[A comparative evaluation of the centering precision performed with 2 different stereotaxic instruments in nonpalpable breast lesions].

Two different instruments for nonpalpable breast lesion localization, with different patient position (prone and sitting), were evaluated in precision performances by measuring the mean needle deviation on X and Y axes in 150 and 100 examinations, respectively. Both instruments yielded precise information: some drawbacks were observed with the stereotaxic instrument fitted to the plain mammographic unit, due to imperfect fixation in the sitting position of the patient. The development of special seats could obviate the problem, thus allowing a further improvement in the performance of this kind of instruments.