18FDG-PET applications for cartilage neoplasms

Objective To assess the value of [¹⁸F]fluoro-2-deoxy-d-glucose positron emission tomography (¹⁸FDG-PET) in defining aggressive cartilage neoplasms, particularly those with problematic or borderline histologic, imaging and clinical characteristics.Design and patients From 2000 to 2003, 29 cartilage lesions were studied with whole-body ¹⁸FDG-PET scans (Siemens Ecat Exact, Knoxville, Tenn.). Analyses of data in 20 females and nine males, 11–85 years old, were based on maximum standard uptake values (SUVs) in regions of interest (ROIs) on axial 3.37 mm thick, 3×3 pixel images. A statistically significant maximum SUV cutoff of 2.0 was used to distinguish benign from malignant cartilage neoplasms and correlated with the postoperative histopathologic findings.Results In 26 operated cases the overall sensitivity of whole-body ¹⁸FDG-PET in separating benign and malignant lesions was 90.9% (10/11), specificity 100% (18/18) and accuracy 96.6%.Conclusions Whole-body ¹⁸FDG-PET is a valuable adjunct in identifying primary, recurrent and metastatic cartilage malignancies. It supplements classic histology and morphologic imaging with functional data which may facilitate management in individual cases.     

Crohn's disease: less common radiographic manifestations

Unusual manifestations of common diseases are still relatively common events. Crohn's disease may involve the entire gastrointestinal tract from the pharynx to the anus. Although the classic findings of ileocolic disease are well known, the changes described above are less commonly encountered. They may be subject to misdiagnosis unless the protean manifestations of Crohn's disease are kept in mind.     

State-of-the-Art FDG-PET imaging of lung cancer

The D-glucose analog 2-(fluorine-18)-fluoro-2-deoxy-D-glucose (FDG) is the most commonly used radionuclide in positron emission tomography (PET) of lung cancer. FDG-PET is a molecular imaging technique that images the preferential accumulation of FDG in malignant tissues with increased metabolism. Although FDG-PET is sensitive in the detection of lung cancer, FDG is not tumor specific and may accumulate in a variety of nonmalignant conditions. Occasional false-negative results may also occur. Whole body FDG-PET is a useful noninvasive technique to stage known or suspected non-small-cell lung cancer. The results allow more efficient use of invasive methods for histopathological staging. The combined use of CT and PET in dual imaging increases the number of patients with correctly staged non-small-cell lung cancer. CT/PET is also useful in the assessment of recurrent or residual disease. Future imaging agents are being developed which may allow more selective accumulation of radiopharmaceutical in malignant tissues.     

MDCT in diagnosing acute aortic syndromes: reviewing common and less common CT findings

Nontraumatic acute thoracic aortic syndromes (AAS) describe a spectrum of life-threatening aortic pathologies with significant implications on diagnosis, therapy and management. In this context, multidetector computed tomography (MDCT) is the gold standard due to its intrinsic diagnostic value; its performance approaches 100% sensitivity and specificity, and it is accepted as a first-line modality for suspected acute aortic disease. MDCT allows early recognition and characterisation of acute aortic syndromes as well as the presence of any associated complications - findings that are essential for optimising treatment and improving clinical outcomes. Although classic CT findings have long been known, other unusual signs are continually reported in the medical literature. We reviewed the classic and less common CT findings, correlating them with pathophysiology, timing and management options, to achieve a definite and timely diagnostic and therapeutic definition.     

More than just stones: a pictorial review of common and less common gallbladder pathologies

Although stone disease is by far the most commonly encountered pathology of the gallbladder, there are several other important disease processes affecting it. These include adenomyomatosis, cholesterolosis, polyps, porcelain gallbladder, acalculous cholecystitis, xanthogranulomatous cholecystitis, emphysematous cholecystitis, gallbladder cancer, and gallbladder hemorrhage. The purpose of this article was to review the different gallbladder pathologies encountered in everyday radiological practice and to describe their features in the standard imaging modalities.     

FDG-PET findings in sclerosing hemangioma of the lung: a case report

We report a case of sclerosing hemangioma of the lung that showed an intermediately increased accumulation of 18F-fluorodeoxyglucose (FDG) on positron emission tomography (PET). We suggest that FDG-PET may be useful for considering a lesion as benign or low-grade malignant.     

