Role of FDG-PET in the evaluation and staging of hepatocellular carcinoma with comparison of tumor size, AFP level, and histologic grade

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has proven to be a valuable tool in the initial diagnosis, staging, and restaging of a variety of cancers. The potential use of FDG-PET in the evaluation and management of hepatocellular carcinoma (HCC) continues to evolve. The purpose of this study was to investigate the effectiveness of FDG-PET for the detection and staging of HCC. In addition, we also assessed the correlation between FDG-PET positivity, tumor size, a-fetal protein level (AFP), and histologic grade. All patients on the hepatobiliary and liver transplant service with biopsy proven HCC that underwent FDG-PET between January 2000 and December 2004 were selected for a retrospective review. Results of the FDG-PET scan were compared with other imaging studies [computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography], intraoperative findings, tumor size, AFP levels, and histologic grade. Of the 20 patients who underwent 18F-FDG PET, increased FDG uptake was noted in 14 scans (70%). These 20 patients fell into 2 groups: 1 for detecting HCC (Group A) and 1 for staging HCC (Group B). There were 7 patients in Group A; only 2 scans (28.6%) showed increased uptake. There were 13 patients in Group B; 12 scans (92.3%) showed increased uptake. In Group B, 11 of the 13 scans (84.6%) provided an accurate representation of the disease process. Two scans failed to accurately portray the disease; one scan failed to show any increase in uptake, and the other scan failed to detect positive nodes that were found during surgery. FDG-PET detected only 2 of 8 tumors (25%) < or = 5 cm in size. All 12 PET scans (100%) in tumors > or = 5 cm and/or multiple in number were detected by FDG-PET. FDG-PET scans with AFP levels < 100 ng/ml were positive in 5 of 9 patients (55.6%). In patients with levels > 100 ng/ml, 6 of 7 patients (85.7%) had positive scans. Histologically, there were 6 well-differentiated, 6 moderately differentiated, and 2 poorly differentiated HCCs. FDG-PET detected 4 of 6 for both well- and moderately differentiated HCCs. Both poorly differentiated HCCs were detected. The intensity was evenly distributed between the different histologic grades. There was a strong correlation of FDG uptake with tumor size. There were 5 HCCs with primary tumors >10 cm in size; 4 showed intense uptake on the scan. In contrast, of the 8 tumors < or = 5 cm in size, 6 were negative for uptake. The sensitivity of FDG-PET in detecting HCC < or = 5 cm in size is low and therefore may not be helpful in detecting all of these tumors. For larger tumors, there is a strong correlation of sensitivity and uptake intensity with tumor size and elevated AFP levels. FDG-PET sensitivity and uptake intensity did not correlate with histologic grade. In the setting of extrahepatic disease, FDG-PET seems to be an effective accurate method for HCC staging; however, whether PET offers any benefit over traditional imaging has yet to be determined.

Whole-body [18F]fluoro-2-deoxyglucose positron emission tomography scan staging prior to planned radical hysterectomy and pelvic lymphadenectomy

The aim of the study was to determine the effectiveness of whole-body [18F]fluoro-2-deoxyglucose positron emission tomography (FDG PET) imaging in properly selecting candidates for radical hysterectomy who are at low risk for subsequent chemoradiation. Retrospective study of 14 women undergoing planned radical hysterectomy and pelvic lymphadenectomy with clinically localized cervical cancer and either negative or inconclusive metastatic nodal disease by PET scan was performed. Pelvic lymph nodes were clearly negative by FDG PET scan in 12 of the 14 women. Two women had focal FDG uptake suspicious, although not definitive, for nodal metastasis, and pelvic nodes were positive at surgery in both. Computed tomography (CT) scan failed to detect nodal disease in either woman. Neither PET nor CT was effective at detecting parametrial disease, and both also failed to detect the primary tumor in some cases. Women with FDG PET scans that are clearly negative for nodal disease are good candidates for radical hysterectomy and are at low risk for subsequent chemoradiation.

Continuous speech recognition in MR imaging reporting: advantages, disadvantages, and impact

OBJECTIVE

Our objective was to describe our experience with a commercially available continuous speech recognition system, highlighting the advantages, disadvantages, and costs compared with those of conventional transcription for MR imaging reports.

MATERIALS AND METHODS

Data from 5072 reports generated in our MR imaging section during a 9-month period after the implementation of a commercial continuous speech recognition system were compared with 4552 reports produced during the same period 1 year earlier. Information pertaining to the use of continuous speech recognition, report turnaround time, word recognition rate, report appearance, and equipment costs was collected.

RESULTS

After its system installation, continuous speech recognition was used to dictate 81.8% of all reports. The mean report turnaround time decreased from 87.8 to 43.6 hr, and report availability at 24 hr increased from 10.5% to 62.5%. The system was found to have an average word recognition accuracy of 92.7% for spontaneous dictation. Mean report length declined from 95 to 60 words, with an increase in spacing errors from 0.3 to 8.0 per 1000 words and a decrease in spelling errors from 3.0 to 0.8 per 1000 words. Initial hardware and software costs were approximately $10,000, compared with a yearly cost of $12,000 for human transcription.

CONCLUSION

Although the technology is still evolving and was evaluated in its earliest implementation stages, continuous speech recognition nonetheless markedly improved report turnaround time and proved cost-effective.

MoSearch: a radiologist-friendly tool for finding-based diagnostic report and image retrieval

The diagnostic reports generated in a radiology department contain a wealth of information. Although radiology information systems can greatly facilitate patient-based access to this information, they typically provide only limited finding-based access. A user-friendly personal computer-based software package that allows radiologists to conduct sophisticated real-time searches of diagnostic reports on the basis of patient characteristics, modality used, anatomy examined, and imaging findings and to easily review, refine, and output the results was designed and implemented in a large academic hospital. A notable feature of this system is the use of synonym-matching and syntactic cues, which allow it to identify findings within the text of a diagnostic report much more accurately than a simple keyword search can. This type of system is easily and inexpensively implemented and is a valuable tool in the support of various research and teaching applications in a radiology department.

Accessing picture archiving and communication system text and image information through personal computers

Recent advances in storage technology have made possible the archiving of tremendous amounts of text and image information within a picture archiving and communication system (PACS). However, a radiologist's access to this information typically has been limited to viewing workstations designed primarily to support clinical activities. Unfortunately, these workstations often overlook the benefits of PACS in teaching and research applications, which are of significant importance in an academic institution. To support such activities at our own institution, we have included two major objectives in our second-generation PACS development: (1) to provide access to text and image information archived within our PACS in an environment that is easily accessible to and comfortable for our radiologists, namely, their own Macintosh (Apple Computer, Cupertino, CA) personal computers; and (2) to provide this information in standard Macintosh formats, so that tools with which radiologists are already familiar can be used in frequently performed teaching activities--the production of slides and prints, the maintenance of personal teaching and research files, and specialized image analysis and processing.