MR imaging of the small bowel in Crohn's disease

MR and CT techniques optimized for small bowel imaging are playing an increasing role in the evaluation of small bowel disorders. Several studies have shown the advantage of these techniques over tradition barium fluoroscopic examinations secondary to improvements in spatial and temporal resolution combined with improved bowel distending agents. The preference of MR vs. CT has been geographical and based on expertise and public policy. With the increasing awareness of radiation exposure, there has been a more global interest in implementing techniques that either reduce or eliminate radiation exposure [Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med 2007;357:2277–84]. This is especially important in patients with chronic diseases such as inflammatory bowel disease who may require multiple studies over a lifetime or in studies that require sequential imaging time points such as in assessment of gastrointestinal motility [Froehlich JM, Patak MA, von Weymarn C, Juli CF, Zollikofer CL, Wentz KU. Small bowel motility assessment with magnetic resonance imaging. J Magn Reson Imaging 2005;21:370–75]. A recent study showed that certain subgroups of patients with Crohn's disease may be exposed to higher doses of radiation; those diagnosed at an early age, those with upper tract inflammation, penetrating disease, requirement of intravenous steroids, infliximab or multiple surgeries [Desmond AN, O’Regan K, Curran C, et al. Crohn's disease: factors associated with exposure to high levels of diagnostic radiation. Gut 2008;57:1524–29]. Therefore it has been suggested that techniques that can reduce or eliminate radiation exposure should be considered for imaging [Brenner DJ, Hall EJ. Computed tomography—an increasing source of radiation exposure. N Engl J Med 2007;357:2277–84]. Owing to the excellent softtissue contrast, direct multiplanar imaging capabilities, new ultrafast breath-holding pulse sequences, lack of ionizing radiation and availability of a variety of oral contrast agents, MR is well suited to play a critical role in the imaging of small bowel disorders. In this article we will review the technical issues related to the performance of MR enterography and enteroclysis and discuss the role and controversies of using MR in the assessment of inflammatory bowel disease.     

Crohn's disease at the small bowel imaging by the ultrasound-enteroclysis

SUMMARY: Crohn's disease is more likely a systemic disease governed by a shift in the immune response, thus affecting the whole MALT system. Its treatment should be as conservative as possible and surgery is usually taking place after complications like indolent fistulations, stenoses, bleeding, or bowel perforation started. Standard radiological methods to check the extent of the disease are loaded either with certain radiation exposure (enteroclysis, CT) or lack standardization (ultrasound). The aim of this small study was to evaluate the worth of ultrasound-enteroclysis in detecting the extent and complications of the Crohn's disease in surgically treated patients. MATERIAL AND METHODS: Since 1997, when we started with the ultrasound-enteroclysis, 246 surgical performances were involved into our study. Out of them, 181 had conventional abdominal intestinal ultrasound as well as conventional enteroclysis within 1 week. Remaining 65 cases were diagnosed by the ultrasound-enteroclysis. Intestinal ultrasound was performed on the Ultramark 3000 HDI device with autofocussable convex 5 MHz and linear 7.5 MHz probes or nowadays ATL 5000 HDI, 7-12 MHz linear probe. No contrast enhancement was used. Enteroclysis was done with the Micropaque suspension diluted 1:1 with HP-7000 300 ml with its application rate up to 75 ml/min followed by HP-7000 solution 2000 ml, application rate of 120 ml/min. The patients with ultrasound-enteroclysis were applied HP 7000 solution only (2000 ml, rate 100ml/s) via an enteroclysis catheter. All investigations were video-recorded. RESULTS: Consent with the per-operative finding was reached in 162 from 181 enteroclyses and in 169 of 181 ultrasounds. Ultrasound-enteroclysis was precise in 61 cases from 65. Among these, 60 patients had the recurrence during the treatment proved by clinical and laboratory results. This re-activation was clearly revealed in 38 from 43 cases by enteroclysis, 41 from 43 by US and in 16 from 17 by ultrasound-enteroclysis. From 30 patients that developed acute complication non-responding to the conservative therapy (abscesses, fistulas and intestinal obstructions) there were 18 from 20 accurately diagnosed by enteroclysis, only 12 from 20 by US and 9 from 10 by US-enteroclysis. The differences were either statistically non-significant or there were too small numbers to give sensible statistical results, but low sensitivity of ultrasound in complications (p=0.05). CONCLUSION: US-enteroclysis seems to became the standard examination of patients with Crohn's disease mainly in those with unclear conventional ultrasound. The most important fact is that this examination significantly decreases the radiation load when maintaining high sensitivity. This is very important namely in patients with Crohn's disease that require life-long observation and repeated examinations. This examination is much more easy to standardize than the conventional US.     

