TO THE EDITOR:
We read with great interest the paper by Coover et al. (1) regarding scintimammography using a dedicated breast camera. The results seem to be fascinating. In line with the authors, we agree that efforts to improve the imaging technique may lead to a higher sensitivity for scintimammography, particularly in the selected patient group of women with dense breast tissue. Preliminary experience obtained in other studies (2,3) has shown that use of a pinhole collimator might also improve visualization of breast lesions examined by scintimammography. Just for localization of the tumor, we would prefer the use of a γ-probe (4) for patient convenience instead of the scintimammographic needle localization described by the authors (1).
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REPLY:
Koukouraki et al. (2) described 25 patients with known malignancies who underwent 99mTc-sestamibi (Cardiolite; Dupont) scintimammography using parallel and pinhole collimation in assessing response to radiation therapy. The investigators concluded that tumor avidity for sestamibi could successfully be assessed with pinhole scintimammography.
Tornai et al. (3) used pinhole apertures with small but very high stopping power to evaluate dedicated mammotomography with pinhole incomplete circular orbit (PICO) SPECT of 1 breast that was uncompressed and pendant. This 1 breast had 2 lesions. They compared this method to planar pinhole scintimammography. They concluded that both lesions of the 1 breast were better visualized with PICO SPECT than with planar pinhole imaging.
Barbera et al. (4) performed planar scintimammography and SPECT with 99mTc-sestamibi on patients presenting with axillary lymphadenopathy. Positive findings led to use of a γ-detecting probe to locate the lesion and guide its surgical removal. Five cases were described.
In reference to our study, comparison and comment are not possible because of the different detection techniques and different patient selection criteria. Our study population was quite different from the populations of each of these 3 studies. Our technique was used for screening a population of women with mammographically dense breasts, category 1 or 2 mammography findings, unremarkable clinical examinations, and a strong family history of breast cancer.
The lesions detected in our screening population were small, and only 1 of the 3 was detected using planar imaging with the standard camera. Considering the relatively low target-to-background ratio of the 3 lesions detected in our study, further studies evaluating γ-probe detection of these types of lesions may be warranted.
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- 4.