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1.
M E Miquel A D Scott N D Macdougall R Boubertakh N Bharwani A G Rockall 《The British journal of radiology》2012,85(1019):1507-1512
Objective
To study the in vitro and in vivo (abdomen) variability of apparent diffusion coefficient (ADC) measurements at 1.5 T using a free-breathing multislice diffusion-weighted (DW) MRI sequence.Methods
DW MRI images were obtained using a multislice spin-echo echo-planar imaging sequence with b-values=0, 100, 200, 500, 750 and 1000 s mm−2. A flood-field phantom was imaged at regular intervals over 100 days, and 10 times on the same day on 2 occasions. 10 healthy volunteers were imaged on two separate occasions. Mono-exponential ADC maps were fitted excluding b=0. Paired analysis was carried out on the liver, spleen, kidney and gallbladder using multiple regions of interest (ROIs) and volumes of interest (VOIs).Results
The in vitro coefficient of variation was 1.3% over 100 days, and 0.5% and 1.0% for both the daily experiments. In vivo, there was no statistical difference in the group mean ADC value between visits for any organ. Using ROIs, the coefficient of reproducibility was 20.0% for the kidney, 21.0% for the gallbladder, 24.7% for the liver and 28.0% for the spleen. For VOIs, values fall to 7.7%, 6.4%, 8.6% and 9.6%, respectively.Conclusion
Good in vitro repeatability of ADC measurements provided a sound basis for in vivo measurement. In vivo variability is higher and when considering single measurements in the abdomen as a whole, only changes in ADC value greater than 23.1% would be statistically significant using a two-dimensional ROI. This value is substantially lower (7.9%) if large three-dimensional VOIs are considered.Diffusion-weighted (DW) MRI is based on the Brownian motion of water in biological tissues [1,2]. The technique has played a preponderant role in neuro-imaging over the last two decades and it is known to detect small changes before they are apparent on anatomical imaging [3,4].In recent years DW MRI has been increasingly used in other parts of the body, demonstrating great diagnostic potential in cancer imaging. To date, DW MRI has been successfully used for tissue characterisation and tumour staging. However, the apparent diffusion coefficient (ADC) is a potential biomarker that could be used to monitor treatment response or evaluate post-therapeutic changes. Details of the clinical use of DW MRI can be found in the 2009 consensus paper [5] or in general and organ-specific review articles [6-8].While DW MRI is a potentially powerful tool in diagnostic oncology, the lack of uniform protocols for imaging and data analysis hinder its clinical implementation. Large differences in ADC values are reported in the literature depending on the acquisition parameters, in particular the choice of b-values (e.g. see [9] for ADC values in the kidney or 5] highlighted the importance of quality analysis, validation and reproducibility studies. Although there are some emerging reproducibility and repeatability data in the abdomen [15,19-22], a recent review by Taouli and Koh [7] highlights the need for further work in this area. Recently, coefficients of variability of around 14% were published for both solid tumours [22] and bone marrow [23]. Other studies seem to indicate that only ADC changes of over 27% [20] or 30% [21] are significant. Substantial variations in ADC values have also been found between different scanners and vendors [24-26], further highlighting the difficulty of setting up multicentre trials.Table 1
Apparent diffusion coefficient values measured in normal liver at 1.5 TReference | Mean ADC (10−3 mm2 s−1) | Standard deviation | Range | Number of subjects | b-values (s mm−2) | Comments |
Taouli et al [10] | 1.60 | 0.13 | 1.44–1.88 | 10 v | 0, 500 | Conventional |
1.52 | 0.15 | 1.28–180 | With parallel imaging | |||
1.51 | 0.21 | 1.27–1.99 | Diffusion tensor/parallel imaging | |||
Mürtz et al [11] | 0.92–0.96a | 0.09–0.14 | 0.62–1.20 | 12 v | 50, 300, 700, 1000, 1300 | Pulse triggered |
1.03–1.14 | 0.22–0.40 | 0.67–2.57 | Non-triggered | |||
Kim et al [12] | 1.05/1.02b | 0.30/0.25 | 6 v/126 p | 3, 57, 192, 408, 517, 850 | ||
1.55/1.16 | 0.37/0.42 | 3, 57, 192, 408, 192, 408 | ||||
4.8/3.55 | 2.37/1.75 | 3, 57 | ||||
Ichikawa et al [13] | 2.28 | 1.23 | 46 p | 1.6, 55 | ||
Taouli et al [14] | 1.83 | 0.36 | 1.4–2.55 | 66 p | 0, 500 | |
1.51 | 0.49 | 1.12–2.71 | 0, 134, 267, 400 | |||
Kwee et al [15] | 1.60/1.62/1.57c | 0.14/0.18/0.15 | 11 v | 0, 500 | Breath-hold | |
2.13/2.27/2.07 | 0.33/0.47/0.43 | Respiratory triggered | ||||
1.65/1.62/1.65 | 0.09/0.16/0.17 | Free breathing (7 mm slice) | ||||
1.64/1.66/1.57 | 0.13/0.11/0.19 | Free breathing (5 mm slice) | ||||
Yamada et al [16] | 0.87 | 0.26 | 78 p | 30, 300, 900,1100 | ADC | |
0.76 | 0.27 | Diffusion coefficient (DC) | ||||
Müller et al [17] | 1.39 | 0.16 | 10 v+9 p | 8 b-values; bmax 328–454 | ||
Namimato et al [18] | 0.69 | 0.31 | 51 p | 30, 1200 | ||
This study | 1.04 | 0.05 | 0.95–1.11 | 10 v | 100, 200, 500, 750, 1000 | Free breathing |
2.
