David M. Panicek

Role of video-assisted thoracic surgery in the treatment of pulmonary metastases: Results of a prospective trial

BACKGROUND A retrospective review revealed a 42% error rate between computed tomographic scan reports and thoracotomy findings; therefore, a prospective study was designed to compare the value of computed tomographic scans, video-assisted thoracoscopic exploration, and open thoracotomy in the management of pulmonary metastases. METHODS Eligibility included any patient with only one or two ipsilateral pulmonary metastases identified on computed tomographic scan who was being considered for surgical resection. Initially video-assisted thoracic surgery was performed and all lesions identified were resected. A thoracotomy adequate for complete lung palpation was then carried out and any additional lesions found were removed. RESULTS Eighteen patients of a planned 50 were treated before closure of the study. Four patients (22%) had no additional lesions found at thoracotomy. The primary sites of tumor were colon (10), breast (3), and one patient each skin (squamous), cervix, kidney, melanoma, and sarcoma. Four patients (22%) did have additional lesions at thoracotomy, which were benign. In the remaining 10 patients (56%) additional malignant lesions were found at thoracotomy after video-assisted thoracoscopic exploration. After 18 patients were entered, analysis of the early results disclosed a 56% failure rate of a computed tomographic scan and video-assisted thoracic surgery to detect all lesions. Being within the 95% confidence interval (32% to 78%), the study was abandoned. CONCLUSIONS We conclude that video-assisted thoracic surgery should be used only as a diagnostic tool in managing lung metastasis. A thoracotomy is required to achieve complete resection, which is the major survival prognosticator for satisfactory long-term results.

Improving Communication of Diagnostic Radiology Findings through Structured Reporting

PURPOSE To compare the content, clarity, and clinical usefulness of conventional (ie, free-form) and structured radiology reports of body computed tomographic (CT) scans, as evaluated by referring physicians, attending radiologists, and radiology fellows at a tertiary care cancer center. MATERIALS AND METHODS The institutional review board approved the study as a quality improvement initiative; no written consent was required. Three radiologists, three radiology fellows, three surgeons, and two medical oncologists evaluated 330 randomly selected conventional and structured radiology reports of body CT scans. For nonradiologists, reports were randomly selected from patients with diagnoses relevant to the physicians area of specialization. Each physician read 15 reports in each format and rated both the content and clarity of each report from 1 (very dissatisfied or very confusing) to 10 (very satisfied or very clear). By using a previously published radiology report grading scale, physicians graded each reports effectiveness in advancing the patients position on the clinical spectrum. Mixed-effects models were used to test differences between report types. RESULTS Mean content satisfaction ratings were 7.61 (95% confidence interval [CI]: 7.12, 8.16) for conventional reports and 8.33 (95% CI: 7.82, 8.86) for structured reports, and the difference was significant (P < .0001). Mean clarity satisfaction ratings were 7.45 (95% CI: 6.89, 8.02) for conventional reports and 8.25 (95% CI: 7.68, 8.82) for structured reports, and the difference was significant (P < .0001). Grade ratings did not differ significantly between conventional and structured reports. CONCLUSION Referring clinicians and radiologists found that structured reports had better content and greater clarity than conventional reports.

Evaluation of Tumor Measurements in Oncology: Use of Film-Based and Electronic Techniques

PURPOSE To evaluate the variability in bidimensional computed tomography (CT) measurements obtained of actual tumors and of tumor phantoms by use of three measurement techniques: hand-held calipers on film, electronic calipers on a workstation, and an autocontour technique on a workstation. MATERIALS AND METHODS Three radiologists measured 45 actual tumors (in the lung, liver, and lymph nodes) on CT images, using each of the three techniques. Bidimensional measurements were recorded, and their cross-products calculated. The coefficient of variation was calculated to assess interobserver variability. CT images of 48 phantoms were measured by three radiologists with each of the techniques. In addition to the coefficient of variation, the differences between the cross-product measurements of tumor phantoms themselves and the measurements obtained with each of the techniques were calculated. RESULTS The differences between the coefficients of variation were statistically significantly different for the autocontour technique, compared with the other techniques, both for actual tumors and for tumor phantoms. There was no statistically significant difference in the coefficient of variation between measurements obtained with hand-held calipers and electronic calipers. The cross-products for tumor phantoms were 12% less than the actual cross-product when calipers on film were used, 11% less using electronic calipers, and 1% greater using the autocontour technique. CONCLUSION Tumor size is obtained more accurately and consistently between readers using an automated autocontour technique than between those using hand-held or electronic calipers. This finding has substantial implications for monitoring tumor therapy in an individual patient, as well as for evaluating the effectiveness of new therapies under development.

