Preliminary observation of 99mTc-thymine imaging in breast neoplasms

Abstract

New biological knowledge and new diagnostic tools for breast cancer diagnosis may have an important impact on the strategies followed by oncologists in breast cancer management. So far, it has not been possible to label a nucleotide or its precursor with technetium-99m (99mTc) for use in in vivo studies. In this paper, we report the labelling of a precursor, the nitrogenate base thymine, with 99mTc. It has been used to evaluate breast lesions. After animal studies and with the consent of patients, it was employed for evaluation in humans. Thirty-nine women were studied: 32 patients and seven healthy volunteers. Twenty-three malignant lesions showed uptake of labelled thymine. Of the 12 benign cases, there was one false-positive uptake. Labelled thymine was also taken up by one case of malignant microcalcifications. Labelled thymine can be used as a diagnostic method in the identification of malignant anatomo-radiologic palpable lesions of the breast, observed by mammography, possibly avoiding unnecessary biopsies.

99mTc-thymine scintigraphy may be a promising method in the diagnosis of breast cancer

“…Their results demonstrated that 18F-FMAU was selectively retained in the DNA of proliferating cells and was resistant to degradation (40). We have similarly shown that 99mTc-thymine is incorporated into cellular DNA (22). Unlike PET and PET-CT, which require expensive equipment with limited availability worldwide, conventional gamma cameras are able to perform SPECT imaging and are much more readily available.…”

“…(19,22). Here, we obtained a sensitivity of 70%, a specificity of 85.7%, an accuracy of 82.2%, and positive and negative predictive values of 58.3% and 90.9%, respectively.…”

“…The pattern of 99mTc-thymine uptake could differentiate malignant lesions of the breast from benign lesions and breast densities in which there is uptake of the radiopharmaceutical (22). We also compared the uptake of 99mTc-thymine and 99mTc-sestamibi in malignant breast lesions and found that 99mTc-thymine exhibited higher sensitivity, specificity, accuracy, and positive predictive values compared to 99mTc-sestamibi (19).…”

Radiolabelling of thymine with 99mTc. Preliminary results regarding the stability and biospecificity of [99mTc]thymine

“…1 We used stannous chloride as a reducing agent in accordance with the requirements of the European Pharmacopeia. Several ratios between thymine and stannous chloride were utilized.…”

Use of99mTc-doxorubicin scintigraphy in females with breast cancer: a pilot study

“…[16][17][18][19][20][21][22][23] We previously reported a technique for labelling the thymidine precursor thymine with 99m Tc, with good specificity and high predictive value. [16][17][18] We have also used 99m Tc-doxorubicin in dogs and cats in order to evaluate its uptake in different kinds of tumours, with promising results, which led to the approval of this pilot trial. 24 …”