Diagnostic imaging in the diagnosis of small bowel Crohn's Disease – A literature review

Crohn's Disease can be imaged using Barium sulphate studies, ultrasound, magnetic resonance imaging, computerised tomography and nuclear medicine. However, the radiological pathway used for the diagnosis and management of this disease can vary from hospital to hospital. By evaluating the literature a broad picture can be developed regarding the sensitivity and specificity of each modality. It is often the case that the sensitivity and specificity of a modality can change due to the level of skill of the operator. Barium sulphate studies are still considered to be the recognised route for diagnosing Crohn's Disease, but it is apparent that newer studies are concerned with trying to find a more patient tolerant, less invasive method of radiological diagnosis. It is also important to consider when evaluating a pathway, the availability of each modality within each individual hospital setting.     

Classification of small bowel Crohn's subtypes based on multimodality imaging

This article has reviewed the imaging features that correspond to and support the classification of patients into clinical subtypes of Crohn's disease. One study showed that radiologic features on barium studies closely correlated with the Crohn's Disease Activity Index, and another study indicated that CT findings changed patient management in up to 29% of cases. Knowledge of the location, severity, and presence of complications assist in providing patients with appropriate treatment options. Reports of radiologic studies in Crohn's disease should include the presence or absence of imaging features that support these different subtypes. An additional advantage of the use of a reproducible imaging classification that emphasizes morphologic features would be improved comparison of the results of different investigators and treatment protocols. Whatever method of radiologic investigation is employed, it should be targeted to answer questions relevant to patient management. The imaging modalities used should be able to classify the small bowel Crohn's subtypes and should be reflected in the radiologists' reports.     

Perspective: the small bowel examination in the diagnosis of Crohn's disease

Enteroclysis has been increasingly recommended for radiologic examination of the small intestine, especially for focal lesions, but also for more extensive processes such as regional enteritis. Seventy-four patients were studied who had a final clinical diagnosis of regional enteritis and who had been examined by more conventional peroral ingestion of barium suspension together with fluoroscopy and vigorous manual compression. In only two cases did the radiographic examination fail to identify proven regional enteritis; one who had an isolated ulcer at an ileorectal anastomosis and one in whom jejunal regional enteritis was mistakenly diagnosed as a mesenteric mass. Careful fluoroscopy of the small intestine combined with vigorous manual compression is a sensitive method of detecting regional enteritis.     

小肠腺癌的气钡双对比造影诊断

本文搜集经病理手术证实的小肠腺癌20例,进行分析,旨在探讨小肠气钡双重造影对小肠腺癌的诊断价值.1 材料与方法1.1 临床资料搜集我院2004年～2009年临床及影像资料完整经病理证实的小肠腺癌20例,其中十二指肠10例,空肠4例,回肠6例.男12例,女8例,年龄48～80岁,平均年龄67.5岁.     