Magnetic resonance imaging of bone marrow in oncology, Part 1

Magnetic resonance imaging plays an integral role in the detection and characterization of marrow lesions, planning for biopsy or surgery, and post-treatment follow-up. To evaluate findings in bone marrow on MR imaging, it is essential to understand the normal composition and distribution of bone marrow and the changes in marrow that occur with age, as well as the basis for the MR signals from marrow and the factors that affect those signals; these points have been reviewed and illustrated in part 1 of this two-part article. Part 2 will emphasize the practical application of MR imaging to facilitate differentiation of normal marrow, tumor, and treatment-related marrow changes in oncology patients, and will review complementary MR techniques under development.

Gallbladder carcinoma: findings at MR imaging with MR cholangiopancreatography.

Purpose To describe magnetic resonance (MR) imaging and MR cholangiopancreatography (MRCP) findings in gallbladder carcinoma, and to correlate these findings with available surgical and biopsy information. Methods Preoperative MR images (T1-weighted spin-echo, T2-weighted fast spin-echo, single shot fast spin-echo, and dynamic gadolinium-enhanced gradient echo) in 34 patients with gallbladder carcinoma were retrospectively reviewed for appearance of the primary neoplasm and for demonstration of hepatic, peritoneal, duodenal, and nodal involvement. Imaging findings were then compared with surgical findings (n = 19 patients) and histologic findings (n = 15 patients). Results Gallbladder carcinoma manifested at MR imaging as focal gallbladder wall thickening with an eccentric mass in 76% (26/34) of cases. The most common types of regional spread demonstrated were direct liver invasion in 91% (31/34), lymphadenopathy in 76% (26/34), and biliary tract invasion in 62% (21/34). Sensitivity for direct hepatic invasion was 100%, and was 92% for lymph node metastasis. Conclusion MRI and MRCP can provide information relevant to preoperative staging of gallbladder carcinoma.

Feasibility of using limited-population-based arterial input function for pharmacokinetic modeling of osteosarcoma dynamic contrast-enhanced MRI data

For clinical dynamic contrast‐enhanced (DCE) MRI studies, it is often not possible to obtain reliable arterial input function (AIF) in each measurement. Thus, it is important to find a representative AIF for pharmacokinetic modeling of DCE‐MRI data when individual AIF (Ind‐AIF) measurements are not available. A total of 16 patients with osteosarcomas in the lower extremity (knee region) underwent multislice DCE‐MRI. Reliable Ind‐AIFs were obtained in five patients with a contrast injection rate of 2 cc/s and another five patients with a 1 cc/s injection rate. Average AIF (Avg‐AIF) for each injection rate was constructed from the corresponding five Ind‐AIFs. For each injection rate there are no statistically significant differences between pharmacokinetic parameters of the five patients derived with Ind‐AIFs and Avg‐AIF. There are no statistically significant changes in pharmacokinetic parameters of the 16 patients when the two Avg‐AIFs were applied in kinetic modeling. The results suggest that it is feasible, as well as practical, to use a limited‐population‐based Avg‐AIF for pharmacokinetic modeling of osteosarcoma DCE‐MRI data. Further validation with a larger population and multiple regions is desirable. Magn Reson Med 59:1183–1189, 2008.

Computed Tomography of Ureteral Disruption

Computed tomography in four cases of urine extravasation due to ureteropelvic disruption secondary to blunt trauma were compared with CT in 15 cases of renal parenchymal injury. In three cases of isolated ureteropelvic disruption the renal parenchyma was intact; contrast medium excretion was normal; no perirenal hematoma was present. Contrast medium extravasation was confined predominantly to the medial perirenal space. The ipsilateral ureter was not opacified in three of the four cases of ureteropelvic disruption. These CT findings of ureteral injury are distinct from those of renal parenchymal injury. When these findings are present on CT done for trauma, confident diagnosis of ureteral disruption can be made. In one case, combined renal parenchymal injury and ureteropelvic disruption occurred.

