Evidence that MR diffusion tensor imaging (tractography) predicts the natural history of regional progression in patients irradiated conformally for primary brain tumors.

PURPOSE: Stereotactic radiotherapy (SRT) is fast becoming the method of choice for treatment of nonsuperficial brain lesions. SRT treatment plans of malignant brain tumors typically incorporate a 20-mm isotropic margin to account for microscopic tumor spread; however, distant or progressive tumors occur outside this margin. Our hypothesis is that paths of elevated water diffusion may provide a preferred route for transport or migration of cancer cells. If our hypothesis is correct, then future SRT treatment volumes could be modified to provide elongated treatment margins along the paths of elevated water diffusion, thereby creating a biologically better treatment plan that may reduce the incidence of progression. METHODS AND MATERIALS: Magnetic resonance diffusion tensor imaging (DTI) datasets were acquired on patient subjects before the appearance of >5 mm diameter progressive lesions or secondary tumors. DTI was performed using an echo-planar imaging sequence on a 1.5T clinical General Electric scanner with voxel dimensions of 0.98 x 0.98 x 6 mm. After SRT, patients were given repeated magnetic resonance imaging follow-ups at regular intervals to identify early tumor progression. When progressive disease was detected, DTIstudio and FMRIB Software Library software was used to compute paths of preferred water diffusion through the primary tumor site and the site of progression. RESULTS: Our preliminary results on 14 patient datasets suggest a strong relationship between routes of elevated water diffusion from the primary tumor and the location of tumor progression. CONCLUSIONS: Further investigation is therefore warranted. Future work will employ more sophisticated fiber analysis in a prospective study.

FDG-PET on the trail of an unsuspected primary malignancy in the breast.

Proper identification of the primary malignancy can radically alter clinical management for the patient's benefit. This is a report of an unsuspected primary breast cancer in a patient being worked up for presumptive lymphoma. Prior investigation of lymphedema in the left lower extremity found widespread lymphadenopathy on computed tomography imaging, leading to initial biopsy revealing adenocarcinoma of unknown primary. F-18 fluorodeoxyglucose PET/computed tomography altered management by localizing an F-18 fluorodeoxyglucose avid breast nodule, directing breast biopsy with specific immunohistochemical analysis for breast cancer lineage in metastatic adenocarcinoma. The patient responded well to breast cancer-targeted chemotherapy.

Breast specimen radiography: can it predict margin status of excised breast carcinoma?

RATIONALE AND OBJECTIVES: This study examined the value of intraoperative specimen radiography (SR) in determining margin status of excised breast lesions. Of interest was the concordance between the radiologic and histopathologic interpretation of margins. We investigated the influence of in situ disease and of one versus two radiologic views on this concordance. MATERIALS AND METHODS: Our study consisted of 112 women who underwent breast conservation therapy (BCT) during 2002. Margins were examined with one- or two-view SR. Margins were histologically positive if malignant cells resided < or = 1 mm from the specimen edge. The McNemar's test was used to determine concordance between SR and histopathology (HP). Because surgeons excised extra tissue in cases of positive radiologic margins, we believe that a change in margin status occurred in which true positives became false positives. Accordingly, we analyzed our data with multiple iterations in which, one by one, false positives were considered true positives. RESULTS: Concordance between SR and HP reached statistical significance after 5/17 false positives were considered true positives. Data excluding DCIS reached significance after 6 of 6 false positives were considered true positives. One- and two-view SR reached significance when 2 of 8 and 7 of 9 false positives, respectively, were considered true positives. CONCLUSION: In conclusion, our study suggests that SR can aid in margin assessment for patients undergoing BCT. We did not find that concordance between SR and HP is higher in cases of purely invasive disease. Concordance was higher in one-view SR in comparison to two-view. A larger sample size should be analyzed before recommending against using two views.

Treated needles: do they facilitate sonographically guided biopsies?

OBJECTIVE: We sought to compare needle visualization and diagnostic yield rates resulting from the use of several commercially available treated needles in sonographically guided biopsies. METHODS: We conducted a randomized prospective study in which 61 patients (42 women and 19 men; mean age, 57 years; range, 19-84 years) were assigned to undergo biopsies (37 thyroid and 24 liver, 2 passes per patient) with 1 of 4 different 22-gauge needles: Teflon coated, etched tip, echogenic polymer coated, and untreated. Two blinded radiologists independently scored needle shaft and tip visualization from 0 (no visualization) to 4 (excellent visualization). After blinded cytologic evaluation, the individual passes were rated as adequate or inadequate for establishing a tissue diagnosis. RESULTS: The echogenic polymer-coated needle had the highest mean score +/- SD for visualization of both the shaft (3.4 +/- 0.90) and tip (3.5 +/- 0.87) compared with the untreated (shaft, 2.2 +/- 0.77; P = 0.003; tip, 2.8 +/- 0.92; P = 0.01), Teflon-coated (shaft, 2.7 +/- 0.94; tip, 3.1 +/- 0.75), and etched tip (shaft, 3.0 +/- 0.82; tip, 3.0 +/- 0.56) needles. Diagnostic yield rates for the 4 different needle types were 75.0% for the echogenic polymer-coated, 64.7% for the Teflon-coated, 56.3% for the etched tip, and 75.0% for the untreated needles (no significant difference). CONCLUSIONS: The echogenic polymer-coated needle was the best visualized of all needles evaluated, both treated and untreated. No significant difference was found in diagnostic yield rates, but that may be reflective of the relatively small sample size.

CT in detecting urinary tract calculi: influence on patient imaging and clinical outcomes.

PURPOSE: To determine changes in examination patterns and effectiveness of care since the introduction of unenhanced helical computed tomography (CT) for examination of patients presenting to the emergency department (ED) with symptoms of urinary tract calculi (UTC). MATERIALS AND METHODS: Hospital clinical and radiology information systems were used to retrospectively identify patients presenting with UTC symptoms from January to December 1997 (before introduction of unenhanced CT) and from January to December 1999 (after introduction of unenhanced CT). Chart abstraction was used to confirm the identification of patients with presenting symptoms suggestive of UTC and assess patient outcomes. Two hundred sixty-five patients presented before (1997) and 602 after (1999) unenhanced CT was introduced. Distributions of dichotomous variables were compared between the 1997 and 1999 groups by using logistic regression. Means were compared between the groups by using analysis of variance and mean total numbers of imaging studies by using Poisson regression. RESULTS: Total number of imaging studies increased by 26.7% per patient visit (P <.001). Rates of admission following the initial ED visit (13.7% in 1997 vs 13.4% in 1999), as well as percentage of patients who subsequently returned to the ED (12.0% in 1997 vs 13.7% in 1999) or subsequently were admitted to the hospital (4.5% in 1997 vs 5.3% in 1999) in the month following the initial ED visit, were similar between the two groups. Unsuspected unenhanced CT findings that could affect acute patient care were observed at 5.9% of examinations. CONCLUSION: Use of imaging for suspected UTC has increased markedly since the introduction of unenhanced CT, with little effect on acute care of patients in the ED.