Ultrasound in Crohn's disease of the small bowel

OBJECTIVE: The purpose of this work is to prospectively evaluate high resolution ultrasonography with graded compression in the ability to detect Crohn's disease of the small bowel (CDSB) together with its complications and activity signs, compared with enteroclysis, CT and immunoscintigraphy in the mirror of the final diagnosis. METHODS AND MATERIAL: In a series of 73 consecutive patients, who were referred for enteroclysis with suspected Crohn's disease of the small bowel computed tomography (CT), ultrasound (US), immunoscintigraphy with 99mTc labeled monoclonal antigranulocyte antibody (AGAb) examinations were performed within 10 days from each other. For the final evaluation the diagnosis of CDSB was based on combination of clinical and enteroclysis findings (73 cases) and in 17 cases additional surgical and pathological data were available. The results of other modalities were blinded to the radiologists performing and reading out the exams. The diagnostic values of each modality was assessed also in those 18 patients, who had early Crohn's disease. In the group of 43 patients with proven CDSB who had all the four imaging modalities, the modalities were compared in their ability to demonstrate various pathological conditions related to CD. Increased (>500 ml/min) flow measured by Doppler US in the superior mesenteric artery and increased color signs in the gut wall seen by power Doppler sonography were compared to CDAI. RESULTS: Of the 73 patients the combination of enteroclysis and clinical tests demonstrated CDSB in 47. The sensitivity, specificity and accuracy of ultrasound were 88.4, 93.3 and 90.4%, respectively. Enteroclysis was the most accurate method. CT was more sensitive than US, but less specific. The accuracy of US, CT and scintigraphy were similar. In the group of 18 patients, who had early CDSB, the sensitivity of US decreased to only 67%, CT and scintigraphy had higher values. Intra- and perimural abscesses, and sinus tracts were also more frequently visualized by US, especially if they were small. US was superior than CT in detecting stenoses and skip lesions, but inferior to enteroclysis. US and CT detected more fistulas, than enteroclysis. Compared to CT, US detected more cases with mesenteric lymphadenopathy, equal cases with abscesses and free peritoneal fluids. In detecting mesenteric inflammatory proliferation CT, and in detecting colonic involvement CT and immunoscintigraphy were slightly superior than graded compression US. Patterns of mural stratification detected by ultrasound correlated well with the enteroclysis severity stages. There was only 59% agreement between increased superior mesenteric artery flow detected by Doppler sonography and CDAI, and 60.5% agreement between increased number of Color pixels in the gut wall measured by power Doppler and increased CDAI. CONCLUSION: High resolution graded compression sonography is a valuable tool for detecting small intestinal Crohn's disease. It has similar diagnostic values as CT. However in early disease the sensitivity substantially decreases. In known Crohn's disease for following disease course, evaluating relapses and extramural manifestations US is an excellent tool. Doppler and Power Doppler activity measurements do not correlate well with the more widespread clinical activity index.     

Enteroclysis and spiral CT examination in diagnosis and evaluation of small bowel Crohn's disease

INTRODUCTION: During the last few decades introducing many of new radiologic methods, diagnostic conditions and facilities of Crohn's disease has became markedly improved. Appropriate using of these technics definitely modifies the management of patients with known or suspected Crohn's disease serving reliable information about extent, severity and possible complications of disease. Enteroclysis and Computed tomography are the two major and basic methods to disclose or confirme diagnosis of Crohn's disease, obtain appropriate inforination about disease either with mucosal, transmural or extraintestinal manifestation. METHODS AND PATIENTS: We evaluated 281 patients who were referred in our institution under suspition of Crohn's disease. Enteroclysis and abdominal spiral CT in all cases were carried out usually within 1 week. The 172 patients underwent abdominal spiral CT as the primary examination to evaluate diagnostic value of spiral CT in this entity, while 109 patiens had enteroclysis followed by abdominal CT. In 11 cases we also perforined CT enteroclysis with administration of 0.5% methylcellulose solution thorough nasojejunal tube controlled by electric motor driven contrast pump. Results were compared with final clinical, pathological or surgical data were available. RESULTS: From the 281 patients eventually 74 proved Crohn's disease; sensitivity and specificity of enteroclysis proved to be 96 and 98%, while spiral CT sensitivity and specificity was 94 and 95%, respectively. Enteroclysis was superior to the spiral CT in demonstration of early lesions and functional disorders, while spiral CT proved to be essential in evaluation of transmural and extraintestinal complications. CONCLUSIONS: Regarding enteroclysis and spiral CT as complementary methods, they provide excellent results in diagnosis of Crohn's disease.     

