuracy: flare sign (70%); irregular contour (71%); local infiltration (66%); and nodal necrosis (64%). Nodal entropy combined with irregular contour was the best predictor of ECS (p?=?0.004, accuracy 79%).

Conclusion

First-order nodal MRTA combined with imaging features may improve ECS prediction in oral cavity SCC.

Key Points

? Nodal MR textural analysis can aid in predicting extracapsular spread (ECS). ? Medium filter contrast-enhanced T1 nodal entropy was strongly significant in predicting ECS. ? Combining nodal entropy with irregular nodal contour improves predictive accuracy.

     

Can 18F-FDG PET improve the evaluation of suspicious breast lesions on MRI?

Objective

To evaluate the impact of adding 18F-fluorine-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the evaluation of suspicious breast lesions on magnetic resonance imaging (MRI).

Methods

Sixty patients with suspicious breast lesions on MRI were selected to perform a PET–CT in prone position, dedicated to the evaluation of the breasts. The areas with increased 18F-FDG concentration relative to normal parenchyma were considered positive on PET–CT. Fusion of PET and MRI images (PET–MRI) was performed on a dedicated workstation to better locate corresponding lesions, and its findings were compared with histological results.

Results

76 lesions were evaluated, including 64 mass lesions (84.2%) and 12 non-mass lesions (15.8%). Lesions’ mean diameter on MRI was 29.6 ± 19.2 mm (range 6–94 mm). PET–CT showed increased metabolically activity on 57 lesions (75.0%), with mean maximum SUV of 5.7 ± 5.0 (range 0.8–23.1). On histopathology, there were 17 (22.4%) benign and 59 (79.7%) malignant lesions. Considering all lesions, PET–MRI fusion provided 89.8% sensitivity, 76.5% specificity and 86.8% accuracy. Considering only mass lesions higher than 10 mm, PET–MRI fusion provided 95.8% sensitivity, 83.3% specificity and 93.3% accuracy.

Conclusion

The inclusion of 18F-FDG PET on the evaluation of suspicious breast lesions on MRI helped to differentiate benign from malignant breast lesions, especially for mass lesions with a diameter higher than 10 mm.     

Does primary tumour volumetry performed early in the course of definitive concomitant chemoradiotherapy for head and neck squamous cell carcinoma improve prediction of primary site outcome?

Although previous studies have documented correlations between pre-treatment or post-treatment primary tumour volumes and local outcome following definitive concomitant chemoradiotherapy (CCRT) in head and neck squamous cell carcinoma (HNSCC), no study has included and compared tumour volumes during CCRT. We reviewed the MRIs of 69 HNSCC patients treated with a 6 weeks course of CCRT and who underwent successful MRI pre-treatment (n = 69), 2 weeks intra-treatment (n = 48) and 6 weeks post-treatment (n = 61). Primary tumour volumes on MRI at the three time points were calculated and compared for their predictive value for primary site outcome. Volume thresholds optimised to predict failure with the highest accuracy and positive predictive value (PPV) were calculated. The mean pre-treatment volume was 24.6 cm3 (range, 1.1-187.9 cm3) and the mean follow-up interval was 41 months (range, 12-100 months). 23 primary tumours failed treatment (33%). Volumes before, during and after CCRT were positively associated with local failure (p = 0.015, p = 0.009, p<0.0001). Volume reductions during and after CCRT were negatively associated with local failure (p = 0.021, p = 0.001). Pre-treatment and intra-treatment volume thresholds achieved the highest accuracy and produced intermediate PPVs (51-64%) for predicting local failure. Optimised intra-treatment thresholds did not identify any more treatment failures than the pre-treatment thresholds. By comparison, a 6 weeks post-treatment volume reduction (<35%) achieved 100% PPV for failure, albeit with 26% sensitivity. In conclusion, primary tumour volumetry performed early in CCRT provides minimal additional information compared with pre-treatment volumetry, with respect to predicting post-treatment local failures. Therefore, volumetry during CCRT is unlikely to be useful for guiding individual response-based therapeutic modifications.     

