Breast scintigraphy with breast-specific γ-camera in the detection of ductal carcinoma <i>in situ</i>: a correlation with mammography and histologic subtype

Ductal carcinoma in situ (DCIS) is a subtype of breast cancer encountered increasingly in clinical practice because of the widespread use of screening mammography. In the present study, we evaluated the usefulness of breast-specific g-camera (BSGC) scintigraphy in DCIS identification, describing the scintigraphic findings and their correlation with mammography and histologic subtype. Methods: Thirty-three women, aged 41–81 y, with surgically proven DCIS were retrospectively reviewed. Before surgery, all patients underwent breast scintigraphy using a high-resolution semiconductor-based BSGC, starting 10 min after intravenous injection of 740 MBq of 99mTc-tetrofosmin. All patients had previously undergone mammography. A definitive histologic diagnosis was obtained in all cases after scintigraphy, and the scintigraphic findings were correlated with mammography and histologic subtype. Results: Mammography was positive in 30 of 33 patients (sensitivity, 90.9%), showing calcifications in 22 of 30 (73.3%), masses in 3 of 30 (10%), and masses plus calcifications in the remaining 5 of 30 (16.7%). Scintigraphy was positive in 31 of 33 patients sensitivity, 93.9%), showing patchy irregular uptake in patients with calcifications and focal uptake in masses; sensitivity was higher in low- to intermediate-grade DCIS than in intermediate/high- and high-grade DCIS (100% vs. 91.3%), but the difference was not statistically significant. Two comedo-type DCIS (one 20-mm intermediate/high-grade and one 15-mm high-grade) with heterogeneously or highly dense breasts at mammography and one papillary ow/intermediate-grade DCIS associated with Paget disease were true positive only at scintigraphy. Moreover, scintigraphy better assessed disease extent than did mammography in 5 additional patients. Two comedo-type DCIS (one 6-mm intermediate/highgrade and one 15-mm high-grade) were true positive only at mammography. The difference in sensitivity between scintigraphy and mammography was not statistically significant. The combined use of mammography and scintigraphy achieved 100% sensitivity. Conclusion: BSGC scintigraphy proved to be a highly sensitive diagnostic tool in the detection of DCIS, irrespective of histologic subtype, and with a scintigraphic pattern of uptake that correlated well with mammography findings. In our series, BSGC scintigraphy demonstrated a slightly higher sensitivity than mammography and a better assessment of local disease extent. Thus, BSGC scintigraphy should represent a useful adjunctive tool in breast cancer diagnosis

Breast Scintigraphy with Breast-Specific γ-Camera in the Detection of Ductal Carcinoma In Situ: A Correlation with Mammography and Histologic Subtype

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The Clinical impact of breast scintigraphy acquired with a breast specific γ-camera (BSGC) in the diagnosis of breast cancer: incremental value <i>versus</i> mammography

We investigated the clinical impact of breast scintigraphy acquired with a breast specific γ-camera (BSGC) in the diagnosis of breast cancer (BC) and assessed its incremental value over mammography (Mx). A consecutive series of 467 patients underwent BSGC scintigraphy for different indications: suspicious lesions on physical examination and/or on US/MRI negative at Mx (BI-RADS 1 or 3), characterization of lesions suspicious at Mx (BI-RADS 4), preoperative staging in lesions highly suggestive of malignancy at Mx (BI-RADS 5). Definitive histopathological findings were obtained in all cases after scintigraphy: 420/467 patients had BC, while 47/467 patients had benign lesions. The scintigraphic data were correlated to Mx BI-RADS category findings and to histology. The incremental value of scintigraphy over Mx was calculated. Scintigraphy was true-positive in 97.1% BC patients, detecting 96.2% of overall tumor foci, including 91.5% of carcinomas ≤10 mm, and it was true-negative in 85.1% of patients with benign lesions. Scintigraphy gave an additional value over Mx in 141/467 cases (30.2%). In particular, scintigraphy ascertained BC missed at Mx in 31 patients with BI-RADS 1 or 3, including 26 patients with heterogeneously/high dense breast (19/26 with tumors ≤10 mm) and detected additional clinically occult ipsilateral or controlateral tumor foci (all &lt;10 mm) or the in situ component sited around invasive tumors in 77 BC patients with BI-RADS 4 or 5, changing surgical management in 18.2% of these cases; moreover, scintigraphy ruled out malignancy in 33 patients with BI-RADS 4. BSGC scintigraphy proved a highly sensitive diagnostic tool, even in small size carcinoma detection, while maintaining a high specificity. The procedure increased both the sensitivity of Mx, especially in dense breast and in multifocal/multicentric disease, and the specificity as well as it better defined local tumor extension, thus guiding the surgeon to a more appropriate surgical treatment