Multidetector-row computed tomography and 3-dimensional computed tomography imaging of small bowel neoplasms: current concept in diagnosis

The diagnosis of small bowel neoplasms can present a difficult challenge to the radiologist because the tumors are uncommon, often small, and may be difficult to detect radiographically. The most common small bowel neoplasms include adenocarcinoma, carcinoid, lymphoma, and gastrointestinal stromal tumors. The location and computed tomography (CT) appearance of the small bowel tumors may aid in the diagnosis. For instance, small bowel adenocarcinoma occurs more frequently in the duodenum and may result in obstruction. Carcinoid tumors are more common in the ileum and are typically hypervascular submucosal masses that produce a characteristic mesenteric mass when they spread to the mesenteric nodes. Lymphoma can occur anywhere along the gastrointestinal tract and have a variable CT appearance. It may appear as a single mass, multiple masses, an infiltrating lesion resulting in aneurysmal dilatation of the bowel, or as an exophytic mass. Gastrointestinal stromal tumors are more common in the jejunum and ileum and usually appear exophytic and bulky often with ulceration. Traditionally, small bowel series and enteroclysis have been used for imaging patients with suspected small bowel tumors. More recently, CT is beginning to play a more important role for this clinical indication. The thinner collimation possible with multidetector CT (MDCT) along with water as oral contrast and a good intravenous contrast bolus may improve the sensitivity of CT for detecting small bowel tumors. In addition, MDCT scanners improve the quality of the 3-dimensional CT (3D CT) images that are valuable to the clinicians and surgeons for surgical planning. It is important for the radiologist to be familiar with the CT appearance of these neoplasms and the potential role of MDCT and 3D imaging in their diagnosis and surgical planning.     

The current status of multidetector row CT and three-dimensional imaging of the small bowel

Radiologists have played an important role in evaluation of patients with small bowel pathology. The small bowel series and, later, enteroclysis were the mainstays in radiologic diagnosis of many small bowel diseases, because the resolution and speed of CT was limited. Continued improvements in CT technology over the last 2 decades have resulted in a expanding role of CT for evaluation of the gastrointestinal tract, including the small intestine. Many conditions, such as small bowel obstruction and ischemia, that would traditionally be imaged with other modalities (small bowel series or angiography) are now routinely imaged with CT. The development of MDCT and improvements in 3D imaging systems have greatly improved the ability to examine the small bowel and mesenteric vasculature. With the introduction of new CT oral contrast agents and faster 32-detector row CT scanners, the diagnosis and evaluation of patients with small bowel disease will continue to improve.     

MR imaging of the small bowel

Cross-sectional imaging techniques such as CT and MR imaging have advantages over traditional barium fluoroscopic techniques in their ability to visualize superimposed bowel loops better and to improve visualization of extraluminal findings and complications. This article discusses MR imaging of the small bowel with enterography and enteroclysis techniques. It reviews the advantages, limitations, technique, and indications and reviews the results that have been obtained in evaluating different disease processes.     

Diagnostic imaging of the small bowel

This article describes the different imaging techniques used in the study of the small bowel. We define the technical requirements that conventional small bowel follow through studies must fulfill to be considered an efficacious examination (individualized study of each bowel loop by compression and fluoroscopy); we evaluate the different types of enteroclysis, giving special attention to the biphasic type, which is the most commonly employed; we discuss the advantages and disadvantages of biphasic enteroclysis with respect to conventional small bowel follow through studies; and finally we evaluate the role of modern techniques of image acquisition, tomodensitometry and magnetic resonance imaging used together with traditional techniques. Small bowel studies require accurate indications for radiologic study, thorough and meticulous examination, and careful interpretation of the images obtained. Although the modern techniques of magnetic resonance and computed tomography enteroclysis are no better than conventional small bowel follow through or enteroclysis at demonstrating the details of the intestinal mucosa, they are of great use in solving the problem of the superimposition of intestinal loops and provide information about the intestinal wall and possible extraluminal pathology.     

