Sugama Chicklore

Are Pretreatment 18F-FDG PET Tumor Textural Features in Non–Small Cell Lung Cancer Associated with Response and Survival After Chemoradiotherapy?

There is evidence in some solid tumors that textural features of tumoral uptake in 18F-FDG PET images are associated with response to chemoradiotherapy and survival. We have investigated whether a similar relationship exists in non–small cell lung cancer (NSCLC). Methods: Fifty-three patients (mean age, 65.8 y; 31 men, 22 women) with NSCLC treated with chemoradiotherapy underwent pretreatment 18F-FDG PET/CT scans. Response was assessed by CT Response Evaluation Criteria in Solid Tumors (RECIST) at 12 wk. Overall survival (OS), progression-free survival (PFS), and local PFS (LPFS) were recorded. Primary tumor texture was measured by the parameters coarseness, contrast, busyness, and complexity. The following parameters were also derived from the PET data: primary tumor standardized uptake values (SUVs) (mean SUV, maximum SUV, and peak SUV), metabolic tumor volume, and total lesion glycolysis. Results: Compared with nonresponders, RECIST responders showed lower coarseness (mean, 0.012 vs. 0.027; P = 0.004) and higher contrast (mean, 0.11 vs. 0.044; P = 0.002) and busyness (mean, 0.76 vs. 0.37; P = 0.027). Neither complexity nor any of the SUV parameters predicted RECIST response. By Kaplan–Meier analysis, OS, PFS, and LPFS were lower in patients with high primary tumor coarseness (median, 21.1 mo vs. not reached, P = 0.003; 12.6 vs. 25.8 mo, P = 0.002; and 12.9 vs. 20.5 mo, P = 0.016, respectively). Tumor coarseness was an independent predictor of OS on multivariable analysis. Contrast and busyness did not show significant associations with OS (P = 0.075 and 0.059, respectively), but PFS and LPFS were longer in patients with high levels of each (for contrast: median of 20.5 vs. 12.6 mo, P = 0.015, and median not reached vs. 24 mo, P = 0.02; and for busyness: median of 20.5 vs. 12.6 mo, P = 0.01, and median not reached vs. 24 mo, P = 0.006). Neither complexity nor any of the SUV parameters showed significant associations with the survival parameters. Conclusion: In NSCLC, baseline 18F-FDG PET scan uptake showing abnormal texture as measured by coarseness, contrast, and busyness is associated with nonresponse to chemoradiotherapy by RECIST and with poorer prognosis. Measurement of tumor metabolic heterogeneity with these parameters may provide indices that can be used to stratify patients in clinical trials for lung cancer chemoradiotherapy.

Quantifying tumour heterogeneity in 18F-FDG PET/CT imaging by texture analysis

Abstract18F-Fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is now routinely used in oncological imaging for diagnosis and staging and increasingly to determine early response to treatment, often employing semiquantitative measures of lesion activity such as the standardized uptake value (SUV). However, the ability to predict the behaviour of a tumour in terms of future therapy response or prognosis using SUVs from a baseline scan prior to treatment is limited. It is recognized that medical images contain more useful information than may be perceived with the naked eye, leading to the field of “radiomics” whereby additional features can be extracted by computational postprocessing techniques. In recent years, evidence has slowly accumulated showing that parameters obtained by texture analysis of radiological images, reflecting the underlying spatial variation and heterogeneity of voxel intensities within a tumour, may yield additional predictive and prognostic information. It is hoped that measurement of these textural features may allow better tissue characterization as well as better stratification of treatment in clinical trials, or individualization of future cancer treatment in the clinic, than is possible with current imaging biomarkers. In this review we focus on the literature describing the emerging methods of texture analysis in 18FDG PET/CT, as well as other imaging modalities, and how the measurement of spatial variation of voxel grey-scale intensity within an image may provide additional predictive and prognostic information, and postulate the underlying biological mechanisms.