Can diffusion-weighted imaging distinguish between normal and squamous cell carcinoma of the palatine tonsil?

The utility of diffusion-weighted imaging (DWI) in the detection of squamous cell carcinoma (SCC) of the tonsils has not been previously investigated. This preliminary study compared DWI of apparent SCC tonsillar tumours with normal tonsils. DWI of the tonsils was performed in 10 patients with newly diagnosed tonsil SCC that was evident on conventional MRI and in 17 patients undergoing cranial MRI for other indications. Regions of interest (ROI) were drawn around each identifiable tonsil on the apparent diffusion coefficient (ADC) map and the mean ADC value for each tonsil was calculated. ADC values for normal and SCC tonsils were compared using the Mann–Whitney U-test. The median ADC and range (×10⁻³ mm² s^–1) were found to be 0.814 and 0.548–1.312, respectively, for normal tonsils compared with 0.933 and 0.789–1.175, respectively, for SCC tonsils. ADC values were significantly higher for SCC tonsils than for normal tonsils (p = 0.009). No SCC tonsil had an ADC less than 0.82×10⁻³ mm² s^–1 compared with 58% of normal tonsils. We conclude that there is a difference in the ADC between normal tonsils and SCC tonsils where the cancer is apparent on conventional MRI. These results are promising, although further studies are now required to determine whether DWI can be used to identify or exclude smaller foci of SCC within tonsils where the cancer is not evident on conventional MRI.Cancers in the palatine tonsil can be difficult to identify on conventional imaging using CT or MRI because they can have the same appearance as normal lymphoid tissue at this site. This leads to problems when imaging is used to search for the site of an “unknown primary” in head and neck squamous cell carcinoma (SCC) or to assess the extent of spread of SCC from adjacent sites in the oropharynx. Diffusion-weighted imaging (DWI) is an MR technique that shows potential for improving the detection of cancer. Early studies suggest that there are differences in the apparent diffusion coefficient (ADC) of metastatic nodes involved in SCC and normal nodes [1–3]. The aim of this preliminary study was to compare the ADC of normal tonsils with imaging-apparent SCC tonsils; to our knowledge, this has not been previously investigated. If it can be shown that there are differences in the ADC values of grossly infiltrated SCC tonsils and benign tonsils, this could provide justification for performing larger prospective studies to determine whether DWI can detect small occult cancers within the tonsil.     

Can the three-phase bone scan differentiate osteomyelitis from metabolic or metastatic bone disease?

The three-phase bone scan has been reported of value in the diagnosis of osteomyelitis. The use of a radionuclide angiogram, an immediate postinjection "blood pool" image, and 2 to 3 hour delayed image have been useful in separating nonosseous inflammatory disease from osteomyelitis. However, dependence on increased blood flow and focal hyperemia for this diagnosis may limit the use of the study if other processes are shown to produce similar results. To identify limitations of the three-phase bone scan we studied 14 patients with metastatic bone disease and nine patients with Paget's disease. Blood flow results showed no increase in three of 14 patients with metastases, intermediate increase in seven of 14 patients with metastases and two of nine patients with Paget's, and intense increase in four of 14 patients with metastases and seven of nine patients with Paget's. All patients showed increased focal activity in the immediate "blood pool" and delayed images. We conclude that because of increased flow Paget's disease may be difficult to separate from osteomyelitis. However, metastatic disease can often be differentiated on the basis of quantitative focal hyperemia. The three-phase bone scan remains of value in the diagnosis of osteomyelitis, but other diseases of bone must be included in the differential diagnosis.     

Can Exercise Reduce the Risk of Cancer?

Some evidence suggests that increased physical activity reduces the occurrence rate of certain cancers. Whether this effect is direct or indirect remains to be seen, but some experts are recommending exercise as a means of reducing cancer risk.     

Can we measure accurately the prevalence of doping?