MR imaging of the small bowel

Small-bowel radiology has undergone dramatic changes in the past 2 decades. Despite important recent advances in small-bowel endoscopy, radiologic imaging remains important for patients suspected of having or with established small-bowel disease. Cross-sectional imaging techniques (computed tomography and magnetic resonance [MR] imaging), used to investigate both extraluminal abnormalities and intraluminal changes, have gradually replaced barium contrast examinations, which are, however, still used to examine early mucosal disease. MR imaging techniques clearly highlight endoluminal, mural and extramural enteric details and provide vascular and functional information, thereby enhancing the diagnostic value of these techniques in small-bowel diseases. Two MR imaging based techniques are currently utilized: MR enteroclysis and MR enterography. In enteroclysis, enteric contrast material is administered through a nasoenteric tube, whereas in enterography, large volumes of enteric contrast material are administered orally. MR enteroclysis ensures consistently better luminal distention than does MR enterography in both the jejunum and the ileum and more accurately depicts endoluminal abnormalities and early disease, particularly at the level of the jejunal loops. Moreover, MR enteroclysis provides a high level of accuracy in the diagnosis and exclusion of small-bowel inflammatory and neoplastic diseases and can be used for the first radiologic evaluation, while MR enterography may effectively be used to follow up both Crohn disease patients without jejunal disease and in pediatric patients where nasogastric intubation might be a problem. MR enteroclysis may also reveal subtle transition points or an obstruction in the lower small bowel, which may escape detection when more routine methods, including enterography, are used. MR imaging offers detailed morphologic information and functional data of small-bowel diseases and provides reliable evidence of normalcy, thereby allowing the diagnosis of early or subtle structural abnormalities and guiding treatment and decisions in patient care.     

Radiographic examination of the small bowel: survey of practice patterns in the United States

PURPOSE: To obtain understanding of the current practice patterns of academic and private radiology groups in the United States in radiographic examination of the small bowel. MATERIALS AND METHODS: The survey consisted of questions about small-bowel follow-through (SBFT) examinations, including frequency of overhead radiographs, use of fluoroscopic spot images, personnel performing fluoroscopy, practice settings, and degree of specialization. By using a standard sampling technique, the country was divided into nine regions, and one state from each region was randomly selected. The survey was mailed to 452 full-time chief technologists. The responses were tabulated, and statistical analysis of the data was performed with the chi(2) test. RESULTS: Completed questionnaires were returned by 236 (52%) of 452 chief technologists; 219 (93%) respondents, 176 (80%) in private and 43 (20%) in academic groups, indicated that their group performed SBFT studies. The studies were performed by general radiologists in 205 (94%) of the 219 groups and by gastrointestinal or abdominal radiologists in 11 (5%). Studies included overhead radiographs in all 219 groups, with spot images of the terminal ileum in 201 (92%). Thirty (14%) of 219 groups routinely obtained spot images of the remaining small bowel, 104 (48%) obtained spot images only if there were questionable findings on overhead radiographs, and 82 (37%) obtained no spot images. Eighteen (8%) of 219 groups performed peroral pneumocolon examinations and 80 (37%) performed enteroclysis. CONCLUSION: The majority of radiology groups perform SBFT studies. Regardless of the practice setting, these studies usually consist of a series of overhead radiographs, with routine spot images of the terminal ileum but not of the remaining small bowel. This approach may need to be reassessed in light of the American College of Radiology standards that all accessible small-bowel loops be visualized at fluoroscopy with representative radiographs to optimize the diagnostic yield of the examination.     

Active Crohn's disease in the small bowel: evaluation by diffusion weighted imaging and quantitative dynamic contrast enhanced MR imaging

Purpose

To determine relative diagnostic value of MR diffusion and perfusion parameters in detection of active small bowel inflammation in patients with Crohn's disease (CD).