M Oliver D McConnell M Romani A McAllister A Pearce A Andronowski X Wang K Leszczynski 《The British journal of radiology》2012,85(1020):1539-1545
3.
Y Sone A Sobajima T Kawachi S Kohara K Kato S Naganawa 《The British journal of radiology》2014,87(1042)
Objective:
To determine the prevalence and clinical features of pathologically proven incidental cancer (IC) detected by whole-body fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET)/CT, as well as the incidence of false-positive and false-negative results.Methods:
We retrospectively reviewed reports derived from 18F-FDG PET/CT images of 3079 consecutive patients with known or suspected malignancies for 3 years. Discrete focal uptake indicating IC was identified from reports as well as pathological or clinical diagnoses, and the clinical courses were investigated. The false-positive result was defined as uptake indicating IC but not pathologically confirmed as malignant during follow-up. The false-negative result was defined as pathologically proven IC detected by another modality at initial clinical work-up or diagnosed during the follow-up period.Results:
We found 18F-FDG uptake indicating IC in 6.7% of all patients, and IC was pathologically proven in 2.2% of all patients. The most common sites were the colon, lung and stomach. The median survival duration of patients with IC was 42 months. The results were false positive in 4.5% of all patients, and the results were false negative in 2.3% of all patients.Conclusion:
18F-FDG PET/CT is a valuable tool for detecting IC. The rates of false-positive and false-negative results are within acceptable range.Advances in knowledge:
This is the first report to describe the survival of patients with IC, and the detailed features of false-negative results at actual clinical settings.Integrated whole-body positron emission tomography (PET)/CT using the glucose analogue fluorine-18 fludeoxyglucose (18F-FDG) is an established modality for oncologic imaging. Combined metabolic and morphological images yielded by 18F-FDG PET/CT can provide accurate information on the staging, restaging and therapeutic monitoring of many common cancers.1 Furthermore, 18F-FDG PET and PET/CT have the potential for cancer screening. Owing to the non-specific nature of 18F-FDG uptake, a wide range of malignant tumours can be visualized as incidental foci of hypermetabolism. For instance, new malignant tumours have been detected in asymptomatic individuals,2 patients with head and neck cancer,3 oesophageal cancer4 and malignant lymphoma.5 Incidental focal 18F-FDG uptake within the gastrointestinal tract frequently represents malignant and pre-malignant tumours.6,7 The detection of incidental cancer (IC) significantly impacts clinical oncological practice. Namely, the detection of a primary cancer can lead a patient to a new treatment, and the detection of a second primary cancer can lead a patient to a more suitable treatment.IC has been detected by 18F-FDG PET or PET/CT in the past decade.8–15 8–13 The detection rate of IC ranges from 0.9% to 4.4%,8–15 and a few reports have described a wider range (0.1–4.4%) of false-negative findings.13–15 However, the survival of patients with IC has not been detailed. Differences in detection rates and other findings arise owing to many factors, including country, age, symptomatic or asymptomatic individuals, 18F-FDG PET or PET/CT, judgment criteria, method and period of follow-up.Table 1.