Non–Small Cell Lung Cancer Treated with Erlotinib: Heterogeneity of 18F-FDG Uptake at PET—Association with Treatment Response and Prognosis

PURPOSE To determine if first-order and high-order textural features on fluorine 18 ((18)F) fluorodeoxyglucose (FDG) positron emission tomography (PET) images of non-small cell lung cancer (NSCLC) (a) at baseline, (b) at 6 weeks, or (c) the percentage change between baseline and 6 weeks can predict response or survival in patients treated with erlotinib. MATERIALS AND METHODS Institutional review board approval was obtained for post hoc analysis of data from a prospective single-center study for which informed consent was obtained. The study included 47 patients with NSCLC who underwent (18)F-FDG PET/computed tomography (CT) at baseline (n = 47) and 6 weeks (n = 40) after commencing treatment with erlotinib. First-order and high-order primary tumor texture features reflecting image heterogeneity, standardized uptake values, metabolic tumor volume, and total lesion glycolysis were measured for all (18)F-FDG PET studies. Response to erlotinib was assessed by using the Response Evaluation Criteria in Solid Tumors (RECIST) on CT images obtained at 12 weeks (n = 32). Associations between PET parameters, overall survival (OS), and RECIST-based treatment response were tested by Cox and logistic regression analyses, respectively. RESULTS Median OS was 14.1 months. According to CT RECIST at 12 weeks, there were 21 nonresponders and 11 responders. Response to erlotinib was associated with reduced heterogeneity (first-order standard deviation, P = .01; entropy, P = .001; uniformity, P = .001). At multivariable analysis, high-order contrast at 6 weeks (P = .002) and percentage change in first-order entropy (P = .03) were independently associated with survival. Percentage change in first-order entropy was also independently associated with treatment response (P = .01). CONCLUSION Response to erlotinib is associated with reduced heterogeneity at (18)F-FDG PET. Changes in first-order entropy are independently associated with OS and treatment response.

Radiomics in PET: principles and applications

Radiomics is an evolving field in which the extraction of large amounts of features from diagnostic medical images may be used to predict underlying molecular and genetic characteristics, thereby improving treatment response prediction and prognostication and potentially allowing personalisation of cancer treatment. There is increasing interest in extracting additional data from PET images, particularly novel features that describe the heterogeneity of voxel intensities, but a number of potential limitations need to be recognised and overcome. Nevertheless, some early data suggest that extraction of additional quantitative data may offer further predictive and prognostic information in individual patients.

Patterns of disease progression on 18F-fluorodeoxyglucose positron emission tomography-computed tomography in patients with malignant pleural mesothelioma undergoing multimodality therapy with pleurectomy/ decortication

IntroductionThe aim of this study was to evaluate the patterns of disease progression in patients treated with pleurectomy/decortication (P/D), hyperthermic pleural lavage with povidone-iodine, prophylactic radiotherapy and adjuvant chemotherapy, using 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (PET/CT). Materials and methodsThis was a retrospective study of 65 patients treated with a multimodality therapy including P/D between October 2004 and March 2012. Thirty-two patients underwent 18F-FDG PET/CT within 6 weeks of completion of adjuvant chemotherapy and 6-monthly thereafter at our institution. The first site of relapse on 18F-FDG PET/CT was recorded, and all scans were reviewed by an independent observer. ResultsThirty-two patients (27 male, median age 61 years, range 45–73) underwent their 18F-FDG PET/CT scans at our institution. Eighteen of the 32 patients were alive at last follow-up (median follow-up 42 months, range 16–76). Nine patients were alive with disease recurrence. Fourteen patients died of disease progression (median survival 24.7 months, range 15–38). The median maximum standardized uptake value (SUVmax) in relapsing mesothelioma was 10.9 (range 4.9–27.3). There was a statistically significant correlation between the SUVmax and tumour lesion glycolysis of recurrent mesothelioma and overall survival (P=0.05). The site of disease recurrence was the pleura in the majority of the alive patients and was extrapleural in the dead patients. There was a statistically significant correlation between disease-free survival and complete macroscopic resection (P=0.02). ConclusionAfter P/D with hyperthermic pleural lavage with povidone-iodine, prophylactic radiotherapy and adjuvant chemotherapy, the most frequent site of recurrence is the pleural cavity. Peritoneal seeding is rare. The tumour SUVmax and tumour lesion glycolysis correlate significantly with overall survival.

