Friday, November 05, 2004


Tc 99 most commonly used for radioisotope imaging


Sumer's Radiology Site said...

this is the decay scheme of Tc99..

Anonymous said...

how is Tc99 used in breast cancer?

Sumer's Radiology Site said...

For assessment of bone metasttasis

Anonymous said...

Definition of Technetium tetrofosmin scintimammography

Technetium tetrofosmin scintimammography: Scintimammography is an imaging technique that uses a radioisotope (a radioactive substance) to help visualize the breast and find cancer.

Sumer Sethi

Scintimammography using the radioisotope technetium tetrofosmin (Tc-99 tetrofosmin) can detect breast cancer sometimes in situations in which there is considerable uncertainty, as with dense breast tissue. (Dense breast tissue is particularly difficult to decipher by standard mammography.)

Women with dense breasts have a high incidence of false positives with standard mammography -- test results that appear "falsely" positive in the absence of cancer. The false positives lead to unneeded biopsies and anxiety.

The Tc-99 tetrofosmin scan is especially valuable in these women, who are often younger women and have not gone through menopause. Breast malignancies typically show increased uptake of the Tc-99 tetrofosmin as compared to benign growths. In one study, Tc-99 tetrofosmin test had an accuracy of nearly 90%, while standard mammography yielded a significantly lower value.

Scintimammography with technetium tetrofosmin (Tc-99 tetrofosmin) has been approved by the US Food and Drug (FDA) for the diagnosis of breast cancer. The technique is not meant to replace standard mammography and other current tests, but to be used in conjunction with them.

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