Radiotransparency of the triglyceride mammary prosthesis: a quantitative analysis with mastectomy specimens.

Abstract

Breast cancer is the most frequent malignant tumor in women. It is estimated that 10 percent of women will present with a breast cancer during their lives. It is well known that mammography is the best technique for the early diagnosis of nonpalpable tumors, thus improving life expectancy. However, mammary prostheses may hide between 23 and 82 percent of the normal mammary tissue in mammography, and thus may delay the diagnosis of malignant mammary tumors, making prognosis worse. To solve this problem, oil-filled prostheses have been developed. In this study, 14 mastectomy specimens were used. Mammograms of the tissue pieces alone and also mammograms of the tissue pieces covering a 270-cc Trilucent prosthesis were used to verify whether the prosthesis allows observation of malignant signs in mammography. Mammograms were evaluated by an independent experienced radiologist. The following variables were studied: number of mammograms necessary to examine each specimen; kilovoltage and milliamperage necessary for each mammogram; number of microcalcification groups (malignant); number of macroscopic calcifications (benign); and rarefaction areas that were suspected for malignancy. All of these variables were measured for both mammograms for which the mastectomy specimens were covering and those for which the specimens were not covering the prothesis. Finally, the kilovoltage and milliamperage increases necessary to visualize the mammograms with mastectomy specimens covering the prosthesis were determined. Statistical analysis of the results obtained was performed. There were no significant differences in the number of mammograms (p = 0.391), the number of microcalcifications (p = 0.890), the number of macrocalcifications (p = 0.239), and finally in the presence of rarefaction areas (p = 1.000) observed in the mammograms in specimens either covering or not covering the prosthesis. However, there were significant differences (p < 0.001) between the kilovoltage and milliamperage applied to carry out the mammograms of specimens with and without the prosthesis. Thus, Trilucent prostheses allow visualization of the microscopic and macroscopic calcifications as well as rarefaction areas in mammograms. However, these mammograms required a higher kilovoltage and milliamperage compared with specimens not covering the prosthesis. To explore the whole gland, it might be necessary to perform two series of mammograms: one to detect the area shadowed by the prosthesis and one to observe the rest of the peripheral gland.