Conventional radiological strategy of common gastrointestinal neoplasms

This article summarizes the clinical characteristics and imaging features of common gastrointestinal(GI) neoplasms in terms of conventional radiological imaging methods. Barium studies are readily available for displaying primary malignancies and are minimallyor not at all invasive. A neoplasm may be manifested as various imaging findings, including mucosal disruption, soft mass, ulcer, submucosal invasion and lumen stenosis on barium studies. Benign tumors typically appear as smoothly marginated intramural masses. Malignant neoplasms most often appear as irregular infiltrative lesions on barium examination. Tumor extension to adjacent GI segments may be indistinct on barium images. Cross-sectional images such as computed tomography and magnetic resonance imaging may provide more accurate details of the adjacent organ invasion, omental or peritoneal spread.     

Radiofrequency ablation of 40 lung neoplasms: preliminary results

OBJECTIVE: Radiofrequency thermal ablation is a minimally invasive treatment widely used for treatment of liver neoplasms and has also been tested on other types of tumor. Few studies have been published regarding the use of radiofrequency thermal ablation in the treatment of lung neoplasms. This study was performed to evaluate the technical feasibility, the safety, and the efficacy of lung radiofrequency thermal ablation. SUBJECTS AND METHODS: Between February 2002 and March 2003, 18 subjects with unresectable lung neoplasms, four of whom had primary neoplasms and 14 of whom had metastatic neoplasms, underwent lung radiofrequency ablation. The technique was performed percutaneously using a monopolar cooled-tip electrode needle under CT guidance with the patient under general anesthesia. Patients had no more than three nodules with a total diameter of 10 cm and no evidence of extrathoracic disease. A total of 40 nodules were treated in 24 therapeutic sessions. After treatment, patients underwent follow-up every 3 months by CT and nuclear MRI with gadolinium for a median time of 8 months (range, 2-14 months). RESULTS: No evidence of local relapse was discovered in 94.4% of subjects. The treatment was safe and well tolerated. Complications encountered included massive pneumothorax, which occurred in one subject, requiring pleural drainage. Other complications were moderate pneumothorax (also requiring pleural drainage), cough, fever, slight dyspnea, and pain, but these complications were short in duration and successfully treated. CONCLUSION: Radiofrequency thermal ablation is a promising technique in the treatment of patients with lung neoplasms and has been found to be both safe and technically feasible.     

Cost-effectiveness of FDG-PET in staging non-small cell lung cancer: the PLUS study

Currently, up to 50% of the operations in early-stage non-small cell lung cancer (NSCLC) are futile owing to the presence of locally advanced tumour or distant metastases. More accurate pre-operative staging is required in order to reduce the number of futile operations. The cost-effectiveness of fluorine-18 fluorodeoxyglucose positron emission tomography ((18)FDG-PET) added to the conventional diagnostic work-up was studied in the PLUS study. Prior to invasive staging and/or thoracotomy, 188 patients with (suspected) NSCLC were randomly assigned to conventional work-up (CWU) and whole-body PET or to CWU alone. CWU was based on prevailing guidelines. Pre-operative staging was followed by 1 year of follow-up. Outcomes are expressed in the percentage of correctly staged patients and the associated costs. The cost price of PET varied between 736 and 1,588 depending on the (hospital) setting and the procurement of (18)FDG commercially or from on-site production. In the CWU group, 41% of the patients underwent a futile thoracotomy, whereas in the PET group 21% of the thoracotomies were considered futile ( P=0.003). The average costs per patient in the CWU group were 9,573 and in the PET group, 8,284. The major cost driver was the number of hospital days related to recovery from surgery. Sensitivity analysis on the cost and accuracy of PET showed that the results were robust, i.e. in favour of the PET group. The addition of PET to CWU prevented futile surgery in one out of five patients with suspected NSCLC. Despite the additional PET costs, the total costs were lower in the PET group, mainly due to a reduction in the number of futile operations. The additional use of PET in the staging of patients with NSCLC is feasible, safe and cost saving from a clinical and from an economic perspective.     