The Role of planar scintimammography with high-resolution dedicated breast camera in the diagnosis of primary breast cancer

Planar scintimammography (SM) acquired with a conventional γ camera has proved a useful complementary tool to mammography (Mx) in breast cancer (BC) diagnosis, but with unsatisfactory sensitivity in small size carcinomas. In this study we assessed the role of planar SM with a high-resolution dedicated breast camera (DBC) in BC diagnosis, comparing the results with those of Mx. A consecutive series of 145 patients scheduled for biopsy for suspected BC underwent Tc-99m tetrofosmin planar SM using a newly developed DBC. Scintigraphic data were compared with Mx findings and correlated to histology. Histopathologic analysis revealed 165 lesions: 143 malignant and 22 benign. SM detected 139/143 carcinomas (overall sensitivity: 97.2%) and was true negative in 19/22 benign lesions (overall specificity: 86.4%). SM sensitivity was 91% in ≤=10-mm carcinomas. SM was more accurate than Mx in 42/145 cases (29%), detecting cancer in 9 patients with Mx indeterminate for dense breasts (8/9 tumors were &lt;10 mm), assessing additional tumor foci (all &lt;10 mm) in 5 points with multifocal disease and correctly classifying 28 patients with inconclusive mammographic findings as affected by cancer or by benign disease. Mx was more accurate than SM in 3 patients, in each detecting 1 subcentimeter BC false negative on SM. DBC planar SM seems a highly sensitive diagnostic tool in the detection of BC, even when small in size, and in the assessment of multifocal disease. A wider employment of this procedure is thus suggested, especially in indeterminate or inconclusive mammographic findings to improve sensitivity and specificity of Mx

Occult breast cancer presenting as axillary lymph node metastases: a single-institution experience with a challenging diagnostic and therapeutic dilemma

Background: Occult breast cancer with axillary lymph node metastases but without evidence of primary tumor on clinical examination and conventional imaging is a rare but serious scenario. Due to diagnostic difficulties and prognostic uncertainties, evidence to guide the management of such patients is lacking. Here, we review the cases of occult breast cancer treated at our institution and discuss recent advances in its management. Methods: We searched our database for patients with occult breast cancer operated on between 2002 and 2011. The following data were extracted: clinical presentation; diagnostic work-up; surgical treatment; adjuvant management; and duration of follow-up. Results: Out of 1405 patients operated on for breast cancer, 7 (0.5%) had occult breast cancer. The mean age at diagnosis was 60.5 years. Six patients were postmenopausal. All patients had one or more metastatic axillary lymph nodes but no signs of malignancy at either conventional imaging (mammography and ultrasonography) or clinical examination. Magnetic resonance imaging revealed the primary breast tumor in 1 patient. Histopathology showed positive estrogen receptors in 3 patients. After preoperative staging, neoadjuvant chemotherapy and subsequent mastectomy was performed in 1 patient with N3 disease, primary surgical treatment in 5 patients (4 mastectomies, 1 breast-conserving procedure), and chemotherapy alone in 1 patient. Postoperative management included chemotherapy in 5 patients, endocrine therapy in 2, and radiation therapy in 5. An infiltrating carcinoma was found in 5 mastectomy specimens (4 ductal histotype and 1 lobular histotype). The mean tumor size was 11 mm (range, 7-17). At a mean follow-up of 51 months, 6 patients were disease-free, and 1 patient died of pulmonary embolism. Conclusions: Occult breast cancer poses difficult management issues, especially when estrogen receptor status is negative. No consensus exists on the need for breast surgery in such patients, as recent literature suggests that breast irradiation might be an alternative treatment. Management decisions should be taken on an individual basis with a multidisciplinary approach. Considering the results of this series, we believe that breast surgery should be proposed to patients with occult breast cancer.</br

^99mTc-tetrofosmin SPET in the detection of both primary breast cancer and axillary lymph node metastasis

