Brain tumor imaging with Tc-99m-Ethylenedicysteine

Background: Ethylenedicystine (EC) is a commonly used renal perfusion-imaging agent. In the past other renal imaging agents like technetium labeled diethyltriamine penta acetic acid (DTPA) and glucoheptonic acid had been found useful for brain tumor imaging.

Aim of the study: to evaluate whether technetium labeled EC is taken up by brain tumor in a sufficient quantity and retained for sufficient duration to allow imaging.

Materials and Methods: Single Photon Emission Computed Tomography (SPECT) of brain with Tc-99m-EC was performed in 25 patients of brain tumor suffering from tumor recurrence following completion of surgery and radiotherapy. Contrast enhanced computed tomography (CECT) of brain was performed in all patients within one week of brain SPECT study. Findings of CECT were considered as gold standard.

Result: CECT brain revealed 26 sites suggestive of tumor mass in 25 patients (one patient had 2 lesions). Brain SPECT revealed increased tracer concentration in 25 corresponding sites suggesting recurrent tumor. On a lesion-to-lesion basis brain SPECT could detect 25 out of the 26 sites of tumor growth.

Conclusion: Tc99m-EC does localize in recurrent brain tumor in a sufficient quantity and retained for sufficient duration to allow imaging.