Questionnaires are used in the majority of the studies on doping prevalence in sport. Nevertheless, prevalence is not easy to evaluate and previous epidemiologic studies demonstrated a wide variance. This variance has mostly been explained by sample differences. The way to evaluate doping prevalence in the survey is questioned in this paper. A questionnaire was administered to 1810 amateur athletes (993 males, 817 females). Doping use was ascertained in various ways, using different definitions of doping and types of question in the survey. Depending on the definition of doping and the type of question used, the prevalence of doping obtained can differ enormously, between 1.3 and 39.2% of athletes. Marijuana and drugs for asthma were the two banned substances most used. The majority of athletes often ignored the banned list and did not use prohibited substances to dope. Using various ways to question athletes, observing the usage of substances, cross checking the data, taking into account the aim of substances uses and the various definitions of doping are necessary to give more reliable prevalence of doping. Moreover, doping at an amateur level seems to be less of a sport problem than a social problem.     

Can radiation research impact the estimation of risk?

Abstract

Purpose: This review is a contribution to the memory of Dr William (Bill) Morgan and highlights an area of research and deliberation that he considered extremely important in support of the setting of protective radiation dose limits. Biological research has generally played a minor role in the estimation of adverse health outcomes following exposure to low doses and low dose rates of radiation. The reliance has been on the available, quite extensive data base of epidemiology studies. The major concern is that such studies are for moderate to high doses requiring risk extrapolation methodologies for estimating low dose effects. There are significant uncertainties associated with this approach. This review will discuss how radiation biology studies can potentially reduce this uncertainty through the use of a key events/adverse outcome pathways approach to identify bioindicators of cancer and non-cancer effects for use as parameters in biologically-based dose-response (BBDR) models. Such models would allow for an improved extrapolation approach for estimating health effects at low doses and low dose rates of radiation.

Conclusion: Based on reported and ongoing studies for environmental chemicals, the adverse outcome/key events approach is a viable one for enhanced risk assessment (and risk management practice). The identification of informative bioindicators of adverse health effects will be a challenge but with modern molecular and advanced computational techniques, it is certainly feasible. This approach provides a framework for defining a low dose radiation research program; something that was of great importance to Bill Morgan.     

Artificial intelligence?driven radiomics study in cancer: the role of feature engineering and modeling

Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’ anatomy.However, the interpretation of medical images can be highly subjective and dependent on the expertise of clinicians.Moreover, some potentially useful quantitative information in medical images, especially that which is not visible to the naked eye, is often ignored during clinical practice. In contrast, radiomics performs high-throughput feature extraction from medical images, which ...     

Can an enhanced thin-slice computed tomography delineate the right adrenal vein and improve the success rate?

Purpose

To evaluate the usefulness of enhanced thin-slice computed tomography (TSCT) for delineating the right adrenal vein (RAV) anatomy before adrenal vein sampling (AVS).

Materials and methods

A total of 151 consecutive AVSs with CT during angiography (interventional CT) were included. Of them, TSCT was performed before AVS for 72 patients. Successful RAV cannulation was confirmed using cortisol measurement. The RAV on TSCT was classified as certain, probable, or unidentified, and cases with certain or probable RAV identification were classified as useful. In the cases where AVS was successful, the anatomical features of the presumed RAV from the useful TSCT, including the position along the inferior vena cava, vertebral level, and distance from the upper pole of the right kidney, were compared with the RAV features identified on interventional CT. Estimated successful cannulation rates before interventional CT were compared between patients with and without useful TSCT.

Results

In total, 66 TSCTs were classified as useful. The anatomical features identified on TSCT were significantly correlated with those on interventional CT. The estimated successful cannulation rates for cases with and without useful TSCT were 92.4 and 82.4 %, respectively.

Conclusions

TSCT clearly shows the anatomical features of the RAV, facilitating accurate sampling and increasing the success rate.

     

Does bowel preparation improve the quality of abdominal gallium scintigraphy?