Imaging features of common and uncommon bladder neoplasms

In this article, the authors discuss imaging features of common and less-common epithelial and nonepithelial bladder neoplasms. Epithelial tumors include entities, such as urothelial cell carcinoma, squamous cell carcinoma, and adenocarcinoma, along with less-common entities, such as small cell and carcinoid tumors. Nonepithelial or mesenchymal tumors are also less commonly encountered and include benign entities, such as leiomyoma and neurofibroma, and malignant entities, including leiomyosarcoma and lymphoma. Their imaging features with an emphasis on computed tomography and magnetic resonance imaging are described.     

Percutaneous radiofrequency ablation of lung neoplasms: initial therapeutic response

PURPOSE: To evaluate the feasibility, safety, and initial therapeutic effect of radiofrequency (RF) ablation in the treatment of unresectable malignant lung tumors. MATERIALS AND METHODS: Fifty-four lung neoplasms in 31 patients were treated with RF ablation. Thirteen tumors were primary lung cancers and 41 were pulmonary metastases. Tumor sizes ranged from 0.7 to 6.0 cm, with a mean size of 2.7 +/- 1.3 cm. After the RF electrode was placed in the tumor with computed tomographic (CT) fluoroscopic guidance, RF energy was applied. Initial therapeutic response was evaluated by (18) F fluorodeoxyglucose positron emission tomography (FDG-PET) and contrast-enhanced CT. The disappearance of FDG uptake on PET images and tumor enhancement on CT images were considered to indicate complete tumor necrosis. Complete necrosis rates were evaluated according to tumor size and type (primary or secondary lung neoplasm). RESULTS: RF ablation was technically successful in all lesions. Complete necrosis was achieved in 32 of the 54 tumors (59%) after initial RF session. There was a significant difference in the rate of complete tumor necrosis between tumors 3 cm or less and tumors larger than 3 cm (69% vs. 39%; P <.05). Tumor type did not influence complete necrosis rates. Lung abscesses developed in two patients with large tumors. CONCLUSION: Lung RF ablation is a feasible, relatively safe, and promising treatment for unresectable lung neoplasms. Tumor size is an important factor in achieving complete tumor necrosis.     

Ultrasonographic studies in hepatic neoplasms: patterns and comparisons with radiological contrast studies

A prospective blind study of 100 patients with hepatic neoplasms was performed using the grey-scale linear-array ultrasonographic technique. Seventy-four patients had hepatocellular carcinoma, eight had cholangiocarcinoma, 17 had metastases and one had haemangiosarcoma. The overall diagnostic accuracy was 96%, comparable to the 98% diagnostic accuracy of other radiological studies which were performed in 70 patients. The sites and extent of the lesions and the state of the portal system were identical in both the ultrasonographic and radiological contrast studies. No false positives were found in 254 patients who had ultrasonography of the liver for non-maligant disorders during the period of study. We conclude that linear-array ultrasonography is a simple, sensitive, specific and non-invasive procedure for the investigation of suspected hepatic neoplasms and is useful in assessing operability.     

Analysis of various malignant neoplasms detected by FDG-PET cancer screening program: based on a Japanese Nationwide Survey

Objective

The most distinctive feature of FDG-PET cancer screening program is the ability to find various kinds of malignant neoplasms in a single test. The aim of this survey is to clarify the range and frequency of various malignant neoplasms detected by FDG-PET cancer screening performed in Japan.

Methods

“FDG-PET cancer screening” was defined as FDG-PET or positron emission tomography and computed tomography (PET/CT) scan with or without other tests performed for cancer screening of healthy subjects. This survey was based on a questionnaire regarding FDG-PET cancer screening. We analyzed the situation of 9 less frequently found malignant neoplasms including malignant lymphoma, malignancy of head and neck, esophagus, hepatobiliary and gallbladder, pancreas, kidney, cervical and uterine, ovary, and bladder.