Materials and Methods

We reviewed 18 patients with active CD of terminal ileum (TI) who underwent MR enterography (MRE; including dynamic contrast enhanced MRI and diffusion‐weighted MRI). Conventional MRI findings of TI were recorded. Regions of interest were drawn over TI and normal ileum to calculate apparent diffusion coefficient (ADC), the volume transfer constant (K^trans) and the contrast media distribution volume (v_e). Receiver operating characteristic analysis was used to determine their diagnostic performance.

Results

Among conventional MR findings, mural thickening and increased enhancement were present in all actively inflamed small bowel. K^trans, v_e, and ADC values differed significantly between actively inflamed TI and normal ileum (0.92 s^?1 versus 0.36 s^?1; 0.31 versus 0.15 ± 0.08; 0.00198 mm²/s versus 0.00311 mm²/s; P < 0.001). Area under the curve (AUC) for K^trans, v_e, and ADC values ranged from 0.88 to 0.92 for detection of active inflammation. Combining K^trans and ADC data provided an AUC value of 0.95.

Conclusion

Dynamic contrast‐enhanced MRI (DCE‐MRI) and diffusion‐weighted imaging (DWI) provide quantitative measures of small bowel inflammation that can differentiate actively inflamed small bowel segments from normal small bowel in CD. DWI provides better sensitivity compared with DCE‐MRI and combination of ADC and K^trans parameters for analysis can potentially improve specificity. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.

     

FDG-PET imaging for the staging and follow-up of small cell lung cancer

The staging procedures for small cell lung cancer do not differ appreciably from those for other forms of lung cancer. For practical purposes, the TNM stages are usually collapsed into a simple binary classification: limited disease and extensive disease. This study was performed to answer the question of whether fluorine-18 labelled 2-deoxy-2-D-glucose positron emission tomography (FDG-PET) imaging permits appropriate work-up (including both primary and follow-up staging) of patients presenting with small cell lung cancer, as compared with currently recommended staging procedures. Thirty-six FDG-PET examinations were performed in 30 patients with histologically proven small cell lung cancer. Twenty-four patients were examined for primary staging while four were imaged for therapy follow-up only. Two patients underwent both primary staging and up to four examinations for therapy follow-up. Static PET imaging was performed according to a standard protocol. Image reconstruction was based on an ordered subset expectation maximization algorithm including post-injection segmented attenuation correction. Results of FDG-PET were compared with those of the sum of other staging procedures. Identical results from FDG-PET and the sum of the other staging procedures were obtained in 23 of 36 examinations (6x limited disease, 12x extensive disease, 5x no evidence of disease). In contrast to the results of conventional staging, FDG-PET indicated extensive disease resulting in an up-staging in seven patients. In one patient in whom there was no evidence for tumour on conventional investigations following treatment, FDG-PET was suggestive of residual viability of the primary tumour. Furthermore, discordant results were observed in five patients with respect to lung, bone, liver and adrenal gland findings, although in these cases the results did not affect staging as limited or extensive disease. Moreover, FDG-PET appeared to be more sensitive for the detection of metastatic mediastinal and hilar lymph nodes and bone metastases. Finally, all findings considered suspicious for tumour involvement on the other staging procedures were also detected by FDG-PET. It is concluded that FDG-PET has potential for use as a simplified staging tool for small cell lung cancer.     

Radiotherapy treatment of non-melanoma skin cancer: a survey of current UK practice and commentary

Objective:

In the ongoing absence of available trial data, a national survey was carried out to provide details on radiotherapy treatment strategy for non-melanoma skin cancer (NMSC).

Methods:

A survey of clinical oncologists treating NMSC was performed. The respondents were asked for basic information on workload as well as a proposed treatment strategy for various clinical scenarios for patients of varying fitness.