Low-Grade Myxofibrosarcoma: CT and MRI Patterns in Recurrent Disease

OBJECTIVE Low-grade myxofibrosarcoma often relentlessly recurs after surgical resection, with an unusual infiltrative growth pattern and sometimes without a discrete tumor nodule at pathologic examination. This study was undertaken to determine and show patterns of recurrent low-grade myxofibrosarcoma at CT and MRI. CONCLUSION Unlike in most other histologic types of low-grade soft-tissue sarcoma, recurrent low-grade myxofibrosarcoma often is infiltrative; shows a tapering, tail-like margin and superficial spreading configuration; and metastasizes to various distant sites, including lungs, pleura, bone, adrenal gland, soft tissue, and mesentery. Knowledge of these unusual characteristics is important in assessing the presence and extent of recurrent low-grade myxofibrosarcoma before surgical reexcision.

Qualitative assessment of liver for fatty infiltration on contrast-enhanced CT : Is muscle a better standard of reference than spleen?

PURPOSE Our goal was to determine whether spleen or muscle can be used as a qualitative standard of reference for diagnosing fatty infiltration of liver on contrast-enhanced CT. METHOD Qualitative visual comparisons and quantitative region-of-interest measurements of liver, spleen, and muscle were made on scans of 96 patients who underwent dynamic CT before and after injection of intravenous contrast material. As the standard of reference, the portion of liver assessed was considered fatty if its attenuation measured less than spleen on noncontrast CT. RESULTS In 16 (17%) scans, the portion of liver assessed was fatty on noncontrast CT. After contrast material administration, the attenuation of that portion of liver measured less than splenic attenuation in 93 (97%) of 96 cases (including all 16 fatty livers). Only four (25%) fatty livers, and no nonfatty livers, were visually judged to be less attenuating than muscle after contrast material; these four were the most fatty shown on noncontrast CT. Comparing hepatic and splenic attenuation on postcontrast CT resulted in a specificity of 30% and a positive predictive value of 20%; comparing hepatic and muscle attenuation on postcontrast CT yielded corresponding values of 100 and 100% but a sensitivity of 25%. CONCLUSION For the visual assessment of fatty liver, spleen is not an accurate reference standard on contrast-enhanced CT. However, fatty liver can be diagnosed on contrast-enhanced CT if liver appears less attenuating than muscle-a situation that occurs only if fatty infiltration is pronounced.

Correlation of the findings of thallium-201 chloride scans with those of other imaging modalities and histology following therapy in patients with bone and soft tissue sarcomas.

We performed a retrospective [corrected] study to evaluate the imaging potential of thallium-201 as compared with other imaging modalities in differentiating residual/recurrent tumors from post-therapy changes in patients with musculoskeletal sarcomas. 201Tl scans, magnetic resonance imaging (17), X-ray computed tomography (6) or contrast angiography (6) studies in 29 patients previously treated for musculoskeletal sarcomas were correlated with either histopathologic findings (26 patients) or 2-year clinical follow-up (three patients). All imaging studies were acquired within 2 weeks. Ratios of 201Tl tumor uptake to the contralateral (28 patients) or adjacent region of interest were calculated. When qualitative interpretation was in doubt, only those cases with a ratio of 1.5 or more were considered suggestive of recurrent of residual viable tumor tissue. Residual or recurrent tumor tissue was verified in 21 patients by biopsy. All had true-positive 201Tl scans while the other imaging modalities were true-positive in 20 and equivocal in one. In eight patients, there was no evidence of viable tumor tissue as proven by biopsy in five and long-term clinical follow-up in three. 201Tl scan was false-positive (ratio 1.5) in one patient and true-negative in seven while the other imaging modalities had four false-positives. The average 201Tl ratios were 2.8+/-1.1 in the true-positive cases and 1.3+/-0.3 in the true-negative cases. The percentage sensitivities, specificities, and accuracy for 201Tl were 100%, 87.5%, and 96.5% versus 95%, 50%, and 82.7% respectively for other imaging modalities. These results indicate that 201Tl scintigraphy is more accurate than other imaging modalities in differentiating residual/recurrent musculoskeletal sarcomas from post-therapy changes.