TETRAHEDRON RADIOGRAPHY OF THE MICROCALCIFICATIONS OF COMEDO DUCTAL CARCINOMA IN-SITU - 3-DIMENSIONAL ASSESSMENT OF SURGICAL EXCISION

A series of 45 chilled surgical specimens containing comedo ductal car cinoma in situ (DCIS) of the breast with prominent microcalcifications was radiographed in the laboratory from four viewpoints in a rigid te trahedron. There was considerable variation (0-22 mm) in the distances between the surgically resected edge and the microcalcifications. The least satisfactory view, and the one displaying the greatest variance was the conventional projection with the specimen laid flat with its minimum axis parallel to the X-ray beam (mean distance between outermo st microcalcification and specimen edge = 7.2 mm; SEM 0.82). The other three views showed closer proximity of the microcalcifications to the plane of surgical excision (< 5 mm) in 19/45 of specimens where the c learance from the microcalcifications in the conventional view was > 5 mm. The implications are that this radiographic method in the laborat ory can enhance critical evaluation of surgical resection by identifyi ng the appropriate planes for histological examination.