The aim of this study was to evaluate the usefulness of 99mTc-tetrofosmin single-photon emission tomography (SPET) in the detection of both primary breast cancer and axillary lymph node metastasis. We studied 192 consecutive patients in whom primary breast cancer was suspected on the basis of mammography and/or physical examination. After intravenous injection of 740 MBq 99mTc-tetrofosmin, both planar and SPET scintimammography was performed in all patients using a rectangular dual-head gamma camera equipped with low-energy, high-resolution, parallel-hole collimators. In 175 patients with breast cancer at histology, the per-lesion overall sensitivity of SPET and planar imaging for the detection of breast cancer was 95.8% and 75.9% (P&lt;0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 96.5% and 79.5% in palpable (P&lt;0.0005) and 90% and 45% in non-palpable lesions (P&lt;0.01). With regard to lesion size, the sensitivity of SPET and planar imaging was, respectively, 90.5% and 45.2% in lesions h10 mm (P&lt;0.0005), 95.3% and 81.4% in lesions of 11-20 mm (P&lt;0.005), 100% and 84.6% in lesions of 21-30 mm (P&lt;0.05) and 100% and 95.8% in lesions &gt;30 mm (P&gt;0.05). In the remaining 17 patients with benign mammary lesions at histology, per-lesion overall specificity of SPET and planar imaging was 76.2% and 85.7% (P&gt;0.05), respectively. Neither SPET nor planar imaging showed false-positive results in non-palpable lesions or in those h10 mm. In 173 breast cancer patients submitted to axillary lymph node dissection (ALND), per-axilla overall sensitivity of SPET and planar imaging in the detection of axillary lymph node metastasis was 93% and 52.3% (P&lt;0.0005), respectively. The sensitivity of SPET and planar imaging was, respectively, 100% and 82.6% in palpable nodes (P&gt;0.05), 90.5% and 41.3% in non-palpable nodes (P&lt;0.0005), 92.8% and 35.7% in the presence of h3 nodes (P&lt;0.0005) and 93.2% and 68.2% in the presence of &gt;3 nodes (P6lt;0.005). The specificity of SPET and planar imaging was 91% and 100% (P&lt;0.05), respectively. 99mTc-tetrofosmin SPET appears to be a reliable method for the detection of both primary BC and axillary lymph node metastasis, and its diagnostic accuracy exceeds that of 99mTc-tetrofosmin planar scintimammography. The use of SPET is particularly important in the identification of small non-palpable primary carcinomas and metastatic axillae with ≤3 non-palpable lymph nodes. More extensive use of SPET appears warranted in the management of breast cancer patients

^99mTc-Tetrofosmin pinhole-SPECT (P-SPECT) and radioguided sentinel node (SN) biopsy and in breast cancer axillary lymph node staging

We compared 99mTc-Tetrofosmin P-SPECT with radioguided SN biopsy in 101 T1/T2 BC pts to predict axillary lymph node status. The day before surgery all pts underwent lymphoscintigraphy (LS) to mark the SN, following subdermal injection of 99mTc-colloidal sulphur surrounding the breast lesion. LS was combined with pre and intraoperative gamma probe. Previously, all pts had also undergone P-SPECT. ALND was performed in all cases. The SN(s) was detected in 97/101 cases (96%) by LS and gamma probe; in the 4 missed cases P-SPECT predicted lymph node status. In the 97 comparable cases, radioguided SN biopsy showed a slightly higher accuracy than P-SPECT (94.8% vs 93.8%), but a higher false-negative rate (14.3% vs 8.6%); P-SPECT had a higher NPV (95.2% vs 92.5%). The two procedures when combined achieved 100% accuracy. Radioguided SN biopsy alone had 100% accuracy only in pts with BC &lt; 15 mm. P-SPECT had 3 false negative cases, 2 of which were micrometastatic SNs, and 3 false positives. P-SPECT identified 81.2% of cases with a single node, determined the exact number of nodes in 82.6% of cases with 1 to 3 node and correctly classified 93.7% of pts as having ≤ 3 or &gt; 3 metastatic nodes. Radioguided SN biopsy seems indicated in selected, early stage, small BC pts, while P-SPECT shows a high sensitivity independent of primary tumor size, giving additional important preoperative prognostic information. The two procedures combined provided a better axillary lymph node status prediction in T1/T2 carcinomas, and could thus improve ALND pt selection