Physiological accumulation of gallium in the intestine is a major weakness of gallium scintigraphy in evaluating the abdomen. In this study, we used two different cathartics to evaluate the efficacy of bowel cleansing in improving the quality of abdominal gallium imaging. One hundred and fifty patients underwent gallium scintigraphy and were randomly divided into three groups. Group A received no bowel preparation, Group B received 30 ml of castor oil the night before imaging, and Group C received bisacodyl the night before imaging. Gallium activity in the intestine was rated on a three-point scale from 0 to II based on the anterior view of a delayed 48-h gallium image. Our data showed that the incidence of gallium accumulation in the small intestine was low. On the contrary, there was high prevalence of gallium activity in the colon. Forty-eight percent of Group A patients had obvious gallium activity in the colon. The percentage decreased significantly to 28% and 22% in Groups B and C, respectively. No significant difference was noted between Group B and Group C. In conclusion, our data suggest that the application of either castor oil or bisacodyl significantly improves the quality of 48-h abdominal gallium scintigraphy. There were no significant differences in the efficacy of bowel cleansing on gallium activity between these two laxatives.     

Can pretreatment CT perfusion predict response of advanced squamous cell carcinoma of the upper aerodigestive tract treated with induction chemotherapy?

BACKGROUND AND PURPOSE: Treatment of advanced stage squamous cell carcinoma of the upper aerodigestive tract with nonsurgical organ preservation protocols demonstrates improved cure rates with fewer comorbidities compared with surgery and radiation. The purpose of this study was to prospectively assess whether pretreatment evaluation of the primary site with quantitative CT perfusion measurements predicted response to induction chemotherapy and to create a prediction model to predict the response to induction chemotherapy in future patients. METHODS: Seventeen patients who were enrolled in a prospective trial assessing surgical intervention versus a nonsurgical protocol underwent a pretreatment CT perfusion followed by direct laryngoscopy. After induction chemotherapy, tumor response was determined by the surgeon's estimate of tumor volume. The CT perfusion parameters were correlated with the clinical response using a Wilcoxon rank-sum analysis. A logistic regression model was used to create a prediction based on the most significant CT perfusion parameter. RESULTS: Elevated values of blood volume (P = .004) and blood flow (P = .03) were significantly correlated with >50% reduction in tumor volume after chemotherapy. A prediction model based on tumor blood volume demonstrated 91.7% sensitivity and 80.0% specificity, with an area under the receiver operating characteristic curve of 0.95. CONCLUSION: Our preliminary data imply that tumors with elevated blood volume and blood flow were statistically associated with response to induction chemotherapy. These results suggest that pretreatment CT perfusion may be able to identify patients who will successfully respond to induction chemotherapy, which could potentially eliminate this step for subsequent patients when deciding on the appropriate treatment regimen.     

Can mechanical imaging increase the specificity of mammography screening?

Objectives

This study aimed to investigate the effects of adding adjunct mechanical imaging to mammography breast screening. We hypothesized that mechanical imaging could detect increased local pressure caused by both malignant and benign breast lesions and that a pressure threshold for malignancy could be established. The impact of this on breast screening was investigated with regard to reductions in recall and biopsy rates.

Methods

155 women recalled from breast screening were included in the study, which was approved by the regional ethical review board (dnr 2013/620). Mechanical imaging readings were acquired of the symptomatic breast. The relative mean pressure on the suspicious area (RMPA) was defined and a threshold for malignancy was established.

Results

Biopsy-proven invasive cancers had a median RMPA of 3.0 (interquartile range (IQR)?=?3.7), significantly different from biopsy-proven benign at 1.3 (IQR?=?1.0) and non-biopsied cases at 1.0 (IQR?=?1.3) (P?<?0.001). The lowest RMPA for invasive cancer was 1.4, with 23 biopsy-proven benign and 33 non-biopsied cases being below this limit. Had these women not been recalled, recall rates would have been reduced by 36% and biopsy rates by 32%.

Conclusions

If implemented in a screening situation, this may substantially lower the number of false positives.

Key Points

? Mechanical imaging is used as an adjunct to mammography in breast screening. ? A threshold pressure can be established for malignant breast cancer. ? Recalls and biopsies can be substantially reduced.