Performance parameters for screening and diagnostic mammography in a community practice: are there differences between specialists and general radiologists?

OBJECTIVE: The purpose of this study was to compare the performance of general radiologists in interpretation of mammograms with that of breast imaging specialists in a high-volume community hospital-based private practice. MATERIALS AND METHODS: A retrospective observational study was conducted with data prospectively collected over a 5-year period in a community hospital-based practice in which 106,405 screening and 52,149 diagnostic mammograms were performed. The performance of three radiologists specializing in breast imaging was compared with that of six general radiologists. The following data were extracted and analyzed: recall rate, biopsy recommendation rate, and cancer detection rate. Statistical analysis was performed with a chi-square test and two-tailed calculation of p values. RESULTS: The recall rates of the specialists and generalists were nearly the same at 6.5% and 6.7%, respectively. The biopsy recommendation rate at recall from screening examinations was nearly the same for generalists and specialists (1.2% and 1.1%, respectively; p = 0.4504). This rate also was similar for diagnostic examinations (8.5% for generalists; 8.4% for specialists; p = 0.4086). The cancer detection rate in the screening setting was slightly higher for specialists than for generalists: 2.5 and 2.0 cancers per 1,000 cases, respectively (p = 0.0614). The cancer detection rate in the diagnostic setting was 24.2% higher among specialists (20.0 cancers per 1,000 cases) compared with generalists (16.1 cancers per 1,000 cases) (p = 0.0177). CONCLUSION: The only statistically significant difference between generalists and specialists was in cancer detection rate among patients undergoing diagnostic mammography. No statistically significant difference was identified between the two groups in terms of recall rate, biopsy recommendation rate, or percentage of favorable-prognosis cases of cancer detected. There was a trend toward greater cancer detection by specialists in the screening setting.

Clip placement after sonographically guided percutaneous breast biopsy.

A simple and inexpensive technique for deployment of a metallic marker at the site of an ultrasound guided core breast biopsy is described. An illustrative case in which this technique was employed to mark the location of three biopsied lesions is presented.

Metallic marker placement after stereotactic core biopsy of breast calcifications: comparison of two clips and deployment techniques.

OBJECTIVE: Two methods of deployment of metallic clips at the site of stereotactic core biopsy for breast calcifications are compared retrospectively. MATERIALS AND METHODS: One hundred nineteen clips deployed through an 11-gauge vacuum-assisted biopsy probe at core biopsy sites were compared with 109 vascular ligating clips deployed at biopsy sites using an 18-gauge spinal needle. The distance of each clip from the position of the target calcification was assessed using stereotactic coordinates in 52 sequential cases and was measured on mammograms before and after biopsy in 108 clips deployed through an 11-gauge probe and 98 clips deployed using an 18-gauge needle. Variance in clip position between postbiopsy and follow-up mammograms was measured in 43 clips placed with an 11-gauge probe and in 44 clips placed with an 18-gauge needle. Comparable measurements of variance in position of fat necrosis calcifications between screening mammograms were used as controls. RESULTS: Ninety-seven percent of the clips placed with an 11-gauge probe and 98% of the clips placed using an 18-gauge needle were within 1 cm of the target calcifications using stereotactic coordinates. On mammograms obtained after biopsy, 70% of the clips placed with an 11-gauge probe and 63% of the clips placed using an 18-gauge needle were within 1 cm of the target calcifications, and the position of 91% of the clips placed with an 11-gauge probe and 90% of the clips placed using an 18-gauge needle varied less than 15 mm on follow-up mammograms. Both clips provided accurate targets for wire-localized excisions. The cost of the 11-gauge needle and clip is $320. The 14-gauge probe, vascular clip, and 18-gauge spinal needle cost $191.58. CONCLUSION: A vascular ligating clip delivered to a stereotactic core biopsy site by an 18-gauge spinal needle is comparable in apparent accuracy and stability to a clip deployed through an 11-gauge probe. This technique allows core biopsies to be performed with instruments smaller than 11-gauge and at a 40% savings in equipment cost.

Stereotactic core breast biopsy of malignant calcifications: diagnostic yield of cores with and cores without calcifications on specimen radiographs.

PURPOSE: To retrospectively compare core biopsy diagnosis with final diagnosis at surgical excision in cores with and cores without calcification on specimen radiographs. MATERIALS AND METHODS: One hundred thirteen consecutive patients underwent vacuum-assisted 11- or 14-gauge needle stereotactic core biopsy for calcifications with malignant histologic results in core samples from 116 lesions. For each lesion, calcification was identified in at least one core at specimen radiography. Cores with and those without calcification seen on magnified specimen radiographs were separately submitted to and reported on by pathologists, who obtained additional levels in cores with calcification. All patients underwent surgical excision of the lesion area within 7 weeks. The pathologic diagnosis in core samples with and those without calcification on specimen radiographs was compared with final diagnosis at surgical excision. Fisher exact test was used for all chi(2) determinations of statistical significance. RESULTS: Cores with calcification on specimen radiographs were more likely to enable a final diagnosis of malignancy than were cores without calcification (98 [84%] vs 82 [71%] of 116; P =.02). Cores without calcification were significantly more likely to cause a diagnosis of cancer to be missed than were those with calcification on specimen radiographs (13 [11%] vs one [1%] of 116; P <.001). Underestimates of malignancy were more frequent in 14- than in 11-gauge specimens (11 [18%] of 60 vs six [10%] of 56; P =.30). Regardless of needle size, there was no significant difference in underestimation of malignancy between cores with and without radiographically evident calcification (17 [15%] vs 21 [18%] of 116; P =.60). CONCLUSION: Specimen radiography is essential to document calcification retrieval. Cores without radiographically demonstrated calcification may fail to show a malignant lesion. Separate identification of calcium-containing cores may assist the pathologist, who can more thoroughly evaluate these cores with additional levels of section.