The Preparation and use of Tc-99m metronidazole for cervical cancer imaging

Introduction: Non-invasive detection of tumour hypoxia theoretically adds value to the. outcome of treatment; however the practical aspect of using 99mTc-EC-MN in cervical cancer remains un-attempted. 99mTc-EC-MN has been used to indirectly detect hypoxia in many tumours (head and neck) and other hypoxic states such as strokes and MI. This study aims to determine the value of using this tracer in early stage cervical cancer. Objectives: This study aimed to investigate the use of 99mTc-EC-MN to determine the degree of hypoxia in cervical cancer. The original study design was to determine whether SPECT with 99mTc-EC-MN would detect ~l'poxi~cervicalc;ancer 'lesions and compare the results with the histological report. The practice of safe handling of radiopharmaceuticals and gaining knowledge in conducting research formed part of the secondary objective of the study. Due to circumstances beyond the control of the researcher, the focus of the study changed from a clinical to a chemistry-based project. Method development: Safety of EC-MN was tested through determination of the labelling efficiency with pertechnetate initially by ITLC-SG. Ethyl acetate, ethanol, saline and ac;etone were selected to develop 99mTc-EC-MN chromatograms to identify the system which best displays separation. Radio-ITLC displayed multiple peaks due to high residual activity in ethyl acetate- and acetone-developed scans. Saline- and ethanol-developed scans showed better separation of 99mTc-EC-MN but separation from free pertechnetate was difficult. Radio HPLC coupled with a diode array detector was used to successfully separate the labelled product, 99mTc-EC-MN from free pertechnetate, thereby achieving good radiolabelling. Clinical application: After the relative safety of the product was established, it was injected IV in the selected patient who had early stage cervical carcinoma. Clinical examinations which included pre-operative WBC, ultrasonography of the kidneys and bladder, and c