Technetium-99m

A dent in the head.

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A 40-year-old man, with no medical history of note, came to see us with a dent in his head

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. He had noticed the asymmetry about 5 years before, and it had increased progressively ever since. On examination, the scalp was normal. CT of the head showed massive destruction of bone, within a well defined area. A technetium-99m methylene diphosphate bone scan showed increased metabolic activity at the edges of the area. These findings were consistent with Gorham’s disease—a rare idiopathic disorder in which one or several bones are destroyed and replaced by connective and vascular tissue. Gorham’s disease of the ribs or thoracic vertebrae can lead to chylothorax and life-threatening respiratory failure. Radiotherapy and surgery are the main therapeutic options.

Source: Lancet

Targeted molecular imaging in oncology.

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Improvement of scintigraphic tumor imaging is extensively determined by the development of more tumor specific radiopharmaceuticals. Thus, to improve the differential diagnosis, prognosis, planning and monitoring of cancer treatment, several functional pharmaceuticals have been developed. Application of molecular targets for cancer imaging, therapy and prevention using generator-produced isotopes is the major focus of ongoing research projects. Radionuclide imaging modalities (positron emission tomography, PET; single photon emission computed tomography,

SPECT) are diagnostic cross-sectional imaging techniques that map the location and concentration of radionuclide-labeled radiotracers.

99mTc- and 68Ga–labeled agents using ethylenedicysteine (EC) as a chelator were synthesized and their potential uses to assess tumor targets were evaluated.

99mTc (t1/2 = 6 hr, 140 keV) is used for SPECT and 68Ga (t1/2 = 68 min, 511 keV) for PET. Molecular targets labeled with Tc-99m and Ga-68 can be utilized for prediction of therapeutic response, monitoring tumor response to treatment and differential diagnosis. Molecular targets for oncological research in (1) cell apoptosis, (2) gene and nucleic acid-based approach, (3) angiogenesis (4) tumor hypoxia,and (5) metabolic imaging are discussed. Numerous imaging ligands in these categories have been developed and evaluated in animals and humans. Molecular targets were imaged and their potential to redirect optimal cancer diagnosis and therapeutics were demonstrated.

Source: http://www.jsnm.org