Safety of Silicone Breast Implants (1999) / Chapter Skim
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12 Silicone Implants and Breast Imaging
12 Silicone Implants and Breast Imaging
Pages 264-284
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From page 264... ...
This does not necessarily imply a complete disruption of the implant shell, but indicates only loss of shell integrity and movement of silicone gel outside the elastomer shell. As discussed earlier, rupture, which includes what some have termed leakage, is different from gel fluid diffusion, which refers to the diffusion of the lower molecular weight silicone fluid that permeates the silicone gel through the implant shell into the capsule or surrounding tissues.
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From page 265... ...
Extrusion implies a sudden flow of silicone gel through defects in the implant shell and fibrous capsule, which may occur with traumatic events. Infiltration is a slow movement of extracapsular silicone gel into surrounding breast or other tissue.
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From page 266... ...
Direct mammographic evidence of rupture is related to demonstration of extravasated silicone, silicone droplets, or calcified silicone in surrounding breast tissue as a result of an extracapsular rupture. Because of the radiodensity of silicone, direct evidence of intracapsular rupture contained by the intact fibrous capsule may not be possible.
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From page 267... ...
as well as the presence of either single, multiple and continuous, multiple and discontinuous, or parallel ("stepladder" sign) echogenic lines or bands may correspond to a disrupted and collapsed implant shell contained within an intact fibrous capsule, i.e., an intracapsular rupture (DeBruhl et al., 1993; Gorczyca et al., 1992~.
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From page 268... ...
Although sensitivity and specificity show wide variation, it appears that ultrasound is more specific than it is sensitive. Several authors calculated the sensitivity and specificity of the various ultrasound signs of altered implant integrity.
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From page 269... ...
, allowing silicone detection by determining which signals are lost after the RODEO technique is applied. The accuracy of MRI in evaluating the integrity of breast implants derives from its ability to detect rupture of the implant shell contained by an intact fibrous capsule, that is, intracapsular rupture.
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From page 270... ...
Silicone completely surrounds the shell and highlights the implant envelope as a low-signal line subtended by intra- and extracapsular silicone gel closely paralleling the intact fibrous capsule (Benjamin and Guy, 1977~. As noted earlier, the various types of breast implants and surgical procedures must be considered to avoid false-positive diagnoses of implant rupture.
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From page 271... ...
Studies that provided such data and analysis might allow a firm conclusion on whether screening for rupture is indicated or not indicated in asymptomatic women with silicone breast implants, either as a routine procedure, or in specific situations such as women with rupture prone implants or in circumstances of changing technologies or certain clinical comorbidities. To justify routine screening of the general population of asymptomatic women with silicone breast implants, such studies would
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From page 272... ...
The presence of silicone gel-filled breast implants may interfere with standard mammography since silicone is radiopaque, and the physical presence of the implant compresses fat and glandular tissues, creating more homogeneous dense tissue that frequently lacks the contrast needed to detect subtle early features associated with breast cancer. Eklund et al.
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From page 273... ...
In one of the first actual estimates, Wolfe (1978) reported breast tissue nonvisibility in the presence of silicone gel implants at about 25%.
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From page 274... ...
274 TABLE 12-1 Implant Integrity Determination SAFETY OF SILICONE BREAST IMPLANTS No. (patients/ Study breasts)
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From page 275... ...
SILICONE IMPLANTS AND BREAST IMAGING 275 Sensitivity Specificity PPV (%)
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From page 276... ...
The shells filled with silicone gel or a mixture of saline and silicone gel completely obscured the phantom. Shells filled with gelatin allowed limited visibility of the simulated calcifications but obscured the masses.
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From page 277... ...
(1993b) , a patient scheduled to undergo a mastectomy consented to a series of CC views utilizing implant shells filled with various filler materials interposed between the breast and the film cassette.
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From page 278... ...
The presence of bilateral symmetric soft-tissue masses posterior to the glandular tissue, as well as coarse plaque-like calcification from residual calcified capsules left behind, should suggest the possibility of a prior explantation (Peters et al., 1996d; Stewart et al., 1992; Young et al., 1989~. At times, residual fibrous capsule remaining after explantation may be particularly thick walled, especially if calcified, and seromas may form within these capsules.
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From page 279... ...
Thus, these studies may not represent the detection capabilities of mammography for preclinical disease in women with silicone breast implants. In some of these studies, women with implants had larger primary tumors, more positive axillary nodes, or a lower percentage of palpable tumors visible on mammography than comparison groups of women without breast implants (for example, Carlson et
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From page 280... ...
280 SAFETY OF SILICONE BREAST IMPLANTS TABLE 12-2 Augmentation and Breast Cancer Detection No. of Both Patient Patients / Mammo Accrural Mammo/ Mammo Palpable and Study Dates Cancers Only Only Palpable Douglas et al., 1991 1978-1988 8/6/8 1 6 1 Schirber et al, 1993 6 years (no 9/7/9 0 8 dates given)
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From page 281... ...
? Augmented: Mammography Subglandular 18 without palpable mass, 17% 16 IDC 2 ILC 5 DCIS 7 nodes positive 3 12/18 Mammography only Subglandular 17 1 DCIS, node negative Subpectoral 1 1 IDC palp + /or mammography 14 IDC, 7 nodes positive 1 mets 1 DCIS 19 None Augmented: 3 DCIS 33 IDC lesions 1 ILC 16 nodes positive 2 distant mets 1 None 19 21 7 Augmented: 4 DCIS 34 IDC 4 ILC 19 nodes positive Sub glandular 29 Subpectoral 6 Sub glandular 4 0 Subpectoral 14 Free 5 Subglandular 37 Subpectoral 5 Continued
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From page 282... ...
Studies are needed to determine whether, among women who routinely undergo screening mammography, there are differences in the stage of breast cancers diagnosed in women with and without silicone breast implants. A study by Deapen et al.
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From page 283... ...
SILICONE IMPLANTS AND BREAST IMAGING 283 Both Mammo Palpable and ID Only Palpable Views Cancer Statistics Implant Location 14 11 Done Augmented: O post-1988 Tumor size < 2 cm, 82% Lymph node positive, 19% Stage O/I, 70% Stage II/II, 30% Nonaugmented: Tumor size < 2 cm, 63% Lymph node positive, 41% 12 Done Augmented: O post-1988 18 IDC 5 DCIS 2 LCIS 7 nodes positive 4 None Augmented: O 6 IDC 1 DCIS infiltrating breast cancer among women with implants was essentially the same as among women without implants. Women with reconstruction after mastectomy for cancer were not included in this study, so the authors included only first breast cancers in the control group.
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From page 284... ...
. Although silicone breast implants definitely obscure some of the breast tissue which in theory at least might reduce visualization of breast tumors, the committee noted that some studies of cancer detection in women with silicone breast implants found the implants hindering and some studies found them not hindering detection.
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