Development and evaluation of remotely operated synthesizer for [18F]-fluorocholine synthesis

Abstract

ABSTRACT

Among the cancer imaging modality that is utilized by Malaysia today is the Positron Emission Tomography (PET). Even though PET studies are usually done with [¹⁸F]-fluoro-2-dioxyglucose (FDG) as the tracer, [¹⁸F]FDG exhibits several weakness in detecting certain kind of tumours such as brain tumour and prostate metastasis. A new tracer namely [¹⁸F]-fluorocholine (FCH) has been identified as an alternative to [¹⁸F]FDG. The absence of specific synthesizer for FCH production hampers the application of this tracer in PET studies at local premises. This study will discuss about the development of the [¹⁸F]FCH synthesizer prototype and its challenges. The design would emphasized on its simplicity, relatively low cost, semi-automated during synthesis and purification, reliable and safe to be use. The [¹⁸F]FCH was synthesized in two step approaches; reacting [¹⁸F]-fluoride with dibromomethane into [¹⁸F]-fluorobromethane before purification using Sep-Pak silica cartridges and finally converted into [¹⁸F]FCH by reacting with N,N-dimethylaminoethanol. We have successfully developed the synthesizer and are able to achieve decay-corrected radiochemical yield of 1.45 % in under 100 min. Optimization of the radiochemical yield is still underway.

ABSTRAK

Antara kanser mengimejkan modus yang digunakan oleh Malaysia hari ini ialahPositron Emission Tomography (PET). Walaupun kajian-kajian PET biasanya merupakan habis selesai [¹⁸F]-fluoro-2-dioxyglucose (FDG) sebagai penyurih, [¹⁸F]FDG mempamerkan beberapa kelemahan dalam mengesan tertentu agak tumorseperti metastasis barah otak dan prostat. Seorang penyurih baru iaitu [¹⁸F]-fluorocholine (FCH) telah dikenal pasti sebagai satu alternatif untuk [¹⁸F]FDG.Ketiadaan alat sintesis khusus untuk pengeluaran FCH menghalang permohonanpenyurih ini di kajian-kajian PET di premis-premis tempatan. Kajian ini akanmembincangkan mengenai pembangunan [¹⁸F]Prototaip alat sintesis FCH dancabaran-cabarannya. Reka bentuk akan menekankan tentang kesederhanaannya,kos agak rendah, semi automatik semasa sintesis dan penulenan, boleh dipercayaidan selamat guna. [¹⁸F]FCH disintesiskan di dua pendekatan langkah; bertindak balas [¹⁸F]-fluorida dengan dibromomethane ke dalam [¹⁸F]-fluorobromethane sebelum penulenan menggunakan Sep Pak silika catridges dan akhirnya bertukar ke dalam [¹⁸F]FCH dengan bertindak balas dengan N, N-dimethylaminoethanol. Kami telah berjaya membangunkan alat sintesis dan mampu mencapai hasil radiokimiadibetulkan reputan 1.45 % di di bawah 100 min. Pengoptimuman hasil radiokimiamasih sedang dijalankan.