Preparation of 99mTc-labelled methotrexate by direct labeling technique and its use as a potential diagnostic agent for breast cancer: First clinical trial

Objectives The aim of the present study was the direct labelling of MTX with 99mTc by using Sn/pyrophosphate as reducing agent.

Methods Labelling efficiency was determined by paper chromatography and instant thin layer chromatography in acetone and saline as mobile phase and found to be more than 95%±1.5%. In vitro stability of labeled MTX in serum was studied up to 5h. Partition coefficient in n-octanol and saline indicated that the labeled radiopharmaceutical was hydrophilic in nature. Protein binding showed rapid clearance of 99mTc-MTX from blood.

Results The biodistibution data suggested that 99mTc-MTX was cleared by the kidneys and the liver. The patient data also showed highly significant uptake of 99mTc-MTX in breast cancer.

Conclusions In conclusion, this study indicated that 99mTc-MTX may be used as a potential diagnostic agent for breast cancer patients as well as for monitoring their response to chemotherapy.