Do emergency physicians and radiologists reliably interpret pelvic radiographs obtained as part of a trauma series

Introduction Interpretation of pelvic radiography is an important component of the primary survey and is commonly performed by emergency physicians. Radiologists bring unique skills to trauma care, including choice of imaging modality and image interpretation. It is not clear if this limited resource is most efficiently used in the resuscitation room. No studies have compared radiologists and trauma clinicians in their ability to interpret pelvic radiographs following trauma. Objective To determine the sensitivity and specificity of trauma experienced and trauma inexperienced emergency physicians in detecting pelvic fractures compared with radiologists, the latter subgroup combined report being used as the gold standard. Setting and methods Prospective cohort study conducted in two large teaching hospitals in central London. All participants reviewed 144 consecutive pelvic radiographs performed each as part of a ‘trauma series’ and known to have undergone concomitant pelvic CT imaging. Results No statistically significant difference was found between radiologists and emergency physicians from a trauma centre in pelvic radiograph interpretation. Radiologist reporting was associated with an improved specificity compared with emergency physicians working in a non-trauma hospital (p=0.049). The study population missed 30% of fractures on plain radiography against the gold standard of CT. Discussion The ability to interpret trauma series pelvic radiographs is comparable between emergency physicians and radiologists. If this were also true of trauma chest radiographs, then the most valuable use of the radiologist may not be the resuscitation room but in rapid reporting of more complex imaging techniques. However, plain radiography is insensitive for pelvic fracture detection compared with CT, even in expert hands.

18F-FDG PET rarely provides additional information to 11C-methionine PET imaging in hyperparathyroidism

Aim The aim of this study was to assess the utility of combined 11C-methionine and 18F-FDG PET/CT imaging in hyperparathyroidism. Patients and Methods We reviewed all scans performed for hyperparathyroidism with both 11C-methionine and 18F-FDG PET/CT or PET in our institution since 1993. Forty-three patients (47 pairs of scans) were included (13 men and 30 women) with a mean age of 63 years. 11C-methionine and 18F-FDG PET/CT scans were classified as positive or negative for localization of abnormal parathyroid tissue, and the site of uptake was noted in the positive scans. Other concurrent imaging (99mTc-MIBI scintigraphy, ultrasonography, CT, or MRI) findings were also noted when performed. Clinical follow-up information was available in 27 patients (30 episodes). Results Of the 47 PET scan episodes, 23 (49%) were positive. Twenty-two 11C-methionine scans showed abnormal focal localization of which 10 also showed concordant abnormal 18F-FDG uptake. One patient was positive with 18F-FDG and negative with 11C-methionine. Of the 16 patients who underwent subsequent surgery, 6 had concordant 11C-methionine, 18F-FDG, and surgical findings; 6 had concordant 11C-methionine and surgical findings; 1 had concordant 18F-FDG and surgical findings; and 3 had both PET scans negative but had adenomas excised during surgery. Of the 3 with both PET scans negative and discordant surgical findings, 1 had mediastinal parathyroid lipoadenoma excised and 2 had normally sited parathyroid adenoma excised. Conclusions 18F-FDG PET/CT rarely provides additional information and could be saved for patients in whom 11C-methionine PET/CT is negative.

Tc-99m MDP bone scintigraphy in septic shock

An 8-year-old girl presented with a history of diarrhea, vomiting, and drowsiness. Clinical examination confirmed septic shock with marked metabolic acidosis. As a complication of septicemia, severe ischemia of all 4 limbs was noted from day 1 and she subsequently developed peripheral gangrene. Tc-99m MDP bone scan showed extensive bone infarction in all 4 limbs. Early diagnosis of osteonecrosis and amputation may prevent worsening of sepsis. However, it is not possible to clinically demarcate the level of amputation. Bone scan is a useful diagnostic tool in determining the appropriate level of amputation.

Common orthopaedic presentations

Trauma and orthopaedic surgery is a speciality that is rapidly evolving. Research and technological developments have resulted in advances both in the understanding and in the management of injuries and congenital and acquired disorders of the bones, joints and their associated soft tissues, including ligaments, nerves and muscles.