Results

The detailed information of subjects with the suspected 9 kinds of malignant neoplasms mentioned above in the FDG-PET cancer screening program was studied in a total of 1,219 cases from 212 facilities. A statistical significance between PET/CT and PET was found in relative sensitivity and PPV for renal cell cancer. Malignant lymphoma was frequently of indolent type, suspected head and neck cancers had many false-positive results, and pancreatic cancer detected in this program was often in the advanced stage even in asymptomatic subjects. The recommendation of combined screening modality to PET or PET/CT was as follows: gastric endoscopy for assessing early esophageal cancer; abdominal ultrasound for screening hepatobiliary and gallbladder cancer; pelvic magnetic resonance imaging for assessing gynecological and pelvic cancers; and the CA125 blood test for screening ovarian cancer. Delayed image was helpful depending on the type of suspected malignant neoplasm.

Conclusion

We analyzed various types of malignant neoplasms detected by the FDG-PET cancer screening program and presented recommended combination of examinations to cover FDG-PET and PET/CT.     

Short dynamic FDG-PET imaging protocol for patients with lung cancer

This positron emission tomography (PET) study was designed to compare 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) kinetic parameters of tumours derived from imaging frames of 0-60 min post FDG injection with those derived from shorter imaging frames of 0-30 min. Dynamic FDG-PET scans were performed on 20 patients with primary lung cancers for 1 h after intravenous injection of FDG. Images were reconstructed with attenuation correction using transmission images obtained with a germanium-68 ring source immediately before FDG injection. A region of interest (ROI) was placed on the plane of the maximal tumour FDG uptake. Arterial input function was estimated from an ROI defined in the left atrium. Based on the standard three-compartment metabolic model, we calculated the rate constants (K1-k3) and influx constant Ki = K1k3/(k2+k3) using the imaging frames for 60 min and 30 min post FDG injection. The standardized uptake value (SUV) of tumour was measured using the imaging frame of 50-60 min post injection. High correlations were observed between kinetic parameters (K1, k2, k3 and Ki) derived from imaging frames of 0-60 min and 0-30 min [0.231+/-0.114 vs 0.260+/-0.174 (r=0.958), 1.149+/-1.038 vs 1.565+/-2.027 (r=0.968), 0.259+/-0.154 vs 0.311+/-0.194 (r=0.886) and 0.044+/-0.022 vs 0.048+/-0.023 (r=0.961), respectively, P<0.001]. Ki showed an excellent agreement between the two methods (y=-0.0041+0.9831x). Mean SUV of the lung cancers was 6.58+/-2.85. It is concluded that the briefer 30-min acquisition may yield essentially the same results as the standard 60-min imaging protocol, thus offering a time saving in dynamic PET studies in which the model parameters are desired.     

Prognostic value of preoperative FDG-PET in stage IA lung adenocarcinoma

Background

Maximum standardized uptake value (SUVmax) of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has been found to have prognostic value. We previously reported the correlation between SUVmax and pathological invasive area, and determined an SUVmax cut-off value of 2.15 for predicting the recurrence potential of an invasive area of diameter 5 mm. Here, we evaluate the validity of FDG-PET for prediction of recurrence in pathological stage IA lung adenocarcinoma.

Methods

From February 2006 to May 2008, 100 patients with pathological stage IA lung adenocarcinoma underwent complete resection at our hospital. Tumors were classified as air-type or solid-type based on thin-section computed tomography (TS-CT) findings and the influence of TS-CT classification, SUVmax, and clinicopathologic features were evaluated in terms of the incidence of recurrence.

Results

Unlike air-type adenocarcinomas, recurrent disease was detected in 8 of 62 solid-type adenocarcinomas. SUVmax and diameter of invasive area were significantly correlated with recurrence and a shorter time to recurrence. All 8 recurrent cases had pathological invasive area >5 mm. All except one case of recurrence were solid-type adenocarcinomas with SUVmax ≥ 2.15. Three-year disease-free survival rates were 100% in air-type adenocarcinomas, 97.1% in solid-type adenocarcinomas with SUVmax < 2.15, and 74.1% in solid-type adenocarcinoma with SUVmax ≥ 2.15.

Conclusion

Combined evaluation of TS-CT classification and SUVmax had significant value in predicting recurrence in stage IA lung adenocarcinoma, reflecting the aggressiveness of primary lung adenocarcinoma. Prediction of tumor aggressiveness could contribute to decision-making regarding the choice of surgical procedure and treatment after surgery.