Tc-99m labelled amino acid (methionine) SPECT/computed tomography imaging in carcinoma prostate

Recently Tc-99m labelled methionine has shown promising results with breast and brain tumour imaging. This amino acid is facilitated by upregulation of amino acid transporters and transported in tumour cell by LAT1 transporter. ⁶⁸Ga-PSMA in PET is an established modality with excellent results for evaluation of prostate cancer. However, in many places the facility may not be immediately available and it may be expensive. Tc-99m labelled methionine could prove to be an effective method for evaluation of tumours using Tc 99m which is readily available at low cost. This is the first clinical study of Tc-99m labelled methionine in patients with prostate cancer. Our pilot study shows that Tc-99m- methionine does not concentrate in bone metastasis from adenocarcinoma prostate so may not be an appropriate modality for evaluation of the same. Its role in evaluation of local disease can be further assessed