Previous studies evaluating detection rate of incidental cancer (IC)Author | Study design | Patients (n)/mean age (years) | Modality | Rate of uptake indicating IC (%) | Rate of IC detected by PET or PET/CT (%) | Three most common sites of IC | Rate of PET or PET/CT negative IC (%) | Survival data |
---|---|---|---|---|---|---|---|---|
Agress Jr and Cooper8 | P patients | 1750/NA | PET | 3.0 | 1.7a | Colon, breast and larynx | NA | NA |
Ishimori et al9 | R patients | 1912/58.9 | PET/CT | 4.1 | 1.2 | Lung, thyroid and colon | NA | NA |
Choi et al10 | P patients | 547/60.5 | PET/CT | 8.2 | 4.4 | Head and neck, lung and stomach | NA | NA |
Wang et al11 | R patients | 1727/63.0 | PET/CT | 11.5 | 0.9b | Lung, colon and breast | NA | NA |
Beatty et al12 | R patients | 2219/61.0 | PET/CT | 12.3 | 1.8 | Lung, breast and colon | NA | Nine dead (median follow-up of 22 months) |
Xu et al13 | R patients | 677/NA | PET/CT | 5.2 | 3.0 | Colon, lung and thyroid | 0.1 | NA |
Terauchi et al14 | P healthy participants | 2911/59.8 | PET | Not described | 1.0 | Colon, breast and thyroid | 4.4 | NA |
Nishizawa et al15 | P healthy participants | 1197/46.7 | PET/CT | Not described | 1.3c | Thyroid, lung and breast | 0.6 | NA |
4.
M H Seegenschmiedt O Micke R Muecke the German Cooperative Group on Radiotherapy for Non-malignant Diseases 《The British journal of radiology》2015,88(1051)
Every year in Germany about 50,000 patients are referred and treated by radiotherapy (RT) for “non-malignant disorders”. This highly successful treatment is applied only for specific indications such as preservation or recovery of the quality of life by means of pain reduction or resolution and/or an improvement of formerly impaired physical body function owing to specific disease-related symptoms. Since 1995, German radiation oncologists have treated non-malignant disorders according to national consensus guidelines; these guidelines were updated and further developed over 3 years by implementation of a systematic consensus process to achieve national upgraded and accepted S2e clinical practice guidelines. Throughout this process, international standards of evaluation were implemented. This review summarizes most of the generally accepted indications for the application of RT for non-malignant diseases and presents the special treatment concepts. The following disease groups are addressed: painful degenerative skeletal disorders, hyperproliferative disorders and symptomatic functional disorders. These state of the art guidelines may serve as a platform for daily clinical work; they provide a new starting point for quality assessment, future clinical research, including the design of prospective clinical trials, and outcome research in the underrepresented and less appreciated field of RT for non-malignant disorders.Every year about 50,000 patients in Germany are treated for “non-malignant disorders” respectively “benign disease conditions” by using ionizing radiation applied in >300 radiotherapy (RT) facilities.1–4 The aim of these treatments are and will be the preservation or recovery of various quality of life aspects, for example, by prevention of or reduction of pain and/or improvement of formerly disabled physical body functions.Non-malignant indications for RT comprise about 10–30% of all treated patients in most academic, public and private RT facilities in Germany. Over the past decade, various so called patterns of care studies (PCSs) have focused on the general and various specific aspects of these diseases and their RT treatment conditions and concepts in Germany.1–5 Overall, there is not a single RT institution among all 300 active RT facilities in Germany that does not offer RT for these benign or “non-malignant diseases”.1–4Since 1995 and together with the foundation of the German Society of Radiation Therapy and Oncology (DEGRO), a scientific task force group was formed, the German Cooperative Group on Radiotherapy for Benign Diseases (GCG-BD), which undertook the task to review the large amount of clinical experience gained in several decades from 1930 to 1990 in Germany about the use of RT for non-malignant disorders; the relevant articles and clinical data were systematically discussed and evaluated by a scientific panel and a “Delphi” consensus process involving all active RT providers. The first National guideline was defined and published in the year 2000.1 From then on, specific PCSs and prospective randomized clinical trials were developed to improve the available levels of evidence (LOEs) for various non-malignant disorders.5–8 Meanwhile, a considerable number of clinical trials have been carried out and published.9–14The updated National practice guideline v. 2.0 of the most common RT indications for non-malignant diseases were developed between 2010 and 2013 by a nominated group of specialists in conjunction with all members of the German Radiation Oncology Society (DEGRO) and GCG-BD; the Delphi consensus process comprised several national-held symposia, working group meetings and the circulation of all preliminary text versions within the responsible writing committee group members and the final presentation in the national scientific DEGRO meeting in the year 2013.These updated practice guidelines focus on those clearly defined RT indications that have become clinically relevant in terms of the high clinical demand (i.e. number of referrals from other medical disciplines), and the currently achieved quantity and quality of treatments, which had been determined by an evaluation of the continuously increasing number of treated patients between the first two evaluation periods within Germany (Non-malignant diseases (treatment groups) 1999 2004 Increase (%) Inflammatory 456 503 10.9 Degenerative 12,600 23,754 88.5 Hyperproliferative 972 1252 28.8 Functional/other 6099 10,637 74.4 Overall 20,082 37,410 86.3