A study on the cost effectiveness of sestamibi scintimammography for screening women with dense breasts for breast cancer

Clinical applications of 99mTc-sestamibi scintimammography

Mammography is the imaging modality of choice in detection of early, nonpalpable breast cancer. However, scintimammography may prove to be a very useful adjunct to a nondiagnostic or difficult mammography. Future prospective studies will have to be designed so that the specific clinical applications of scintimammography will be well defined. To be clinically relevant, each niche where scintimammography is potentially indicated should be clearly evaluated and incorporated into an algorithm of investigation of breast cancer, taking into consideration the relative advantages and limitations of scintimammography. Special care to obtain high-quality scintimammographic studies is mandatory. Because poor quality studies may be the major drawback, the nuclear medicine community should remind the lesson learned from radiologic mammography. Furthermore, it is also hoped that significant improvement in the scintigraphic equipment and data acquisition will be seen in a very near future to have more widespread clinical diagnostic applications of scintimammography.

Usefulness of 99m-Tc-sestamibi scintimammography in suspected breast cancer and in axillary lymph node metastases detection

AIMS

To evaluate the usefulness of 99m-Tc-sestamibi scintimammography (SSM) in the detection of T1-2, N0-1, M0 breast cancer (BC) and axillary node (AN) metastases.

PATIENTS AND METHODS

A series of 239 women (median age 55 years) who had already been selected for breast biopsy underwent both mammography (MG) and SSM before surgery. The final diagnosis confirmed in 207 (86.6%) patients, and benign breast lesions in 32 (13.4%).

RESULTS

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MG and SSM in BC detection were 88.9% vs 87.9%, 62.5% vs 93.8% (P<0.01), 93.9% vs 98.9%, 46.5% vs 54.5%, and 85.4% vs 88.7%, respectively. Age did not affect (P=NS) SSM sensitivity, and in premenopausal patients (n=80 (33.5%)) its specificity was 100%. Overall sensitivity and specificity of SSM for assessing AN involvement were 82.3% and 94.1%, respectively. In patients with <3 AN metastases (n=33 (53.2%)) SSM sensitivity was 69.7%, and only one out of six patients with a single AN metastasis had a positive scan.

CONCLUSIONS

In patients with suspicious MG undergoing biopsy, SSM should be considered before surgery because of its high specificity, especially in younger patients. At present, its usefulness in detection of AN metastases is still modest and does not allow a correct pre-operative staging of patients with BC.

Scintimammography enhances negative predictive value of non-invasive pre-operative assessment of breast lesions

AIMS

The aim of this study was to develop a criterion with a high negative predictive value for the evaluation of breast lesions. We aimed to determine the value of combining three non-invasive tests, mammography (MM), ultrasonography (USS) and 99mTc-methoxyisobutylisonitrite (99mTc-MIBI) scintimammography (scinti-MM).

METHODS

We included 94 consecutive patients with suspected lesions detected by mammography or on physical examination. MM, USS and scinti-MM were performed no more than 4 weeks prior to excisional biopsy in all patients. We then compared the biopsy results with a score calculated for each patient, derived from the results of the three tests, which we termed 'mamma malignancy index' (MMI).

RESULTS

Each of the three exams yielded a score ranging from 0 to 2, with 0 representing an almost certainly benign lesion, 1 an indeterminate finding and 2 a likely malignant lesion, and hence giving a total score ranging from 0 to 6. The biopsy results showed that the lesions in 64 patients were benign. Forty-nine (77%) of these patients had received an MMI score of 0 or 1. The negative predictive value for malignancy in patients with a score less than 2 was 100%.

CONCLUSIONS

Since the smallest detected lesion was 9 mm in diameter, we conclude that MMI may be a highly useful diagnostic tool in the delineation of breast lesions > or =1 cm which should not be routinely referred for biopsy but may be followed non-invasively. Although fine needle aspiration has limitations, we would recommend it as a less invasive method to evaluate suspected lesions smaller than 1 cm.

Integration of breast imaging into cancer management

This article reviews the use of breast imaging for screening, diagnosis, and staging. Its focus is on the ways in which imaging techniques can most effectively be integrated into clinical management.