Results:

A total of 43 completed and 20 partially completed surveys were received. There was a wide variation in the workload and additional disease sites that respondents had responsibility for. Kilovoltage radiotherapy was available to 81% of responders. The respondents'' approach was affected by the fitness of patients, with longer fractionation regimes proposed for younger, fitter patients and shorter or non-standard fractionations more likely for the infirm elderly. Four daily fractionation regimes (18–20 Gy in 1 fraction, 35 Gy in 5 fractions, 45 Gy in 10 fractions and 55 Gy in 20 fractions) were most commonly suggested. There was a large degree of variation in non-standard fractions proposed with significant potential differences in radiobiological effect. Concern over the use of kilovoltage photons on skin over cartilage was apparent, as was a reluctance to use radiotherapy in areas of increased risk of poor wound healing.

Conclusion:

The survey results largely showed practice to be in line with available published evidence. The variation seen in some areas, such as non-standard fractionation, would benefit from the publication of local outcomes to achieve a more consistent approach.

Advances in knowledge:

This study provides information on national practices and identifies variations, particularly within widespread use of non-standard fractionation.Non-melanoma skin cancer (NMSC) is the most common malignancy in the UK. In 2010, around 100,000 people were diagnosed with NMSC, and there were 585 related deaths in 2011.¹ The vast majority of these lesions are basal cell carcinomas (BCCs) or, less commonly, squamous cell carcinomas (SCCs). Various treatment modalities can be utilized to manage this condition, with a potential for excellent local control and cosmesis, including topical therapies, surgical excision, electrocautery, cryotherapy and radiotherapy. The choice of treatment approach is influenced by the stage and location of disease, patient fitness and preference. For patients who are not fit enough to be considered for surgery or for disease in locations where excision would be cosmetically undesirable, the use of radiotherapy is commonly recommended.Various methods of radiotherapy delivery are available, including electron, kilovoltage and megavoltage external beam radiotherapy as well as brachytherapy, although there is variable access to these methods between centres in the UK. A lack of prospective trial data to guide treatment has led to the development of local practice regarding dose fractionation schedules, and it is unclear how much variation currently exists nationally. In the absence of likely forthcoming trials, there is little impetus for variable practice to change.To potentially streamline clinical practice, details on the most commonly used strategies employed in various clinical scenarios would be of interest as a basis for harmonizing dose/fractionation schedules.     

FDG-PET imaging for the staging and follow-up of small cell lung cancer

The staging procedures for small cell lung cancer do not differ appreciably from those for other forms of lung cancer. For practical purposes, the TNM stages are usually collapsed into a simple binary classification: limited disease and extensive disease. This study was performed to answer the question of whether fluorine-18 labelled 2-deoxy-2-D-glucose positron emission tomography (FDG-PET) imaging permits appropriate work-up (including both primary and follow-up staging) of patients presenting with small cell lung cancer, as compared with currently recommended staging procedures. Thirty-six FDG-PET examinations were performed in 30 patients with histologically proven small cell lung cancer. Twenty-four patients were examined for primary staging while four were imaged for therapy follow-up only. Two patients underwent both primary staging and up to four examinations for therapy follow-up. Static PET imaging was performed according to a standard protocol. Image reconstruction was based on an ordered subset expectation maximization algorithm including post-injection segmented attenuation correction. Results of FDG-PET were compared with those of the sum of other staging procedures. Identical results from FDG-PET and the sum of the other staging procedures were obtained in 23 of 36 examinations (62 limited disease, 122 extensive disease, 52 no evidence of disease). In contrast to the results of conventional staging, FDG-PET indicated extensive disease resulting in an up-staging in seven patients. In one patient in whom there was no evidence for tumour on conventional investigations following treatment, FDG-PET was suggestive of residual viability of the primary tumour. Furthermore, discordant results were observed in five patients with respect to lung, bone, liver and adrenal gland findings, although in these cases the results did not affect staging as limited or extensive disease. Moreover, FDG-PET appeared to be more sensitive for the detection of metastatic mediastinal and hilar lymph nodes and bone metastases. Finally, all findings considered suspicious for tumour involvement on the other staging procedures were also detected by FDG-PET. It is concluded that FDG-PET has potential for use as a simplified staging tool for small cell lung cancer.